AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE UPTON NY 753 AM EST FRI FEB 8 2008 .SYNOPSIS... A WEAK AREA OF LOW PRESSURE WILL MOVE ACROSS THE AREA THIS MORNING...WITH WEAK HIGH PRESSURE BUILDING SOUTH OF THE REGION THIS AFTERNOON AND TONIGHT. A STRONGER AREA OF LOW PRESSURE DIVING DOWN FROM CANADA WILL PULL A WARM FRONT TOWARDS THE REGION LATE TONIGHT AND SAT AS IT MOVES ACROSS THE SOUTHERN CANADIAN PROVINCES. THIS SYSTEMS TRAILING ARCTIC COLD FRONT WILL CROSS THE TRI-STATE AREA ON SUNDAY. ARCTIC HIGH PRESSURE BUILDS IN FROM THE GREAT PLAINS FROM SUNDAY NIGHT THROUGH MONDAY...THEN RETREATS NORTHEAST MONDAY NIGHT AND TUESDAY...AS AN AREA OF LOW PRESSURE APPROACHES FROM THE SOUTHWEST. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WEAK SFC MOISTURE CONVERGENCE ACROSS LONG ISLAND AND CT...INDICATED BY MSAS AND ALSO BEING PICKED UP BY THE RUC HAS ALLOWED FOR SOME LIGHT RA AND SN SHOWERS TO DEVELOP. 00Z OKX SOUNDING VERY DRY ABOVE 775 MB WITH MOISTURE BECOMING TRAPPED BELOW A SUBSIDENCE INVERSION. NE WINDS HAVE ALLOWED ADDITIONAL MOISTURE TO FILTER IN OFF THE OCEAN WITH STRATUS PUSHING FROM EAST TO WEST. A NEGATIVELY TILTED UPPER LEVEL TROUGH MOVING INTO THE MID ATLANTIC STATES WILL FLATTEN OUT AS IT PIVOTS TOWARDS THE LOCAL AREA THIS MORNING. RUC/SREF SEEM TO BE HANDLING THE CURRENT SITUATION THE BEST. THERE ARE SOME LIGHT RETURNS ON MOSAIC RADAR IMAGERY ACROSS WEST VIRGINIA...OHIO AND WESTERN PA...BUT VERY LITTLE IS REACHING THE GROUND. THE BETTER FORCING REMAINS WITH AN OLD FRONTAL BOUNDARY OFF THE SOUTHEAST COAST. AS THE UPPER TROUGH LIFTS NEWD THIS MORNING...WEAK LOW PRESSURE OFF THE NORTH CAROLINA COAST WILL PASS WELL SOUTH OF THE LOCAL AREA. CANNOT RULE OUT A STRAY RAIN/SNOW SHOWER INTO EARLY THIS AFTN WITH ABUNDANT LOW LEVEL MOISTURE IN PLACE AND SFC MOISTURE CONVERGENCE BEING DEPICTED BY THE RUC SO WILL KEEP LOW CHC POPS THROUGH EARLY AFTN. NORTHERLY WINDS WILL BECOME MORE W/NW THIS AFTERNOON AS THE OFFSHORE LOW MOVES OUT INTO THE OPEN ATLANTIC WATERS AND WEAK HIGH PRESSURE BUILDS IN. CLOUD COVER SHOULD BECOME PARTLY CLOUDY AS WELL. TEMPS WILL REMAIN ABOVE NORMAL TODAY. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/... WEAK SFC RIDGING BUILDS SOUTH OF THE AREA TONIGHT AS THE NEXT STORM SYSTEM APPROACHES FROM THE WEST. MODELS TRENDS HAVE BEEN SLOWER OVER THE LAST FEW RUNS SO HAVE REFLECTED THIS IN THE GRIDS BY KEEPING THINGS DRY UNTIL SAT MORNING. A WARM FRONT APPROACHES FROM THE SOUTH LATE TONIGHT...BUT ONLY WEAK WAA EXISTS BETWEEN 06Z AND 12Z TONIGHT...SUPPORTING THE SLOWER START TO PRECIP. WARM ADVECTION RAINS WILL CONTINUE THROUGH THE DAY...THEN A COLD FRONT WILL SLIDE THROUGH SAT EVENING. LEFT CHC POPS SAT NIGHT WITH TROUGHINESS AND STRONG VORT MAXES ROUNDING THE BASE OF THE UPPER LOW. ARCTIC FRONT WILL SWEEP ACROSS THE AREA BETWEEN 12Z AND 18Z SUN WITH HIGHS LIKELY BEING REACHED IN THE MORNING AS VERY COLD AIR FILTERS IN BEHIND IT. GFS AND EC HAVE H85 TEMPS AROUND THE -20 DEGREE MARK WHICH WOULD TRANSLATE TO TEMPS FALLING INTO THE UPPER 20S TO LOWER 30S DURING THE AFTN. VERY STEEP LAPSE RATES FROM THE SFC UP TO H7 WITH THE FROPA INDICATES THE POTENTIAL FOR SNOW SQUALLS...POSSIBLY ACCOMPANIED BY A FEW RUMBLES OF THUNDER...A CLASSIC WINDEX EVENT...BUT WON`T GET TOO EXCITED YET AS NGM (WHICH VERIFIES THE BEST WITH THIS) DOESN`T GO OUT FAR ENOUGH YET. WINDS WILL DEFINITELY BE AN ISSUE BEHIND THE FROPA AND WE`LL PROBABLY NEED A WIND ADVISORY (MOSTLY FOR GUSTS UP TO 50 MPH...BUT COULD SEE A FEW PLACES HIT IT ON SUSTAINED TOO)...BUT WILL JUST MENTION THE POTENTIAL IN THE HWO FOR NOW SINCE IT`S A 5TH PERIOD EVENT. TEMPS REMAIN ABOVE NORMAL SAT AND SAT NIGHT...AND MAY REACH NORMAL LEVELS BRIEFLY SUN BEFORE ARCTIC AIRMASS FILTERS IN AND TEMPERATURES BEGIN TO DROP. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... NEEDLESS TO SAY A COMPLICATED FORECAST FOR THE EXTENDED PERIOD... WITH THE EMPHASIS HERE PUT ON DAYS 6 AND 7. PRIOR TO THAT TIME... THE UPPER TROUGH LIFTS OUT OF THE NE SUN NIGHT WITH A STRONG PUSH OF COLD AIR TO FOLLOW. A STRONG NW FLOW SUN NIGHT WILL GRADUALLY DIMINISH ON MON AS LOW PRESSURE LIFTS UP INTO THE CANADIAN MARITIMES AND POLAR HIGH PRESSURE OVER THE OHIO VALLEY BUILDS EASTWARD. THE DIFFICULT PART OF THE FORECAST COMES TUE INTO THU...AS THE NEARLY ZONAL FLOW ACROSS THE NORTHERN TWO THIRDS OF THE COUNTRY BEGINS TO UNDERGO AMPLIFICATION...WITH HEIGHT RISES ALONG THE WEST COAST AND A COMPLEX INTERACTION BETWEEN THE NORTHERN AND SOUTHERN BRANCHES OF THE POLAR JET ALONG THE US/CANADIAN BORDER. IT IS THIS INTERACTION THAT SEEMS TO BE PLAYING HAVOC WITH THE SOLUTIONS OF THE GLOBAL MODELS. THE 12Z GFS...GLOBAL CANADIAN...AND UKMET ALL POINT TO PHASING OF THESE TWO BRANCHES WITH A LESS PROGRESSIVE AND DEEPER LOW OVER THE OHIO VALLEY AND GREAT LAKES STATES TUE INTO WED. THIS IS A WARMER SOLUTION THAN RECENT DAYS. THE 00Z ECMWF KEEPS THE TWO BRANCHES UNPHASED...WITH A MORE PROGRESSIVE AND WEAKER LOW. THIS SCENARIO WAS COLDER AND MORE SUPPORTIVE OF WINTRY MIX...IF NOT AN ALL SNOW EVENT. THE GOOD NEWS THOUGH...IS THAT THE 12Z ECMWF SEEMS TO FOLLOWING SUIT WITH A DEEPER SYSTEM IN THE EAST. IN ADDITION...BOTH THE 12Z GFS AND ECMWF ARE FORMING A SECONDARY ALONG THE MID ATLANTIC COAST...BUT ARE ABOUT 12 HR OFF IN TIMING. THE ECMWF HAS A DEEPER...MORE CONSOLIDATED UPPER TROUGH ALONG THE EASTERN SEABOARD WITH A 984 MB SFC LOW EAST OF CAPE COD AT 00Z THU. THE GFS IS WEAKER AND MORE PROGRESSIVE WITH A 1001 MB LOW OFF THE MIDDLE ATLANTIC COAST. THERE IS OBVIOUS UNCERTAINTY WITH THIS FORECAST...BUT BETTER AGREEMENT TOWARD A DEEPER...WARMER SYSTEM OVER THE EAST APPEARS EVIDENT. HOWEVER...RATHER THAN WHOLEHEARTEDLY BUYING INTO THESE NEW SCENARIOS....THE GRIDS REPRESENT A GRADUAL TRANSITION TO THIS SOLUTION DURING DAYS 5 THROUGH 7. TEMPS DURING THE PERIOD STILL LOOKS TO BE AT OR SLIGHTLY BELOW NORMAL. THUS...THE POTENTIAL FOR WINTRY WEATHER STILL EXISTS TUE AFT INTO EARLY THU. THERE IS BOUND TO BE SIGNIFICANT CHANGES THIS FAR OUT IN THE FORECAST PERIOD. && .AVIATION /13Z FRIDAY THROUGH TUESDAY/... MOISTURE CONVERGENCE INVOF WEAK SURFACE TROUGH EAST OF LONG ISLAND CONTINUES TO HOLD IN LOW LEVEL MOISTURE...WITH HIGH END IFR CIGS ACROSS LONG ISLAND AND PORTIONS OF COASTAL CT...AND LOW END MVFR CIGS AT MOST OF THE NYC AREA TERMINALS. RADAR ALSO SHOWS SOME VERY LIGHT PRECIP...IN THE FORM OF RAIN ACROSS EASTERN LONG ISLAND...AND LIGHT SNOW OVER SOUTHERN CT. AS SURFACE TEMPS WARM UP THIS MORNING...WOULD EXPECT GRADUAL IMPROVEMENT TO HIGHER END MVFR CIGS. AS DRIER AIR STARTS TO FILTER IN FROM THE NORTH/WEST...LOWER CIGS SHOULD SCATTER OUT AND GIVE WAY TO A MID LEVEL CLOUD DECK BY MIDDAY AS AN UPPER LEVEL DISTURBANCE APPROACHES...BUT MVFR CIGS SHOULD HANG IN UNTIL MID TO LATE AFTERNOON OUT EAST. VFR BY FRI EVENING. OUTLOOK FOR 12Z SATURDAY THROUGH TUESDAY...WE COULD SEE SUB VFR CONDITIONS ON SAT WITH PRECIPITATION AHEAD OF AND WITH THE PASSAGE OF AN ARCTIC FRONT. STRONG WINDS ARE LIKELY FROM SAT NIGHT THROUGH MON...ESPECIALLY SUN AND SUN NIGHT WHEN SOME TERMINALS COULD SEE WEST WINDS 20-30G40KT. SUB-VFR CONDITIONS ARE ALSO POSSIBLE BY LATE TUE AS ANOTHER STORM SYSTEM APPROACHES FROM THE SW. && .MARINE... SCA FOR HAZARDOUS OCEAN SEAS REMAINS IN EFFECT E OF FIRE ISLAND INLET...AS 5 FT SOUTHERLY SWELL CONTINUES TO IMPACT THE WATERS... LIKELY ALSO CREATING ROUGH CONDITIONS AT THE INLETS. SWELLS SHOULD GRADUALLY SUBSIDE TODAY...FALLING BELOW 5 FT W OF MORICHES INLET BY THIS AFTERNOON...BUT TAKING THE BETTER PART OF THE DAY TO SO SO IN THE EASTERNMOST OCEAN WATERS. SCA CONDITIONS ARE LIKELY TO RETURN SAT NIGHT AS FLOW TURNS WESTERLY AFTER A COLD FRONTAL PASSAGE. GALES NOW APPEAR LIKELY ON ALL WATERS LATE SUN MORNING INTO SUN NIGHT VIA STRONG COLD AIR ADVECTION AND A TIGHT PRESSURE GRADIENT AFTER A STRONG ARCTIC COLD FRONTAL PASSAGE. A FEW GUSTS JUST SHY OF STORM FORCE MAY OCCUR ON THE OCEAN. THE STRONG OFFSHORE FLOW MAY ALSO LEAD TO LOW WATER PROBLEMS ON WESTERN LONG ISLAND SOUND AND NY HARBOR WITH THE LOW TIDE CYCLES SUN NIGHT THROUGH MON MORNING...AS WELL AS POSSIBLE FREEZING SPRAY ON THE OCEAN AND SOUND. CONDITIONS SHOULD SETTLE DOWN TO BELOW SCA CRITERIA ON THE SOUND/HARBOR/BAYS BY MON MORNING...BUT SCA CONDITIONS COULD CONTINUE ON THE OCEAN INTO MON NIGHT. SCA CONDITIONS MAY AGAIN OCCUR ON THE OCEAN WATERS TUE AND TUE NIGHT IN ASSOCIATION WITH AN APPROACHING FRONTAL SYSTEM. && .HYDROLOGY... THE NEXT CHANCE OF SOMEWHAT SIGNIFICANT PRECIPITATION WILL BE SAT INTO SAT EVENING WITH UP TO 1/4 INCH EXPECTED (SOME IN FROZEN FORM). NO HYDRO ISSUES ARE EXPECTED. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EST THIS AFTERNOON FOR ANZ350. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 AM EST THIS MORNING FOR ANZ353. && $$ AVIATION...GOODMAN ct AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBANY NY 635 AM EST FRI FEB 8 2008 .SYNOPSIS... A WEAK RIDGE OF SURFACE HIGH PRESSURE WILL BE OVER NORTHERN NEW YORK AND NEW ENGLAND TODAY. CLOUDY CONDITIONS WITH SCATTERED FLURRIES OR AN ISOLATED SNOW SHOWER WILL PERSIST INTO THE AFTERNOON. A CLIPPER LOW WILL APPROACH FROM THE GREAT LAKES REGION FRIDAY NIGHT. A PERIOD OF LIGHT SNOW MIXED WITH RAIN FROM THE CAPITAL REGION SOUTH WILL OCCUR AHEAD OF THE WARM FRONT TO THIS SYSTEM SATURDAY AFTERNOON INTO THE EARLY EVENING. AN ARCTIC COLD FRONT WITH POTENTIALLY SOME SNOW SQUALLS WILL BLAST THROUGH EASTERN NEW YORK AND WESTERN NEW ENGLAND LATE SUNDAY MORNING. BLUSTERY CONDITIONS AND WIND CHILLS IN THE SINGLE DIGITS TO BELOW ZERO WILL FOLLOW SUNDAY AFTERNOON INTO MONDAY. && .NEAR TERM /UNTIL 6 PM TODAY/... TODAY...DESPITE A BUBBLE ANTICYCLONE AT THE SFC THIS MORNING...PLENTY OF LOW LEVEL MOISTURE IS TRAPPED BELOW AN INVERSION INHIBITING ANY BONAFIDE CLEARING. A MID/UPPER LEVEL SHORT WAVE OVER NRN NY THIS MORNING WILL KEEP THE THREAT OF AN ISOLD SNOW SHOWER OVER THE SRN ADIRONDACKS...AND WRN NEW ENGLAND NORTH OF THE BERKSHIRES. THE IR PICTURE WITH H500 HEIGHTS FROM THE RUC13 OVERLAYED SHOWS SOME MID AND HIGH CLOUDINESS IN THE W/SW FLOW ALOFT STREAMING IN FROM THE OH VALLEY AND PA. WE BELIEVE ANOTHER SHORT WAVE MAY TAP INTO THE LOW LEVEL MOISTURE AND TRIGGER AND ISOLD SNOW SHOWERS WEST OF THE HUDSON RIVER VALLEY IN THE PM...WITH PERHAPS SOME SCT FLURRIES NORTH OF THE MID HUDSON VALLEY AND LITCHFIELD HILLS. AGAIN...CLOUDY/MOSTLY CLOUDY CONDITIONS WILL PREVAIL...EXCEPT NEAR KPOU WHERE A FEW BREAKS OF SUN MAY OCCUR IN THE PM. NOT TOO MUCH BOUNDARY LAYER WARMING IS EXPECTED DESPITE WEAK LOW LEVEL WARM ADVECTION AT H850 BTWN 18Z AND 00Z. WE WENT A FEW DEGREES COOLER THAN THE GFSMOS MAX TEMPS. GENERALLY 20S TO L30S TO THE NORTH AND OVER THE HILLS AND MTNS...MID 30S OVER THE CAPITAL REGION...AND UPPER 30S TO AROUND 40 SOUTH OF ALY. && .SHORT TERM /6 PM FRIDAY TO SUNDAY/... TONIGHT...TRANQUIL WEATHER PERSISTS FOR A BRIEF SPELL LONGER WITH TH WEAK SFC ANTICYCLONE MOVING SOUTH OF LONG ISLAND. MID LEVEL HEIGHTS CONTINUE TO RISE WITH CLIPPER LOW AND ITS ASSOCIATED SHORT WAVE/MID LEVEL TROUGH APPROACHING FROM THE WRN GREAT LAKES REGION. THIS FEATURE WILL BE THE PRELIMINARY PLAYER FOR A ROUND OF MAINLY LIGHT SNOW FOR THE REGION ON SATURDAY. SOME RAIN MAY MIX IN TO THE SOUTH OF ALY INITIALLY. THE DISTURBANCE TO KICK IN AN ARCTIC BLAST WILL BE THE PV ANOMALY MOVING SOUTHEAST OF LAKE WINNIPEG SAT MORNING. THE LATEST GFS40 DEPICTING POTENTIAL TEMP ON THE 1.5 PVU SFC SHOWS THIS ANOMALY DIGGING SOUTHEAST INTO WI/MI BY 00Z SUN. OVERALL...LOW TEMPS WILL BE TRICKY FRI NIGHT WITH SKIES POSSIBLY CLEARING BRIEFLY WITH A QUICK SHOT OF RADIATIONAL COOLING BEFORE MID AND HIGH CLOUDINESS INCREASE WITH THERMAL ADVECTION PATTERN ADVANCING N/NE. WE WENT A SHADE WARMER THAN THE COOLEST GFSMOS VALUES HERE. SATURDAY...CLIPPER MOVES NORTH OF LAKE HURON DURING THE PM WITH OVER RUNNING PCPN IMPACTING THE FCST AREA. A QUICK QG ANALYSIS SHOWS THE DIFFERENTIAL THICKNESS ADVECTION IN ADVANCE OF A WARM FRONT OVER PA AND MD COUPLED WITH DIFFERENTIAL VORTICITY ADVECTION IN THE H850-500 LAYER WILL PRODUCE ENOUGH QG OMEGA FOR A BURST OF PCPN. RIGHT NOW...TOTAL QPF PRIOR TO 00Z SUN LOOKS TO BE IN THE TENTH TO QUARTER INCH CATEGORY. THE BOUNDARY LAYER MAY WARM ENOUGH FOR THE SNOW TO MIX WITH RAIN FROM ALY SOUTH DOWN THE MID HUDSON RIVER VALLEY. HOWEVER...EVAPORATIVE COOLING AND THE INTENSITY OF THE PCPN SHOULD INCREASE ENOUGH TO COOL THE COLUMN DOWN FOR SNOW OVER THE HILLS AND MTNS...AND EVEN OVER THE VALLEYS LATE IN THE DAY. WE ARE EXPECTING 1-3" OF SNOW...MAYBE UP TO 4" OVER THE HIGH TERRAIN. WE RAISED POPS TO CATEGORICAL VALUES...AND PHRASED IT AS LIGHT SNOW PRIOR TO NOONTIME. SATURDAY NIGHT...SNOWFALL MAY LINGER THE LONGEST NORTH OF THE MOHAWK RIVER VALLEY WITH THE WARM FRONT AND ITS ASSOCIATED SHORT WAVE TROUGH LIFTING NORTH OF THE CAPITAL REGION. MEANWHILE...THE CLIPPER LOW GETS CAPTURED BY THE POTENT H500 CLOSED LOW OVER ERN ONTARIO. THE PV ANOMALY CONTINUES TO ALLOW HEIGHTS TO FALL IN ADVANCE OF IT WITH A FULL BLOWN LONGWAVE TROUGH EVOLVING. SUB 500 DECAMETER H1000-500 THICKNESSES ENCROACH WRN NY BY 12Z SUNDAY...AS AN ARCTIC FRONT MARCHES TOWARD ERN NY AND WRN NEW ENGLAND. SUNDAY...IMPRESSIVE MID AND UPPER LEVEL CUTOFF SLIDES EAST FROM THE NRN GREAT LAKES REGION. ARCTIC FRONT TRANSVERSES REGION IN THE 12Z-18Z TIME FRAME. MID LEVEL LAPSE RATES STEEPEN SIGNIFICANTLY AHEAD OF FRONTAL PASSAGE. STRONG LOW LEVEL CONVERGENCE WITH FRONT SHOULD ALLOW A BAND OF SNOW SHOWERS...AND POTENTIALLY SNOW SQUALLS TO IMPACT THE FCST AREA. SOME OF THESE INTENSE SQUALLS MAY SNEAK DOWN THE MOHAWK RIVER VALLEY AND HIT THE CAPITAL REGION WITH SNOW RATES OF AN INCH OR TWO AN HOUR. WE WOULDN/T RULE OUT A COUPLE RUMBLES OF THUNDER EITHER WITH THE STEEP LAPSE RATES AND STRONG DYNAMICS. TEMPS WILL LIKELY TOP OUT BEFORE NOONTIME...WITH -20C AIR AT 850 MB MOVING OVER THE REGION BY THE EARLY TO MID PM. TEMPS WILL FALL THROUGH THE TWENTIES AND TEENS IN THE AFTERNOON. THE POST FRONTAL WINDS WILL BE BLUSTERY WITH 925 MB WINDS OF 35-40 KTS POSSIBLE. GOOD MOMENTUM TRANSFER IS LIKELY IN THE WAKE OF THE FRONT. WE COULD SEE WINDS OF 15-30 MPH WITH GUSTS UP TO AND POSSIBLY EXCEEDING 45 MPH. IT COULD BE A BORDERLINE ADVISORY EVENT ESPECIALLY FOR THE NRN CATSKILLS...CAPITAL REGION...BERKSHIRES NORTHWARD. FOR NOW...WE WILL HIGHLIGHT THE ENTIRE FORECAST AREA IN THE HAZARDOUS WEATHER OUTLOOK. TEMPS WILL FALL DURING THE DAY...AND WIND CHILLS FROM 10 ABOVE TO 10 BELOW ZERO WILL BE COMMON. SOME LAKE EFFECT SNOW MAY MATERIALIZE LATE IN THE DAY...BUT WITH THE SFC-H700 FLOW SHIFTING NW QUICKLY THIS WILL LIKELY BE MULTIBANDS...IMPACTING CNTRL NY MORE THAN OUR AREA. NONETHELESS WITH THE UPPER LEVEL LOW OVERHEAD WILL KEEP CHANCE POPS IN OVER THE WRN ADIRONDACKS SUNDAY PM. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... ARCTIC SURGE OF COLD AIR POURING INTO THE REGION SUNDAY NIGHT WILL BE SHORT LIVED. CORE OF THE ARCTIC AIR QUICKLY EXITS THE REGION EARLY MONDAY MORNING...WITH RAPID MID LEVEL WARMING EXPECTED MONDAY AND MONDAY NIGHT. BY LATE MONDAY NIGHT AND TUESDAY...OVERUNNING PATTERN WILL SET UP IN THIS WARM ADVECTION WITH A HIGH CHANCE OF SNOW FORECAST FOR TUESDAY. THE OVERUNNING PATTERN WILL CONTINUE INTO TUESDAY NIGHT AND WEDNESDAY...WITH A DEVELOPIONG SURFACE LOW FORECAST TO RIDE ALONG THE FRONTAL BOUNDARY AND MOVE OFF THE MID ATLANTIC COAST WEDNESDAY NIGHT. A LONG PERIOD WITH A CHANCE OF MAINLY SNOW HAS BEEN FORECAST FOR TUESDAY THROUGH WEDNESDAY NIGHT. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... NO SIGNIFICANT AVIATION PROBLEMS EXPECTED DURING THE TAF PERIOD ENDING 12Z SATURDAY WITH MAINLY VFR CONDITIONS AT KGFL/KALB/KPOU THROUGH THE PERIOD. THERE WILL BE A PERIOD OF MVFR CIGS AT KGFL THIS MORNING...OTHERWISE EXPECT VFR CIGS AT ALL THREE SITES BETWEEN 4000 AND 5000 FEET...WITH THE LOWER CLOUDS TENDING TO BREAK UP LATER TODAY AND THIS EVENING...LEAVING MAINLY MID CLOUDS TONIGHT. SURFACE WINDS WILL BE LIGHT AND VARIABLE. OUTLOOK... SAT...MVFR/IFR...-SN LIKELY. SUN...MVFR/VFR...SCT -SHSN. MON...VFR...NO SIG WX. TUE...MVFR/VFR...CHC -SHSN. && .HYDROLOGY... ISOLATED MINOR FLOODING CONTINUES IN THE WRN MOHAWK VALLEY AND IN THE HOUSATONIC BASIN THIS MORNING FROM THE ONE TO TWO INCHES OF QPF FROM YESTERDAY. A FEW POINTS ON THE HOUSATONIC REMAIN A FEW INCHES TO HALF A FOOT ABOVE FLOOD STAGE...AS WELL AS THE MOHAWK RIVER AT UTICA. THESE POINTS SHOULD FALL BELOW THEIR CRESTS LATER TODAY. SEE INDIVIDUAL FLW/S AND FLS/S FOR MORE DETAILS. MAIN STEM RIVERS WILL CONTINUE TO RECEDE DUE TO SEASONABLY COLD WEATHER...AND MAINLY LIGHT QPF THROUGH THE WEEKEND. THE MAIN PTYPE WILL BE SNOW SAT INTO SUN. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...TAW NEAR TERM...TAW SHORT TERM...TAW LONG TERM...GJM AVIATION...GJM HYDROLOGY...TAW/KL ct AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 335 PM EST FRI FEB 8 2008 .SYNOPSIS... 19Z WATER VAPOR AND H4 RUC ANALYSIS CONTINUES TO SHOW LOW AMPLITUDE LONG WAVE TROUGHING ACROSS MUCH OF NORTH AMERICA. ALL OF THE ACTION IN TERMS OF WEATHER CONTINUES TO BE ASSOCIATED WITH THE NORTHERN STREAM. SHORTWAVE TROUGHS EMBEDDED WITHIN THE FLOW ARE SEEN EXITING THE NORTHEAST AND ALSO PUSHING THROUGH THE NORTHERN AND CENTRAL PLAINS. FURTHER UPSTREAM OVER BRITISH COLUMBIA WE SEE THE FIRST SIGNS OF A VERY POTENT SHORTWAVE THAT WILL EVOLVE AND AMPLIFY OVER THE NEXT 24 HOURS USHERING A SIGNIFICANT ARCTIC BLAST INTO THE NORTHERN PLAINS AND GREAT LAKES REGION THIS WEEKEND. THE SOUTHERN STREAM IS MUCH LESS ACTIVE AT THIS TIME WITH NEAR ZONAL FLOW FROM NORTHERN MEXICO EASTWARD ALONG THE GULF COAST. AT THE SURFACE...1019MB HIGH PRESSURE REMAINS CENTERED OVER THE FORECAST AREA. OLD FRONTAL BOUNDARY LIES WELL TO OUR SOUTH ACROSS THE CENTRAL FL PENINSULA AND INTO THE SOUTHEAST GULF OF MEXICO. A BAND OF CLOUDS AND SHOWERS IS SEEN WITH THIS FEATURE...BUT THESE WILL STAY TO OUR SOUTH. VERY PLEASANT AFTERNOON UNDERWAY WITH TEMPERATURES INTO THE MIDDLE 60S AND LOWER 70S REGIONWIDE. && .SHORT TERM... (TONIGHT THROUGH SUNDAY)...LITTLE CHANGE IN PATTERN TONIGHT WITH HIGH PRESSURE STILL CENTERED NEAR OR OVER THE REGION. WILL LIKELY SEE TEMPS A FEW DEGREES WARMER TONIGHT WITH UPPER 30S TO MIDDLE 40S MORE COMMON. FAIR WEATHER AGAIN FOR SATURDAY. HIGH PRESSURE WEAKENS AND MOVES OFF TO THE EAST DURING THE DAY AS A WEAK SHORTWAVE AND ASSOCIATED WEAK COLD FRONT APPROACHES FROM THE NORTHWEST. THE FRONT WILL LIKELY CROSS DURING EVENING HOURS...HOWEVER WITH A VERY MOISTURE STARVED ENVIRONMENT...THE PASSAGE WILL REALLY ONLY BE DISTINGUISHED BY A WIND SHIFT AND A SLIGHT INCREASE IN CLOUDS DURING THE AFTERNOON INTO SATURDAY NIGHT. HIGH PRESSURE TO OUR NORTHWEST WILL THEN QUICKLY BUILD IN BEHIND THE FRONT LATER SATURDAY NIGHT INTO SUNDAY. JUST A SLIGHTLY COOLER AIRMASS WILL ARRIVE BEHIND THE FRONT RESULTING IN ANOTHER VERY NICE FEBRUARY DAY (ALTHOUGH POTENTIALLY A BIT BREEZY) ACROSS THE REGION. EXPECTING PLENTY OF SUNSHINE WITH HIGH TEMPERATURES IN THE 60S. && .LONG TERM... (SUNDAY NIGHT THROUGH THURSDAY) WINDS VEER FROM NORTH TO EAST AS SURFACE HIGH PRESSURE CENTERED OVER THE MIDWEST SUNDAY NIGHT MOVES OFF THE MID ATLANTIC STATES MONDAY NIGHT. A VIGOROUS SHORTWAVE DROPS FROM THE CENTRAL ROCKIES MONDAY NIGHT CLOSING OFF AN UPPER LOW OVER THE TEXAS PANHANDLE TUESDAY AFTERNOON. THIS FEATURE CONTINUES TO INTENSIFY AS IT TRANSLATES ACROSS THE LOWER MISSISSIPPI VALLEY...TENNESSEE VALLEY AND EAST OF THE MID ATLANTIC STATES WEDNESDAY THROUGH THURSDAY. AT THE SURFACE...A WARM FRONT DEVELOPS IN THE EAST CENTRAL GULF TUESDAY AND LIFTS ACROSS THE LOCAL REGION TUESDAY NIGHT FOLLOWED BY THE COLD FRONT SWEEPING FROM WEST TO EAST WEDNESDAY. WILL HAVE TO MONITOR FOR POSSIBLE SEVERE WEATHER WITH THIS SYSTEM. FOR NOW WILL CONTINUE THE TREND OF INCREASING POPS FOR THIS TIME FRAME. TEMPS WILL BE NEAR TO ABOVE CLIMO THROUGH THE PERIOD. && .AVIATION.... VFR CONDITIONS WILL PREVAIL THROUGHOUT THE FORECAST PERIOD WITH HIGH PRESSURE AND DRY AIR IN PLACE. GFS RH TIME-HEIGHT CROSS SECTION INDICATING SOME LOW-LEVEL MOISTURE IN THE EARLY MORNING SATURDAY. WITH DEW POINT DEPRESSION DROPPING TO NEAR 2-3 DEGREES AND NEAR CALM WINDS...SOME ISOLATED AREAS OF FOG IN THE EARLY MORNING SATURDAY ARE POSSIBLE. WENT WITH MVFR TEMPO GROUPS FOR FOG FOR VLD AND TLH. && .MARINE... THE SURFACE HIGH MOVES OFF TO THE EAST TONIGHT AND EARLY SATURDAY...AS A WEAK COLD FRONT APPROACHES FROM THE NORTHWEST. THIS FRONT WILL CROSS THE FORECAST WATERS DURING SATURDAY EVENING OR NIGHT WITH HIGH PRESSURE BUILDING IN FROM THE NORTH FOR SUNDAY. THE FRONT WILL BE FOLLOWED BY INCREASING FLOW FROM THE NORTH AND NORTHWEST. A PERIOD OF NEAR CAUTION CONDITIONS IS POSSIBLE SATURDAY NIGHT INTO EARLY SUNDAY...ESPECIALLY ACROSS THE OFFSHORE LEGS...AND THEN ANOTHER ROUND OF CAUTION OR EVEN ADVISORY LEVEL CONDITIONS SUNDAY NIGHT INTO EARLY MONDAY. THE SURFACE HIGH WILL THEN MOVE OFF THE SOUTHEAST COAST LATER MONDAY INTO EARLY TUESDAY AS THE NEXT WEATHER SYSTEM APPROACHES FROM THE WEST DURING THE MID WEEK PERIOD. && .FIRE WEATHER... A BIT OF ONSHORE FLOW HAS KEPT RH VALUES UP ACROSS PORTIONS OF THE FORECAST AREA THIS AFTERNOON. WILL DROP BAY...FRANKLIN...AND GULF COUNTIES FROM THE RED FLAG WARNING FOR THIS REASON. WILL LEAVE UP THE WARNING FOR THE REST OF THE AREA...ALTHOUGH CRITICAL DURATIONS OF RH BELOW 35 PERCENT MAY BE DIFFICULT TO STILL REACH. WILL LEAVE THE FIRE WEATHER WATCH UP FOR SATURDAY AFTERNOON ACROSS THE EASTERN FL PANHANDLE AND BIG BEND ZONES FOR NOW. WILL NOT UPGRADE TO A WARNING AT THIS TIME AS CONFIDENCE IS A BIT LOW ON HOW MUCH MOISTURE WILL RIDE NORTH AHEAD OF AN APPROACHING COLD FRONT. BEHIND THIS FRONT DRIER AIR WILL CERTAINLY INVADE FROM THE NORTH WITH FIRE WX CONCERNS POTENTIALLY ARRIVING FOR THE ENTIRE FORECAST AREA BY SUNDAY AFTERNOON. && .PRELIMINARY POINT TEMPS/POPS... TALLAHASSEE 38 74 42 70 33 / 0 0 0 0 0 PANAMA CITY 46 71 45 69 41 / 0 0 0 0 0 DOTHAN 38 70 42 69 36 / 0 0 0 0 0 ALBANY 37 71 40 68 33 / 0 0 0 0 0 VALDOSTA 39 73 41 69 35 / 0 0 0 0 0 CROSS CITY 39 75 44 71 34 / 0 0 0 0 0 && .TAE WATCHES/WARNINGS/ADVISORIES... AL...NONE. GA...NONE. FL...RED FLAG WARNING UNTIL 6 PM EST /5 PM CST/ THIS AFTERNOON FOR THE FOLLOWING ZONES: CALHOUN...DIXIE...GADSDEN...HOLMES... INLAND WALTON...JACKSON...JEFFERSON...LAFAYETTE...LEON... LIBERTY...MADISON...TAYLOR...WAKULLA...WASHINGTON. FIRE WEATHER WATCH SATURDAY AFTERNOON FOR THE FOLLOWING ZONES: BAY...CALHOUN...DIXIE...FRANKLIN...GADSDEN...GULF... HOLMES...INLAND WALTON...JACKSON...JEFFERSON...LAFAYETTE... LEON...LIBERTY...MADISON...TAYLOR...WAKULLA...WASHINGTON. GM...NONE. && $$ AVIATION...BLOCK/WOODRUM PUBLIC/MARINE/FIRE WX...MROCZKA LONG TERM...BARRY fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 950 AM EST FRI FEB 8 2008 .SYNOPSIS... 14Z WATER VAPOR AND H4 RUC ANALYSIS CONTINUES TO SHOW LOW AMPLITUDE LONG WAVE TROUGHING ACROSS MUCH OF NORTH AMERICA. ALL OF THE ACTION IN TERMS OF WEATHER IS ASSOCIATED WITH THE NORTHERN STREAM AT THIS TIME. SHORTWAVE TROUGHS EMBEDDED WITHIN THE FLOW ARE SEEN MOVING THROUGH THE NORTHEAST AND ALSO EJECTING OUT INTO THE NORTHERN AND CENTRAL PLAINS. FURTHER UPSTREAM OVER BRITISH COLUMBIA WE SEE THE FIRST SIGNS OF A VERY POTENT SHORTWAVE THAT WILL EVOLVE AND AMPLIFY OVER THE NEXT 24 HOURS USHERING A SIGNIFICANT ARCTIC BLAST INTO THE NORTHERN PLAINS AND GREAT LAKES REGION THIS WEEKEND. THE SOUTHERN STREAM IS MUCH LESS ACTIVE AT THIS TIME WITH NEAR ZONAL FLOW FROM NORTHERN MEXICO EASTWARD ALONG THE GULF COAST. AT THE SURFACE...1019MB HIGH PRESSURE REMAINS CENTERED OVER THE FORECAST AREA AND WILL MOVE LITTLE THROUGH THE REMAINDER OF THE DAY. OLD FRONTAL BOUNDARY LIES WELL TO OUR SOUTH ACROSS THE CENTRAL FL PENINSULA AND INTO THE SOUTHEAST GULF OF MEXICO. A BAND OF CLOUDS AND SHOWERS IS SEEN WITH THIS FEATURE...BUT THESE WILL STAY TO OUR SOUTH WITH THE MOSTLY CLEAR SKIES CURRENTLY OVERHEAD PERSISTING INTO TONIGHT. && .SHORT TERM... TEMPERATURES BEGINNING TO WARM RAPIDLY FROM LOWS AROUND SUNRISE IN THE MIDDLE 30S TO LOWER 40S. WILL SEE THESE TEMPS CONTINUE TO RISE TOWARD AFTERNOON HIGHS IN THE MIDDLE AND UPPER 60S. VERY LIKELY THAT A FEW SPOTS ACROSS THE FLORIDA BIG BEND WILL REACH 70F. LITTLE CHANGE IN PATTERN TONIGHT WITH HIGH PRESSURE STILL CENTERED OVER THE REGION. WILL LIKELY SEE TEMPS A FEW DEGREES WARMER TONIGHT WITH UPPER 30S TO MIDDLE 40S MORE COMMON. FAIR WEATHER AGAIN FOR SATURDAY. HIGH PRESSURE WEAKENS AND MOVES OFF TO THE EAST DURING THE DAY AS A WEAK SHORTWAVE AND ASSOCIATED WEAK COLD FRONT APPROACHES FROM THE NORTHWEST. THE FRONT WILL CROSS DURING THE LATE AFTERNOON OR EVENING HOURS...HOWEVER WITH A VERY MOISTURE STARVED ENVIRONMENT...THE PASSAGE WILL REALLY ONLY BE DISTINGUISHED BY A WIND SHIFT. HIGH PRESSURE TO OUR NORTHWEST WILL THEN QUICKLY BUILD IN BEHIND THE FRONT SATURDAY NIGHT KEEPING OUR WEATHER TRANQUIL INTO THE EARLY PART OF NEXT WEEK. && .AVIATION... VFR CONDITIONS WITH GENERALLY CLEAR SKIES MARRED ONLY BY A FEW THIN CIRRUS AND LIGHT WEST WINDS AT ALL TERMINALS THROUGH THE PERIOD. && .MARINE... WINDS HAVE BEEN RUNNING FROM THE NORTHWEST OR NORTH AROUND 10 KNOTS THIS MORNING WITH SEAS RANGING FROM AROUND 1 FOOT NEAR THE COAST TO AROUND 3 FEET AT THE OFFSHORE BUOYS. THE FLOW IS EXPECTED TO BECOME MORE VARIABLE AT LESS THAN 10 KNOTS THIS AFTERNOON WITH THE SURFACE HIGH NEARLY DIRECTLY OVERHEAD. WITH THE HIGH THEN PUSHING OFF TO THE EAST TONIGHT AND EARLY SATURDAY...AND A WEAK COLD FRONT APPROACHES FROM THE NORTHWEST...FLOW SHOULD BECOME SOUTHWEST AND THEN VEER AROUND TO THE WEST WITH TIME. WITH THE FRONTAL PASSAGE LATER SATURDAY...WINDS COME AROUND TO THE NORTH AND NORTHEAST. MAY SEE A PERIOD OF NEAR CAUTION CONDITIONS FOR A PERIOD SATURDAY NIGHT INTO EARLY SUNDAY...ESPECIALLY ACROSS THE OFFSHORE LEGS...AND THEN ANOTHER ROUND OF CAUTION CONDITIONS SUNDAY NIGHT INTO EARLY MONDAY. && .FIRE WEATHER... RED FLAG WARNINGS ARE UP FOR ALL OF THE EASTERN FLORIDA PANHANDLE AND FLORIDA BIG BEND DUE TO EXPECTED EXTENDED DURATIONS OF RELATIVE HUMIDITY AT OR BELOW 35 PERCENT THIS AFTERNOON COMBINED WITH FAIRLY HIGH DISPERSION INDICIES. CONTINUED DRY CONDITIONS AND WARM TEMPS WILL LIKELY RESULT IN SIMILAR CONDITIONS ON SATURDAY OVER THESE AREAS. && .PRELIMINARY POINT TEMPS/POPS... TALLAHASSEE 69 43 71 40 67 / 0 0 0 0 0 PANAMA CITY 67 50 70 43 68 / 0 0 0 0 0 DOTHAN 66 41 67 41 66 / 0 0 0 0 0 ALBANY 66 39 68 38 66 / 0 0 0 0 0 VALDOSTA 67 43 70 39 66 / 0 0 0 0 0 CROSS CITY 70 44 73 41 69 / 0 0 0 0 0 && .TAE WATCHES/WARNINGS/ADVISORIES... AL...NONE. GA...NONE. FL...RED FLAG WARNING FROM 1 PM EST /NOON CST/ TO 6 PM EST /5 PM CST/ THIS AFTERNOON FOR THE FOLLOWING ZONES: BAY...CALHOUN... DIXIE...FRANKLIN...GADSDEN...GULF...HOLMES...INLAND WALTON...JACKSON...JEFFERSON...LAFAYETTE...LEON...LIBERTY... MADISON...TAYLOR...WAKULLA...WASHINGTON. FIRE WEATHER WATCH SATURDAY AFTERNOON FOR THE FOLLOWING ZONES: BAY...CALHOUN...DIXIE...FRANKLIN...GADSDEN...GULF... HOLMES...INLAND WALTON...JACKSON...JEFFERSON...LAFAYETTE... LEON...LIBERTY...MADISON...TAYLOR...WAKULLA...WASHINGTON. GM...NONE. && $$ AVIATION...BLOCK PUBLIC/MARINE/FIRE WX...MROCZKA fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 325 PM EST THU FEB 7 2008 .SYNOPSIS... 19Z WATER VAPOR AND H4 RUC ANALYSIS SHOWING A FAIRLY PROGRESSIVE PATTERN ACROSS THE CONUS. MOST OF THE COUNTRY CHARACTERIZED BY LONG WAVE TROUGHING WITH SEVERAL SMALLER SHORTWAVE FEATURES SEEN EMBEDDED WITHIN THE LARGE SCALE FLOW. THE FIRST IS MOVING ACROSS THE NORTHEASTERN STATES...FOLLOWED BY A SECOND THROUGH THE CENTRAL AND SOUTHERN PLAINS TO THE WESTERN GOMEX AND A THIRD MOVING ASHORE ACROSS THE PACIFIC NORTHWEST. AT THE SURFACE...COLD FRONT REMAINS STALLED SOUTH OF THE FORECAST AREAS ACROSS THE CENTRAL FL PENINSULA AND INTO THE SOUTHEAST GOMEX. 1020MB HIGH PRESSURE HAS PUSHED EAST IN THE WAKE OF THIS FRONT FROM THE CENTRAL GULF COAST AND IS NOW IN CONTROL OF MUCH OF THE AREA. AFTERNOON VISIBLE SATELLITE IMAGERY SHOWS MOSTLY CLEAR SKIES NORTH AND WEST OF A LINE FROM PANAMA CITY TO GADSDEN COUNTY AND INTO SOUTH-CENTRAL GEORGIA. SOUTH AND EAST OF THIS LINE...CLOUDS HAVE FILLED IN THROUGH THE DAY WITH SCATTERED SHOWERS BREAKING OUT ACROSS THE SOUTHEAST FL BIG BEND AND ADJACENT COASTAL WATERS. THE SHOWERS ARE RESULTING FROM DECENT ISENTROPIC ASCENT ALONG THE 300-310 K SURFACES TO THE NORTH OF THE OLD FRONT (PER GFS/NAM/RUC ANALYSIS). THIS LIFT IS BEGINNING TO BE AIDED BY SYNOPTIC DEEP LAYER Q-VECTOR CONVERGENCE AHEAD OF AN APPROACHING MID-LEVEL SHORTWAVE AND ALSO DEVELOPING DIVERGENCE ALOFT ASSOCIATED WITH THE RIGHT ENTRANCE REGION OF A 150 KNOT UPPER JET FROM THE LOWER MISSISSIPPI VALLEY TO THE MIDDLE ATLANTIC STATES. && .SHORT TERM... (TONIGHT THROUGH SATURDAY)...DYNAMICS FOR LIFT MAXIMIZE DURING THE EVENING HOURS AS THE SHORTWAVE APPROACHES AND THE MOST FAVORABLE UPPER DIVERGENCE MOVES OVERHEAD. WILL EXPECT SCATTERED SHOWERS DURING THIS TIME SOUTH AND EAST OF A LINE IN THE VICINITY OF APALACHICOLA TO TALLAHASSEE AND VALDOSTA. THE SHOWERS MAY EVEN BECOME MORE NUMEROUS AT TIMES ACROSS TAYLOR...LAFAYETTE AND DIXIE COUNTIES WHERE THE ISENTROPIC UPGLIDE WILL BE MAXIMIZED. NORTH AND WEST OF THIS LINE THE CLOUDS SHOULD RAPIDLY THIN AND REMAIN MOSTLY CLEAR ACROSS A LARGE PORTION OF THE NORTHWEST FORECAST AREA. AFTER MIDNIGHT THE SHORTWAVE TROUGH WILL BE PASSING TO THE EAST WITH THE UPPER JET ALSO PUSHING OFF THE ATLANTIC SEABOARD ENDING THE MIDDLE AND UPPER LEVEL FORCING. THE PASSING OF THE SHORTWAVE WILL ALSO HELP PUSH THE SURFACE FRONT FURTHER SOUTH TAKING ANY LINGERING ISENTROPIC LIFT WITH IT. WITH THIS IN MIND...WILL TAPER THE CHANCE TO LIKELY POPS DURING THE EVENING HOURS OVER THE EASTERN BIG BEND RAPIDLY DOWN TO A SLIGHT RISK AFTER MIDNIGHT WITH MOST SHOWER ENDING BY AROUND 2 AM EST. THE ONLY EXCEPTION WILL BE THE AREA FROM DIXIE TO LAFAYETTE COUNTIES WHERE A FEW LIGHT SHOWERS OR SPRINKLES MAY HOLD ON INTO THE LATE NIGHT HOURS. THE MOSTLY CLEAR SKIES TO THE NORTH AND WEST WILL SLOWLY PUSH SOUTH AFTER MIDNIGHT WITH ANY CLOUDS CONFINED TO FAR SOUTHEAST PORTIONS OF THE AREA BY SUNRISE ON FRIDAY. A COOL NIGHT IN STORE FOR MOST WITH LOW TEMPS FROM THE MIDDLE TO UPPER 30S OVER INLAND LOCATIONS. ALONG THE IMMEDIATE COAST AND OVER INTO THE SOUTHEASTERN FL BIG BEND TEMPS WILL BE A BIT WARMER WITH LOWER AND MIDDLE 40S MORE COMMON. WITH THE EXIT OF THE SHOWERS TONIGHT...A FAIRLY LONG PERIOD OF FAIR AND SEASONABLE WEATHER WILL BEGIN AND LINGER THROUGH THE UPCOMING WEEKEND. HIGH PRESSURE TAKES CONTROL OF THE ENTIRE FORECAST AREA FRIDAY MORNING AND REMAINS IN PLACE THROUGH SATURDAY. ALOFT WE WILL SEE NEARLY ZONAL FLOW ALONG THE NORTHERN GULF COAST HELPING TO KEEP ANY SIGNIFICANT MOISTURE/RAIN CHANCES FAR TO THE SOUTH. MOSTLY TO PARTLY CLEAR SKIES CAN BE EXPECTED THROUGH THE PERIOD WITH LIGHT WINDS. HIGH TEMPERATURES GENERALLY IN THE MIDDLE TO UPPER 60S ON FRIDAY AND PERHAPS A FEW DEGREES WARMER FOR SATURDAY. LOW TEMPERATURES FRIDAY NIGHT FROM THE UPPER 30S TO LOWER 40S INLAND AND IN THE LOWER TO MIDDLE 40S ALONG THE COAST...AND THEN A FEW DEGREES COOLER FOR SATURDAY NIGHT WITH MIDDLE AND UPPER 30S MORE COMMON AWAY FROM THE COAST. && .LONG TERM... (SATURDAY NIGHT THROUGH WEDNESDAY) UPPER FLOW WILL BE WEST NORTHWEST OR ZONAL FROM SATURDAY NIGHT THROUGH MONDAY NIGHT. THEN...A THROUGH DIGS AND SHARPENS FROM THE CENTRAL PLAINS EARLY TUESDAY WITH AXIS SWINGING ACROSS THE SOUTHEAST CORNER OF THE U.S. WEDNESDAY. SURFACE HIGH PRESSURE OVER THE LOCAL REGION SATURDAY NIGHT WILL BE RE-ENFORCED BY A STRONGER AREA OF HIGH PRESSURE THAT WILL SPILL OUT OF THE NORTHERN PLAINS EARLY SUNDAY AND INTO THE SOUTHEAST CORNER OF THE U.S. MONDAY. THE HIGH WILL SHIFT EAST MONDAY NIGHT THROUGH TUESDAY ALLOWING A COLD FRONT TO APPROACH AND ENTER THE CWA LATE TUESDAY THROUGH EARLY WEDNESDAY. THE GFSX NOW SHOWS A MORE PROMISING CHANCE OF RAIN WITH THIS FRONT. ALTHOUGH...ITS DEVELOPMENT OF A SURFACE LOW IN THE GULF AHEAD OF THE FRONT BRINGING DEEP LAYER MOISTURE AND A SWATH OF RAIN TO MOST OF THE FLORIDA PENINSULA TUESDAY NIGHT INTO EARLY WEDNESDAY LOOKS SUSPICIOUS. WILL INCREASE POPS FROM SLIGHT TO LOWER END CHANCE FOR THIS TIME FRAME. TEMPS THROUGH THE PERIOD WILL NOT DEVIATE TOO FAR FROM CLIMO. && .AVIATION.... THE FRONT HAS NOW STALLED OVER THE NRN PORTION OF THE FL PENINSULA. A LAYER OF MID LEVEL CLOUDS IS MOVING PARALLEL TO THE FRONT. THE NWRN EDGE OF THE CLOUD SHIELD WILL IMPACT TLH AND VLD FOR THE FIRST HALF OF THE FORECAST PERIOD WITH CEILINGS GENERALLY ABOVE 7 KFT. OTHERWISE LOOK FOR CLEAR SKIES AND LIGHT WINDS. && .MARINE... HIGH PRESSURE BUILDS OVER THE COASTAL WATERS FROM THE WEST TONIGHT INTO FRIDAY MORNING AND THEN REMAIN IN CONTROL INTO THE UPCOMING WEEKEND. WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW HEADLINE CRITERIA THROUGH SATURDAY. AS THE HIGH SHIFT TO THE NORTH SATURDAY NIGHT INTO SUNDAY THE GRADIENT WILL TIGHTEN A BIT WITH NORTHEAST FLOW APPROACHING CAUTION LEVELS. THIS HIGH WILL THEN PUSH OFF THE MID ATLANTIC COAST ON MONDAY WITH FLOW COMING AROUND TO THE SOUTHEAST. && .FIRE WEATHER... WE ARE LOOKING FOR THE MARGINAL 4-HR DURATION OF RH BELOW 35 PERCENT ACROSS OUR FL ZONES FOR FRI. BECAUSE IT WILL BE A CLOSE CALL, WILL JUST ISSUE A WATCH FOR NOW AND LEAVE THE WARNING DECISION TO THE MID SHIFT. A RED FLAG EVENT LOOKS MORE LIKELY ON SAT. && .PRELIMINARY POINT TEMPS/POPS... TALLAHASSEE 38 68 42 71 39 / 10 0 10 0 0 PANAMA CITY 43 66 44 69 44 / 05 0 10 0 0 DOTHAN 38 66 40 68 39 / 0 0 0 0 0 ALBANY 35 67 39 68 38 / 0 0 0 0 0 VALDOSTA 39 69 41 69 39 / 30 0 10 0 0 CROSS CITY 44 70 44 72 39 / 60 10 10 0 0 && .TAE WATCHES/WARNINGS/ADVISORIES... AL...NONE. GA...NONE. FL...FIRE WEATHER WATCH FRIDAY AFTERNOON FOR THE FOLLOWING ZONES: CALHOUN...DIXIE...GADSDEN...HOLMES...INLAND WALTON... JACKSON...JEFFERSON...LAFAYETTE...LEON...LIBERTY... MADISON...TAYLOR...WAKULLA...WASHINGTON. GM...NONE. && $$ AVIATION/FIRE WX...WOOL PUBLIC/MARINE...MROCZKA LONG TERM...BARRY fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 1005 AM EST THU FEB 7 2008 .SYNOPSIS... 14Z WATER VAPOR AND H4 RUC ANALYSIS SHOWING A FAIRLY PROGRESSIVE PATTERN ACROSS THE CONUS THIS MORNING. MOST OF THE COUNTRY CHARACTERIZED BY LONG WAVE TROUGHING. SEVERAL SMALLER SHORTWAVE FEATURES ARE SEEN EMBEDDED WITHIN THE LARGE SCALE TROUGH. THE FIRST IS MOVING ACROSS THE NORTHEASTERN STATES...FOLLOWED BY A SECOND THROUGH THE CENTRAL AND SOUTHERN PLAINS AND A THIRD MOVING ASHORE ACROSS THE PACIFIC NORTHWEST. AT THE SURFACE...COLD FRONT THAT BROUGHT THE SHOWERS AND THUNDERSTORMS TO THE REGION ON WEDNESDAY HAS PUSHED SOUTH OF THE FORECAST AREAS AND NOW LIES ACROSS THE CENTRAL FL PENINSULA AND OUT INTO THE SOUTHEAST GOMEX. IN THE FRONTS WAKE...1020MB HIGH PRESSURE IS MOVING EAST FROM THE CENTRAL GULF COAST. && .SHORT TERM... CURRENTLY LOOKING AT MOSTLY CLEAR SKIES ACROSS THE NORTHWEST HALF OF THE AREA WITH PARTLY CLOUDY SKIES TO THE SOUTHEAST CLOSER TO THE FRONT. AS THE DAY PROGRESSES WILL LIKELY SEE THE FRONT BUCKLE BACK TO THE NORTH A BIT AS A WEAK WAVE RIPPLES ALONG THE BOUNDARY. THIS WAVE WILL HAVE SOME ENHANCEMENT AS MID-LEVEL SHORTWAVE ENERGY MOVES FROM THE SOUTHERN PLAINS TOWARD THE WESTERN AND CENTRAL GULF COAST THIS EVENING. SHOULD SEE JUST ENOUGH ISENTROPIC UPGLIDE OVER THE BOUNDARY ALONG THE 300-310K SURFACES TO PRODUCE A FEW SHOWERS SOUTH AND EAST OF A LINE FROM AROUND APALACHICOLA TO VALDOSTA DURING THE LATER AFTERNOON AND EVENING HOURS. NOT EXPECTING ALL THAT MUCH RAINFALL ACCUMULATION AT THIS TIME...BUT POTENTIALLY ENOUGH TO IMPACT SOME OUTDOOR ACTIVITIES. AT THE VERY LEAST WILL BE LOOKING AT SKIES BECOME MOSTLY CLOUDY OVER THESE AREAS AND PARTLY CLOUDY FURTHER TO THE NORTHWEST. CURRENT POPS ARE GENERALLY IN THE CHANCE 30-50% RANGE ACROSS THE SOUTHEAST BIG BEND AND THIS AGREES WELL WITH THE LATEST MOS GUIDANCE. WILL HAVE TO KEEP A CLOSE EYE ON THE EVOLUTION OF THE ISENTROPIC LIFT AS THE LATEST 09Z SREF ENSEMBLE GUIDANCE IS SHOWING A BIT BETTER CHANCE OF A WETTING RAIN TO THE SOUTH OF A LINE FROM AROUND PERRY TO JACKSONVILLE. THIS WOULD INCLUDE PORTION OF TAYLOR...LAFAYETTE...AND DIXIE COUNTIES. WILL SIMPLY MONITOR FOR THE TIME BEING AND MAKE ANY NEEDED ADJUSTMENTS WITH THE UPCOMING AFTERNOON FORECAST PACKAGE. AS THE MID-LEVEL SHORTWAVE ENERGY MOVES EAST OVERHEAD DURING THE OVERNIGHT PERIOD INTO FRIDAY MORNING...THE FRONT...AND ANY ASSOCIATED FORCING FOR SHOWERS WILL BE FORCED BACK FURTHER SOUTH AND EAST INTO THE CENTRAL PART OF THE FL PENINSULA. HIGH PRESSURE WILL THEN RE-ESTABLISH ITSELF DURING THE MORNING HOURS. && .AVIATION... CURRENT FORECAST SHOWS VFR CONDITIONS PREVAILING AT THE TERMINALS. THE ONLY FLY IN THE OINTMENT IS THE CLOUD COVER WE SEE OUT OVER THE GULF. WE HAVE NO OBS OUT THERE THAT GIVE US AN INDICATION OF CLOUD BASES. MODEL TIME HEIGHT CROSS SECTIONS INDICATE THAT ANY CEILINGS WOULD BE VFR AT ABOUT 5 KFT, AND THE BEST CHANCE FOR THIS WOULD BE AT TLH AND VLD. FOR NOW, THE FORECAST INDICATES SCATTERED CLOUDS AT THIS LEVEL TODAY. && .MARINE... WINDS AND SEAS WILL REMAIN BELOW HEADLINE CRITERIA INTO FRIDAY WITH HIGH PRESSURE IN THE VICINITY. WEAK FRONT TO OUR SOUTH WILL MOVE NORTH A BIT DURING TODAY BUT SHOULD REMAIN SOUTH OF THE FORECAST WATERS. DO EXPECT A LEAST SCT SHOWERS DURING THE MID/LATE AFTERNOON AND EVENING HOURS OVER THE WATERS TO THE SOUTH AND EAST OF APALACHICOLA. THESE SHOWERS SHOULD END LATER TONIGHT OR DURING THE EARLY MORNING ON FRIDAY. && .FIRE WEATHER... STILL EXPECTING A FEW LOCATIONS ACROSS THE INLAND FL PANHANDLE TO REACH 35 PERCENT RH VALUES FOR A COUPLE OF HOURS THIS AFTERNOON... HOWEVER CRITICAL DURATIONS STILL APPEAR UNLIKELY. && .PRELIMINARY POINT TEMPS/POPS... TALLAHASSEE 66 40 69 46 70 / 10 10 10 0 0 PANAMA CITY 63 47 67 52 69 / 10 10 0 0 0 DOTHAN 62 40 67 45 67 / 10 10 10 0 0 ALBANY 62 37 66 43 67 / 10 10 10 0 0 VALDOSTA 66 42 69 45 69 / 15 10 10 0 0 CROSS CITY 67 45 70 48 72 / 50 40 10 0 0 && .TAE WATCHES/WARNINGS/ADVISORIES... AL...NONE. GA...NONE. FL...NONE. GM...NONE. && $$ AVIATION...WOOL PUBLIC/MARINE/FIRE WX...MROCZKA fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 1239 PM EST FRI FEB 8 2008 .AVIATION... WK WARM FRONT HAS MOVED THROUGH NRN INDIANA EARLY THIS AFTN WITH DRIER AIR MOVG IN BEHIND IT. THIS SHOULD ALLOW FOR SOME VFR CONDITIONS AT FWA THIS AFTN/EVE. SBN A LITTLE DEEPER INTO THE MOIST LOW LEVEL AIRMASS SHOULD GO VFR FOR A SHORT PD LATE THIS AFTN/EARLY THIS EVE, BEFORE SNOW MOVES IN AGAIN CAUSING CIGS/VSBYS TO LOWER TO IFR OVERNIGHT AS A WK CDFNT MOVES INTO THE AREA. LOW LEVELS MAY BE WARM ENOUGH TO KEEP PRECIP AS A RN/SN MIX AT FWA AND WITH NAM CONTG TO INDICATE LESS LOW LEVEL MOISTURE IN THIS AREA... FCST CIGS/VSBYS ONLY LOWERING TO MVFR OVERNIGHT. LINGERING LOW LEVEL MOISTURE BEHIND THIS AREA OF PRECIP SHOULD BE SUFFICIENT FOR MVFR CLOUD DECK TO PERSIST THROUGH SAT MORNING WITH INCRSG W-SW WIND FLOW AS LOW PRESSURE DEEPENS OVER THE UPR GRTLKS AND A STRONG ARCTIC CDFNT MOVES INTO THE MS VALLEY. && .PREV DISCUSSION... /ISSUED 1148 AM EST FRI FEB 8 2008/ UPDATE... AREA OF LIGHT SNOW AHEAD OF WARM FRONT WAS MOVG NE AT 25KT ACROSS NE 1/2 OF CWA LATE THIS MORNING. SOME CLEARING OF LOW CLOUDS HAS DEVELOPED OVER NW IN/NE IL AS DRIER AIR IN LOW LEVELS TRYING TO MOVE INTO THE AREA. BASED ON THIS AND LACK OF ECHOES/PRECIP REPORTS UPSTREAM ACROSS NRN IL HAVE LOWERED POPS THIS AFTN AND GONE WITH AN OPTIMISTIC PARTLY SUNNY FCST ACROSS THE SW PORTION OF THE CWA. OTRWS, NO CHANGES TO PREVIOUS GRIDS ATTM. PREV DISCUSSION... /ISSUED 910 AM EST FRI FEB 8 2008/ UPDATE... UPDATED TO REMOVE EARLY MORNING WORDING IN ZFP AND ALSO TO INCREASE POPS ACROSS NW OH AND PORTIONS OF NE INDIANA. WK WARM FRONT WAS MOVG NE INTO THE AREA THIS MORNING RESULTING IN AN AREA OF LIGHT SNOW ACROSS NRN INDIANA/SRN MI AND PORTIONS OF NW OH. THIS AREA OF LIGHT SNOW SHOULD MOVE OUT OF THE CWA BY 18Z WITH PERHAPS SOME LIGHT RN/SN LINGERING THIS AFTN AS LOW LEVELS REMAIN SATURATED AND MID LEVEL MOISTURE MOVES OUT OF THE AREA. PREV DISCUSSION... /ISSUED 505 AM EST FRI FEB 8 2008/ SHORT TERM... TODAY AND TONIGHT. FAVORING NAM/RUC IN SHORT TERM WITH SOME CHANGES TO GOING FCST...THOUGH ONLY TWO RELATIVELY MINOR EVENTS OF CONCERN IN SHORT TERM. FIRST IS WEAK 8H-7H SPEED MAX ACRS CNTRL IL INTO NWRN IN DRIVING SOME LIGHT SNOW ACRS PRIMRLY NRN CWA THIS AM. HAVE SIGNIFICANTLY INCREASED POPS FOR EARLY AM HIGH PROB/LOW QPF EVENT PER UPSTREAM METAR/KLOT REF DATA. LULL IN WAKE OF SHORTWAVE WITH ONLY SMALL CHC LIGHT SPRINKLES OR FLURRIES MOST OF DAY WITH BL TEMPS WARMING ENOUGH TO SUPPORT AT LEAST PARTIAL MELT. CYCLONIC 8H FLOW EMBEDDED IN BROAD UL TROF AND AMPLE LLVL MOISTURE SHOULD KEEP INSOLATION AT MINIMUM AND HAVE SQUELCHED HIGHS TODAY A DEGREE OR TWO. FOR TONIGHT SFC LOW PRESSURE OVR DAKOTAS INTO NE BECOMES A REENERGIZED AS STRONG BC SHORTWAVE DIVES INTO NRN PLAINS BY DAYBREAK SAT. THIS LEAD WAVE TO THE ARCTIC INTRUSION IS ASSOCIATED WITH NEAR 60-70M MIDTROPOSPHERIC HEIGHT FALLS AND I285K UPGLIDE WITH MODEST 2-2.5G/KG MOISTURE TAP THROUGHOUT THE CWA. CPD FALL TO NEAR 0 BY 03 UTC NWRN CWA AND NRN CWA APPEARS TO SATURATE BEST AND HIT THIS AREA AOA MET POPS FOR AGAIN A HIGH PROB EVENT/RELATIVELY LOW QPF EVENT. GOOD DGZ MOISTURE AND DEPTH OF COLD AIR/HOWEVER LAST 2KFT OF FALL INITIALLY AOA 1-2C WETBULB TEMPS A CONCERN FOR AN INITIAL MIX/HOWEVER DYNAMIC/EVAPORATIVE PROCESSES SHOULD QUICKLY OVERCOME AND ANY RASN MIX SHOULD BE BRIEF/NEGLIGIBLE. LONG TERM... ARCTIC INTRUSION HIGHLIGHTS THIS PD W/EXTREMELY COLD AIRMASS NOTED OVR THE INTERIOR OF AK AND THE CANADIAN YUKON W/MAYO REPORTING AN AMAZING -58 DEGREES. VAPOR SHOWS ROBUST SW TROUGH DIGGING SEWD THROUGH NRN BC AND TAPPING INTO A PORTION OF THIS AIRMASS. 00Z SOLUTIONS IN GOOD AGREEMENT W/PREV RUNS INDICATING BC TROUGH WILL QUICKLY DROP SEWD AND AMPLIFY W/WHAT MAY BE THE COLDEST AIR OF THE SEASON YET COME SUNDAY AS 850MB TEMPS BOTTOM AROUND -25C. TALK HERE THIS MORNING IS W/FACT THAT SUNDAYS HIGHS ARE LIKELY A FALLACY W/NON-DIURNAL FALL MORE LIKELY. WILL EDGE LOWER WHILE MAINTAINING COLLABORATION BUT NONE THE LESS FRIGID THE KEY WORD. BIG BLOW FOLLOWING FROPA SATURDAY NIGHT W/INTENSE CAA AND STG MOMENTUM XFER ESP W/UNIDIRECTIONAL LL WINDS. SHLD SEE SOME GUSTS AOA 50 MPH. W/THAT AND SCANT MSTR WILL SCALE BACK LIMITED LK EFFECT. NO DOUBT SHEARED BL FLW AND LACK OF SYNOPTIC MSTR INPUT WILL GROSSLY LIMIT SNOW ACCUMULATIONS YET RETAIN MID RANGE CHC POPS FOR XPCD LIGHT BUT MEASURABLE SNOW ACCUMS OF 1-2 INCHES W/FAVORED NEEDLE ICE CRYSTALS AS DENDRITIC GROWTH ZONE SITTING ON THE GROUND. BEYOND THAT...WILL STICK W/ECMWF SOLUTION AND ITS HANDLING OF NXT SIG UPSTREAM SW SOUTH OF THE ALEUTIANS THIS MORNING. GFS CONTINUITY QUITE POOR AND QUITE A DEPARTURE FM PRIOR RUNS MON-TUE NXT WEEK. SUFFICE IT TO SAY...DOUBT ARCTIC RIDGE WILL DISLODGE AS RAPIDLY AS EITHER THE GFS/OR NAM/WRF INDICATE MONDAY AND LIKELY AN INDICATION OF BEING TOO PROGRESSIVE AND TOO AMPLIFIED. ECMWF ON THE OTHER HAND SLOWER AND LESS AMPLIFIED AND THE PREFERRED SOLUTION AS THIS POINT GIVEN UNCERTAINTY W/SUCH HIGHLY VARIABLE MED RANGE SOLUTIONS. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SHORT TERM...MURPHY LONG TERM...HOLSTEN AVIATION...TAYLOR UPDATE...TAYLOR in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 1148 AM EST FRI FEB 8 2008 .UPDATE... AREA OF LIGHT SNOW AHEAD OF WARM FRONT WAS MOVG NE AT 25KT ACROSS NE 1/2 OF CWA LATE THIS MORNING. SOME CLEARING OF LOW CLOUDS HAS DEVELOPED OVER NW IN/NE IL AS DRIER AIR IN LOW LEVELS TRYING TO MOVE INTO THE AREA. BASED ON THIS AND LACK OF ECHOES/PRECIP REPORTS UPSTREAM ACROSS NRN IL HAVE LOWERED POPS THIS AFTN AND GONE WITH AN OPTIMISTIC PARTLY SUNNY FCST ACROSS THE SW PORTION OF THE CWA. OTRWS, NO CHANGES TO PREVIOUS GRIDS ATTM. && .PREV DISCUSSION... /ISSUED 910 AM EST FRI FEB 8 2008/ UPDATE... UPDATED TO REMOVE EARLY MORNING WORDING IN ZFP AND ALSO TO INCREASE POPS ACROSS NW OH AND PORTIONS OF NE INDIANA. WK WARM FRONT WAS MOVG NE INTO THE AREA THIS MORNING RESULTING IN AN AREA OF LIGHT SNOW ACROSS NRN INDIANA/SRN MI AND PORTIONS OF NW OH. THIS AREA OF LIGHT SNOW SHOULD MOVE OUT OF THE CWA BY 18Z WITH PERHAPS SOME LIGHT RN/SN LINGERING THIS AFTN AS LOW LEVELS REMAIN SATURATED AND MID LEVEL MOISTURE MOVES OUT OF THE AREA. PREV DISCUSSION... /ISSUED 505 AM EST FRI FEB 8 2008/ SHORT TERM... TODAY AND TONIGHT. FAVORING NAM/RUC IN SHORT TERM WITH SOME CHANGES TO GOING FCST...THOUGH ONLY TWO RELATIVELY MINOR EVENTS OF CONCERN IN SHORT TERM. FIRST IS WEAK 8H-7H SPEED MAX ACRS CNTRL IL INTO NWRN IN DRIVING SOME LIGHT SNOW ACRS PRIMRLY NRN CWA THIS AM. HAVE SIGNIFICANTLY INCREASED POPS FOR EARLY AM HIGH PROB/LOW QPF EVENT PER UPSTREAM METAR/KLOT REF DATA. LULL IN WAKE OF SHORTWAVE WITH ONLY SMALL CHC LIGHT SPRINKLES OR FLURRIES MOST OF DAY WITH BL TEMPS WARMING ENOUGH TO SUPPORT AT LEAST PARTIAL MELT. CYCLONIC 8H FLOW EMBEDDED IN BROAD UL TROF AND AMPLE LLVL MOISTURE SHOULD KEEP INSOLATION AT MINIMUM AND HAVE SQUELCHED HIGHS TODAY A DEGREE OR TWO. FOR TONIGHT SFC LOW PRESSURE OVR DAKOTAS INTO NE BECOMES A REENERGIZED AS STRONG BC SHORTWAVE DIVES INTO NRN PLAINS BY DAYBREAK SAT. THIS LEAD WAVE TO THE ARCTIC INTRUSION IS ASSOCIATED WITH NEAR 60-70M MIDTROPOSPHERIC HEIGHT FALLS AND I285K UPGLIDE WITH MODEST 2-2.5G/KG MOISTURE TAP THROUGHOUT THE CWA. CPD FALL TO NEAR 0 BY 03 UTC NWRN CWA AND NRN CWA APPEARS TO SATURATE BEST AND HIT THIS AREA AOA MET POPS FOR AGAIN A HIGH PROB EVENT/RELATIVELY LOW QPF EVENT. GOOD DGZ MOISTURE AND DEPTH OF COLD AIR/HOWEVER LAST 2KFT OF FALL INITIALLY AOA 1-2C WETBULB TEMPS A CONCERN FOR AN INITIAL MIX/HOWEVER DYNAMIC/EVAPORATIVE PROCESSES SHOULD QUICKLY OVERCOME AND ANY RASN MIX SHOULD BE BRIEF/NEGLIGIBLE. LONG TERM... ARCTIC INTRUSION HIGHLIGHTS THIS PD W/EXTREMELY COLD AIRMASS NOTED OVR THE INTERIOR OF AK AND THE CANADIAN YUKON W/MAYO REPORTING AN AMAZING -58 DEGREES. VAPOR SHOWS ROBUST SW TROUGH DIGGING SEWD THROUGH NRN BC AND TAPPING INTO A PORTION OF THIS AIRMASS. 00Z SOLUTIONS IN GOOD AGREEMENT W/PREV RUNS INDICATING BC TROUGH WILL QUICKLY DROP SEWD AND AMPLIFY W/WHAT MAY BE THE COLDEST AIR OF THE SEASON YET COME SUNDAY AS 850MB TEMPS BOTTOM AROUND -25C. TALK HERE THIS MORNING IS W/FACT THAT SUNDAYS HIGHS ARE LIKELY A FALLACY W/NON-DIURNAL FALL MORE LIKELY. WILL EDGE LOWER WHILE MAINTAINING COLLABORATION BUT NONE THE LESS FRIGID THE KEY WORD. BIG BLOW FOLLOWING FROPA SATURDAY NIGHT W/INTENSE CAA AND STG MOMENTUM XFER ESP W/UNIDIRECTIONAL LL WINDS. SHLD SEE SOME GUSTS AOA 50 MPH. W/THAT AND SCANT MSTR WILL SCALE BACK LIMITED LK EFFECT. NO DOUBT SHEARED BL FLW AND LACK OF SYNOPTIC MSTR INPUT WILL GROSSLY LIMIT SNOW ACCUMULATIONS YET RETAIN MID RANGE CHC POPS FOR XPCD LIGHT BUT MEASURABLE SNOW ACCUMS OF 1-2 INCHES W/FAVORED NEEDLE ICE CRYSTALS AS DENDRITIC GROWTH ZONE SITTING ON THE GROUND. BEYOND THAT...WILL STICK W/ECMWF SOLUTION AND ITS HANDLING OF NXT SIG UPSTREAM SW SOUTH OF THE ALEUTIANS THIS MORNING. GFS CONTINUITY QUITE POOR AND QUITE A DEPARTURE FM PRIOR RUNS MON-TUE NXT WEEK. SUFFICE IT TO SAY...DOUBT ARCTIC RIDGE WILL DISLODGE AS RAPIDLY AS EITHER THE GFS/OR NAM/WRF INDICATE MONDAY AND LIKELY AN INDICATION OF BEING TOO PROGRESSIVE AND TOO AMPLIFIED. ECMWF ON THE OTHER HAND SLOWER AND LESS AMPLIFIED AND THE PREFERRED SOLUTION AS THIS POINT GIVEN UNCERTAINTY W/SUCH HIGHLY VARIABLE MED RANGE SOLUTIONS. AVIATION... LOWER DEWPOINT DEPRESSIONS AND VSBY RESTRICTIONS UPSTREAM OF KSBN HAVE ADJUSTED TIMING AND ALLOWED FOR TEMPO PD OF IFR CONDITIONS 09-13 UTC. WILL MONITOR TRENDS FOR POSSIBLE FURTHER LWRG AS KLOT RADAR CONTS TO SHOW SOME INCREASE IN REFLECTIVITY RETURNS...HOWEVER OVERALL TREND WILL NOT BE FOR SIG SNOW EVENT AS MODELS/PROFILER DATA INDICATING SHORTWAVE CENTRAL IL 850-700MB SHORTWAVE DRIVING EVENT RATHER WEAK AND ON THE WANE THROUGH REMAINDER OF THE OVERNIGHT. PRIMARILY MVFR CIGS WITH PD OF RESTRICTED/MVFR VSBYS TOWARD DAYBREAK ANTICIATED AT KFWA IN LIGHT FOG/FLURRIES. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SHORT TERM...MURPHY LONG TERM...HOLSTEN AVIATION...MURPHY UPDATE...TAYLOR in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 910 AM EST FRI FEB 8 2008 .UPDATE... UPDATED TO REMOVE EARLY MORNING WORDING IN ZFP AND ALSO TO INCREASE POPS ACROSS NW OH AND PORTIONS OF NE INDIANA. WK WARM FRONT WAS MOVG NE INTO THE AREA THIS MORNING RESULTING IN AN AREA OF LIGHT SNOW ACROSS NRN INDIANA/SRN MI AND PORTIONS OF NW OH. THIS AREA OF LIGHT SNOW SHOULD MOVE OUT OF THE CWA BY 18Z WITH PERHAPS SOME LIGHT RN/SN LINGERING THIS AFTN AS LOW LEVELS REMAIN SATURATED AND MID LEVEL MOISTURE MOVES OUT OF THE AREA. && .PREV DISCUSSION... /ISSUED 505 AM EST FRI FEB 8 2008/ SHORT TERM... TODAY AND TONIGHT. FAVORING NAM/RUC IN SHORT TERM WITH SOME CHANGES TO GOING FCST...THOUGH ONLY TWO RELATIVELY MINOR EVENTS OF CONCERN IN SHORT TERM. FIRST IS WEAK 8H-7H SPEED MAX ACRS CNTRL IL INTO NWRN IN DRIVING SOME LIGHT SNOW ACRS PRIMRLY NRN CWA THIS AM. HAVE SIGNIFICANTLY INCREASED POPS FOR EARLY AM HIGH PROB/LOW QPF EVENT PER UPSTREAM METAR/KLOT REF DATA. LULL IN WAKE OF SHORTWAVE WITH ONLY SMALL CHC LIGHT SPRINKLES OR FLURRIES MOST OF DAY WITH BL TEMPS WARMING ENOUGH TO SUPPORT AT LEAST PARTIAL MELT. CYCLONIC 8H FLOW EMBEDDED IN BROAD UL TROF AND AMPLE LLVL MOISTURE SHOULD KEEP INSOLATION AT MINIMUM AND HAVE SQUELCHED HIGHS TODAY A DEGREE OR TWO. FOR TONIGHT SFC LOW PRESSURE OVR DAKOTAS INTO NE BECOMES A REENERGIZED AS STRONG BC SHORTWAVE DIVES INTO NRN PLAINS BY DAYBREAK SAT. THIS LEAD WAVE TO THE ARCTIC INTRUSION IS ASSOCIATED WITH NEAR 60-70M MIDTROPOSPHERIC HEIGHT FALLS AND I285K UPGLIDE WITH MODEST 2-2.5G/KG MOISTURE TAP THROUGHOUT THE CWA. CPD FALL TO NEAR 0 BY 03 UTC NWRN CWA AND NRN CWA APPEARS TO SATURATE BEST AND HIT THIS AREA AOA MET POPS FOR AGAIN A HIGH PROB EVENT/RELATIVELY LOW QPF EVENT. GOOD DGZ MOISTURE AND DEPTH OF COLD AIR/HOWEVER LAST 2KFT OF FALL INITIALLY AOA 1-2C WETBULB TEMPS A CONCERN FOR AN INITIAL MIX/HOWEVER DYNAMIC/EVAPORATIVE PROCESSES SHOULD QUICKLY OVERCOME AND ANY RASN MIX SHOULD BE BRIEF/NEGLIGIBLE. LONG TERM... ARCTIC INTRUSION HIGHLIGHTS THIS PD W/EXTREMELY COLD AIRMASS NOTED OVR THE INTERIOR OF AK AND THE CANADIAN YUKON W/MAYO REPORTING AN AMAZING -58 DEGREES. VAPOR SHOWS ROBUST SW TROUGH DIGGING SEWD THROUGH NRN BC AND TAPPING INTO A PORTION OF THIS AIRMASS. 00Z SOLUTIONS IN GOOD AGREEMENT W/PREV RUNS INDICATING BC TROUGH WILL QUICKLY DROP SEWD AND AMPLIFY W/WHAT MAY BE THE COLDEST AIR OF THE SEASON YET COME SUNDAY AS 850MB TEMPS BOTTOM AROUND -25C. TALK HERE THIS MORNING IS W/FACT THAT SUNDAYS HIGHS ARE LIKELY A FALLACY W/NON-DIURNAL FALL MORE LIKELY. WILL EDGE LOWER WHILE MAINTAINING COLLABORATION BUT NONE THE LESS FRIGID THE KEY WORD. BIG BLOW FOLLOWING FROPA SATURDAY NIGHT W/INTENSE CAA AND STG MOMENTUM XFER ESP W/UNIDIRECTIONAL LL WINDS. SHLD SEE SOME GUSTS AOA 50 MPH. W/THAT AND SCANT MSTR WILL SCALE BACK LIMITED LK EFFECT. NO DOUBT SHEARED BL FLW AND LACK OF SYNOPTIC MSTR INPUT WILL GROSSLY LIMIT SNOW ACCUMULATIONS YET RETAIN MID RANGE CHC POPS FOR XPCD LIGHT BUT MEASURABLE SNOW ACCUMS OF 1-2 INCHES W/FAVORED NEEDLE ICE CRYSTALS AS DENDRITIC GROWTH ZONE SITTING ON THE GROUND. BEYOND THAT...WILL STICK W/ECMWF SOLUTION AND ITS HANDLING OF NXT SIG UPSTREAM SW SOUTH OF THE ALEUTIANS THIS MORNING. GFS CONTINUITY QUITE POOR AND QUITE A DEPARTURE FM PRIOR RUNS MON-TUE NXT WEEK. SUFFICE IT TO SAY...DOUBT ARCTIC RIDGE WILL DISLODGE AS RAPIDLY AS EITHER THE GFS/OR NAM/WRF INDICATE MONDAY AND LIKELY AN INDICATION OF BEING TOO PROGRESSIVE AND TOO AMPLIFIED. ECMWF ON THE OTHER HAND SLOWER AND LESS AMPLIFIED AND THE PREFERRED SOLUTION AS THIS POINT GIVEN UNCERTAINTY W/SUCH HIGHLY VARIABLE MED RANGE SOLUTIONS. AVIATION... LOWER DEWPOINT DEPRESSIONS AND VSBY RESTRICTIONS UPSTREAM OF KSBN HAVE ADJUSTED TIMING AND ALLOWED FOR TEMPO PD OF IFR CONDITIONS 09-13 UTC. WILL MONITOR TRENDS FOR POSSIBLE FURTHER LWRG AS KLOT RADAR CONTS TO SHOW SOME INCREASE IN REFLECTIVITY RETURNS...HOWEVER OVERALL TREND WILL NOT BE FOR SIG SNOW EVENT AS MODELS/PROFILER DATA INDICATING SHORTWAVE CENTRAL IL 850-700MB SHORTWAVE DRIVING EVENT RATHER WEAK AND ON THE WANE THROUGH REMAINDER OF THE OVERNIGHT. PRIMARILY MVFR CIGS WITH PD OF RESTRICTED/MVFR VSBYS TOWARD DAYBREAK ANTICIATED AT KFWA IN LIGHT FOG/FLURRIES. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SHORT TERM...MURPHY LONG TERM...HOLSTEN AVIATION...MURPHY UPDATE...TAYLOR in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 505 AM EST FRI FEB 8 2008 .SHORT TERM... TODAY AND TONIGHT. FAVORING NAM/RUC IN SHORT TERM WITH SOME CHANGES TO GOING FCST...THOUGH ONLY TWO RELATIVELY MINOR EVENTS OF CONCERN IN SHORT TERM. FIRST IS WEAK 8H-7H SPEED MAX ACRS CNTRL IL INTO NWRN IN DRIVING SOME LIGHT SNOW ACRS PRIMRLY NRN CWA THIS AM. HAVE SIGNIFICANTLY INCREASED POPS FOR EARLY AM HIGH PROB/LOW QPF EVENT PER UPSTREAM METAR/KLOT REF DATA. LULL IN WAKE OF SHORTWAVE WITH ONLY SMALL CHC LIGHT SPRINKLES OR FLURRIES MOST OF DAY WITH BL TEMPS WARMING ENOUGH TO SUPPORT AT LEAST PARTIAL MELT. CYCLONIC 8H FLOW EMBEDDED IN BROAD UL TROF AND AMPLE LLVL MOISTURE SHOULD KEEP INSOLATION AT MINIMUM AND HAVE SQUELCHED HIGHS TODAY A DEGREE OR TWO. FOR TONIGHT SFC LOW PRESSURE OVR DAKOTAS INTO NE BECOMES A REENERGIZED AS STRONG BC SHORTWAVE DIVES INTO NRN PLAINS BY DAYBREAK SAT. THIS LEAD WAVE TO THE ARCTIC INTRUSION IS ASSOCIATED WITH NEAR 60-70M MIDTROPOSPHERIC HEIGHT FALLS AND I285K UPGLIDE WITH MODEST 2-2.5G/KG MOISTURE TAP THROUGHOUT THE CWA. CPD FALL TO NEAR 0 BY 03 UTC NWRN CWA AND NRN CWA APPEARS TO SATURATE BEST AND HIT THIS AREA AOA MET POPS FOR AGAIN A HIGH PROB EVENT/RELATIVELY LOW QPF EVENT. GOOD DGZ MOISTURE AND DEPTH OF COLD AIR/HOWEVER LAST 2KFT OF FALL INITIALLY AOA 1-2C WETBULB TEMPS A CONCERN FOR AN INITIAL MIX/HOWEVER DYNAMIC/EVAPORATIVE PROCESSES SHOULD QUICKLY OVERCOME AND ANY RASN MIX SHOULD BE BRIEF/NEGLIGIBLE. && .LONG TERM... ARCTIC INTRUSION HIGHLIGHTS THIS PD W/EXTREMELY COLD AIRMASS NOTED OVR THE INTERIOR OF AK AND THE CANADIAN YUKON W/MAYO REPORTING AN AMAZING -58 DEGREES. VAPOR SHOWS ROBUST SW TROUGH DIGGING SEWD THROUGH NRN BC AND TAPPING INTO A PORTION OF THIS AIRMASS. 00Z SOLUTIONS IN GOOD AGREEMENT W/PREV RUNS INDICATING BC TROUGH WILL QUICKLY DROP SEWD AND AMPLIFY W/WHAT MAY BE THE COLDEST AIR OF THE SEASON YET COME SUNDAY AS 850MB TEMPS BOTTOM AROUND -25C. TALK HERE THIS MORNING IS W/FACT THAT SUNDAYS HIGHS ARE LIKELY A FALLACY W/NON-DIURNAL FALL MORE LIKELY. WILL EDGE LOWER WHILE MAINTAINING COLLABORATION BUT NONE THE LESS FRIGID THE KEY WORD. BIG BLOW FOLLOWING FROPA SATURDAY NIGHT W/INTENSE CAA AND STG MOMENTUM XFER ESP W/UNIDIRECTIONAL LL WINDS. SHLD SEE SOME GUSTS AOA 50 MPH. W/THAT AND SCANT MSTR WILL SCALE BACK LIMITED LK EFFECT. NO DOUBT SHEARED BL FLW AND LACK OF SYNOPTIC MSTR INPUT WILL GROSSLY LIMIT SNOW ACCUMULATIONS YET RETAIN MID RANGE CHC POPS FOR XPCD LIGHT BUT MEASURABLE SNOW ACCUMS OF 1-2 INCHES W/FAVORED NEEDLE ICE CRYSTALS AS DENDRITIC GROWTH ZONE SITTING ON THE GROUND. BEYOND THAT...WILL STICK W/ECMWF SOLUTION AND ITS HANDLING OF NXT SIG UPSTREAM SW SOUTH OF THE ALEUTIANS THIS MORNING. GFS CONTINUITY QUITE POOR AND QUITE A DEPARTURE FM PRIOR RUNS MON-TUE NXT WEEK. SUFFICE IT TO SAY...DOUBT ARCTIC RIDGE WILL DISLODGE AS RAPIDLY AS EITHER THE GFS/OR NAM/WRF INDICATE MONDAY AND LIKELY AN INDICATION OF BEING TOO PROGRESSIVE AND TOO AMPLIFIED. ECMWF ON THE OTHER HAND SLOWER AND LESS AMPLIFIED AND THE PREFERRED SOLUTION AS THIS POINT GIVEN UNCERTAINTY W/SUCH HIGHLY VARIABLE MED RANGE SOLUTIONS. && .AVIATION... LOWER DEWPOINT DEPRESSIONS AND VSBY RESTRICTIONS UPSTREAM OF KSBN HAVE ADJUSTED TIMING AND ALLOWED FOR TEMPO PD OF IFR CONDITIONS 09-13 UTC. WILL MONITOR TRENDS FOR POSSIBLE FURTHER LWRG AS KLOT RADAR CONTS TO SHOW SOME INCREASE IN REFLECTIVITY RETURNS...HOWEVER OVERALL TREND WILL NOT BE FOR SIG SNOW EVENT AS MODELS/PROFILER DATA INDICATING SHORTWAVE CENTRAL IL 850-700MB SHORTWAVE DRIVING EVENT RATHER WEAK AND ON THE WANE THROUGH REMAINDER OF THE OVERNIGHT. PRIMARILY MVFR CIGS WITH PD OF RESTRICTED/MVFR VSBYS TOWARD DAYBREAK ANTICIATED AT KFWA IN LIGHT FOG/FLURRIES. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SHORT TERM...MURPHY LONG TERM...HOLSTEN AVIATION...MURPHY in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 1235 PM EST THU FEB 7 2008 .AVIATION... MVFR CONDITIONS WITH SOME BRIEF IFR CIGS THROUGH THIS FORECAST PACKAGE. LIGHT FLURRIES CONTINUING WITH WEAK LIFT AND LOW LEVEL MOISTURE. WEAK SHORT WAVE APPROACHES TONIGHT WITH SOME VERY LIGHT SNOW POSSIBLE. NOT MANY RETURNS UPSTREAM SO HAVE REMAIN OPTIMISTIC WITH VIS FOR NOW. THERE ARE SOME LOWER VIS RESTRICTIONS WITH BR AND THIS POSSIBILITY EXISTS DOWNSTREAM WITH LIGHT WIND FIELD. WILL MONITOR FOR POSSIBLE INCLUSION IN NEXT ISSUANCE. && .PREV DISCUSSION... /ISSUED 424 AM EST THU FEB 7 2008/ SHORT TERM... TODAY AND TONIGHT 08Z ANALYSIS REVEALS SFC LOW PRESSURE CONSOLIDATION OVER THE EASTERN SEABOARD...WITH THE DEPARTING UPPER LEVEL DISTURBANCE PUSHING INTO THAT REGION. AREA OF LIGHT SNOW ASSOCIATED WITH THIS SYSTEM HAS PUSHED OUT OF THE FA. OVERCAST CONDITIONS WERE WIDESPREAD ACROSS THE GREAT LAKES SAVE NW WI...WITH A FEW AREAS OF FLURRIES REPORTED THOUGH THE REGION. WEAK CAA HAS ALLOWED TEMPS TO DROP INTO THE UPPER 20S IN THE NORTH AND WEST. FARTHER UPSTREAM...WATER VAPOR IMAGERY AND MODEL ANALYZED H5 FIELDS CONFIRM A LONG WAVE TROUGH OVER THE PLAIN STATES. TROUGH FRACTURING IS ONGOING WITH THIS SYSTEM AS INDICATED BY THE DEVELOPMENT OF TWO DISTINCT VORT CENTERS OVER MB AND WESTERN OK. LIGHT PRECIP WAS ONGOING ACROSS PARTS OF THE DAKOTAS AND WESTERN KS...WITH THE MAJORITY OF THE PRECIP IN THE FORM OF VIRGA. TODAY...USED A BLEND OF THE GFS/EASTNMM4/AND RUC 13. GENERALLY BENIGN WEATHER TODAY AS THE AFOREMENTIONED UPPER IMPULSE RACES TOWARD THE REGION. DUE TO THE FRACTURING NATURE OF THE H5 TROUGH...NOT EXPECTING MUCH INFLUENCE OVER THE CWA WITH ASCENT AREAS SLIDING NORTH AND SOUTH OF THE FA. HAVE RETAINED FLURRY MENTIONED/ALL BE IT SMALL/WITH WEAK UPWARD VERTICAL MOTION PROGGED IN THE STEADFAST STRATUS DECK OVER THE REGION. AS MENTIONED IN THE PREVIOUS DISCUSSION...BEST CHANCE FOR ANY SORT OF MEASURABLE PRECIP WILL BE TONIGHT...AS INDICATED BY ISENTROPIC LIFT AND Q-VECTOR PROGS. HOWEVER...WITH THE MAJORITY OF ASCENT PASSING TO THE SOUTH OF THE REGION...EXPECTING LIGHT SNOW CHANCES TO BE VERY MINIMAL...AND IF SNOW DOES MATERIALIZE AMOUNTS WOULD BE AT MOST A COUPLE TENTHS. EXPECT LOW STRATUS DECK TO HOLD STRONG THROUGH THE DAY WITH WEAK MIXING AND A STRENGTHENING INVERSION ABOVE THE CLOUD DECK. MAY SEE A FEW BREAKS BUT WITH CU RULE VALUES APPROACHING -7...GAPS WOULD QUICKLY FILL IN. HAVE DROPPED HIGHS A COUPLE DEGREES WITH WEAK MIXING UNDER CLOUDY CONDITIONS....RESIDING BELOW MOS VALUES. EXPECT NEARLY STEADY TEMPS TONIGHT WITH THICKENING CLOUD DECK AND WEAK SOUTHERLY FLOW. LONG TERM (FRIDAY THROUGH WEDNESDAY)... FRIDAY THROUGH SUNDAY... STRONG MODEL AGREEMENT THROUGH THE PERIOD...WITH OPERATIONAL EURO AND GFS MODELS VERY SIMILAR THRU MONDAY MORNING. OVERALL VERY LITTLE ADJUSTMENTS NEEDED FROM PREVIOUS FORECAST. GENERALLY BAGGINESS ACROSS THE EASTERN TWO-THIRDS OF THE CONUS WITH ONE SHRTWV DEPARTING THE REGION EARLY FRIDAY AN ANOTHER DROPPING SOUTHEAST TOWARDS THE REGION FROM THE PLAINS REACHING THE REGION FRIDAY NIGHT. RIDGING ACROSS HT EASTERN PACIFIC WILL BUILD INTO THE WESTERN PORTIONS OF NORTH AMERICA...ALLOWING ARCTIC AIR TO DRIVE SOUTH INTO THE CENTRAL AND EASTERN CONUS THIS WEEKEND WITH THE HELP OF A STRONG POLAR VORT DROPPING INTO THE GREAT LAKES SATURDAY NIGHT INTO SUNDAY. PRECIP CHCS EXIST LATE FRIDAY AFTN AND INTO THE NIGHTTIME HOURS AS THE SHRTWV MOVES THRU...MARGINAL TEMPS PROFILE FOR SNOW EARLY ON AS TEMPS WILL BE ABOVE NORMAL INTO THE UPPER 30S OR LOWER 40S ACROSS THE REGION. BUFKIT ANALYSIS WOULD SUPPORT MAINLY SNOW ACROSS THE NORTHERN PORTIONS OF THE REGION IN THE EVENING...WITH A MIX POSSIBLE ACROSS THE SOUTH. CONCERN HERE THAT THE BIAS OF UNDERPLAYING THE WAA IN THE LOWER LEVELS MAY OCCUR HERE AND THAT RAIN WOULD BE MORE LIKELY. WILL KEEP MIX ACROSS THE REGION THROUGH MIDNIGHT AND THEN TRANSIT TO ALL SNOW ACROSS THE NORTHERN PORTIONS OF THE REGION. LIGHT ACCUMS POSSIBLE...WITH A BUMP TO THE POP INTO THE LIKELY RANGE. FLURRIES/LIGHT SNOW WILL BE POSSIBLE SATURDAY MORNING WITH THE ARCTIC FRONT DROPPING THRU DURING THE AFTERNOON/EVENING TIMEFRAME WHICH MAY PRODUCE SOME LIGHT SNOW. WEAK OMEGAS IN THE SNOW GROWTH REGION START TO INCREASE IN THE AFTN AND EVENING AS THE FRONT PUSHES ACROSS THE REGION. TEMPS WILL DROP QUICKLY OVERNIGHT AS VERY STRONG CAA WILL DRIVE TEMPS INTO THE SINGLE DIGITS FOR MOST. WIND CHILLS WILL APPROACH -20 DEGREES BY DAYBREAK SUNDAY. H850 TEMPS DROP FROM NEAR -6C TO AROUND -26C BY SUNDAY MORNING. WINDS WILL BE STRONG...WITH SUSTAINED VALUES NEAR 25-30 MPH WITH GUSTS ABOVE 40-45 MPH POSSIBLE SATURDAY EVENING INTO SUNDAY. LAKE EFFECT SNOW POSSIBLE ACROSS THE NORTH AND EAST PORTIONS OF THE REGION SATURDAY EVENING INTO THE AFTERNOON ON SUNDAY. NICE SOUNDINGS AS PER BUFKIT FOR LAKE EFFECT SNOWS LATE SATURDAY NIGHT INTO SUNDAY AFTN. THE DRY ARCTIC AIR COULD BE A LIMITING FACTOR WITH A MORE WESTERLY WIND COMPONENT. MONDAY THROUGH WEDNESDAY... SOME MILD DISAGREEMENT IN THIS PERIOD...BUT THE ENSEMBLE MEANS HAVE BEEN VERY STABLE THE LAST FEW DAYS...AND HAVE STARTED TO SHOW THE TREND TO THE NORTH THAT MOST SYSTEMS AND BOUNDARIES HAVE SHOWN THIS SEASON. WITH NO BLOCKING IN PLACE ACROSS THE ATLC...THE COLDER AIR WILL SLIDE EAST AND START TO MODIFY SLOWLY. ANOTHER BOUNDARY WILL DROP THRU ON MONDAY EVENING AND POSSIBLY STALL JUST TO THE SOUTH OF THE REGION. OPERATIONAL MODELS ARE SHOWING SIMILAR SOLUTIONS BUT THE GFS IS A BIT MORE DEEP WITH THE TROUGH ACROSS THE REGION. UNCERTAINTY STARTS TO INCREASE DRAMATICALLY THRU THE END OF THE PERIOD...WILL LEAN TOWARDS THE ENSEMBLE GFS TO SMOOTH OUT THE DIFFERENCES FOR NOW. THE CURRENT GFS ENSEMBLE SHOWS A SYSTEM MOVING ALONG THE BOUNDARY ACROSS THE OHIO VALLEY LATE MONDAY INTO TUESDAY WITH THE POTENTIAL FOR DECENT SNOWS ACROSS A WIDE AREA. BEHIND THE FRONT IT WOULD REINFORCE THE COLDER AIR WITH MODERATE CAA WHICH WOULD BRING BACK SOME VERY CHILLY CONDITIONS FOR THE MID WEEK. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SHORT TERM...CHAMBERLAIN LONG TERM...SCHOTT AVIATION...LASHLEY in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 618 AM EST THU FEB 7 2008 .AVIATION (12Z TAFS)... MVFR CONDITIONS WILL CONTINUE THROUGH THE MORNING HOURS WITH LOW CIGS AROUND 1-1.5K FEET...AND SOME LIGHT FZ DZ POSSIBLE. CIGS SHOULD START TO LIFT SOME THROUGH THE LATE MORNING INTO THE EARLY AFTERNOON INTO THE 3-3.5 K FT RANGE AS WINDS COME AROUND TO THE SOUTH SOUTHWEST. THROUGH THE OVERNIGHT HOURS LIGHT SOUTHERLY WINDS WITH VFR OR MVFR CIGS AROUND 2.5 TO 3 K FT WILL CONTINUE THRU THE END OF THE PERIOD. && .PREV DISCUSSION... /ISSUED 424 AM EST THU FEB 7 2008/ SHORT TERM... TODAY AND TONIGHT 08Z ANALYSIS REVEALS SFC LOW PRESSURE CONSOLIDATION OVER THE EASTERN SEABOARD...WITH THE DEPARTING UPPER LEVEL DISTURBANCE PUSHING INTO THAT REGION. AREA OF LIGHT SNOW ASSOCIATED WITH THIS SYSTEM HAS PUSHED OUT OF THE FA. OVERCAST CONDITIONS WERE WIDESPREAD ACROSS THE GREAT LAKES SAVE NW WI...WITH A FEW AREAS OF FLURRIES REPORTED THOUGH THE REGION. WEAK CAA HAS ALLOWED TEMPS TO DROP INTO THE UPPER 20S IN THE NORTH AND WEST. FARTHER UPSTREAM...WATER VAPOR IMAGERY AND MODEL ANALYZED H5 FIELDS CONFIRM A LONG WAVE TROUGH OVER THE PLAIN STATES. TROUGH FRACTURING IS ONGOING WITH THIS SYSTEM AS INDICATED BY THE DEVELOPMENT OF TWO DISTINCT VORT CENTERS OVER MB AND WESTERN OK. LIGHT PRECIP WAS ONGOING ACROSS PARTS OF THE DAKOTAS AND WESTERN KS...WITH THE MAJORITY OF THE PRECIP IN THE FORM OF VIRGA. TODAY...USED A BLEND OF THE GFS/EASTNMM4/AND RUC 13. GENERALLY BENIGN WEATHER TODAY AS THE AFOREMENTIONED UPPER IMPULSE RACES TOWARD THE REGION. DUE TO THE FRACTURING NATURE OF THE H5 TROUGH...NOT EXPECTING MUCH INFLUENCE OVER THE CWA WITH ASCENT AREAS SLIDING NORTH AND SOUTH OF THE FA. HAVE RETAINED FLURRY MENTIONED/ALL BE IT SMALL/WITH WEAK UPWARD VERTICAL MOTION PROGGED IN THE STEADFAST STRATUS DECK OVER THE REGION. AS MENTIONED IN THE PREVIOUS DISCUSSION...BEST CHANCE FOR ANY SORT OF MEASURABLE PRECIP WILL BE TONIGHT...AS INDICATED BY ISENTROPIC LIFT AND Q-VECTOR PROGS. HOWEVER...WITH THE MAJORITY OF ASCENT PASSING TO THE SOUTH OF THE REGION...EXPECTING LIGHT SNOW CHANCES TO BE VERY MINIMAL...AND IF SNOW DOES MATERIALIZE AMOUNTS WOULD BE AT MOST A COUPLE TENTHS. EXPECT LOW STRATUS DECK TO HOLD STRONG THROUGH THE DAY WITH WEAK MIXING AND A STRENGTHENING INVERSION ABOVE THE CLOUD DECK. MAY SEE A FEW BREAKS BUT WITH CU RULE VALUES APPROACHING -7...GAPS WOULD QUICKLY FILL IN. HAVE DROPPED HIGHS A COUPLE DEGREES WITH WEAK MIXING UNDER CLOUDY CONDITIONS....RESIDING BELOW MOS VALUES. EXPECT NEARLY STEADY TEMPS TONIGHT WITH THICKENING CLOUD DECK AND WEAK SOUTHERLY FLOW. LONG TERM (FRIDAY THROUGH WEDNESDAY)... FRIDAY THROUGH SUNDAY... STRONG MODEL AGREEMENT THROUGH THE PERIOD...WITH OPERATIONAL EURO AND GFS MODELS VERY SIMILAR THRU MONDAY MORNING. OVERALL VERY LITTLE ADJUSTMENTS NEEDED FROM PREVIOUS FORECAST. GENERALLY BAGGINESS ACROSS THE EASTERN TWO-THIRDS OF THE CONUS WITH ONE SHRTWV DEPARTING THE REGION EARLY FRIDAY AN ANOTHER DROPPING SOUTHEAST TOWARDS THE REGION FROM THE PLAINS REACHING THE REGION FRIDAY NIGHT. RIDGING ACROSS HT EASTERN PACIFIC WILL BUILD INTO THE WESTERN PORTIONS OF NORTH AMERICA...ALLOWING ARCTIC AIR TO DRIVE SOUTH INTO THE CENTRAL AND EASTERN CONUS THIS WEEKEND WITH THE HELP OF A STRONG POLAR VORT DROPPING INTO THE GREAT LAKES SATURDAY NIGHT INTO SUNDAY. PRECIP CHCS EXIST LATE FRIDAY AFTN AND INTO THE NIGHTTIME HOURS AS THE SHRTWV MOVES THRU...MARGINAL TEMPS PROFILE FOR SNOW EARLY ON AS TEMPS WILL BE ABOVE NORMAL INTO THE UPPER 30S OR LOWER 40S ACROSS THE REGION. BUFKIT ANALYSIS WOULD SUPPORT MAINLY SNOW ACROSS THE NORTHERN PORTIONS OF THE REGION IN THE EVENING...WITH A MIX POSSIBLE ACROSS THE SOUTH. CONCERN HERE THAT THE BIAS OF UNDERPLAYING THE WAA IN THE LOWER LEVELS MAY OCCUR HERE AND THAT RAIN WOULD BE MORE LIKELY. WILL KEEP MIX ACROSS THE REGION THROUGH MIDNIGHT AND THEN TRANSIT TO ALL SNOW ACROSS THE NORTHERN PORTIONS OF THE REGION. LIGHT ACCUMS POSSIBLE...WITH A BUMP TO THE POP INTO THE LIKELY RANGE. FLURRIES/LIGHT SNOW WILL BE POSSIBLE SATURDAY MORNING WITH THE ARCTIC FRONT DROPPING THRU DURING THE AFTERNOON/EVENING TIMEFRAME WHICH MAY PRODUCE SOME LIGHT SNOW. WEAK OMEGAS IN THE SNOW GROWTH REGION START TO INCREASE IN THE AFTN AND EVENING AS THE FRONT PUSHES ACROSS THE REGION. TEMPS WILL DROP QUICKLY OVERNIGHT AS VERY STRONG CAA WILL DRIVE TEMPS INTO THE SINGLE DIGITS FOR MOST. WIND CHILLS WILL APPROACH -20 DEGREES BY DAYBREAK SUNDAY. H850 TEMPS DROP FROM NEAR -6C TO AROUND -26C BY SUNDAY MORNING. WINDS WILL BE STRONG...WITH SUSTAINED VALUES NEAR 25-30 MPH WITH GUSTS ABOVE 40-45 MPH POSSIBLE SATURDAY EVENING INTO SUNDAY. LAKE EFFECT SNOW POSSIBLE ACROSS THE NORTH AND EAST PORTIONS OF THE REGION SATURDAY EVENING INTO THE AFTERNOON ON SUNDAY. NICE SOUNDINGS AS PER BUFKIT FOR LAKE EFFECT SNOWS LATE SATURDAY NIGHT INTO SUNDAY AFTN. THE DRY ARCTIC AIR COULD BE A LIMITING FACTOR WITH A MORE WESTERLY WIND COMPONENT. MONDAY THROUGH WEDNESDAY... SOME MILD DISAGREEMENT IN THIS PERIOD...BUT THE ENSEMBLE MEANS HAVE BEEN VERY STABLE THE LAST FEW DAYS...AND HAVE STARTED TO SHOW THE TREND TO THE NORTH THAT MOST SYSTEMS AND BOUNDARIES HAVE SHOWN THIS SEASON. WITH NO BLOCKING IN PLACE ACROSS THE ATLC...THE COLDER AIR WILL SLIDE EAST AND START TO MODIFY SLOWLY. ANOTHER BOUNDARY WILL DROP THRU ON MONDAY EVENING AND POSSIBLY STALL JUST TO THE SOUTH OF THE REGION. OPERATIONAL MODELS ARE SHOWING SIMILAR SOLUTIONS BUT THE GFS IS A BIT MORE DEEP WITH THE TROUGH ACROSS THE REGION. UNCERTAINTY STARTS TO INCREASE DRAMATICALLY THRU THE END OF THE PERIOD...WILL LEAN TOWARDS THE ENSEMBLE GFS TO SMOOTH OUT THE DIFFERENCES FOR NOW. THE CURRENT GFS ENSEMBLE SHOWS A SYSTEM MOVING ALONG THE BOUNDARY ACROSS THE OHIO VALLEY LATE MONDAY INTO TUESDAY WITH THE POTENTIAL FOR DECENT SNOWS ACROSS A WIDE AREA. BEHIND THE FRONT IT WOULD REINFORCE THE COLDER AIR WITH MODERATE CAA WHICH WOULD BRING BACK SOME VERY CHILLY CONDITIONS FOR THE MID WEEK. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SHORT TERM...CHAMBERLAIN LONG TERM...SCHOTT AVIATION...SCHOTT in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 424 AM EST THU FEB 7 2008 .SHORT TERM... TODAY AND TONIGHT 08Z ANALYSIS REVEALS SFC LOW PRESSURE CONSOLIDATION OVER THE EASTERN SEABOARD...WITH THE DEPARTING UPPER LEVEL DISTURBANCE PUSHING INTO THAT REGION. AREA OF LIGHT SNOW ASSOCIATED WITH THIS SYSTEM HAS PUSHED OUT OF THE FA. OVERCAST CONDITIONS WERE WIDESPREAD ACROSS THE GREAT LAKES SAVE NW WI...WITH A FEW AREAS OF FLURRIES REPORTED THOUGH THE REGION. WEAK CAA HAS ALLOWED TEMPS TO DROP INTO THE UPPER 20S IN THE NORTH AND WEST. FARTHER UPSTREAM...WATER VAPOR IMAGERY AND MODEL ANALYZED H5 FIELDS CONFIRM A LONG WAVE TROUGH OVER THE PLAIN STATES. TROUGH FRACTURING IS ONGOING WITH THIS SYSTEM AS INDICATED BY THE DEVELOPMENT OF TWO DISTINCT VORT CENTERS OVER MB AND WESTERN OK. LIGHT PRECIP WAS ONGOING ACROSS PARTS OF THE DAKOTAS AND WESTERN KS...WITH THE MAJORITY OF THE PRECIP IN THE FORM OF VIRGA. TODAY...USED A BLEND OF THE GFS/EASTNMM4/AND RUC 13. GENERALLY BENIGN WEATHER TODAY AS THE AFOREMENTIONED UPPER IMPULSE RACES TOWARD THE REGION. DUE TO THE FRACTURING NATURE OF THE H5 TROUGH...NOT EXPECTING MUCH INFLUENCE OVER THE CWA WITH ASCENT AREAS SLIDING NORTH AND SOUTH OF THE FA. HAVE RETAINED FLURRY MENTIONED/ALL BE IT SMALL/WITH WEAK UPWARD VERTICAL MOTION PROGGED IN THE STEADFAST STRATUS DECK OVER THE REGION. AS MENTIONED IN THE PREVIOUS DISCUSSION...BEST CHANCE FOR ANY SORT OF MEASURABLE PRECIP WILL BE TONIGHT...AS INDICATED BY ISENTROPIC LIFT AND Q-VECTOR PROGS. HOWEVER...WITH THE MAJORITY OF ASCENT PASSING TO THE SOUTH OF THE REGION...EXPECTING LIGHT SNOW CHANCES TO BE VERY MINIMAL...AND IF SNOW DOES MATERIALIZE AMOUNTS WOULD BE AT MOST A COUPLE TENTHS. EXPECT LOW STRATUS DECK TO HOLD STRONG THROUGH THE DAY WITH WEAK MIXING AND A STRENGTHENING INVERSION ABOVE THE CLOUD DECK. MAY SEE A FEW BREAKS BUT WITH CU RULE VALUES APPROACHING -7...GAPS WOULD QUICKLY FILL IN. HAVE DROPPED HIGHS A COUPLE DEGREES WITH WEAK MIXING UNDER CLOUDY CONDITIONS....RESIDING BELOW MOS VALUES. EXPECT NEARLY STEADY TEMPS TONIGHT WITH THICKENING CLOUD DECK AND WEAK SOUTHERLY FLOW. && .LONG TERM (FRIDAY THROUGH WEDNESDAY)... FRIDAY THROUGH SUNDAY... STRONG MODEL AGREEMENT THROUGH THE PERIOD...WITH OPERATIONAL EURO AND GFS MODELS VERY SIMILAR THRU MONDAY MORNING. OVERALL VERY LITTLE ADJUSTMENTS NEEDED FROM PREVIOUS FORECAST. GENERALLY BAGGINESS ACROSS THE EASTERN TWO-THIRDS OF THE CONUS WITH ONE SHRTWV DEPARTING THE REGION EARLY FRIDAY AN ANOTHER DROPPING SOUTHEAST TOWARDS THE REGION FROM THE PLAINS REACHING THE REGION FRIDAY NIGHT. RIDGING ACROSS HT EASTERN PACIFIC WILL BUILD INTO THE WESTERN PORTIONS OF NORTH AMERICA...ALLOWING ARCTIC AIR TO DRIVE SOUTH INTO THE CENTRAL AND EASTERN CONUS THIS WEEKEND WITH THE HELP OF A STRONG POLAR VORT DROPPING INTO THE GREAT LAKES SATURDAY NIGHT INTO SUNDAY. PRECIP CHCS EXIST LATE FRIDAY AFTN AND INTO THE NIGHTTIME HOURS AS THE SHRTWV MOVES THRU...MARGINAL TEMPS PROFILE FOR SNOW EARLY ON AS TEMPS WILL BE ABOVE NORMAL INTO THE UPPER 30S OR LOWER 40S ACROSS THE REGION. BUFKIT ANALYSIS WOULD SUPPORT MAINLY SNOW ACROSS THE NORTHERN PORTIONS OF THE REGION IN THE EVENING...WITH A MIX POSSIBLE ACROSS THE SOUTH. CONCERN HERE THAT THE BIAS OF UNDERPLAYING THE WAA IN THE LOWER LEVELS MAY OCCUR HERE AND THAT RAIN WOULD BE MORE LIKELY. WILL KEEP MIX ACROSS THE REGION THROUGH MIDNIGHT AND THEN TRANSIT TO ALL SNOW ACROSS THE NORTHERN PORTIONS OF THE REGION. LIGHT ACCUMS POSSIBLE...WITH A BUMP TO THE POP INTO THE LIKELY RANGE. FLURRIES/LIGHT SNOW WILL BE POSSIBLE SATURDAY MORNING WITH THE ARCTIC FRONT DROPPING THRU DURING THE AFTERNOON/EVENING TIMEFRAME WHICH MAY PRODUCE SOME LIGHT SNOW. WEAK OMEGAS IN THE SNOW GROWTH REGION START TO INCREASE IN THE AFTN AND EVENING AS THE FRONT PUSHES ACROSS THE REGION. TEMPS WILL DROP QUICKLY OVERNIGHT AS VERY STRONG CAA WILL DRIVE TEMPS INTO THE SINGLE DIGITS FOR MOST. WIND CHILLS WILL APPROACH -20 DEGREES BY DAYBREAK SUNDAY. H850 TEMPS DROP FROM NEAR -6C TO AROUND -26C BY SUNDAY MORNING. WINDS WILL BE STRONG...WITH SUSTAINED VALUES NEAR 25-30 MPH WITH GUSTS ABOVE 40-45 MPH POSSIBLE SATURDAY EVENING INTO SUNDAY. LAKE EFFECT SNOW POSSIBLE ACROSS THE NORTH AND EAST PORTIONS OF THE REGION SATURDAY EVENING INTO THE AFTERNOON ON SUNDAY. NICE SOUNDINGS AS PER BUFKIT FOR LAKE EFFECT SNOWS LATE SATURDAY NIGHT INTO SUNDAY AFTN. THE DRY ARCTIC AIR COULD BE A LIMITING FACTOR WITH A MORE WESTERLY WIND COMPONENT. MONDAY THROUGH WEDNESDAY... SOME MILD DISAGREEMENT IN THIS PERIOD...BUT THE ENSEMBLE MEANS HAVE BEEN VERY STABLE THE LAST FEW DAYS...AND HAVE STARTED TO SHOW THE TREND TO THE NORTH THAT MOST SYSTEMS AND BOUNDARIES HAVE SHOWN THIS SEASON. WITH NO BLOCKING IN PLACE ACROSS THE ATLC...THE COLDER AIR WILL SLIDE EAST AND START TO MODIFY SLOWLY. ANOTHER BOUNDARY WILL DROP THRU ON MONDAY EVENING AND POSSIBLY STALL JUST TO THE SOUTH OF THE REGION. OPERATIONAL MODELS ARE SHOWING SIMILAR SOLUTIONS BUT THE GFS IS A BIT MORE DEEP WITH THE TROUGH ACROSS THE REGION. UNCERTAINTY STARTS TO INCREASE DRAMATICALLY THRU THE END OF THE PERIOD...WILL LEAN TOWARDS THE ENSEMBLE GFS TO SMOOTH OUT THE DIFFERENCES FOR NOW. THE CURRENT GFS ENSEMBLE SHOWS A SYSTEM MOVING ALONG THE BOUNDARY ACROSS THE OHIO VALLEY LATE MONDAY INTO TUESDAY WITH THE POTENTIAL FOR DECENT SNOWS ACROSS A WIDE AREA. BEHIND THE FRONT IT WOULD REINFORCE THE COLDER AIR WITH MODERATE CAA WHICH WOULD BRING BACK SOME VERY CHILLY CONDITIONS FOR THE MID WEEK. && .AVIATION.../06Z TAFS/ LOW PRESSURE SYSTEM OVER NW OHIO...WILL CONTINUE TO EXIT THE REGION AS DRIER AIR PUSHES IN FROM THE NW. LOOK FOR SCATTERED SNOW SHOWERS IN EASTERN AREAS TO CONTINUE TO EXIT THE REGION. EXPECT VISBYS TO CONTINUE TO IMPROVE FROM WEST TO EAST...WITH CIGS RAISING TO MVFR CAT. EXPECTING MVFR CONDITIONS THROUGH THE PERIOD WITH POSSIBLE VFR CONDITIONS BY AFTERNOON WITH DRY PUSH CONTINUING AHEAD OF THE NEXT UPPER LEVEL DISTURBANCE. THERE IS THE OUTSIDE CHANCE FOR A FEW LIGHT SNOW SHOWERS/FLURRIES LATE THIS AFTERNOON AND EVENING. HOWEVER...LOW CONFIDENCE WILL PRECLUDE MENTION IN TAF AT THIS TIME. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SHORT TERM...CHAMBERLAIN LONG TERM...SCHOTT AVIATION...CHAMBERLAIN in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DODGE CITY KS 300 AM CST FRI FEB 8 2008 .DISCUSSION... DAYS 1-2... MAIN CHALLENGE IN THE FORECAST THROUGH SATURDAY WILL CONTINUE TO BE HIGH TEMPERATURES...ESPECIALLY OVER REMAINING SNOW COVERED AREAS FROM NEAR LIBERAL TO GARDEN CITY NORTHEASTWARD TO INTERSTATE 70. MAGNITUDE OF SFC WINDS ALSO A BIT OF A CHALLENGE...PARTICULARLY HOW STRONG THEY WILL BE THROUGH THE AFTERNOON HOURS. 00Z/08 UPPER AIR ANALYSIS REVEALED FAIRLY STRONG UPPER LEVEL JET CORE IMPACTING THE INTERMOUNTAIN WEST INTO THE CENTRAL ROCKIES. AHEAD OF THIS FEATURE...SOME MODERATE LIFTING WAS OCCURRING SUPPORTING PRECIPITATION ALOFT. NONE OF THE PRECIPITATION WAS REACHING THE GROUND...IN FACT CEILINGS WERE MAINLY AT OR ABOVE 10 THOUSAND FEET. WEAK SFC LOW WAS LOCATED OVER FAR SOUTHWEST KANSAS WHICH WILL SHIFT EAST AHEAD OF THE ADVANCING UPPER DISTURBANCE TODAY. IN ITS WAKE...STRONG NORTHWEST LOWER TROP WINDS WILL EXIST THROUGH AT LEAST THE FIRST HALF OF THE DAYLIGHT HOURS. AM EXPECTING SURFACE WINDS SUSTAINED IN THE 19 TO 23 KNOT RANGE. RUC13 IS SUGGESTING SURFACE WINDS TOUCHING ADVISORY CRITERIA (26 KNOTS OR 30 MPH)...ALTHOUGH THERE IS NOT MUCH SUPPORT FROM OTHER GUIDANCE GIVEN THE FAIRLY FAST MOVEMENT OF THE UPPER SYSTEM. DAY SHIFT WILL HAVE TO MONITOR MORNING OBS SHOULD RUC13 SURFACE WINDS COME TO FRUITION. AS FAR AS TEMPERATURES GO TODAY...SHOULD ONCE AGAIN SEE QUITE A BIT OF SUNSHINE. COLD AIR ADVECTION IN THE 850-700MB LAYER WILL EXIST BEHIND THE SYSTEM ALBEIT DOWNSLOPE MODIFIED. SHOULD ACTUALLY SEE TEMPERATURES SOMEWHAT SIMILAR TO THURSDAYS BUT PERHAPS A COUPLE DEGREES HIGHER. SNOW COVERED AREAS SHOULD CONTINUE TO SEE DEGRADATION OF THE SNOWPACK WITH HIGHS OVER THESE AREAS IN THE 39 TO 43F RANGE. OUTSIDE OF THE SNOWPACK...HIGHS WILL EASILY REACH UPPER 40S WITH A FEW LOW 50S POSSIBLE ESPECIALLY AROUND ELKHART. LIGHT WINDS THROUGH MOST OF TONIGHT WILL ALLOW LOWS TO DIP DOWN INTO THE LOWER 20S OVER MOST AREAS. WESTERN KANSAS WILL REMAIN UNDER THE INFLUENCE OF STRONG NORTHWEST FLOW ALOFT THROUGH SATURDAY. AS THE NORTHWEST FLOW JET CORE SHIFTS EASTWARD THOUGH DURING THE DAY SATURDAY...MID LEVEL HEIGHTS/THICKNESSES WILL RISE AND WARMER TEMPS WILL BE SEEN. SHOULD SEE MORE WIDESPREAD LOWER TO MID 50S ON SATURDAY WITH READINGS PERHAPS TOUCHING LOWER 60S IN THE ELKHART AREA. ANY LINGERING SNOW COVER AREAS WILL BE COOLER WITH MID-UPPER 40S AS A RULE. AS SUBSTANTIAL NORTHWEST FLOW JET CORE PUSHES INTO THE MIDWEST REGION LATE SATURDAY INTO SATURDAY NIGHT...SIGNIFICANT ANTICYCLOGENESIS WILL OCCUR IN ITS WAKE ACROSS THE NORTHERN PLAINS. THIS HIGH WILL BE OF PURE ARCTIC ORIGINS. THE SOURCE REGION OF THIS AIRMASS HAS BITTERLY -15 TO -25C H85 TEMPS ASSOCIATED WITH IT ACROSS THE CANADIAN PRAIRIES AT THIS TIME. A HEALTHY DOSE OF THIS ARCTIC AIR WILL PUSH SOUTH SATURDAY NIGHT...PERHAPS REACHING AS FAR SOUTHWEST AS SOUTHWESTERN KANSAS BY DAYBREAK SUNDAY MORNING. -UMSCHEID DAYS 3-7... THE MAIN FORECAST CHALLENGE CONTINUES TO BE HIGH TEMPERATURES ON SUNDAY WITH ARCTIC SURGE, THEN HOW WARM IT CAN GET ON WEDNESDAY WITH WARMING AND RIDGING. ONLY MODEL HANDLING SHALLOW ARCTIC AIRMASS SEEMS TO BE THE NEW ECMWF WITH 850MB TEMPS AROUND 2C AT DODGE BY 00Z MONDAY. THAT SAID THE GFS WHILE STILL WARM AT 850MB ALSO SHOWS AN BOUNDARY SOUTH INTO OKLAHOMA, BUT KNOW WITH THESE SHALLOW ARCTIC SURGES MODELS STRUGGLE WITH LOW LEVEL TEMPS. UKMET SHOWS BETTER DOWNSLOPE WITH THE SURFACE COLD HIGH FARTHER EAST AND SHALLOW ARCTIC BROKEN IN FAR WEST. WILL CONTINUE WITH THE COLD FORECAST OF HIGHS ON SUNDAY RANGING FROM AROUND 30 AT HAYS TO THE MID 40S FAR SOUTHWEST. COULD ALSO BE LOTS OF CLOUDS WITH EASTERLY UPSLOPE AND COLD AIR TRAPPED TOWARD GROUND IN INVERSION. CLOUDS AND COLD CONTINUE INTO MONDAY NIGHT. SOME NORTHWEST FLOW SHORTWAVES MOVE ACROSS ON MONDAY AND TUESDAY WITH THE GFS STILL TRENDING TOWARD -6C AT 850MB ON TUESDAY MORNING WHILE EC IS STILL WARM INTO WEDNESDAY. WITH SUCH DISCONTINUITY WILL MAINTAIN CURRENT WARM TREND WITH HIGHS ON WEDNESDAY REACHING THE 50S AND POSSIBLY 60S IF ECMWF VERIFIES. THEN NEXT COLD FRONT COMES IN ON LATE THURSDAY. LIKE PREVIOUS SHIFT MENTIONED TEMPS WILL BE AUGMENTED BY ANY SNOW ON THE GROUND SO TRIED TO KEEP COOLER HIGHS WEST AND NORTH. && .AVIATION... MID CLOUDS WILL CLEAR RAPIDLY THIS MORNING WITH EXITING SHORTWAVE ALLOWING MOSTLY SUNNY TO SUNNY SKIES WITH VFR CONDITIONS. WITH SUN COMING OUT THERE WILL BE SOME GOOD MIXING WITH WINDS OF 20 TO 30KTS THIS MORNING DECREASING TO 10 TO 20 MPH LATE. VFR CONDITIONS CONTINUE INTO 12Z SATURDAY. && .PRELIMINARY POINT TEMPS/POPS... DDC 47 24 52 18 / 10 0 0 0 GCK 41 21 48 14 / 0 0 0 0 EHA 51 24 59 20 / 0 0 0 0 LBL 48 24 54 21 / 0 0 0 0 HYS 41 21 45 14 / 10 0 0 0 P28 49 25 56 21 / 0 0 0 0 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ FN25/06/06 ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 1034 PM MST THU FEB 7 2008 .AVIATION... VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD. THE PRESSURE GRADIENT WILL CONTINUE TO TIGHTEN AND BY MID-DAY STRONG NORTHWEST WINDS WILL GUST PAST 30 KNOTS AT BOTH TERMINALS. CLOUD COVER WILL DECREASE IN COVERAGE AND SHOULD BE MOSTLY CLEAR BY THE END OF THE TAF PERIOD. && .PREV DISCUSSION... /ISSUED 237 PM MST THU FEB 7 2008/ .DISCUSSION...17Z WATER VAPOR IMAGERY/RUC ANALYSIS INDICATED SHORT WAVE TROUGH LIFTING MOVING ACROSS EASTERN KANSAS WITH ANOTHER TROUGH ENTERING THE PAC NORTHWEST. AT THE SFC...RIDGE AXIS WAS LOCATED ACROSS EASTERN CWA...WHILE TROUGH WAS DEVELOPING ACROSS EASTERN COLORADO AND WYOMING. WITH THE EXCEPTION OF SHORT WAVE TROUGH MOVING OVER THE AREA TONIGHT...MAIN CONCERN THROUGH THE WEEKEND WILL BE TEMPS. TONIGHT-TOMORROW...STRONG COLD FRONT WILL SLIDE ACROSS THE AREA OVERNIGHT...WITH WINDS AT AND ABOVE H85 INCREASE TO 45-50KTS OVERNIGHT. THINK WINDS WILL BECOME BREEZY/WINDY BEHIND FROPA...BUT POINT SOUNDINGS INDICATE WINDS ALL ABOVE THE FRONTAL INVERSION SO DO NOT ANTICIPATE ANY KIND OF WIND HIGHLIGHT TONIGHT. WINDS WILL STAY UP THROUGH THE MORNING HOURS AS MIXING BEGINS. AT THIS TIME IT LOOKS LIKE THERE WILL BE A BRIEF PERIOD WITH WINDS GUSTING TO AROUND 37KTS BUT LOOKS LIKE WINDS ALOFT WILL DECREASE BEFORE DEEP MIXING SETS UP AND DO NOT ANTICIPATE A WIND HIGHLIGHT ATTM. SHORT WAVE TROUGH...CURRENTLY ACROSS THE NORTHWESTERN CONUS WILL SLIDE ACROSS THE CWA OVERNIGHT. MODELS SUGGEST TO AREAS OF ASCENT WILL DEVELOP...ON IN AREA WAA ACROSS THE NORTHEAST AHEAD OF THE TROUGH...AND ANOTHER ACROSS WEST WHEN TROUGH AND COLD FRONT SWEEP ACROSS THE AREA. LOWER ATMOSPHERE APPEARS VERY DRY BASED ON RAOBS AND CURRENT T-TD SPREADS AND WITH QUICK NATURE OF THE SYSTEM AM NOT CONFIDENT ON PRECIP CHANCES. HOWEVER LAPSE RATES...ESPECIALLY ON THE GFS...ARE VERY STEEP WHEN COLD (H5 T AROUND -31C) TROUGH MOVES ACROSS THE AREA. NO REAL PERSISTENT AREAS OF FRONTOGENESIS TO FOCUS ANY PRECIP...AND SREF POPS ARE VERY LOW. HARD TO IGNORE POTENTIAL INSTABILITY AND FORCING SO WILL ADD SOME LOW POPS OVERNIGHT...BUT WITH CONCERNS ABOUT MOISTURE AVAILABILITY AND LACK OF SUPPORT BY SREF AND NAM WILL KEEP POPS IN SLIGHT CHANCE CATEGORY. IF SNOW DOES DEVELOP...WILL PROBABLY HAVE BLOWING SNOW PROBLEMS AS WELL BUT WITH SUCH LOW PROBABILITIES OF SNOW WILL NOT INCLUDE BLSN AT THIS TIME. TOMORROW NIGHT-SUNDAY NIGHT...H5 RIDGE WILL BEGIN TO BUILD ACROSS THE SOUTHERN ROCKIES...WITH CWA APPEARING TO BE ON THE FRINGE OF THIS FEATURE THROUGH THE PERIOD. WITH A RIDGE BUILDING INTO THE AREA...EXPECT WX TO QUIET THROUGH THE PERIOD. CONCERN WILL BE TEMPERATURES HOWEVER...AS MODELS ALL SUGGEST VERY COLD AIRMASS TO SLIDE ACROSS THE NORTHERN AND CENTRAL PLAINS ON SATURDAY. WITH RIDGE AXIS IN ITS EXPECTED LOCATION...COLD FRONT WILL LIKELY STALL SOMEWHERE IN OUR AREA AND SHOULD HAVE A VERY SHARP TEMPERATURE GRADIENT. ALSO WITH SHALLOW COLD FRONT AND STRONG WAA OVER THE TOP OF IT...MAY HAVE SOME LIGHT FZDZ PROBLEMS ON SUNDAY. NOT CONFIDENT ENOUGH ON FRONTAL LOCATION AND ANY POSSIBLE MOISTURE RETURN TO MENTION THIS IN FORECAST AT THIS TIME...BUT WILL HAVE TO KEEP AN EYE ON THIS TIMEFRAME. MONDAY-TUESDAY...MEDIUM RANGE MODELS BEGIN TO DIVERGE WITH HANDLING OF NEXT SHORT WAVE TROUGH TO IMPACT THE AREA DURING THE BEGINNING OF THE WEEK. 00Z GFS AND ECMWF SHOW SOME AGREEMENT AND 00Z AND 06Z GFS ENSEMBLES SUPPORT A SOLUTION SIMILAR TO THESE MODELS...WHILE THE SLOWER AND MORE AMPLIFIED 06Z GFS APPEARS TO BE AN OUTLIER WITH AVAILABLE ENS DATA AND AT THIS TIME WILL LEAN MORE TOWARDS A 00Z GFS/ECMWF SOLUTION. MAIN CONCERNS FOR THE PERIOD WILL BE ANY POTENTIAL PRECIP WITH PASSAGE OF UPPER TROUGH ON MONDAY NIGHT AND TEMPERATURES THROUGH THE PERIOD. ALTHOUGH THERE IS A LARGE AMOUNT OF DISAGREEMENT WITH TIMING/STRENGTH OF NEXT TROUGH...ENSEMBLE DATA WARRANTS ENOUGH OF A THREAT TO MENTION SOME LOW POPS THROUGH THE PERIOD. FOR TEMPS...STRENGTH OF THE TROUGH IS ALSO TIED TO HOW COLD AIRMASS BEHIND TROUGH WILL BE ON TUESDAY. WHILE LARGE DISAGREEMENT REMAINS WITH HOW MUCH AND HOW LONG COLD AIR WILL PERSIST OVER THE AREA...AM GOING TO KEEP TEMPS IN THE MIDDLE OF THE WARM ECMWF AND COLD GFS SOLUTIONS UNTIL THINGS BECOME A BIT CLEARER. WEDNESDAY AND THURSDAY...UPPER TROUGH ADVANCES TOWARD THE AREA WEDNESDAY WITH MID AND HIGH LEVEL MOISTURE NOT REACHING THE AREA TIL LATE IN THE DAY. AS THE TROUGH MOVES THROUGH WEDNESDAY NIGHT SOME LIGHT PRECIPITATION IS POSSIBLE BUT FOR NOW WILL NOT GET TOO EXCITED AS TIMING DIFFERENCES ALBEIT SUBTLE COULD ACCELERATE OR DELAY THE ONSET OF PRECIP. SHOULD CURRENT MODEL SOLUTIONS VERIFY PRECIP AND CLOUDS WOULD EXIT THE AREA THURSDAY MORNING WITH ONLY SOME HIGH LEVEL CLOUDINESS MOVING BACK IN AS UPPER RIDGING REBUILDS. ASIDE FROM THE SMALL CHANCES OF PRECIPITATION WINDS MAY BE OF CONCERN WEDNESDAY NIGHT AND THURSDAY AS THE FRONT MOVES THROUGH. SHOULD SEE BREEZY TO WINDY CONDITIONS AND HAVE UPPED WINDS AS A RESULT. 850 TEMPERATURES THURSDAY ARE GENERALLY IN THE 8C-12C RANGE EXCEPT ACROSS THE NORTHWEST WHERE PROXIMITY TO UPPER TROUGH MAY ONLY PRODUCE READINGS IN THE 4C-6C RANGE. SHOULD THIS VERIFY CURRENT ADVERTISED HIGHS IN THE 50S WILL NEED TO BE ADJUSTED UPWARD. BEHIND THE TROUGH TEMPERATURES WILL BE COLDER BUT HOW MUCH IS IN QUESTION AS GFS WARMER THAN THE ECMWF. FOR NOW HAVE GONE MID 40S WHICH IS A GOOD COMPROMISE WITH SURROUNDING OFFICES AND 06Z ENSEMBLE 850 TEMPS WITH BIAS ADDED FROM THE PREVIOUS 10 DAYS PERFORMANCE FROM THE GFS FOR ASOS SITES. ANOTHER THING TO CONSIDER WITH TEMPS WILL BE HOW MUCH IF ANY AND WHERE LINGERING SNOW PACK EXISTS. GOODLAND LOST 2 INCHES OF SNOW DEPTH YESTERDAY AND MORE IS LIKELY TODAY. IF THIS TREND CONTINUES MUCH OF IT SHOULD BE GONE BY DAY 6 IF NOT SOONER AND NOT MUCH IMPACT ON TEMPS. && && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$ KJ/JRM/DDT ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 424 PM MST THU FEB 7 2008 .AVIATION... FOR THE 00Z TAF...CURRENT WV/VIS IMAGERY SHOWS DECK OF MID AND UPPER LEVEL CLOUDS OVER THE NORTHWESTERN PORTION OF THE CWA INCLUDING BOTH KGLD AND KMCK IN ASSOCIATION WITH A SHORTWAVE TROUGH MOVING THROUGH THE AREA. HAVE A SLIGHT CHANCE OF SNOW SHOWERS BUT CONFIDENCE WAS TOO LOW TO MENTION IN THE TAF. AS THE TROUGH AXIS PUSHES EAST OF THE CWA BY AROUND 09Z...PRESSURE GRADIENT WILL TIGHTEN SUBSTANTIALL CAUSING WINDS TO INCREASE. EXPECTING SUSTAINED WINDS OF 15 TO 25 MPH WITH GUSTS REACHING AS HIGH AS 40 MPH ESPECIALLY AFTER 15Z FRIDAY WITH SKIES CLEARING SLOWLY. && .PREV DISCUSSION... /ISSUED 237 PM MST THU FEB 7 2008/ .DISCUSSION...17Z WATER VAPOR IMAGERY/RUC ANALYSIS INDICATED SHORT WAVE TROUGH LIFTING MOVING ACROSS EASTERN KANSAS WITH ANOTHER TROUGH ENTERING THE PAC NORTHWEST. AT THE SFC...RIDGE AXIS WAS LOCATED ACROSS EASTERN CWA...WHILE TROUGH WAS DEVELOPING ACROSS EASTERN COLORADO AND WYOMING. WITH THE EXCEPTION OF SHORT WAVE TROUGH MOVING OVER THE AREA TONIGHT...MAIN CONCERN THROUGH THE WEEKEND WILL BE TEMPS. TONIGHT-TOMORROW...STRONG COLD FRONT WILL SLIDE ACROSS THE AREA OVERNIGHT...WITH WINDS AT AND ABOVE H85 INCREASE TO 45-50KTS OVERNIGHT. THINK WINDS WILL BECOME BREEZY/WINDY BEHIND FROPA...BUT POINT SOUNDINGS INDICATE WINDS ALL ABOVE THE FRONTAL INVERSION SO DO NOT ANTICIPATE ANY KIND OF WIND HIGHLIGHT TONIGHT. WINDS WILL STAY UP THROUGH THE MORNING HOURS AS MIXING BEGINS. AT THIS TIME IT LOOKS LIKE THERE WILL BE A BRIEF PERIOD WITH WINDS GUSTING TO AROUND 37KTS BUT LOOKS LIKE WINDS ALOFT WILL DECREASE BEFORE DEEP MIXING SETS UP AND DO NOT ANTICIPATE A WIND HIGHLIGHT ATTM. SHORT WAVE TROUGH...CURRENTLY ACROSS THE NORTHWESTERN CONUS WILL SLIDE ACROSS THE CWA OVERNIGHT. MODELS SUGGEST TO AREAS OF ASCENT WILL DEVELOP...ON IN AREA WAA ACROSS THE NORTHEAST AHEAD OF THE TROUGH...AND ANOTHER ACROSS WEST WHEN TROUGH AND COLD FRONT SWEEP ACROSS THE AREA. LOWER ATMOSPHERE APPEARS VERY DRY BASED ON RAOBS AND CURRENT T-TD SPREADS AND WITH QUICK NATURE OF THE SYSTEM AM NOT CONFIDENT ON PRECIP CHANCES. HOWEVER LAPSE RATES...ESPECIALLY ON THE GFS...ARE VERY STEEP WHEN COLD (H5 T AROUND -31C) TROUGH MOVES ACROSS THE AREA. NO REAL PERSISTENT AREAS OF FRONTOGENESIS TO FOCUS ANY PRECIP...AND SREF POPS ARE VERY LOW. HARD TO IGNORE POTENTIAL INSTABILITY AND FORCING SO WILL ADD SOME LOW POPS OVERNIGHT...BUT WITH CONCERNS ABOUT MOISTURE AVAILABILITY AND LACK OF SUPPORT BY SREF AND NAM WILL KEEP POPS IN SLIGHT CHANCE CATEGORY. IF SNOW DOES DEVELOP...WILL PROBABLY HAVE BLOWING SNOW PROBLEMS AS WELL BUT WITH SUCH LOW PROBABILITIES OF SNOW WILL NOT INCLUDE BLSN AT THIS TIME. TOMORROW NIGHT-SUNDAY NIGHT...H5 RIDGE WILL BEGIN TO BUILD ACROSS THE SOUTHERN ROCKIES...WITH CWA APPEARING TO BE ON THE FRINGE OF THIS FEATURE THROUGH THE PERIOD. WITH A RIDGE BUILDING INTO THE AREA...EXPECT WX TO QUIET THROUGH THE PERIOD. CONCERN WILL BE TEMPERATURES HOWEVER...AS MODELS ALL SUGGEST VERY COLD AIRMASS TO SLIDE ACROSS THE NORTHERN AND CENTRAL PLAINS ON SATURDAY. WITH RIDGE AXIS IN ITS EXPECTED LOCATION...COLD FRONT WILL LIKELY STALL SOMEWHERE IN OUR AREA AND SHOULD HAVE A VERY SHARP TEMPERATURE GRADIENT. ALSO WITH SHALLOW COLD FRONT AND STRONG WAA OVER THE TOP OF IT...MAY HAVE SOME LIGHT FZDZ PROBLEMS ON SUNDAY. NOT CONFIDENT ENOUGH ON FRONTAL LOCATION AND ANY POSSIBLE MOISTURE RETURN TO MENTION THIS IN FORECAST AT THIS TIME...BUT WILL HAVE TO KEEP AN EYE ON THIS TIMEFRAME. MONDAY-TUESDAY...MEDIUM RANGE MODELS BEGIN TO DIVERGE WITH HANDLING OF NEXT SHORT WAVE TROUGH TO IMPACT THE AREA DURING THE BEGINNING OF THE WEEK. 00Z GFS AND ECMWF SHOW SOME AGREEMENT AND 00Z AND 06Z GFS ENSEMBLES SUPPORT A SOLUTION SIMILAR TO THESE MODELS...WHILE THE SLOWER AND MORE AMPLIFIED 06Z GFS APPEARS TO BE AN OUTLIER WITH AVAILABLE ENS DATA AND AT THIS TIME WILL LEAN MORE TOWARDS A 00Z GFS/ECMWF SOLUTION. MAIN CONCERNS FOR THE PERIOD WILL BE ANY POTENTIAL PRECIP WITH PASSAGE OF UPPER TROUGH ON MONDAY NIGHT AND TEMPERATURES THROUGH THE PERIOD. ALTHOUGH THERE IS A LARGE AMOUNT OF DISAGREEMENT WITH TIMING/STRENGTH OF NEXT TROUGH...ENSEMBLE DATA WARRANTS ENOUGH OF A THREAT TO MENTION SOME LOW POPS THROUGH THE PERIOD. FOR TEMPS...STRENGTH OF THE TROUGH IS ALSO TIED TO HOW COLD AIRMASS BEHIND TROUGH WILL BE ON TUESDAY. WHILE LARGE DISAGREEMENT REMAINS WITH HOW MUCH AND HOW LONG COLD AIR WILL PERSIST OVER THE AREA...AM GOING TO KEEP TEMPS IN THE MIDDLE OF THE WARM ECMWF AND COLD GFS SOLUTIONS UNTIL THINGS BECOME A BIT CLEARER. WEDNESDAY AND THURSDAY...UPPER TROUGH ADVANCES TOWARD THE AREA WEDNESDAY WITH MID AND HIGH LEVEL MOISTURE NOT REACHING THE AREA TIL LATE IN THE DAY. AS THE TROUGH MOVES THROUGH WEDNESDAY NIGHT SOME LIGHT PRECIPITATION IS POSSIBLE BUT FOR NOW WILL NOT GET TOO EXCITED AS TIMING DIFFERENCES ALBEIT SUBTLE COULD ACCELERATE OR DELAY THE ONSET OF PRECIP. SHOULD CURRENT MODEL SOLUTIONS VERIFY PRECIP AND CLOUDS WOULD EXIT THE AREA THURSDAY MORNING WITH ONLY SOME HIGH LEVEL CLOUDINESS MOVING BACK IN AS UPPER RIDGING REBUILDS. ASIDE FROM THE SMALL CHANCES OF PRECIPITATION WINDS MAY BE OF CONCERN WEDNESDAY NIGHT AND THURSDAY AS THE FRONT MOVES THROUGH. SHOULD SEE BREEZY TO WINDY CONDITIONS AND HAVE UPPED WINDS AS A RESULT. 850 TEMPERATURES THURSDAY ARE GENERALLY IN THE 8C-12C RANGE EXCEPT ACROSS THE NORTHWEST WHERE PROXIMITY TO UPPER TROUGH MAY ONLY PRODUCE READINGS IN THE 4C-6C RANGE. SHOULD THIS VERIFY CURRENT ADVERTISED HIGHS IN THE 50S WILL NEED TO BE ADJUSTED UPWARD. BEHIND THE TROUGH TEMPERATURES WILL BE COLDER BUT HOW MUCH IS IN QUESTION AS GFS WARMER THAN THE ECMWF. FOR NOW HAVE GONE MID 40S WHICH IS A GOOD COMPROMISE WITH SURROUNDING OFFICES AND 06Z ENSEMBLE 850 TEMPS WITH BIAS ADDED FROM THE PREVIOUS 10 DAYS PERFORMANCE FROM THE GFS FOR ASOS SITES. ANOTHER THING TO CONSIDER WITH TEMPS WILL BE HOW MUCH IF ANY AND WHERE LINGERING SNOW PACK EXISTS. GOODLAND LOST 2 INCHES OF SNOW DEPTH YESTERDAY AND MORE IS LIKELY TODAY. IF THIS TREND CONTINUES MUCH OF IT SHOULD BE GONE BY DAY 6 IF NOT SOONER AND NOT MUCH IMPACT ON TEMPS. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$ CSF/JRM/DDT ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 237 PM MST THU FEB 7 2008 .DISCUSSION...17Z WATER VAPOR IMAGERY/RUC ANALYSIS INDICATED SHORT WAVE TROUGH LIFTING MOVING ACROSS EASTERN KANSAS WITH ANOTHER TROUGH ENTERING THE PAC NORTHWEST. AT THE SFC...RIDGE AXIS WAS LOCATED ACROSS EASTERN CWA...WHILE TROUGH WAS DEVELOPING ACROSS EASTERN COLORADO AND WYOMING. WITH THE EXCEPTION OF SHORT WAVE TROUGH MOVING OVER THE AREA TONIGHT...MAIN CONCERN THROUGH THE WEEKEND WILL BE TEMPS. TONIGHT-TOMORROW...STRONG COLD FRONT WILL SLIDE ACROSS THE AREA OVERNIGHT...WITH WINDS AT AND ABOVE H85 INCREASE TO 45-50KTS OVERNIGHT. THINK WINDS WILL BECOME BREEZY/WINDY BEHIND FROPA...BUT POINT SOUNDINGS INDICATE WINDS ALL ABOVE THE FRONTAL INVERSION SO DO NOT ANTICIPATE ANY KIND OF WIND HIGHLIGHT TONIGHT. WINDS WILL STAY UP THROUGH THE MORNING HOURS AS MIXING BEGINS. AT THIS TIME IT LOOKS LIKE THERE WILL BE A BRIEF PERIOD WITH WINDS GUSTING TO AROUND 37KTS BUT LOOKS LIKE WINDS ALOFT WILL DECREASE BEFORE DEEP MIXING SETS UP AND DO NOT ANTICIPATE A WIND HIGHLIGHT ATTM. SHORT WAVE TROUGH...CURRENTLY ACROSS THE NORTHWESTERN CONUS WILL SLIDE ACROSS THE CWA OVERNIGHT. MODELS SUGGEST TO AREAS OF ASCENT WILL DEVELOP...ON IN AREA WAA ACROSS THE NORTHEAST AHEAD OF THE TROUGH...AND ANOTHER ACROSS WEST WHEN TROUGH AND COLD FRONT SWEEP ACROSS THE AREA. LOWER ATMOSPHERE APPEARS VERY DRY BASED ON RAOBS AND CURRENT T-TD SPREADS AND WITH QUICK NATURE OF THE SYSTEM AM NOT CONFIDENT ON PRECIP CHANCES. HOWEVER LAPSE RATES...ESPECIALLY ON THE GFS...ARE VERY STEEP WHEN COLD (H5 T AROUND -31C) TROUGH MOVES ACROSS THE AREA. NO REAL PERSISTENT AREAS OF FRONTOGENESIS TO FOCUS ANY PRECIP...AND SREF POPS ARE VERY LOW. HARD TO IGNORE POTENTIAL INSTABILITY AND FORCING SO WILL ADD SOME LOW POPS OVERNIGHT...BUT WITH CONCERNS ABOUT MOISTURE AVAILABILITY AND LACK OF SUPPORT BY SREF AND NAM WILL KEEP POPS IN SLIGHT CHANCE CATEGORY. IF SNOW DOES DEVELOP...WILL PROBABLY HAVE BLOWING SNOW PROBLEMS AS WELL BUT WITH SUCH LOW PROBABILITIES OF SNOW WILL NOT INCLUDE BLSN AT THIS TIME. TOMORROW NIGHT-SUNDAY NIGHT...H5 RIDGE WILL BEGIN TO BUILD ACROSS THE SOUTHERN ROCKIES...WITH CWA APPEARING TO BE ON THE FRINGE OF THIS FEATURE THROUGH THE PERIOD. WITH A RIDGE BUILDING INTO THE AREA...EXPECT WX TO QUIET THROUGH THE PERIOD. CONCERN WILL BE TEMPERATURES HOWEVER...AS MODELS ALL SUGGEST VERY COLD AIRMASS TO SLIDE ACROSS THE NORTHERN AND CENTRAL PLAINS ON SATURDAY. WITH RIDGE AXIS IN ITS EXPECTED LOCATION...COLD FRONT WILL LIKELY STALL SOMEWHERE IN OUR AREA AND SHOULD HAVE A VERY SHARP TEMPERATURE GRADIENT. ALSO WITH SHALLOW COLD FRONT AND STRONG WAA OVER THE TOP OF IT...MAY HAVE SOME LIGHT FZDZ PROBLEMS ON SUNDAY. NOT CONFIDENT ENOUGH ON FRONTAL LOCATION AND ANY POSSIBLE MOISTURE RETURN TO MENTION THIS IN FORECAST AT THIS TIME...BUT WILL HAVE TO KEEP AN EYE ON THIS TIMEFRAME. MONDAY-TUESDAY...MEDIUM RANGE MODELS BEGIN TO DIVERGE WITH HANDLING OF NEXT SHORT WAVE TROUGH TO IMPACT THE AREA DURING THE BEGINNING OF THE WEEK. 00Z GFS AND ECMWF SHOW SOME AGREEMENT AND 00Z AND 06Z GFS ENSEMBLES SUPPORT A SOLUTION SIMILAR TO THESE MODELS...WHILE THE SLOWER AND MORE AMPLIFIED 06Z GFS APPEARS TO BE AN OUTLIER WITH AVAILABLE ENS DATA AND AT THIS TIME WILL LEAN MORE TOWARDS A 00Z GFS/ECMWF SOLUTION. MAIN CONCERNS FOR THE PERIOD WILL BE ANY POTENTIAL PRECIP WITH PASSAGE OF UPPER TROUGH ON MONDAY NIGHT AND TEMPERATURES THROUGH THE PERIOD. ALTHOUGH THERE IS A LARGE AMOUNT OF DISAGREEMENT WITH TIMING/STRENGTH OF NEXT TROUGH...ENSEMBLE DATA WARRANTS ENOUGH OF A THREAT TO MENTION SOME LOW POPS THROUGH THE PERIOD. FOR TEMPS...STRENGTH OF THE TROUGH IS ALSO TIED TO HOW COLD AIRMASS BEHIND TROUGH WILL BE ON TUESDAY. WHILE LARGE DISAGREEMENT REMAINS WITH HOW MUCH AND HOW LONG COLD AIR WILL PERSIST OVER THE AREA...AM GOING TO KEEP TEMPS IN THE MIDDLE OF THE WARM ECMWF AND COLD GFS SOLUTIONS UNTIL THINGS BECOME A BIT CLEARER. WEDNESDAY AND THURSDAY...UPPER TROUGH ADVANCES TOWARD THE AREA WEDNESDAY WITH MID AND HIGH LEVEL MOISTURE NOT REACHING THE AREA TIL LATE IN THE DAY. AS THE TROUGH MOVES THROUGH WEDNESDAY NIGHT SOME LIGHT PRECIPITATION IS POSSIBLE BUT FOR NOW WILL NOT GET TOO EXCITED AS TIMING DIFFERENCES ALBEIT SUBTLE COULD ACCELERATE OR DELAY THE ONSET OF PRECIP. SHOULD CURRENT MODEL SOLUTIONS VERIFY PRECIP AND CLOUDS WOULD EXIT THE AREA THURSDAY MORNING WITH ONLY SOME HIGH LEVEL CLOUDINESS MOVING BACK IN AS UPPER RIDGING REBUILDS. ASIDE FROM THE SMALL CHANCES OF PRECIPITATION WINDS MAY BE OF CONCERN WEDNESDAY NIGHT AND THURSDAY AS THE FRONT MOVES THROUGH. SHOULD SEE BREEZY TO WINDY CONDITIONS AND HAVE UPPED WINDS AS A RESULT. 850 TEMPERATURES THURSDAY ARE GENERALLY IN THE 8C-12C RANGE EXCEPT ACROSS THE NORTHWEST WHERE PROXIMITY TO UPPER TROUGH MAY ONLY PRODUCE READINGS IN THE 4C-6C RANGE. SHOULD THIS VERIFY CURRENT ADVERTISED HIGHS IN THE 50S WILL NEED TO BE ADJUSTED UPWARD. BEHIND THE TROUGH TEMPERATURES WILL BE COLDER BUT HOW MUCH IS IN QUESTION AS GFS WARMER THAN THE ECMWF. FOR NOW HAVE GONE MID 40S WHICH IS A GOOD COMPROMISE WITH SURROUNDING OFFICES AND 06Z ENSEMBLE 850 TEMPS WITH BIAS ADDED FROM THE PREVIOUS 10 DAYS PERFORMANCE FROM THE GFS FOR ASOS SITES. ANOTHER THING TO CONSIDER WITH TEMPS WILL BE HOW MUCH IF ANY AND WHERE LINGERING SNOW PACK EXISTS. GOODLAND LOST 2 INCHES OF SNOW DEPTH YESTERDAY AND MORE IS LIKELY TODAY. IF THIS TREND CONTINUES MUCH OF IT SHOULD BE GONE BY DAY 6 IF NOT SOONER AND NOT MUCH IMPACT ON TEMPS. && .AVIATION...FOR THE 18Z TAF...WV/VIS IMAGERY SHOWING MID LEVEL CLOUD DECK SLIDING SOUTHEASTWARD TOWARD THE KGLD AND KMCK TERMINALS IN ASSOCIATION WITH A FAST MOVING SHORTWAVE TROUGH. LOOKING AT OBS UPSTREAM...EXPECT FEW-SCT CLOUDS AT AROUND 10000 FT OVER KGLD WITH A BKN DECK OVER KMCK THROUGH AROUND 12Z FRIDAY. AS THE SHORTWAVE TROUGH SLIDES TO THE EAST...WILL SEE WINDS PICK UP. GIVEN TIGHT PRESSURE GRADIENT...SHOULD SEE SUSTAINED WINDS OF 15 TO 20 MPH WITH GUSTS UP TO 25 MPH AFTER 12Z FRIDAY. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$ JRM/DDT/CSF ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TOPEKA KS 414 AM CST THU FEB 7 2008 .DISCUSSION... THE LATEST WATER VAPOR SATELLITE ALONG WITH THE 00Z UPPER AIR MAPS SHOWED AN UPPER LEVEL TROUGH MOVING ACROSS THE HIGH PLAINS THIS MORNING. THE UPPER LOW RESPONSIBLE FOR TUESDAY NIGHT`S SNOW FALL CONTINUED TO MOVE NORTHEAST ACROSS THE LOWER GREAT LAKES STATES. ANOTHER UPPER LEVEL TROUGH WAS MOVING ONSHORE ACROSS THE PACIFIC NORTHWEST. TODAY...THE 5H TROUGH NOW MOVING INTO WESTERN KS WILL MOVE EAST ACROSS THE STATE THIS MORNING. THE RUC MODEL SEEMS TO BE HANDLING THE DRIER AIR ABOVE THE SFC UP TO 700MB BETTER THAN THE GFS AND NAM. CLOUD BASES ARE ALL ABOVE 8KFT ACROSS WESTERN AND CENTRAL KS AHEAD OF THE FRONT. I CAN`T RULE OUT SOME SNOW FLURRIES BUT IF THE RUC POINT SOUNDING ARE CORRECT ABOUT THE DRY LAYER UP TO 700MB THE SNOW MAY SUBLIMATE BEFORE REACHING THE SURFACE. AS THE 5H TROUGH MOVES EAST ACROSS KS...A WEAK COLD FRONT WILL PUSH EAST ACROSS THE CWA THROUGH THE MID MORNING AND EARLY AFTERNOON HOURS. THERE MAY BE A PERIOD OF STRATUS IN THE MID AND LATE MORNING HOURS BEHIND THE WEAK FRONT. SOUTH TO SOUTHWEST WINDS WILL SWITCH TO THE WEST AND NORTHWEST BEHIND THE FRONT. THE AIRMASS BEHIND THE FRONT WAS NOT MUCH COOLER...IN FACT THE SLIGHT DOWNSLOPE COMPONENT MAY HELP TO WARM TEMPS A BIT TODAY. HOWEVER THE EXTENSIVE SNOW PACK WILL KEEP HIGHS IN THE LOWER TO MID 30S. SKIES WILL CLEAR DURING THE AFTERNOON FROM WEST TO EAST ACROSS THE CWA. TONIGHT AND FRIDAY...THE 5H TROUGH OVER THE PACIFIC NORTHWEST WILL DIG SOUTHEAST ACROSS THE CENTRAL AND SOUTHERN PLAINS EARLY FRIDAY MORNING. AGAIN THERE WILL BE VERY LITTLE LOW-LEVEL MOISTURE AVAILABLE AHEAD OF THE 5H TROUGH...THUS ANY LIFT AHEAD OF THE 5H TROUGH MAY ONLY RESULT IN MID LEVEL CLOUDS AND PERHAPS SOME SNOW FLURRIES. THE 5H TROUGH WILL MOVE EAST AND SOUTHEAST OF THE CWA FRIDAY AFTERNOON...THUS SKIES MAY BECOME MOSTLY SUNNY THROUGH THE AFTERNOON HOURS. ANOTHER WEAK WIND COLD FRONT WILL SHIFT WINDS AROUND TO THE NORTHWEST AND WEST THROUGH THE DAY FRIDAY. HIGHS WILL BE IN THE MID TO UPPER 30S ALONG AND NORTH OF I-70 WHERE THE DEEPER SNOW FIELD IS LOCATED. THE SOUTHEAST COUNTIES MAY NOT HAVE MUCH SNOW COVER LEFT AND MAY WARM INTO THE MID 40S. SATURDAY AND SATURDAY NIGHT...BOTH THE GFS AND ECMWF CONTINUE TO SHOW AN INTENSE 5H TROUGH DIGGING SOUTHEAST OUT OF NORTHWEST CANADA INTO THE MIDWEST AND GREAT LAKES STATES LATE FRIDAY INTO SATURDAY. THE STRONG CAA WILL BUILD AN ARCTIC SURFACE HIGHS SOUTH ACROSS THE EASTERN PLAINS AND MIDWEST INTO THE LOWER MS RIVER VALLEY. THIS WILL CAUSE A STRONG COLD FRONT TO MOVE SOUTHWARD ACROSS THE CWA SATURDAY AFTERNOON. HIGH TEMPERATURES MAY OCCUR DURING THE LATE MORNING AND EARLY AFTERNOON HOURS WITH TEMPERATURES FALLING THROUGH THE REMAINDER OF THE DAY. LOWS SATURDAY NIGHT MAY REACH INTO THE SINGLE DIGITS. SUNDAY...THE ARCTIC AIRMASS WILL CONTINUE ACROSS THE CWA WITH HIGHS ONLY REACHING INTO THE LOWER TO MID 20S. THE ECMWF IS A BIT COLDER AND IF IT WERE TO VERIFY HIGHS MAY BE 5 DEGREES OR SO TOO WARM ON SUNDAY. SUNDAY NIGHT...THE ARCTIC RIDGE WILL SHIFT EAST OF THE CWA AND SOUTHERLY WINDS WILL ADVECT RESIDUAL LOW LEVEL MOISTURE OVER TX AND OK NORTHWARD INTO KS. WE SHOULD SEE MORE CLOUD COVER AND THERE MAY BE A SLIGHT CHANCE FOR PRECIP JUST SOUTH OF THE CWA. CLOUD COVER AND SOUTHERLY WINDS WILL KEEP LOW TEMPERATURES IN THE TEENS. MONDAY THROUGH MONDAY NIGHT...A 5H TROUGH WILL DIG SOUTHEAST ACROSS THE NORTHERN AND CENTRAL PLAINS AND CAUSE OUR LOW-LEVEL WINDS TO VEER...ADVECTING THE DEEPER MOISTURE EAST OF THE CWA. THERE MAY BE A CHANCE OF PRECIP ACROSS THE SOUTHEAST COUNTIES. THE COLDER AIR MAY ADVECT SOUTH AGAIN ACROSS THE CWA LATE MONDAY AFTERNOON AND MONDAY NIGHT. HIGHS MONDAY WILL BE IN THE MID 30S TO LOWER 40S. LOWS IN THE UPPER TEENS AND LOWER 20S. TUESDAY AND WEDNESDAY...THE SFC RIDGE WILL MOVE EAST AS AN UPPER LEVEL RIDGE MOVES EAST ACROSS THE PLAINS. HIGHS WILL WARM INTO 40S. LOWS WILL BE IN THE 20S. THE EXTENDED FORECAST GRIDS LOOKED GOOD AND NO CHANGES WERE MADE. 66 && .AVIATION... PATCHY DENSE FOG THAT DEVELOPED DURING THE EARLY MORNING HOURS HAS WITHERED TO ONLY SLIGHTLY REDUCED VISIBILITIES UPON THE APPROACH OF MORE DENSE HIGH CLOUDINESS. MID LEVEL CLOUDS WILL BEGIN TO ENTER THE REGION IN ADVANCE OF A SHORTWAVE TROUGH. A SURFACE WIND SHIFT WILL MOVE THROUGH DURING THE MID/LATE MORNING HOURS...WITH WESTERLY WINDS BECOMING DOMINANT. LOW CLOUDS ARE EXPECTED TO DEVELOP ALONG AND IMMEDIATELY BEHIND THE SURFACE FEATURE OWING TO GREATER RH. THERE MAY BE A BRIEF PERIOD OF FLURRIES AND CEILINGS NEAR 1000FT DURING THE DAY. CEILINGS IMPROVE AROUND SUNSET...WITH MID LEVEL CLOUDS REENTERING THE REGION BY MIDNIGHT IN RESPONSE TO THE NEXT SHORTWAVE TROUGH. BLAIR && .TOP WATCHES/WARNINGS/ADVISORIES...NONE. && $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PADUCAH KY 236 AM CST THU FEB 7 2008 .DISCUSSION... STRATO-CU CONTINUED TO COVER THE FA EARLY THIS MORNING...WITH SNOW FLURRIES NOTED ACROSS THE KEVV TRI-STATE. THE RUC SHOWS THE BACK EDGE OF THE LOW CLOUDS MAKING IT INTO SE MISSOURI. HOWEVER THE FLOW AT 925 MB IS FORECAST TO BACK TO SW AND WEAKEN SLIGHTLY THROUGH 18Z. THEN THE MODELS PICK UP THE H9 FLOW AFT 18Z TO 10-20KTS. SO AM NOT SURE HOW FAR EAST THE BACK EDGE WILL PROGRESS. MEANWHILE...A LARGE AREA OF MID AND UPPER LEVEL MOISTURE WAS SEEN ON FOG IMAGERY AND WVAPOR IN ASSOC WITH A SHARP UPPER LEVEL TROF MOVG ESE FROM THE CENTRAL ROCKIES INTO THE CENTRAL AND SOUTHERN HIGH PLAINS. THE AXIS OF THE TROF WILL MOVE RAPIDLY ESE TODAY. IT SHOULD BE OVER LOWER AND MID MISSISSIPPI RIVER VALLEY REGIONS BY 00Z. SO WHILE WE MAY HAVE A WINDOW OF TIME WHERE THERE IS REDUCED CLOUD COVER...THINK MOST OF THE DAY WILL SEE CLOUDS. HARD TO FIGURE OUT WHERE TRACE PRECIP WILL END UP. BETTER DYNAMIC FORCING WILL PASS SOUTH OF THE FA LATE TODAY AND THIS EVENING...WHERE NUMERICAL POPS ARE SLIGHTLY HIGHER. HOWEVER THE MODELS CARRY BETTER MOISTURE TO THE NORTH ACROSS INTO CENTRAL ILLINOIS AND INDIANA. THEREFORE...DO NOT PLAN ON ALTERING OUR LOW PROB FOR SPRINKLES AT THIS TIME THIS AFTERNOON AND EVENING. DAY SHIFT CAN ADJUST AS NECESSARY. ANOTHER WAVE SEEN APPROACHING THE PACIFIC NW WILL MOVE RAPIDLY SE AND EVENTUALLY REACH THE MISSISSIPPI AND OHIO VALLEY REGIONS BY LATE FRIDAY...IN A SIMILAR FASHION TO WAVE NUMBER 1 LATE TODAY. AVAILABLE MOISTURE AGAIN A QUESTION MARK. GFS SHOWS MORE ROBUST COLUMNAR MOISTURE THAN THE NAM WITH THIS SYSTEM. WHAT WE HAVE NOW LOOKS FINE AND WILL NOT CHANGE. WILL KEEP THE SLIGHT CHC POP GOING ACROSS THE NORTH AND NORTHEAST FRIDAY AFTERNOON AND EVENING (MAYBE A MIX...BUT SHOULD BE LIGHT / MINIMAL NONE THE LESS). NO MODIFICATIONS WERE MADE BEYOND FRIDAY NIGHT TO THE POP / WX ELEMENTS. GUIDANCE AND SURROUNDING OFFICES WERE RUNNING WARMER FOR MAX TEMPS SATURDAY. GUIDANCE WAS NOT QUITE AS COLD SATURDAY NIGHT AND SUNDAY AS WELL. THEREFORE WE MADE SOME MINOR MODIFICATIONS TO ACCOUNT FOR THIS. && .AVIATION... BACK EDGE OF LOW CLOUDS WILL CONTINUE MOVING EAST ABOUT 15 KT ACROSS MISSOURI EARLY THIS MORNING. AT THIS RATE...CLEARING LINE SHOULD APPROACH THE MISSISSIPPI RIVER AROUND 18Z. KEVV/KOWB SITES FORECAST TO DECREASE THE LOWER CLOUDS AROUND 00Z. EXTENSIVE MID CLOUDS WILL FOLLOW...WITH CIGS AROUND 10K FEET OR HIGHER. WEST WINDS WILL CONTINUE TO SLOWLY DIMINISH THIS MORNING...THEN TURN LIGHT SOUTHERLY. NO VSBY ISSUES FORESEEN AT THIS TIME. && .PAH WATCHES/WARNINGS/ADVISORIES... KY...NONE. MO...NONE. IL...NONE. IN...NONE. && $$ ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CARIBOU ME 356 AM EST FRI FEB 8 2008 .SYNOPSIS... A TROUGH OF LOW PRESSURE WILL MOVE ACROSS THE REGION TODAY INTO TONIGHT. HIGH PRESSURE WILL BUILD OVER THE STATE ON SATURDAY. A LARGE STORM SYSTEM WILL APPROACH FROM THE GREAT LAKES SATURDAY NIGHT AND REDEVELOP ALONG THE COAST ON SUNDAY. THIS STORM SYSTEM IS THEN EXPECTED TO MOVE INTO THE CANADIAN MARITIMES ON MONDAY. && .NEAR TERM /THROUGH TONIGHT/... MAIN CHALLENGE WILL BE THE TEMPS THIS MORNING & SNOW TODAY INTO THE EVENING. USED A BLEND OF THE RUC13 AND SREF THIS MORNING AND THEN WENT W/33% BLEND OF THE NAM/GFS & SREF THIS AFTERNOON INTO TONIGHT. TEMPS CURRENTLY RUNNING MUCH BELOW MOS GUIDANCE ESP FOR THE NRN AREAS. SOME SITES RUNNING AT LEAST SOME 10 DEGS BELOW MOS PER 06Z OBS. STG INVERSION IN PLACE ATTM W/CLR SKIES TO COLDER TEMPS. LOCAL STUDY USING 925 DELTA T`S WORKING QUITE WELL FROM EVEVING CREW/S ADJUSTMENTS. TEMPS WILL START TO WARM AFT 12Z W/WEAK WAA PROGGED TO ARRIVE W/WEAK INVERTED TROF. WENT BELOW THE MOS GUIDANCE TODAY BASED ON PAST PERFORMANCE. CUT THE NUMBERS BACK ESP FOR THE N AND W BY SOME 3-5 DEGS. THEREFORE LOOKING AT UPPER TEENS LOWER 20S ACROSS THE N AND W AND MID-UPPER 20S DOWNEAST TO THE COAST. SATL IR IMAGERY SHOWING CLOUDS WORKING THEIR WAY NORTHWARD THIS MORNING AND PROGGED TO OVERSPREAD THE REGION BY MIDDAY. STARTED SKY GRIDS OFF W/THE LAPS AND THEN LOADED THE GFS SKY FOR TODAY. LIKED A 50/50 BLEND OF THE GFS/NAM12 FOR SKY CONDITIONS TONIGHT W/CNTL AND DOWNEAST AREAS BECMG PARTLY CLOUDY AFT 06Z. INVERTED SFC TROF TO MOVE THROUGH THE REGION TODAY TONIGHT. WEAK WAA AND LLVL CONVERGENCE IN CONJUNCTION W/MID-LVL FORCING WILL AID IN AREA OF LIGHT SNOW BREAKING OUT. THEREFORE...DECIDED ON LIKELY TO CATEGORICAL POPS FOR LIGHT SNOW THIS AFTERNOON AND THEN HAVE THE POPS DROPPING BACK TO CHC CATEGORY BY 06Z W/ERN AREAS HANGING ONTO 60% POPS AS LLVL CONVERGENCE FROM INVERTED SFC TROF AND UPPER LVL FORCING TO KEEP LIGHT SNOW GOING A WHILE LONGER. DAYCREW/S ASSESSMENT FOR QPF/SNOW AMOUNTS LOOKED PRETTY GOOD. TWEAKED THEM A BIT BASED ON LATEST HPC QPF GUIDANCE AND USING 12-15:1 RATIO WHICH SHOWS 1-2 INCH SNOWFALL AMTS W/HIGHER AMOUNTS FOR THE CNTL AND DOWNEAST AREAS. && .SHORT TERM /SATURDAY THROUGH MONDAY/... ANY LINGERING LIGHT SNOW ACROSS DOWNEAST SATURDAY MORNING ASSOCIATED WITH WEAK WARM ADVECTION AND WEAK TROF OF LOW PRESSURE WILL QUICKLY DIMINISH. EXPECT A BRIEF BREAK SATURDAY AFTERNOON BEFORE SNOW ASSOCIATED WITH THE WARM ADVECTION IN ADVANCE OF NEXT SYSTEM BEGINS TO OVERSPREAD THE REGION SATURDAY EVENING. MODELS CONTINUE TO ADVERTISE AN ELONGATED AREA OF LOW PRESSURE STRETCHING FROM NORTH OF THE GREAT LAKES TO NORTHERN ENGLAND TO AFFECT THE REGION ON SUNDAY. FORECAST CONFIDENCE CONTINUES TO BE HIGH WITH REGARD TO AREA SEEING AN ACCUMULATING SNOWFALL FROM LATER SATURDAY NIGHT THROUGH SUNDAY. WHAT IS UNCERTAIN IS WHETHER OR NOT THIS SYSTEM WILL CONSOLIDATE INTO A STRONGER LOW ACROSS THE GULF OF MAINE AND BE ABLE TO TAP INTO A BIT MORE IN THE WAY OF MOISTURE. CONSENSUS OF MODELS INCLUDING THE SREF SEEMS TO BE FOR SERIES OF WEAKER LOWS TO EVENTUALLY CONSOLIDATE INTO A BROAD AREA OF LOW PRESSURE JUST EAST OF THE STATE AND THEN TRACK TOWARD THE MARITIMES SUNDAY NIGHT WITH AN EXTENSION OF THIS TROUGH HANGING BACK ACROSS THE REGION THROUGH SUNDAY NIGHT. THIS WILL LIKELY RESULT IN A STEADY LIGHT/MODERATE SNOWFALL ACROSS THE REGION SATURDAY NIGHT INTO SUNDAY NIGHT. && .LONG TERM /MONDAY NIGHT THROUGH THURSDAY/... ACTIVE PATTERN WILL CONTINUE THROUGH THE PERIOD WITH THE POTENTIAL FOR A SIGNIFICANT STORM AROUND THE MIDDLE OF NEXT WEEK. ANY LINGERING SNOW SHOWERS WILL DIMINISH EARLY MONDAY AS LOW PRESSURE CONTINUES TO MOVE NORTHEAST AWAY FROM THE REGION. A NORTHWEST FLOW OF DRIER AIR WILL FOLLOW FOR LATER MONDAY AND MONDAY NIGHT AS HIGH PRESSURE BRIEFLY BUILD ACROSS THE REGION INTO EARLY TUESDAY. MODELS CONTINUE TO HINT AT THE POTENTIAL FOR A SYSTEM TO DEVELOP ACROSS THE EAST COAST EARLY NEXT WEEK. TIMING AND DETAILS ARE STILL UNCERTAIN OF COURSE THIS FAR OUT BUT THERE IS AT LEAST THE POTENTIAL FOR A SIGNIFICANT SNOW EVENT AROUND THE MIDDLE OF NEXT WEEK. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... NEAR TERM: VFR DOWNEAST GOING TO MVFR/IFR THIS MORNING AND HANGING ONTO THESE CONDITIONS INTO TONIGHT. VFR HANGING ON A WHILE LONGER THIS MORNING ACROSS THE NRN TAF SITES AND THEN CONDITIONS DROP TO MVFR W/-SN MOVING IN. WIDESPREAD MVFR/IFR CONDITIONS EXPECTED SATURDAY NIGHT THROUGH SUNDAY NIGHT IN SNOW. MAINLY VFR RETURNS MONDAY AS HIGH PRESSURE BRIEFLY BUILDS ACROSS. VFR SHOULD CONTINUE AT LEAST INTO EARLY TUESDAY. && .MARINE... NEAR TERM: EXTENDED THE SCA FOR HAZARDOUS SEAS TIL 17Z AS SEAS RUNNING ABOUT 1-2 FT ABOVE WNAWAVE. NICE SWELL ATTM W/PERIODS OF 11-12 SECONDS. NE WIND 15-20 KT WILL TURN ESE LATER THIS MORNING BUT WE ARE ANTICIPATING SPDS TO DROP BACK TO 10-15 KT BY AFTERNOON W/THE SWELL DROPPING BACK TO 3-5 FT W/THE EXCEPTION OF THE INTRA-COASTAL BAYS WHERE 2-3 FT SHOULD HOLD AS THE SWELL WILL BREAK UP AS IT HITS THE SHALLOWER WATER. SHORT TERM: NEXT CHANCE OF HEADLINES WILL BE LATER SUNDAY AND INTO MONDAY AS WINDS/SEAS INCREASE AS LOW PRESSURE MOVES NORTHEAST THROUGH THE MARITIMES. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL NOON EST TODAY FOR ANZ050-051. && $$ NEAR TERM...HEWITT SHORT TERM...DUDA LONG TERM...DUDA AVIATION...HEWITT MARINE...HEWITT/DUDA me AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CARIBOU ME 359 AM EST THU FEB 7 2008 .SYNOPSIS... LOW PRESSURE WILL SLIDE SOUTH OF THE REGION TODAY AS HIGH PRESSURE BUILDS OVER QUEBEC. THIS HIGH WILL SLIDE INTO THE MARITIMES TONIGHT INTO FRIDAY AS A WEAK TROUGH OF LOW PRESSURE MOVES THROUGH THE REGION. HIGH PRESSURE WILL RETURN TO THE STATE ON SATURDAY THEN A LARGER STORM SYSTEM MAY TAKE SHAPE OFF THE COAST SATURDAY NIGHT INTO SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... MAIN FOCUS WILL BE SNOW OVER INTERIOR DOWNEAST AND THE COAST TODAY WITH HOW MUCH AND HOW FAR NORTH WILL IT EXTEND. DECIDED TO TAKE A RUC13/NAM/GFS BLEND FOR TODAY. RUC13 MATCHING CLOSE TO THE 00Z NAM/GFS AND PRETTY CLOSE TO THE LATEST REGIONAL RADAR MOSAIC W/BANDS OF PRECIP IN THE FORM OF SNOW EXTENDING FROM SRN MAINE NE THROUGH INTERIOR DOWNEAST SECTIONS. RADAR LOOP SHOWING THESE BANDS EXPANDING IN AREAL COVERAGE. LOW PRES WILL SLIDE S OF THE GULF OF MAINE TODAY W/PRECIP SHIELD SHIFTING FURTHER TO THE SE BY THE AFTERNOON. KEPT THE SNOW ADVISORY GOING FOR MEZ015>017 AND 029-030 INTO THE AFTERNOON. ALSO...EXPANDING THE SNOW SHIELD INTO CNTL AREAS OF MEZ011-031-032 W/THE POTENTIAL FOR AROUND AN INCH OR SNOW ACCUMULATION THERE. FOR THE ADVISORY AREAS...WE ARE LOOKING FOR 3 TO 7 INCHES WITH THE HIGHEST AMOUNTS ON THE COAST. NAM AND GFS SNOW TOOLS PUMPING 7 TO 8 INCHES FROM BGR TO BHB BUT THEY APPEAR TO BE OVERDONE PER SOME REPORTS FROM GYX. DECIDED TO GO UNDER THESE AMOUNTS BY AN INCH OR SO. TEMPERATURES IN THE CNTL AND DOWNEAST AREAS WILL REMAIN STEADY FOR THE MOST PART TODAY. A BLEND OF THE GFS AND SREF WAS TAKEN FOR TONIGHT AS UPPER LVL DISTURBANCE IN CONJUNCTION W/A SFC TROF MOVES INTO THE REGION LATER TONIGHT. ATTM...WENT W/3-40% POPS FOR SNOW SHOWERS BEST FORCING APPEARS TO BE OVER THE W AND SRN AREAS. GMOS TEMPERATURES WERE LOADED BUT ONCE AGAIN WERE TWEAKED DOWNWARD ESP ACROSS THE N AND E WHERE CLOUDS WILL TAKE SOME TIME TO THICKEN. IN THESE AREAS...TEMPERATURES WILL DROP TO AROUND 5 DEGS OR SO BEFORE LEVELING OFF. .SHORT TERM /FRIDAY THROUGH SUNDAY/... SHORT WAVE PROGGED BY BOTH THE GFS AND NAM TO MOVE ACROSS THE FORECAST AREA DURING FRIDAY. THE SHORT WAVE WILL EXIT TO THE EAST FRIDAY NIGHT AS A WEAK RIDGE AXIS MOVES ACROSS THE REGION. THE FOCUS THEN TURNS TO THE POTENTIAL STORM SYSTEM LATER SATURDAY NIGH THROUGH SUNDAY AS AN UPPER LEVEL LOW TRACKS ACROSS NORTHERN NEW ENGLAND. GFS/EC/CAN GLOBAL MODELS ALL SHOWING LOW PRESSURE TRACKING EAST FROM NORTH OF THE GREAT LAKES ON SUNDAY. WHAT IS STILL NOT SO CERTAIN IS THE EVENTUAL REDEVELOPMENT OF THE SYSTEM SOMEWHERE ACROSS NORTHERN NEW ENGLAND. HAVE UTILIZED GMOS POPS SATURDAY/SATURDAY NIGHT. DECIDED TO BUMP POPS TO LIKELY ON SUNDAY SINCE GMOS LOOKED LOW WITH THE UPPER LEVEL LOW STILL ACROSS THE REGION. && .LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/... LOW PRESSURE WILL MOVE EAST AWAY FROM THE REGION SUNDAY NIGHT AND MONDAY WITH A NORTHWEST FLOW OF DRIER AIR EXPECTED. EXPECT ANOTHER CHANCE FOR SNOW SHOWERS EARLY NEXT WEEK AS LOW PRESSURE APPROACHES FROM THE WEST TUESDAY AND INTO WEDNESDAY, OVERALL IT APPEARS AS THE ACTIVE WILL PATTERN WILL CONTINUE. && .AVIATION /08Z THURSDAY THROUGH MONDAY/... NEAR TERM: VFR OVER THE REGION ATTM...BUT THINKING THAT IFR/MVFR CONDITIONS WILL OCCUR THIS MORNING ACROSS BGR AND BHB. THE N WILL KEEP VFR INTO THE AFTERNOON AND THEN THINKING HERE IS THAT MVFR CIGS WILL DEVELOP THIS AFTERNOON INTO TONIGHT ACROSS THE ENTIRE CWA. EXPECT THE CHANCE FOR SOME MVFR/IFR CONDITIONS FRIDAY AFTERNOON WITH PASSAGE OF THE SHORT WAVE. VFR FRIDAY NIGHT AND INTO SATURDAY. MVFR/IFR ONCE AGAIN POSSIBLE SATURDAY NIGHT THROUGH SUNDAY NIGHT IN SNOW/SNOW SHOWERS. VFR RETURNS FOR MONDAY WITH HIGH PRESSURE BUILDING ACROSS. && .MARINE... NEAR TERM: SCA WILL STAY UP TODAY AS WINDS/SEAS ALREADY RESPONDING W/SUSTAINED WINDS OUT THERE ATTM OF 20 KTS AND SEAS HITTING 5 FT. PREV GRIDS WERE RIGHT THERE AND ONLY MADE SLIGHT ADJUSTMENTS TO THEM FOR TODAY W/20-25 KT AND SEAS INCG TO 4-6 FT. A 50/50 BLEND OF THE NAM12/GFS WAS TAKEN FOR TONIGHT WHICH LEADS TO CONDITIONS GOING BELOW SCA THRESHOLDS. A SWELL IS POSSIBLE TONIGHT IN THE WAKE OF TH DEPARTING LOW. THIS WILL NEED TO BE WATCHED AS SEAS COULD STAY UP A BIT LONGER AND THIS WILL NEED TO BE MONITORED. SHORT TERM: NO HEADLINES FRIDAY INTO SATURDAY. POTENTIAL FOR SCA OR POSSIBLE GALE CONDITIONS SATURDAY NIGHT THROUGH SUNDAY. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...SNOW ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR MEZ015>017-029- 030. MARINE...SMALL CRAFT ADVISORY FROM 7 AM THIS MORNING TO 7 PM EST THIS EVENING FOR ANZ050>052. && $$ NEAR TERM...HEWITT SHORT TERM...DUDA LONG TERM...DUDA AVIATION...HEWITT MARINE...HEWITT/DUDA me AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 1055 PM EST FRI FEB 8 2008 .UPDATE... SFC LOW BEGINNING TO STRENGTHEN NOW AS IT LIFTS NORTHEAST INTO SOUTHERN WISCONSIN. LATEST SATELLITE DATA AND UPSTREAM OBSERVATIONS DEPICTING THE RESULTANT INCREASE IN LARGE SCALE ACCENT...WITH COOLING CLOUD TOPS AND AN EXPANSION IN LGT PCPN REPORTS ACROSS EASTERN IL. MORE PRONOUNCED WARM AIR ADVECTION IN CLOSER PROXIMITY TO THE SFC FEATURE ALLOWING THE LOW LEVEL THERMAL PROFILE TO WARM ENOUGH FOR ALL RAIN AS FAR NORTH AS EXTREME SOUTHEAST WISCONSIN. THIS REMAINS A CONCERN LOCALLY TONIGHT... MAINLY ACROSS THE SOUTHERN TIER...AS THIS MOISTURE TRANSLATES NORTHEAST INTO THE AREA LATE TONIGHT. SFC TEMPERATURES PER LATEST OBSERVATIONS CONTINUE TO HOVER AROUND FREEZING...WITH LOCATIONS JUST SOUTH INTO THE TOLEDO AREA NOW IN THE 33-35F RANGE. CHECK OF THE LATEST 00Z NAM SOUNDING DATA INDICATES A BOUNDARY LAYER THAT IS AT LEAST MARGINALLY SUPPORTIVE OF RAIN MIX WITH THE SNOW FROM ROUGHLY ANN ARBOR-DETROIT SOUTHWARD. THUS...WILL INTRODUCE A RAIN/SNOW MIX FOR AFTER 09Z ACROSS THIS CORRIDOR. A DEEP SATURATED LAYER AND MODEST FORCING CONTINUES TO SUPPORT ACCUMULATIONS OF 1 TO 2 INCHES BETWEEN ROUGHLY 09-14Z EARLY THIS MORNING...ESPECIALLY FROM I-69 NORTH WHERE THE THERMAL PROFILE WILL CLEARLY REMAIN SUPPORTIVE OF ALL SNOW AND WHERE MORE PRONOUNCED FORCING WILL EXIST. WILL CUT INTO AMOUNTS SLIGHTLY ACROSS THE OHIO BORDER COUNTIES GIVEN THE HIGHER POTENTIAL FOR SOME MIXING BASED ON CURRENT AND UPSTREAM THERMAL TRENDS. && .PREV DISCUSSION...ISSUED 630 PM EST FRI FEB 8 2008 AVIATION... MVFR STRATUS DECK WILL REMAIN IN PLACE ACROSS SOUTHEAST LOWER MICHIGAN THROUGH THE DURATION OF THE TAF PERIOD. BACK EDGE OF AN AREAS OF LGT SNOW SHOWERS ASSOCIATED WITH A WEAK UPPER LEVEL IMPULSE WILL TAPER OFF AT FNT/MBS BY 02Z...BRINGING VISIBILITY BACK INTO VFR FOR THE DURATION OF THE EVENING. WEAK WARM AIR ADVECTION AHEAD OF A STRONGER SYSTEM WILL HELP SPREAD ANOTHER ROUND OF LIGHT SNOW ACROSS ALL TERMINALS DURING THE EARLY/MID MORNING HOURS. STRONG LIFT AND DEEPER MOISTURE WILL BE LACKING... AND THUS EXPECT VISIBILITY TO HOLD AT MVFR DURING THIS TIME. SOUTHWEST WINDS WILL STRENGTHEN DURING AFTERNOON/EVENING BEHIND AN INITIAL COLD FRONT...WITH GUSTS OVER 20 KNOTS. PREV DISCUSSION...ISSUED 348 PM EST FRI FEB 8 2008 SHORT TERM...THIS AFTERNOON AND TONIGHT VERY LIGHT SNOW ACTIVITY CONTINUES TO SWEEP ACROSS SOUTHEASTERN MICHIGAN THIS AFTERNOON...WITH CURRENT LOCATION ACROSS THE TRI CITIES AND THUMB. THIS AREA OF SNOW IS ASSOCIATED WITH LIFT ALONG LEADING THETA E BUBBLE AND EMBEDDED SHORTWAVE ENERGY THE RUC HAS A GREAT HANDLE ON. KDTX RADAR IS GIVING THE DRIZZLE LOOK BEHIND THIS SNOW ACTIVITY AND EXPECTING THIS TO CONTINUE WITH THE SATURATED LOWER TROPOSPHERE. HAVE CUT THE POPS THIS EVENING BACK DOWN TO CHANCE AS METARS HAVE BEEN COMING IN ONLY A TRACE. DESPITE TEMPERATURES A TOUCH BELOW FREEZING...NOT EXPECTING ANY LARGE HEADACHES DUE TO FREEZING DRIZZLE AS AREA ROADWAYS SHOULD BE HEAVILY TREATED AND TEMPERATURES SHOULD LARGELY HOLD STEADY JUST UNDER THE FREEZING MARK. DESPITE WEAK CONTINUED WARMING...MODEL GUIDANCE IS BULLISH ON ALL SNOW MENTION LATER TONIGHT IN THE BUFFER SOUNDINGS AND IN AGREEMENT WITH THE AMOUNT OF COLD AIR IN RESIDENCE NORTH OF THE IOWAN SURFACE REFLECTION. TWO WEAK SHORTWAVES...ONE OVER NORTHERN MINNESOTA...THE OTHER OVER CENTRAL PLAINS WILL MERGE OVER MICHIGAN TONIGHT IN QUASI-CONFLUENT FLOW. THIS RESULTS IN A SURFACE LOW TRACK FROM SOUTHERN WISCONSIN...NORTHEASTWARD TO FRANKFORT MICHIGAN BY THE END OF THE PERIOD. AM FAIRLY IMPRESSED WITH THE THERMODYNAMICS OVERNIGHT AS LOW STATIC STABILITY EXISTS FROM 900MB UPWARD. GIVEN MOIST LOWER TROPOSPHERIC ENVIRONMENT...FEEL THERE ARE NO NEGATIVE ISSUES REGARDING MOISTURE. ON THE OTHER HAND...SYNOPTIC SCALE DYNAMICS ARE FAIRLY LACKLUSTER...GIVEN RAGGED APPEARANCE TO MIDLEVEL VORTS...LACK OF ANY OBVIOUS JET DYNAMICS...AND WEAK MODELED FRONTOGENESIS. SO IT APPEARS...FORCING FOR SNOW WILL BE TIED STRICTLY TO 285K ISENTROPIC LIFT/WARM AIR/MOISTURE ADVECTION. WITH THE A LACK OF AN INVERSION...AN EXPECTED SATURATED ATMOSPHERE THROUGH 400MB...THERE IS A GOOD SHOT AT MEASURABLE SNOWFALL. EXPECTATIONS ARE FOR 1 TO 2 INCHES OF ACCUMULATION FOR EVERYONE WITH ISOLATED 3 INCH AMOUNTS (BEST BET UP NORTH CLOSER TO SURFACE LOW). HAVE SLOWED THE ONSET...AFTER 6Z...WITH THE HEAVIEST ACTIVITY FROM 9-12Z. DID DROP LOWS A COUPLE OF DEGREES AS WET BULB PROCESSES SHOULD ALLOW A QUICK DROP IN TEMPS ONCE THE HEAVIER SNOWS MOVE IN...AT OR JUST UNDER 30 DEGREES. LONG TERM...SATURDAY THROUGH FRIDAY THE MAIN FORECAST CONCERN FOR THIS WEEKEND CONTINUES TO BE WITH THE SHOT OF ARCTIC AIR POISED TO INFILTRATE THE GREAT LAKES SATURDAY NIGHT AND SUNDAY AND THE ASSOCIATED STRONG WINDS AND DANGEROUSLY COLD WIND CHILLS. THE UPPER WAVE CURRENTLY OVER BRITISH COLUMBIA IS STILL FORECAST TO RACE INTO THE WESTERN GREAT LAKES BY SATURDAY EVENING PER 12Z MODEL SUITE AND DEVELOP INTO A CUT OFF CIRCULATION BY SUN MORNING. THE ASSOCIATED SURFACE LOW IS FORECAST TO DEEPEN OVER NORTHERN MINNESOTA ON SATURDAY...THEN MERGE WITH THE SURFACE LOW LIFTING ACROSS NORTHERN MICHIGAN SATURDAY EVENING. WEAK SURFACE RIDGING AND MID LEVEL DRYING SHOULD END THE SNOWFALL BY LATE SATURDAY MORNING. LIFT ASSOCIATED WITH THE NEXT UPPER WAVE HOWEVER WILL BRING A QUICK SHOT OF LIFT SATURDAY EVENING...LIKELY LEADING TO BRIEF YET INTENSE BURST OF SNOW SHOWER ACTIVITY. THE COLD FRONT ASSOCIATED WITH THE DEEPENING LOW TO THE NORTHEAST OF THE STATE WILL QUICKLY RACE ACROSS SE MI SATURDAY EVENING. THE 12Z UPPER AIR ANALYSIS SHOWED VERY COLD AIR ACROSS NORTHWEST CANADA. THIS AIRMASS WILL QUICKLY GET ADVECTED INTO THE GREAT LAKES SATURDAY NIGHT IN THE WAKE OF THE SURFACE COLD FRONT. 850 MB TEMPS ARE STILL FORECAST TO DROP FROM AROUND -8C 00Z SUN TO AROUND -25C BY 12Z SUN. A DECENT ISALLOBARIC COUPLET WILL ACCOMPANY THE SURFACE FRONT THROUGH THE STATE SAT EVENING. MODEL CROSS SECTIONS OF POTENTIAL TEMPERATURE AND OMEGA INDICATE A GOOD POTENTIAL FOR DOWNWARD MOMENTUM TRANSPORT WITHIN STRONG MID LEVEL SUBSIDENCE EARLY SUNDAY MORNING...WITH MODEL SOUNDINGS INDICATING THE POTENTIAL FOR 40 TO 45 KNOT WINDS TO MIX DOWN TO THE SURFACE. THUS WIND GUSTS OF 40 TO 50 MPH SEEM LIKELY SATURDAY NIGHT INTO SUNDAY MORNING. THE ARCTIC AIRMASS WILL DROP TEMPS INTO THE SINGLE DIGITS BY SUNDAY MORNING...WITH LITTLE RECOVERY EXPECTED DURING THE AFTERNOON. THESE TEMPS COMBINED WITH THE STRONG WINDS WILL PRODUCE WIND CHILL READINGS OF 10 TO 20 BELOW ZERO THROUGH THE DAY SUNDAY. EXPECT THERE WILL BE SOME BLOWING SNOW. THIS MAY HOWEVER NOT BE TOO SIGNIFICANT A HAZARD GIVEN THE HIGH WATER CONTENT OF THE SNOW PACK. THE UPPER LOW AND ARCTIC AIRMASS ARE EXPECTED TO BE SHORT LIVED IN THIS FAST PROGRESSIVE FLOW. SURFACE HIGH PRESSURE BUILDING INTO THE REGION SUNDAY NIGHT SHOULD STILL HOWEVER ALLOW TEMPS TO DROP BELOW ZERO IN MANY PLACES BEFORE TEMPERATURES BEGIN MODERATING EARLY NEXT WEEK. THE 12Z MODEL SUITE HAVE COME INTO A LITTLE BETTER AGREEMENT WITH RESPECT TO THE NEXT WAVE FORECAST TO AMPLIFY OVER THE PLAINS MONDAY AND MONDAY NIGHT. THE GFS...ECMWF...UKMET AND CANADIAN ALL DEPICT SOME LIFT ASSOCIATED WITH LOW LEVEL WARM AIR ADVECTION MONDAY NIGHT. FAVORABLE ENTRANCE REGION JET DYNAMICS SHOULD ALSO ALLOW SOME MID TROPOSPHERIC FRONTOGENESIS. THUS HAVE INCREASED THE CHANCES OF SNOW MONDAY NIGHT. AT THIS STAGE SOME ACCUMULATIONS...POSSIBLY EVEN ADVISORY CRITERIA...ARE POSSIBLE MONDAY NIGHT. THE GFS AND CANADIAN ARE FARTHER NORTH WITH THE ASSOCIATED SURFACE LOW TUESDAY. GIVEN THE UPPER AIR PATTERN...PREFER THE MORE SOUTHERLY ECMWF TRACK...WHICH KEEPS SOUTHEAST MICHIGAN WITHIN THE COLDER AIR...INDICATING ANY LINGERING PRECIP WILL BE IN THE FORM OF SNOW. TEMPS SHOULD CONTINUE TO MODERATE TO NEAR NORMAL BY MID WEEK AS HEIGHTS BUILD IN THE WAKE OF THE DEPARTING UPPER TROUGH. MARINE... MARINE INTERESTS WILL BE FOCUSED ON THE IMPENDING ARCTIC COLD FRONT PASSAGE SATURDAY NIGHT. DEEPENING LOW PRESSURE TO THE NORTHEAST OF LAKE HURON SUNDAY NIGHT WILL DRIVE THE FRONT THROUGH THE REGION. VERY STRONG COLD AIR ADVECTION BEHIND THIS FRONT...COMBINED WITH A STRENGTHENING PRESSURE GRADIENT WILL LEAD TO GALE FORCE WINDS SATURDAY NIGHT THROUGH THE DAY SUNDAY. GUSTS WILL ACTUALLY APPROACH 45 KNOTS ON THE OPEN WATERS OF LAKE HURON ON SUNDAY. IF CURRENT MODEL TRENDS HOLD...MAY ACTUALLY HAVE TO UPGRADE TO STORM WARNINGS OVER PORTIONS OF LAKE HURON. THIS FRONT WILL USHER IN AN ARCTIC AIRMASS...WHICH WILL LEAD TO SIGNIFICANT FREEZING SPRAY. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON... HEAVY FREEZING SPRAY WARNING...LHZ361-LHZ362-LHZ363-LHZ462-LHZ463- LHZ464...FROM 7 PM SATURDAY TO 7 PM SUNDAY. GALE WARNING...LHZ361-LHZ362-LHZ363-LHZ421-LHZ422-LHZ441-LHZ442- LHZ443-LHZ462-LHZ463-LHZ464...FROM 7 PM SATURDAY TO 7 PM SUNDAY. LAKE ST CLAIR... GALE WARNING...FROM 7 PM SATURDAY TO 7 PM SUNDAY. MI WATERS OF LAKE ERIE... GALE WARNING...FROM 7 PM SATURDAY TO 7 PM SUNDAY. && $$ UPDATE.......MR AVIATION.....MR SHORT TERM...CB LONG TERM....SC MARINE.......SC YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE). mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 1008 PM EST FRI FEB 8 2008 .UPDATE... FCST FOR THE OVERNIGHT APPEARS TO BE IN GOOD SHAPE. WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A SHORTWAVE OVER THE UPPER AND MID MISSISSIPPI VALLEY. PCPN ASSOCIATED WITH THIS SYSTEM HAS BEEN GRADUALLY INCREASING IN COVERAGE THIS EVENING. PER 00Z RUC... ISENTROPIC ASCENT ON THE 285K THETA SFC IS BEING MAXIMIZED IN ERN WI AND THAT IS WHERE RADARS SHOW THE BEST RADAR RETURNS. ANOTHER ARC OF -SN HAS BEEN GRADUALLY INCREASING ACROSS CNTRL WI JUST N OF VORT MAX TRACK (DEFORMATION ZONE). TRACK OF SHORTWAVE AND ISENTROPIC ASCENT PER 00Z RUC AND EXTRAPOLATION OF -SN CURRENTLY OVER WI SUGGEST ROUGHLY THE SE HALF OF THE FCST AREA WILL SEE SOME -SN OVERNIGHT. MOST PERSISTENT -SN WILL BE TOWARD LAKE MICHIGAN WHERE BEST ISENTROPIC ASCENT WILL OCCUR. INHERITED FCST HAS THIS COVERED WELL. LOOKS LIKE ABOUT 1 TO 1.5 INCHES SHOULD COVER SNOW AMOUNTS CLOSE TO LAKE MICHIGAN. && .PREV DISCUSSION (ISSUED AT 355 PM EST)... ...BLIZZARD CONDITIONS POSSIBLE IN NORTHWEST FLOW SNOWBELTS SATURDAY EVENING INTO SUNDAY... SYNOPSIS... 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A SPLIT FLOW ACRS NAMERICA WITH TROFFING IN THE ARCTIC AND POLAR BRANCHES CENTERED NEAR HUDSON BAY/THE MS RIVER VALLEY. POLAR BRANCH SHRTWV NOTED MOVING INTO WI SUPPORTING AN AREA OF -SN FM CNTRL MN INTO NW WI WHERE MOIST 12Z MPX SDNG SUGS ATMOSPHERE IS SATURATED ENUF TO SUPPORT PCPN. EARLIER TAMDAR SDNG FM SAW SHOWED A VERY DRY LYR BTWN H9-7...SO LTL GOING ON LOCALLY WITH WEAK RDG OVHD...JUST SOME MID AND HI CLD NOTED ASSOCIATED WITH THE SHRTWV TO THE SW. FARTHER UPSTREAM...A MORE POTENT SHRTWV NOTED DIGGING INTO BRITISH COLUMBIA. H3 WIND SPEEDS APRCHG 150KT NOTED WITHIN UPR JET CORE ACCOMPANYING THIS SYS AND ORIENTED ALG SHARP GRADIENT OF H3 HGT RISES. SHORT TERM (TONIGHT AND SATURDAY)... MAIN FORECAST CONCERN TNGT IS POTENTIAL SN ASSOCIATED WITH SHRTWV NOW DRIFTING THRU THE UPR MIDWEST. FOCUS FOR SAT SHIFTS TO TIMING/ IMPACT OF POTENT SHRTWV NOW OVER BRITISH COLUMBIA...SPECIFICALLY SN/AND ONSET OF POTENTIALLY BLIZZARD CONDITIONS AT LEAST OVER THE W. FOR TNGT INTO SAT MRNG...LO PRES OVER THE UPR MIDWEST FCST TO DRIFT INTO NRN LK MI BY 12Z SAT. ISENTROPIC LIFT/MOISTENING ON THE 280-285K SFCS (H65-8) FCST TO IMPACT MAINLY THE SE HALF OF THE CWA IN ADVANCE OF THIS LO. SINCE THERE MAY ALSO BE SOME MOISTENING OFF LI MI...OPTED TO BUMP UP POPS TO LIKELY NEAR THE LK MI SHORE FM LATE TNGT INTO SAT MRNG BEFORE THE SFC LO/ISENTROPIC LIFT TRACKS TO THE NE AND A WEAK RDG AXIS MOVES OVHD IN ITS WAKE. 1-2G/KG SPECIFIC HUMIDITY NOTED IN THE H7-75 LYR...SO EXPECT AS MUCH AS 2 INCHES OF SN TO FALL DURING THE 9 HR PD OF PCPN IN THIS AREA. EXPECT LTL SN TO THE NW WITH RDG AXIS BTWN LO PRES AREA AND APRCHG COLD FNT ASSOCIATED WITH BRITISH COLUMBIA SHRTWV. ON SAT AFTN...GUIDANCE HAS TRENDED A BIT SLOWER WITH ARRIVAL OF BRITISH COLUMBIA SHRTWV AND ARCTIC FNT...WHICH NOW LOOKS TO REACH IWD JUST ARND 19Z AND THEN P53-ESC ARND 00Z. SHARP PRES RISE/CAD BEHIND THE BNDRY IN CONCERT WITH 45KT WINDS IN THE MIXED LYR WHERE LAPSE RATES WL BE ENHANCED BY THE STRONG CAD SUG SUBSTANTIAL MIXING TO THE SFC...SO LOOK FOR GUSTY WINDS/BLSN TO DVLP QUICKLY AFT FROPA AS TEMPS FALL. ATMOSPHERE WL BE RATHER DRY (PWAT AOB 0.25 INCH)...SO A WHOLE LOT OF SN NOT ON TAP WITH QUICK MOVING FNT EVEN THOUGH VIGOROUS 12Z HR H5 HGT FALLS UP TO 100M/DIFFLUENT UPR FLOW WL TEND TO SQUEEZE OUT THE MEAGER MSTR AVBL. THERE WL BE SOME ENHANCEMENT OVER THE HIER TERRAIN OF THE W...WHERE A COUPLE OF INCHES WL LIKELY FALL BEFORE 24Z. LONG TERM (SATURDAY NIGHT THROUGH NEXT FRIDAY)... LOW PRESSURE SHIFTS JUST NORTH OF SAULT STE MARIE SATURDAY EVENING LEAVING 25-30MB PRESSURE GRADIENT ACROSS NORTHERN UPR MI AND LK SUPERIOR. STRONG BURST OF 20-30MPH WITH GUSTS TO 45 MPH WINDS IN WAKE OF ARCTIC FRONT (AIDED BY 10MB/6HR PRESSURE RISE) SHOULD SWEEP INTO THE EASTERN CWA BY LATE EVENING. AFTERWARD...STRONG WINDS THROUGH THE NIGHT ARE A FUNCTION OF TIGHT PRESSURE GRADIENT MAINTAINING THROUGH 12Z SUN. H95-H85 WINDS FM WEST TO NORTHWEST ALLOW MOST CONCENTRATED CONVERGENCE AND LK EFFECT SNOW SHOWERS TO MOVE INTO ONTONAGON TO BEGIN THE EVENING AND IN THE SNOWBELTS EAST OF MUNISING AFTER LATE SAT EVENING. H85 TEMPS LOWERING BLO -20C IN THE MIXED LAYER LEAD TO VERY SMALL SNOWFLAKE SIZE WHICH WON`T BE SUITABLE FOR LARGE ACCUMS...BUT WILL BE VERY EFFICIENT IN YIELDING SEVERELY REDUCED VSBY OVER KEWEENAW PENINSULA INTO ONTONAGON COUNTY AND IN ALGER THROUGH LUCE COUNTIES IN THE NE CWA. A CONCERN ON KEWEENAW IS A MORE WNW WIND DIRECTION WHICH MAY SHUT OFF THE MORE CONCENTRATED SNOW SHOWERS NORTH OF CALUMET AFTER THE INITIAL SURGE OF SNOW/WIND EARLY SATURDAY EVENING DUE TO SHADOW FM ISLE ROYALE. AREAS WHERE THE MAX LIFT IS PRESENT IN THE -12C TO -18C (BETTER SNOW GROWTH) LAYER ALSO INDICATE THIS TREND WITH MAXIMUM VALUES OVR ONTONAGON AND ALGER/LUCE COUNTIES. SINCE AM NOT QUITE SURE HOW KEWEENAW COUNTY WILL WORK OUT AFTER THE EVENING FOR THE MEETING OF BLIZZARD CONDITIONS WILL OPT TO KEEP BLIZZARD WATCH GOING. PREVIOUS SET TIMES FOR THE BLIZZARD WATCHES LOOKED FINE. ISSUED A WINTER STORM WATCH FOR SOUTHERN HOUGHTON AND NORTHERN SCHOOLCRAFT ZONES DUE TO STRONG WINDS BLOWING THE LK EFFECT SNOW BANDS FARTHER INLAND/SIGNIFICANT BLOWING SNOW AND VERY LOW WIND CHILLS. SPEAKING OF THE WIND CHILLS ADDED MENOMINEE AND DELTA INTO THE GOING WIND CHILL WATCH. EVENTUALLY SOME TYPE OF HEADLINE...BE IT WIND CHILL ADVY OR WINTER WEATHER ADVY (SNOW/BLSN/WIND CHILL COMBO)... WILL BE NEEDED FOR ALL REMAINING AREAS OF THE CWA SATURDAY NIGHT INTO SUNDAY. LOW PRESSURE SYSTEM EXITS INTO QUEBEC BY LATE SUNDAY WITH LK EFFECT SNOW AND SOME BLOWING SNOW DIMINISHING OVER THE NW SNOW BELTS BY SUNDAY EVENING. WINDS BECOME VARIABLE SUNDAY NIGHT AWAY FM THE NW WINDS CLOSER TO LAKE SUPERIOR AND THIS SHOULD ALLOW FOR PARTIAL CLEARING AND PLUMMETING TEMPS OVR WEST INTERIOR. FOLLOWING HPC PREFERENCE OF ECMWF IN THE UPCOMING WEEK RESULTS IN WEAK LOW PRESSURE WITH SOME LIGHT SNOW AFFECTING GREAT LAKES MON-TUE. HIGHEST CHANCES IN THE CWA APPEAR OVR SOUTHERN SECTIONS. ANOTHER LOW PRESSURE SYSTEM AFFECTS THE REGION ON THU. GFS MORE EMPHATIC IN BRINGING ANOTHER SHOT OF ARCTIC AIR BY LATE WEEK BUT ECMWF NOT AS AMPLIFIED. CONFIDENCE IN EXTENDED NOT HIGH AS THERE ARE SIGNIFICANT DISAGREEMENTS BTWN THE GFS AND ECMWF AND ENSEMBLES NOT POINTING TO ANY ONE DIRECTION EITHER. TEMPS NEAR CLIMO/HPC GUIDANCE ARE PREFERRED FOR NOW. && .AVIATION (FOR THE 00Z TAF ISSUANCE)... AT KCMX...CLOUDS SHOULD REMAIN VFR THRU THE NIGHT DUE TO THE LACK OF LOW-LEVEL MOISTURE ADVECTION. EXPECT FOG TO DEVELOP BY MID TO LATE EVENING. HOWEVER...WITH MID/HIGH CLOUD DECK OVERHEAD...VIS SHOULD NOT DROP BLO MVFR. MVFR CIGS SHOULD DEVELOP SAT MORNING AS SW WINDS AHEAD OF APPROACHING ARCTIC COLD FRONT ADVECT LOW-LEVEL MOISTURE (WIDESPREAD MVFR CIGS ARE PRESENT OVER MN RIGHT NOW) INTO THE AREA. STRONG/SHARP ARCTIC COLD FRONT PASSING THRU KCMX LATE IN THE AFTN WILL BRING A RAPID FALL TO VLIFR CONDITIONS IN SN/BLSN. VLIFR CONDITIONS SHOULD PREVAIL WELL BEYOND THIS FCST PERIOD INTO SUN MORNING. AT KSAW...EXPECT VFR CONDITIONS TO GIVE WAY TO MVFR BY LATE EVENING...THEN IFR CIGS/MVFR VIS OVERNIGHT AS PERSISTENT LIGHT S FLOW AHEAD OF WEAK SFC LOW MOVING THRU THE UPR MIDWEST GRADUALLY DRAWS MORE MOISTURE INTO THE AREA. AS THE LOW APPROACHES LATER IN THE NIGHT...EXPECT A PERIOD OF -SN WITH IFR VIS/CIGS PREDOMINATING. CONDITIONS WILL IMPROVE SOME SAT MORNING INTO THE AFTN...BUT DO NOT EXPECT CONDITIONS TO IMPROVE ABOVE MVFR. STRONG/SHARP ARCTIC COLD FRONT ARRIVING LATE AFTN WILL DROP VIS TO IFR IN A PERIOD OF -SN. && .MARINE (FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)... EXPECT NW GALES TO DVLP OVER WRN LK SUP BEHIND STRONG COLD FNT ON SAT AFTN AND THEN OVERSPREAD THE ENTIRE LK BY EARLY EVNG. STORM FORCE WINDS LOOK LIKE A GOOD POSSIBILITY LATER SAT NGT/EARLY SUN IN SHARP CYC NW FLOW BEHIND DEEP LO PRES MOVING INTO SE CAN BEFORE LO MOVES QUICKLY AWAY AND PRES GRADIENT SLACKENS SUN AFTN. RELATIVELY LGT WINDS WL PREVAIL MON THRU WED WITH NEXT DEEPER LO FCST TO TRACK WELL TO THE S EARLY NEXT WEEK. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... BLIZZARD WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY AFTERNOON FOR MIZ001>003. WIND CHILL WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY AFTERNOON FOR MIZ009>013. WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING FOR MIZ085. WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY AFTERNOON FOR MIZ084. BLIZZARD WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING FOR MIZ006-007. LAKE SUPERIOR... GALE WARNING FROM 9 PM SATURDAY TO 6 PM EST SUNDAY FOR LSZ267. GALE WARNING FROM 6 PM SATURDAY TO 6 PM EST SUNDAY FOR LSZ266. GALE WARNING FROM 5 PM SATURDAY TO 4 PM EST SUNDAY FOR LSZ264- 265. GALE WARNING FROM 1 PM SATURDAY TO 10 AM EST SUNDAY FOR LSZ162-263. LAKE MICHIGAN...NONE. && $$ UPDATE...ROLFSON SYNOPSIS/SHORT TERM...KC LONG TERM...JLA AVIATION...ROLFSON MARINE...KC mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 643 PM EST FRI FEB 8 2008 UPDATED AVIATION DISCUSSION FOR 00Z TAFS ...BLIZZARD CONDITIONS POSSIBLE IN NORTHWEST FLOW SNOWBELTS SATURDAY EVENING INTO SUNDAY... .SYNOPSIS (ISSUED AT 355 PM EST)... 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A SPLIT FLOW ACRS NAMERICA WITH TROFFING IN THE ARCTIC AND POLAR BRANCHES CENTERED NEAR HUDSON BAY/THE MS RIVER VALLEY. POLAR BRANCH SHRTWV NOTED MOVING INTO WI SUPPORTING AN AREA OF -SN FM CNTRL MN INTO NW WI WHERE MOIST 12Z MPX SDNG SUGS ATMOSPHERE IS SATURATED ENUF TO SUPPORT PCPN. EARLIER TAMDAR SDNG FM SAW SHOWED A VERY DRY LYR BTWN H9-7...SO LTL GOING ON LOCALLY WITH WEAK RDG OVHD...JUST SOME MID AND HI CLD NOTED ASSOCIATED WITH THE SHRTWV TO THE SW. FARTHER UPSTREAM...A MORE POTENT SHRTWV NOTED DIGGING INTO BRITISH COLUMBIA. H3 WIND SPEEDS APRCHG 150KT NOTED WITHIN UPR JET CORE ACCOMPANYING THIS SYS AND ORIENTED ALG SHARP GRADIENT OF H3 HGT RISES. && .SHORT TERM (TONIGHT AND SATURDAY ISSUED AT 355 PM EST)... MAIN FORECAST CONCERN TNGT IS POTENTIAL SN ASSOCIATED WITH SHRTWV NOW DRIFTING THRU THE UPR MIDWEST. FOCUS FOR SAT SHIFTS TO TIMING/ IMPACT OF POTENT SHRTWV NOW OVER BRITISH COLUMBIA...SPECIFICALLY SN/AND ONSET OF POTENTIALLY BLIZZARD CONDITIONS AT LEAST OVER THE W. FOR TNGT INTO SAT MRNG...LO PRES OVER THE UPR MIDWEST FCST TO DRIFT INTO NRN LK MI BY 12Z SAT. ISENTROPIC LIFT/MOISTENING ON THE 280-285K SFCS (H65-8) FCST TO IMPACT MAINLY THE SE HALF OF THE CWA IN ADVANCE OF THIS LO. SINCE THERE MAY ALSO BE SOME MOISTENING OFF LI MI...OPTED TO BUMP UP POPS TO LIKELY NEAR THE LK MI SHORE FM LATE TNGT INTO SAT MRNG BEFORE THE SFC LO/ISENTROPIC LIFT TRACKS TO THE NE AND A WEAK RDG AXIS MOVES OVHD IN ITS WAKE. 1-2G/KG SPECIFIC HUMIDITY NOTED IN THE H7-75 LYR...SO EXPECT AS MUCH AS 2 INCHES OF SN TO FALL DURING THE 9 HR PD OF PCPN IN THIS AREA. EXPECT LTL SN TO THE NW WITH RDG AXIS BTWN LO PRES AREA AND APRCHG COLD FNT ASSOCIATED WITH BRITISH COLUMBIA SHRTWV. ON SAT AFTN...GUIDANCE HAS TRENDED A BIT SLOWER WITH ARRIVAL OF BRITISH COLUMBIA SHRTWV AND ARCTIC FNT...WHICH NOW LOOKS TO REACH IWD JUST ARND 19Z AND THEN P53-ESC ARND 00Z. SHARP PRES RISE/CAD BEHIND THE BNDRY IN CONCERT WITH 45KT WINDS IN THE MIXED LYR WHERE LAPSE RATES WL BE ENHANCED BY THE STRONG CAD SUG SUBSTANTIAL MIXING TO THE SFC...SO LOOK FOR GUSTY WINDS/BLSN TO DVLP QUICKLY AFT FROPA AS TEMPS FALL. ATMOSPHERE WL BE RATHER DRY (PWAT AOB 0.25 INCH)...SO A WHOLE LOT OF SN NOT ON TAP WITH QUICK MOVING FNT EVEN THOUGH VIGOROUS 12Z HR H5 HGT FALLS UP TO 100M/DIFFLUENT UPR FLOW WL TEND TO SQUEEZE OUT THE MEAGER MSTR AVBL. THERE WL BE SOME ENHANCEMENT OVER THE HIER TERRAIN OF THE W...WHERE A COUPLE OF INCHES WL LIKELY FALL BEFORE 24Z. .LONG TERM (SATURDAY NIGHT THROUGH NEXT FRIDAY)... LOW PRESSURE SHIFTS JUST NORTH OF SAULT STE MARIE SATURDAY EVENING LEAVING 25-30MB PRESSURE GRADIENT ACROSS NORTHERN UPR MI AND LK SUPERIOR. STRONG BURST OF 20-30MPH WITH GUSTS TO 45 MPH WINDS IN WAKE OF ARCTIC FRONT (AIDED BY 10MB/6HR PRESSURE RISE) SHOULD SWEEP INTO THE EASTERN CWA BY LATE EVENING. AFTERWARD...STRONG WINDS THROUGH THE NIGHT ARE A FUNCTION OF TIGHT PRESSURE GRADIENT MAINTAINING THROUGH 12Z SUN. H95-H85 WINDS FM WEST TO NORTHWEST ALLOW MOST CONCENTRATED CONVERGENCE AND LK EFFECT SNOW SHOWERS TO MOVE INTO ONTONAGON TO BEGIN THE EVENING AND IN THE SNOWBELTS EAST OF MUNISING AFTER LATE SAT EVENING. H85 TEMPS LOWERING BLO -20C IN THE MIXED LAYER LEAD TO VERY SMALL SNOWFLAKE SIZE WHICH WON`T BE SUITABLE FOR LARGE ACCUMS...BUT WILL BE VERY EFFICIENT IN YIELDING SEVERELY REDUCED VSBY OVER KEWEENAW PENINSULA INTO ONTONAGON COUNTY AND IN ALGER THROUGH LUCE COUNTIES IN THE NE CWA. A CONCERN ON KEWEENAW IS A MORE WNW WIND DIRECTION WHICH MAY SHUT OFF THE MORE CONCENTRATED SNOW SHOWERS NORTH OF CALUMET AFTER THE INITIAL SURGE OF SNOW/WIND EARLY SATURDAY EVENING DUE TO SHADOW FM ISLE ROYALE. AREAS WHERE THE MAX LIFT IS PRESENT IN THE -12C TO -18C (BETTER SNOW GROWTH) LAYER ALSO INDICATE THIS TREND WITH MAXIMUM VALUES OVR ONTONAGON AND ALGER/LUCE COUNTIES. SINCE AM NOT QUITE SURE HOW KEWEENAW COUNTY WILL WORK OUT AFTER THE EVENING FOR THE MEETING OF BLIZZARD CONDITIONS WILL OPT TO KEEP BLIZZARD WATCH GOING. PREVIOUS SET TIMES FOR THE BLIZZARD WATCHES LOOKED FINE. ISSUED A WINTER STORM WATCH FOR SOUTHERN HOUGHTON AND NORTHERN SCHOOLCRAFT ZONES DUE TO STRONG WINDS BLOWING THE LK EFFECT SNOW BANDS FARTHER INLAND/SIGNIFICANT BLOWING SNOW AND VERY LOW WIND CHILLS. SPEAKING OF THE WIND CHILLS ADDED MENOMINEE AND DELTA INTO THE GOING WIND CHILL WATCH. EVENTUALLY SOME TYPE OF HEADLINE...BE IT WIND CHILL ADVY OR WINTER WEATHER ADVY (SNOW/BLSN/WIND CHILL COMBO)... WILL BE NEEDED FOR ALL REMAINING AREAS OF THE CWA SATURDAY NIGHT INTO SUNDAY. LOW PRESSURE SYSTEM EXITS INTO QUEBEC BY LATE SUNDAY WITH LK EFFECT SNOW AND SOME BLOWING SNOW DIMINISHING OVER THE NW SNOW BELTS BY SUNDAY EVENING. WINDS BECOME VARIABLE SUNDAY NIGHT AWAY FM THE NW WINDS CLOSER TO LAKE SUPERIOR AND THIS SHOULD ALLOW FOR PARTIAL CLEARING AND PLUMMETING TEMPS OVR WEST INTERIOR. FOLLOWING HPC PREFERENCE OF ECMWF IN THE UPCOMING WEEK RESULTS IN WEAK LOW PRESSURE WITH SOME LIGHT SNOW AFFECTING GREAT LAKES MON-TUE. HIGHEST CHANCES IN THE CWA APPEAR OVR SOUTHERN SECTIONS. ANOTHER LOW PRESSURE SYSTEM AFFECTS THE REGION ON THU. GFS MORE EMPHATIC IN BRINGING ANOTHER SHOT OF ARCTIC AIR BY LATE WEEK BUT ECMWF NOT AS AMPLIFIED. CONFIDENCE IN EXTENDED NOT HIGH AS THERE ARE SIGNIFICANT DISAGREEMENTS BTWN THE GFS AND ECMWF AND ENSEMBLES NOT POINTING TO ANY ONE DIRECTION EITHER. TEMPS NEAR CLIMO/HPC GUIDANCE ARE PREFERRED FOR NOW. && .AVIATION (FOR THE 00Z TAF ISSUANCE)... AT KCMX...CLOUDS SHOULD REMAIN VFR THRU THE NIGHT DUE TO THE LACK OF LOW-LEVEL MOISTURE ADVECTION. EXPECT FOG TO DEVELOP BY MID TO LATE EVENING. HOWEVER...WITH MID/HIGH CLOUD DECK OVERHEAD...VIS SHOULD NOT DROP BLO MVFR. MVFR CIGS SHOULD DEVELOP SAT MORNING AS SW WINDS AHEAD OF APPROACHING ARCTIC COLD FRONT ADVECT LOW-LEVEL MOISTURE (WIDESPREAD MVFR CIGS ARE PRESENT OVER MN RIGHT NOW) INTO THE AREA. STRONG/SHARP ARCTIC COLD FRONT PASSING THRU KCMX LATE IN THE AFTN WILL BRING A RAPID FALL TO VLIFR CONDITIONS IN SN/BLSN. VLIFR CONDITIONS SHOULD PREVAIL WELL BEYOND THIS FCST PERIOD INTO SUN MORNING. AT KSAW...EXPECT VFR CONDITIONS TO GIVE WAY TO MVFR BY LATE EVENING...THEN IFR CIGS/MVFR VIS OVERNIGHT AS PERSISTENT LIGHT S FLOW AHEAD OF WEAK SFC LOW MOVING THRU THE UPR MIDWEST GRADUALLY DRAWS MORE MOISTURE INTO THE AREA. AS THE LOW APPROACHES LATER IN THE NIGHT...EXPECT A PERIOD OF -SN WITH IFR VIS/CIGS PREDOMINATING. CONDITIONS WILL IMPROVE SOME SAT MORNING INTO THE AFTN...BUT DO NOT EXPECT CONDITIONS TO IMPROVE ABOVE MVFR. STRONG/SHARP ARCTIC COLD FRONT ARRIVING LATE AFTN WILL DROP VIS TO IFR IN A PERIOD OF -SN. && .MARINE (FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)... EXPECT NW GALES TO DVLP OVER WRN LK SUP BEHIND STRONG COLD FNT ON SAT AFTN AND THEN OVERSPREAD THE ENTIRE LK BY EARLY EVNG. STORM FORCE WINDS LOOK LIKE A GOOD POSSIBILITY LATER SAT NGT/EARLY SUN IN SHARP CYC NW FLOW BEHIND DEEP LO PRES MOVING INTO SE CAN BEFORE LO MOVES QUICKLY AWAY AND PRES GRADIENT SLACKENS SUN AFTN. RELATIVELY LGT WINDS WL PREVAIL MON THRU WED WITH NEXT DEEPER LO FCST TO TRACK WELL TO THE S EARLY NEXT WEEK. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... BLIZZARD WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY AFTERNOON FOR MIZ001>003. WIND CHILL WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY AFTERNOON FOR MIZ009>013. WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING FOR MIZ085. WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY AFTERNOON FOR MIZ084. BLIZZARD WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING FOR MIZ006-007. LAKE SUPERIOR... GALE WARNING FROM 9 PM SATURDAY TO 6 PM EST SUNDAY FOR LSZ267. GALE WARNING FROM 6 PM SATURDAY TO 6 PM EST SUNDAY FOR LSZ266. GALE WARNING FROM 5 PM SATURDAY TO 4 PM EST SUNDAY FOR LSZ264- 265. GALE WARNING FROM 1 PM SATURDAY TO 10 AM EST SUNDAY FOR LSZ162-263. LAKE MICHIGAN...NONE. && $$ SYNOPSIS/SHORT TERM...KC LONG TERM...JLA AVIATION...ROLFSON MARINE...KC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 630 PM EST FRI FEB 8 2008 .AVIATION... MVFR STRATUS DECK WILL REMAIN IN PLACE ACROSS SOUTHEAST LOWER MICHIGAN THROUGH THE DURATION OF THE TAF PERIOD. BACK EDGE OF AN AREAS OF LGT SNOW SHOWERS ASSOCIATED WITH A WEAK UPPER LEVEL IMPULSE WILL TAPER OFF AT FNT/MBS BY 02Z...BRINGING VISIBILITY BACK INTO VFR FOR THE DURATION OF THE EVENING. WEAK WARM AIR ADVECTION AHEAD OF A STRONGER SYSTEM WILL HELP SPREAD ANOTHER ROUND OF LIGHT SNOW ACROSS ALL TERMINALS DURING THE EARLY/MID MORNING HOURS. STRONG LIFT AND DEEPER MOISTURE WILL BE LACKING... AND THUS EXPECT VISIBILITY TO HOLD AT MVFR DURING THIS TIME. SOUTHWEST WINDS WILL STRENGTHEN DURING AFTERNOON/EVENING BEHIND AN INITIAL COLD FRONT...WITH GUSTS OVER 20 KNOTS. && .PREV DISCUSSION...ISSUED 348 PM EST FRI FEB 8 2008 SHORT TERM...THIS AFTERNOON AND TONIGHT VERY LIGHT SNOW ACTIVITY CONTINUES TO SWEEP ACROSS SOUTHEASTERN MICHIGAN THIS AFTERNOON...WITH CURRENT LOCATION ACROSS THE TRI CITIES AND THUMB. THIS AREA OF SNOW IS ASSOCIATED WITH LIFT ALONG LEADING THETA E BUBBLE AND EMBEDDED SHORTWAVE ENERGY THE RUC HAS A GREAT HANDLE ON. KDTX RADAR IS GIVING THE DRIZZLE LOOK BEHIND THIS SNOW ACTIVITY AND EXPECTING THIS TO CONTINUE WITH THE SATURATED LOWER TROPOSPHERE. HAVE CUT THE POPS THIS EVENING BACK DOWN TO CHANCE AS METARS HAVE BEEN COMING IN ONLY A TRACE. DESPITE TEMPERATURES A TOUCH BELOW FREEZING...NOT EXPECTING ANY LARGE HEADACHES DUE TO FREEZING DRIZZLE AS AREA ROADWAYS SHOULD BE HEAVILY TREATED AND TEMPERATURES SHOULD LARGELY HOLD STEADY JUST UNDER THE FREEZING MARK. DESPITE WEAK CONTINUED WARMING...MODEL GUIDANCE IS BULLISH ON ALL SNOW MENTION LATER TONIGHT IN THE BUFFER SOUNDINGS AND IN AGREEMENT WITH THE AMOUNT OF COLD AIR IN RESIDENCE NORTH OF THE IOWAN SURFACE REFLECTION. TWO WEAK SHORTWAVES...ONE OVER NORTHERN MINNESOTA...THE OTHER OVER CENTRAL PLAINS WILL MERGE OVER MICHIGAN TONIGHT IN QUASI-CONFLUENT FLOW. THIS RESULTS IN A SURFACE LOW TRACK FROM SOUTHERN WISCONSIN...NORTHEASTWARD TO FRANKFORT MICHIGAN BY THE END OF THE PERIOD. AM FAIRLY IMPRESSED WITH THE THERMODYNAMICS OVERNIGHT AS LOW STATIC STABILITY EXISTS FROM 900MB UPWARD. GIVEN MOIST LOWER TROPOSPHERIC ENVIRONMENT...FEEL THERE ARE NO NEGATIVE ISSUES REGARDING MOISTURE. ON THE OTHER HAND...SYNOPTIC SCALE DYNAMICS ARE FAIRLY LACKLUSTER...GIVEN RAGGED APPEARANCE TO MIDLEVEL VORTS...LACK OF ANY OBVIOUS JET DYNAMICS...AND WEAK MODELED FRONTOGENESIS. SO IT APPEARS...FORCING FOR SNOW WILL BE TIED STRICTLY TO 285K ISENTROPIC LIFT/WARM AIR/MOISTURE ADVECTION. WITH THE A LACK OF AN INVERSION...AN EXPECTED SATURATED ATMOSPHERE THROUGH 400MB...THERE IS A GOOD SHOT AT MEASURABLE SNOWFALL. EXPECTATIONS ARE FOR 1 TO 2 INCHES OF ACCUMULATION FOR EVERYONE WITH ISOLATED 3 INCH AMOUNTS (BEST BET UP NORTH CLOSER TO SURFACE LOW). HAVE SLOWED THE ONSET...AFTER 6Z...WITH THE HEAVIEST ACTIVITY FROM 9-12Z. DID DROP LOWS A COUPLE OF DEGREES AS WET BULB PROCESSES SHOULD ALLOW A QUICK DROP IN TEMPS ONCE THE HEAVIER SNOWS MOVE IN...AT OR JUST UNDER 30 DEGREES. LONG TERM...SATURDAY THROUGH FRIDAY THE MAIN FORECAST CONCERN FOR THIS WEEKEND CONTINUES TO BE WITH THE SHOT OF ARCTIC AIR POISED TO INFILTRATE THE GREAT LAKES SATURDAY NIGHT AND SUNDAY AND THE ASSOCIATED STRONG WINDS AND DANGEROUSLY COLD WIND CHILLS. THE UPPER WAVE CURRENTLY OVER BRITISH COLUMBIA IS STILL FORECAST TO RACE INTO THE WESTERN GREAT LAKES BY SATURDAY EVENING PER 12Z MODEL SUITE AND DEVELOP INTO A CUT OFF CIRCULATION BY SUN MORNING. THE ASSOCIATED SURFACE LOW IS FORECAST TO DEEPEN OVER NORTHERN MINNESOTA ON SATURDAY...THEN MERGE WITH THE SURFACE LOW LIFTING ACROSS NORTHERN MICHIGAN SATURDAY EVENING. WEAK SURFACE RIDGING AND MID LEVEL DRYING SHOULD END THE SNOWFALL BY LATE SATURDAY MORNING. LIFT ASSOCIATED WITH THE NEXT UPPER WAVE HOWEVER WILL BRING A QUICK SHOT OF LIFT SATURDAY EVENING...LIKELY LEADING TO BRIEF YET INTENSE BURST OF SNOW SHOWER ACTIVITY. THE COLD FRONT ASSOCIATED WITH THE DEEPENING LOW TO THE NORTHEAST OF THE STATE WILL QUICKLY RACE ACROSS SE MI SATURDAY EVENING. THE 12Z UPPER AIR ANALYSIS SHOWED VERY COLD AIR ACROSS NORTHWEST CANADA. THIS AIRMASS WILL QUICKLY GET ADVECTED INTO THE GREAT LAKES SATURDAY NIGHT IN THE WAKE OF THE SURFACE COLD FRONT. 850 MB TEMPS ARE STILL FORECAST TO DROP FROM AROUND -8C 00Z SUN TO AROUND -25C BY 12Z SUN. A DECENT ISALLOBARIC COUPLET WILL ACCOMPANY THE SURFACE FRONT THROUGH THE STATE SAT EVENING. MODEL CROSS SECTIONS OF POTENTIAL TEMPERATURE AND OMEGA INDICATE A GOOD POTENTIAL FOR DOWNWARD MOMENTUM TRANSPORT WITHIN STRONG MID LEVEL SUBSIDENCE EARLY SUNDAY MORNING...WITH MODEL SOUNDINGS INDICATING THE POTENTIAL FOR 40 TO 45 KNOT WINDS TO MIX DOWN TO THE SURFACE. THUS WIND GUSTS OF 40 TO 50 MPH SEEM LIKELY SATURDAY NIGHT INTO SUNDAY MORNING. THE ARCTIC AIRMASS WILL DROP TEMPS INTO THE SINGLE DIGITS BY SUNDAY MORNING...WITH LITTLE RECOVERY EXPECTED DURING THE AFTERNOON. THESE TEMPS COMBINED WITH THE STRONG WINDS WILL PRODUCE WIND CHILL READINGS OF 10 TO 20 BELOW ZERO THROUGH THE DAY SUNDAY. EXPECT THERE WILL BE SOME BLOWING SNOW. THIS MAY HOWEVER NOT BE TOO SIGNIFICANT A HAZARD GIVEN THE HIGH WATER CONTENT OF THE SNOW PACK. THE UPPER LOW AND ARCTIC AIRMASS ARE EXPECTED TO BE SHORT LIVED IN THIS FAST PROGRESSIVE FLOW. SURFACE HIGH PRESSURE BUILDING INTO THE REGION SUNDAY NIGHT SHOULD STILL HOWEVER ALLOW TEMPS TO DROP BELOW ZERO IN MANY PLACES BEFORE TEMPERATURES BEGIN MODERATING EARLY NEXT WEEK. THE 12Z MODEL SUITE HAVE COME INTO A LITTLE BETTER AGREEMENT WITH RESPECT TO THE NEXT WAVE FORECAST TO AMPLIFY OVER THE PLAINS MONDAY AND MONDAY NIGHT. THE GFS...ECMWF...UKMET AND CANADIAN ALL DEPICT SOME LIFT ASSOCIATED WITH LOW LEVEL WARM AIR ADVECTION MONDAY NIGHT. FAVORABLE ENTRANCE REGION JET DYNAMICS SHOULD ALSO ALLOW SOME MID TROPOSPHERIC FRONTOGENESIS. THUS HAVE INCREASED THE CHANCES OF SNOW MONDAY NIGHT. AT THIS STAGE SOME ACCUMULATIONS...POSSIBLY EVEN ADVISORY CRITERIA...ARE POSSIBLE MONDAY NIGHT. THE GFS AND CANADIAN ARE FARTHER NORTH WITH THE ASSOCIATED SURFACE LOW TUESDAY. GIVEN THE UPPER AIR PATTERN...PREFER THE MORE SOUTHERLY ECMWF TRACK...WHICH KEEPS SOUTHEAST MICHIGAN WITHIN THE COLDER AIR...INDICATING ANY LINGERING PRECIP WILL BE IN THE FORM OF SNOW. TEMPS SHOULD CONTINUE TO MODERATE TO NEAR NORMAL BY MID WEEK AS HEIGHTS BUILD IN THE WAKE OF THE DEPARTING UPPER TROUGH. MARINE... MARINE INTERESTS WILL BE FOCUSED ON THE IMPENDING ARCTIC COLD FRONT PASSAGE SATURDAY NIGHT. DEEPENING LOW PRESSURE TO THE NORTHEAST OF LAKE HURON SUNDAY NIGHT WILL DRIVE THE FRONT THROUGH THE REGION. VERY STRONG COLD AIR ADVECTION BEHIND THIS FRONT...COMBINED WITH A STRENGTHENING PRESSURE GRADIENT WILL LEAD TO GALE FORCE WINDS SATURDAY NIGHT THROUGH THE DAY SUNDAY. GUSTS WILL ACTUALLY APPROACH 45 KNOTS ON THE OPEN WATERS OF LAKE HURON ON SUNDAY. IF CURRENT MODEL TRENDS HOLD...MAY ACTUALLY HAVE TO UPGRADE TO STORM WARNINGS OVER PORTIONS OF LAKE HURON. THIS FRONT WILL USHER IN AN ARCTIC AIRMASS...WHICH WILL LEAD TO SIGNIFICANT FREEZING SPRAY. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON... HEAVY FREEZING SPRAY WARNING...LHZ361-LHZ362-LHZ363-LHZ462-LHZ463- LHZ464...FROM 7 PM SATURDAY TO 7 PM SUNDAY. GALE WARNING...LHZ361-LHZ362-LHZ363-LHZ421-LHZ422-LHZ441-LHZ442- LHZ443-LHZ462-LHZ463-LHZ464...FROM 7 PM SATURDAY TO 7 PM SUNDAY. LAKE ST CLAIR... GALE WARNING...FROM 7 PM SATURDAY TO 7 PM SUNDAY. MI WATERS OF LAKE ERIE... GALE WARNING...FROM 7 PM SATURDAY TO 7 PM SUNDAY. && $$ AVIATION.....MR SHORT TERM...CB LONG TERM....SC MARINE.......SC YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE). mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 355 PM EST FRI FEB 8 2008 ...BLIZZARD CONDITIONS POSSIBLE IN NORTHWEST FLOW SNOWBELTS SATURDAY EVENING INTO SUNDAY... .SYNOPSIS... 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A SPLIT FLOW ACRS NAMERICA WITH TROFFING IN THE ARCTIC AND POLAR BRANCHES CENTERED NEAR HUDSON BAY/THE MS RIVER VALLEY. POLAR BRANCH SHRTWV NOTED MOVING INTO WI SUPPORTING AN AREA OF -SN FM CNTRL MN INTO NW WI WHERE MOIST 12Z MPX SDNG SUGS ATMOSPHERE IS SATURATED ENUF TO SUPPORT PCPN. EARLIER TAMDAR SDNG FM SAW SHOWED A VERY DRY LYR BTWN H9-7...SO LTL GOING ON LOCALLY WITH WEAK RDG OVHD...JUST SOME MID AND HI CLD NOTED ASSOCIATED WITH THE SHRTWV TO THE SW. FARTHER UPSTREAM...A MORE POTENT SHRTWV NOTED DIGGING INTO BRITISH COLUMBIA. H3 WIND SPEEDS APRCHG 150KT NOTED WITHIN UPR JET CORE ACCOMPANYING THIS SYS AND ORIENTED ALG SHARP GRADIENT OF H3 HGT RISES. && .SHORT TERM (TONIGHT AND SATURDAY)... MAIN FORECAST CONCERN TNGT IS POTENTIAL SN ASSOCIATED WITH SHRTWV NOW DRIFTING THRU THE UPR MIDWEST. FOCUS FOR SAT SHIFTS TO TIMING/ IMPACT OF POTENT SHRTWV NOW OVER BRITISH COLUMBIA...SPECIFICALLY SN/AND ONSET OF POTENTIALLY BLIZZARD CONDITIONS AT LEAST OVER THE W. FOR TNGT INTO SAT MRNG...LO PRES OVER THE UPR MIDWEST FCST TO DRIFT INTO NRN LK MI BY 12Z SAT. ISENTROPIC LIFT/MOISTENING ON THE 280-285K SFCS (H65-8) FCST TO IMPACT MAINLY THE SE HALF OF THE CWA IN ADVANCE OF THIS LO. SINCE THERE MAY ALSO BE SOME MOISTENING OFF LI MI...OPTED TO BUMP UP POPS TO LIKELY NEAR THE LK MI SHORE FM LATE TNGT INTO SAT MRNG BEFORE THE SFC LO/ISENTROPIC LIFT TRACKS TO THE NE AND A WEAK RDG AXIS MOVES OVHD IN ITS WAKE. 1-2G/KG SPECIFIC HUMIDITY NOTED IN THE H7-75 LYR...SO EXPECT AS MUCH AS 2 INCHES OF SN TO FALL DURING THE 9 HR PD OF PCPN IN THIS AREA. EXPECT LTL SN TO THE NW WITH RDG AXIS BTWN LO PRES AREA AND APRCHG COLD FNT ASSOCIATED WITH BRITISH COLUMBIA SHRTWV. ON SAT AFTN...GUIDANCE HAS TRENDED A BIT SLOWER WITH ARRIVAL OF BRITISH COLUMBIA SHRTWV AND ARCTIC FNT...WHICH NOW LOOKS TO REACH IWD JUST ARND 19Z AND THEN P53-ESC ARND 00Z. SHARP PRES RISE/CAD BEHIND THE BNDRY IN CONCERT WITH 45KT WINDS IN THE MIXED LYR WHERE LAPSE RATES WL BE ENHANCED BY THE STRONG CAD SUG SUBSTANTIAL MIXING TO THE SFC...SO LOOK FOR GUSTY WINDS/BLSN TO DVLP QUICKLY AFT FROPA AS TEMPS FALL. ATMOSPHERE WL BE RATHER DRY (PWAT AOB 0.25 INCH)...SO A WHOLE LOT OF SN NOT ON TAP WITH QUICK MOVING FNT EVEN THOUGH VIGOROUS 12Z HR H5 HGT FALLS UP TO 100M/DIFFLUENT UPR FLOW WL TEND TO SQUEEZE OUT THE MEAGER MSTR AVBL. THERE WL BE SOME ENHANCEMENT OVER THE HIER TERRAIN OF THE W...WHERE A COUPLE OF INCHES WL LIKELY FALL BEFORE 24Z. .LONG TERM (SATURDAY NIGHT THROUGH NEXT FRIDAY)... LOW PRESSURE SHIFTS JUST NORTH OF SAULT STE MARIE SATURDAY EVENING LEAVING 25-30MB PRESSURE GRADIENT ACROSS NORTHERN UPR MI AND LK SUPERIOR. STRONG BURST OF 20-30MPH WITH GUSTS TO 45 MPH WINDS IN WAKE OF ARCTIC FRONT (AIDED BY 10MB/6HR PRESSURE RISE) SHOULD SWEEP INTO THE EASTERN CWA BY LATE EVENING. AFTERWARD...STRONG WINDS THROUGH THE NIGHT ARE A FUNCTION OF TIGHT PRESSURE GRADIENT MAINTAINING THROUGH 12Z SUN. H95-H85 WINDS FM WEST TO NORTHWEST ALLOW MOST CONCENTRATED CONVERGENCE AND LK EFFECT SNOW SHOWERS TO MOVE INTO ONTONAGON TO BEGIN THE EVENING AND IN THE SNOWBELTS EAST OF MUNISING AFTER LATE SAT EVENING. H85 TEMPS LOWERING BLO -20C IN THE MIXED LAYER LEAD TO VERY SMALL SNOWFLAKE SIZE WHICH WON`T BE SUITABLE FOR LARGE ACCUMS...BUT WILL BE VERY EFFICIENT IN YIELDING SEVERELY REDUCED VSBY OVER KEWEENAW PENINSULA INTO ONTONAGON COUNTY AND IN ALGER THROUGH LUCE COUNTIES IN THE NE CWA. A CONCERN ON KEWEENAW IS A MORE WNW WIND DIRECTION WHICH MAY SHUT OFF THE MORE CONCENTRATED SNOW SHOWERS NORTH OF CALUMET AFTER THE INITIAL SURGE OF SNOW/WIND EARLY SATURDAY EVENING DUE TO SHADOW FM ISLE ROYALE. AREAS WHERE THE MAX LIFT IS PRESENT IN THE -12C TO -18C (BETTER SNOW GROWTH) LAYER ALSO INDICATE THIS TREND WITH MAXIMUM VALUES OVR ONTONAGON AND ALGER/LUCE COUNTIES. SINCE AM NOT QUITE SURE HOW KEWEENAW COUNTY WILL WORK OUT AFTER THE EVENING FOR THE MEETING OF BLIZZARD CONDITIONS WILL OPT TO KEEP BLIZZARD WATCH GOING. PREVIOUS SET TIMES FOR THE BLIZZARD WATCHES LOOKED FINE. ISSUED A WINTER STORM WATCH FOR SOUTHERN HOUGHTON AND NORTHERN SCHOOLCRAFT ZONES DUE TO STRONG WINDS BLOWING THE LK EFFECT SNOW BANDS FARTHER INLAND/SIGNIFICANT BLOWING SNOW AND VERY LOW WIND CHILLS. SPEAKING OF THE WIND CHILLS ADDED MENOMINEE AND DELTA INTO THE GOING WIND CHILL WATCH. EVENTUALLY SOME TYPE OF HEADLINE...BE IT WIND CHILL ADVY OR WINTER WEATHER ADVY (SNOW/BLSN/WIND CHILL COMBO)... WILL BE NEEDED FOR ALL REMAINING AREAS OF THE CWA SATURDAY NIGHT INTO SUNDAY. LOW PRESSURE SYSTEM EXITS INTO QUEBEC BY LATE SUNDAY WITH LK EFFECT SNOW AND SOME BLOWING SNOW DIMINISHING OVER THE NW SNOW BELTS BY SUNDAY EVENING. WINDS BECOME VARIABLE SUNDAY NIGHT AWAY FM THE NW WINDS CLOSER TO LAKE SUPERIOR AND THIS SHOULD ALLOW FOR PARTIAL CLEARING AND PLUMMETING TEMPS OVR WEST INTERIOR. FOLLOWING HPC PREFERENCE OF ECMWF IN THE UPCOMING WEEK RESULTS IN WEAK LOW PRESSURE WITH SOME LIGHT SNOW AFFECTING GREAT LAKES MON-TUE. HIGHEST CHANCES IN THE CWA APPEAR OVR SOUTHERN SECTIONS. ANOTHER LOW PRESSURE SYSTEM AFFECTS THE REGION ON THU. GFS MORE EMPHATIC IN BRINGING ANOTHER SHOT OF ARCTIC AIR BY LATE WEEK BUT ECMWF NOT AS AMPLIFIED. CONFIDENCE IN EXTENDED NOT HIGH AS THERE ARE SIGNIFICANT DISAGREEMENTS BTWN THE GFS AND ECMWF AND ENSEMBLES NOT POINTING TO ANY ONE DIRECTION EITHER. TEMPS NEAR CLIMO/HPC GUIDANCE ARE PREFERRED FOR NOW. && .AVIATION (FOR THE 18Z TAF ISSUANCE)... EXPECT VFR CONDITIONS AT SAW TO GIVE WAY TO IFR CIGS/MVFR VSBY TNGT AS PERSISTENT SLY FLOW AHEAD OF WEAK SFC LO MOVING THRU THE UPR MIDWEST GRADUALLY DRAWS MORE MSTR INTO THE AREA. AS THE LO APRCHS LATER TNGT...EXPECT A PD OF LGT SN WITH IFR VSBY/CIGS PREDOMINATING. CONDITIONS WL IMPROVE A BIT ON SAT MRNG...BUT LACK OF SGNFT DRYING IN THE WAKE OF SFC LO SUGS LO CLDS/SOME FOG WL LINGER. AT CMX...MORE IMPRESSIVE LLVL MOISTENING APPEARS WL SLIDE TO THE E...SO LO CLD THERE SHOULD BE MORE TRANSIENT THRU TNGT WITH VFR CIGS PREDOMINATING EVEN IF MVFR CONDITIONS APPEAR FM TIME TO TIME. ALTHOUGH FOG IS LIKELY THERE TNGT...LACK OF LLVL MOISTENING WITH LO/ PCPN SHIELD STAYING TO THE SE AS WELL AS MID CLD DECK SHOULD PREVENT VSBY FM DROPPING TOO FAR. && .MARINE (FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)... EXPECT NW GALES TO DVLP OVER WRN LK SUP BEHIND STRONG COLD FNT ON SAT AFTN AND THEN OVERSPREAD THE ENTIRE LK BY EARLY EVNG. STORM FORCE WINDS LOOK LIKE A GOOD POSSIBILITY LATER SAT NGT/EARLY SUN IN SHARP CYC NW FLOW BEHIND DEEP LO PRES MOVING INTO SE CAN BEFORE LO MOVES QUICKLY AWAY AND PRES GRADIENT SLACKENS SUN AFTN. RELATIVELY LGT WINDS WL PREVAIL MON THRU WED WITH NEXT DEEPER LO FCST TO TRACK WELL TO THE S EARLY NEXT WEEK. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... BLIZZARD WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY AFTERNOON FOR MIZ001>003. WIND CHILL WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY AFTERNOON FOR MIZ009>013. WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING FOR MIZ085. WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY AFTERNOON FOR MIZ084. BLIZZARD WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING FOR MIZ006-007. LAKE SUPERIOR... GALE WARNING FROM 9 PM SATURDAY TO 6 PM EST SUNDAY FOR LSZ267. GALE WARNING FROM 6 PM SATURDAY TO 6 PM EST SUNDAY FOR LSZ266. GALE WARNING FROM 5 PM SATURDAY TO 4 PM EST SUNDAY FOR LSZ264- 265. GALE WARNING FROM 1 PM SATURDAY TO 10 AM EST SUNDAY FOR LSZ162-263. LAKE MICHIGAN...NONE. && $$ SYNOPSIS/SHORT TERM...KC LONG TERM...JLA AVIATION...KC MARINE...KC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 348 PM EST FRI FEB 8 2008 .SHORT TERM...THIS AFTERNOON AND TONIGHT VERY LIGHT SNOW ACTIVITY CONTINUES TO SWEEP ACROSS SOUTHEASTERN MICHIGAN THIS AFTERNOON...WITH CURRENT LOCATION ACROSS THE TRI CITIES AND THUMB. THIS AREA OF SNOW IS ASSOCIATED WITH LIFT ALONG LEADING THETA E BUBBLE AND EMBEDDED SHORTWAVE ENERGY THE RUC HAS A GREAT HANDLE ON. KDTX RADAR IS GIVING THE DRIZZLE LOOK BEHIND THIS SNOW ACTIVITY AND EXPECTING THIS TO CONTINUE WITH THE SATURATED LOWER TROPOSPHERE. HAVE CUT THE POPS THIS EVENING BACK DOWN TO CHANCE AS METARS HAVE BEEN COMING IN ONLY A TRACE. DESPITE TEMPERATURES A TOUCH BELOW FREEZING...NOT EXPECTING ANY LARGE HEADACHES DUE TO FREEZING DRIZZLE AS AREA ROADWAYS SHOULD BE HEAVILY TREATED AND TEMPERATURES SHOULD LARGELY HOLD STEADY JUST UNDER THE FREEZING MARK. DESPITE WEAK CONTINUED WARMING...MODEL GUIDANCE IS BULLISH ON ALL SNOW MENTION LATER TONIGHT IN THE BUFFER SOUNDINGS AND IN AGREEMENT WITH THE AMOUNT OF COLD AIR IN RESIDENCE NORTH OF THE IOWAN SURFACE REFLECTION. TWO WEAK SHORTWAVES...ONE OVER NORTHERN MINNESOTA...THE OTHER OVER CENTRAL PLAINS WILL MERGE OVER MICHIGAN TONIGHT IN QUASI-CONFLUENT FLOW. THIS RESULTS IN A SURFACE LOW TRACK FROM SOUTHERN WISCONSIN...NORTHEASTWARD TO FRANKFORT MICHIGAN BY THE END OF THE PERIOD. AM FAIRLY IMPRESSED WITH THE THERMODYNAMICS OVERNIGHT AS LOW STATIC STABILITY EXISTS FROM 900MB UPWARD. GIVEN MOIST LOWER TROPOSPHERIC ENVIRONMENT...FEEL THERE ARE NO NEGATIVE ISSUES REGARDING MOISTURE. ON THE OTHER HAND...SYNOPTIC SCALE DYNAMICS ARE FAIRLY LACKLUSTER...GIVEN RAGGED APPEARANCE TO MIDLEVEL VORTS...LACK OF ANY OBVIOUS JET DYNAMICS...AND WEAK MODELED FRONTOGENESIS. SO IT APPEARS...FORCING FOR SNOW WILL BE TIED STRICTLY TO 285K ISENTROPIC LIFT/WARM AIR/MOISTURE ADVECTION. WITH THE A LACK OF AN INVERSION...AN EXPECTED SATURATED ATMOSPHERE THROUGH 400MB...THERE IS A GOOD SHOT AT MEASURABLE SNOWFALL. EXPECTATIONS ARE FOR 1 TO 2 INCHES OF ACCUMULATION FOR EVERYONE WITH ISOLATED 3 INCH AMOUNTS (BEST BET UP NORTH CLOSER TO SURFACE LOW). HAVE SLOWED THE ONSET...AFTER 6Z...WITH THE HEAVIEST ACTIVITY FROM 9-12Z. DID DROP LOWS A COUPLE OF DEGREES AS WET BULB PROCESSES SHOULD ALLOW A QUICK DROP IN TEMPS ONCE THE HEAVIER SNOWS MOVE IN...AT OR JUST UNDER 30 DEGREES. && .LONG TERM...SATURDAY THROUGH FRIDAY THE MAIN FORECAST CONCERN FOR THIS WEEKEND CONTINUES TO BE WITH THE SHOT OF ARCTIC AIR POISED TO INFILTRATE THE GREAT LAKES SATURDAY NIGHT AND SUNDAY AND THE ASSOCIATED STRONG WINDS AND DANGEROUSLY COLD WIND CHILLS. THE UPPER WAVE CURRENTLY OVER BRITISH COLUMBIA IS STILL FORECAST TO RACE INTO THE WESTERN GREAT LAKES BY SATURDAY EVENING PER 12Z MODEL SUITE AND DEVELOP INTO A CUT OFF CIRCULATION BY SUN MORNING. THE ASSOCIATED SURFACE LOW IS FORECAST TO DEEPEN OVER NORTHERN MINNESOTA ON SATURDAY...THEN MERGE WITH THE SURFACE LOW LIFTING ACROSS NORTHERN MICHIGAN SATURDAY EVENING. WEAK SURFACE RIDGING AND MID LEVEL DRYING SHOULD END THE SNOWFALL BY LATE SATURDAY MORNING. LIFT ASSOCIATED WITH THE NEXT UPPER WAVE HOWEVER WILL BRING A QUICK SHOT OF LIFT SATURDAY EVENING...LIKELY LEADING TO BRIEF YET INTENSE BURST OF SNOW SHOWER ACTIVITY. THE COLD FRONT ASSOCIATED WITH THE DEEPENING LOW TO THE NORTHEAST OF THE STATE WILL QUICKLY RACE ACROSS SE MI SATURDAY EVENING. THE 12Z UPPER AIR ANALYSIS SHOWED VERY COLD AIR ACROSS NORTHWEST CANADA. THIS AIRMASS WILL QUICKLY GET ADVECTED INTO THE GREAT LAKES SATURDAY NIGHT IN THE WAKE OF THE SURFACE COLD FRONT. 850 MB TEMPS ARE STILL FORECAST TO DROP FROM AROUND -8C 00Z SUN TO AROUND -25C BY 12Z SUN. A DECENT ISALLOBARIC COUPLET WILL ACCOMPANY THE SURFACE FRONT THROUGH THE STATE SAT EVENING. MODEL CROSS SECTIONS OF POTENTIAL TEMPERATURE AND OMEGA INDICATE A GOOD POTENTIAL FOR DOWNWARD MOMENTUM TRANSPORT WITHIN STRONG MID LEVEL SUBSIDENCE EARLY SUNDAY MORNING...WITH MODEL SOUNDINGS INDICATING THE POTENTIAL FOR 40 TO 45 KNOT WINDS TO MIX DOWN TO THE SURFACE. THUS WIND GUSTS OF 40 TO 50 MPH SEEM LIKELY SATURDAY NIGHT INTO SUNDAY MORNING. THE ARCTIC AIRMASS WILL DROP TEMPS INTO THE SINGLE DIGITS BY SUNDAY MORNING...WITH LITTLE RECOVERY EXPECTED DURING THE AFTERNOON. THESE TEMPS COMBINED WITH THE STRONG WINDS WILL PRODUCE WIND CHILL READINGS OF 10 TO 20 BELOW ZERO THROUGH THE DAY SUNDAY. EXPECT THERE WILL BE SOME BLOWING SNOW. THIS MAY HOWEVER NOT BE TOO SIGNIFICANT A HAZARD GIVEN THE HIGH WATER CONTENT OF THE SNOW PACK. THE UPPER LOW AND ARCTIC AIRMASS ARE EXPECTED TO BE SHORT LIVED IN THIS FAST PROGRESSIVE FLOW. SURFACE HIGH PRESSURE BUILDING INTO THE REGION SUNDAY NIGHT SHOULD STILL HOWEVER ALLOW TEMPS TO DROP BELOW ZERO IN MANY PLACES BEFORE TEMPERATURES BEGIN MODERATING EARLY NEXT WEEK. THE 12Z MODEL SUITE HAVE COME INTO A LITTLE BETTER AGREEMENT WITH RESPECT TO THE NEXT WAVE FORECAST TO AMPLIFY OVER THE PLAINS MONDAY AND MONDAY NIGHT. THE GFS...ECMWF...UKMET AND CANADIAN ALL DEPICT SOME LIFT ASSOCIATED WITH LOW LEVEL WARM AIR ADVECTION MONDAY NIGHT. FAVORABLE ENTRANCE REGION JET DYNAMICS SHOULD ALSO ALLOW SOME MID TROPOSPHERIC FRONTOGENESIS. THUS HAVE INCREASED THE CHANCES OF SNOW MONDAY NIGHT. AT THIS STAGE SOME ACCUMULATIONS...POSSIBLY EVEN ADVISORY CRITERIA...ARE POSSIBLE MONDAY NIGHT. THE GFS AND CANADIAN ARE FARTHER NORTH WITH THE ASSOCIATED SURFACE LOW TUESDAY. GIVEN THE UPPER AIR PATTERN...PREFER THE MORE SOUTHERLY ECMWF TRACK...WHICH KEEPS SOUTHEAST MICHIGAN WITHIN THE COLDER AIR...INDICATING ANY LINGERING PRECIP WILL BE IN THE FORM OF SNOW. TEMPS SHOULD CONTINUE TO MODERATE TO NEAR NORMAL BY MID WEEK AS HEIGHTS BUILD IN THE WAKE OF THE DEPARTING UPPER TROUGH. && .MARINE... MARINE INTERESTS WILL BE FOCUSED ON THE IMPENDING ARCTIC COLD FRONT PASSAGE SATURDAY NIGHT. DEEPENING LOW PRESSURE TO THE NORTHEAST OF LAKE HURON SUNDAY NIGHT WILL DRIVE THE FRONT THROUGH THE REGION. VERY STRONG COLD AIR ADVECTION BEHIND THIS FRONT...COMBINED WITH A STRENGTHENING PRESSURE GRADIENT WILL LEAD TO GALE FORCE WINDS SATURDAY NIGHT THROUGH THE DAY SUNDAY. GUSTS WILL ACTUALLY APPROACH 45 KNOTS ON THE OPEN WATERS OF LAKE HURON ON SUNDAY. IF CURRENT MODEL TRENDS HOLD...MAY ACTUALLY HAVE TO UPGRADE TO STORM WARNINGS OVER PORTIONS OF LAKE HURON. THIS FRONT WILL USHER IN AN ARCTIC AIRMASS...WHICH WILL LEAD TO SIGNIFICANT FREEZING SPRAY. && .PREV DISCUSSION...ISSUED 1252 PM EST FRI FEB 8 2008 AVIATION... THE MOIST PATTERN WILL BRING A COUPLE OF SNOW CHANCES THROUGHOUT THE PERIOD. AN AREA OF LIGHT SNOW/FLURRIES/BR WILL LIFT THROUGH SOUTHEASTERN MICHIGAN THIS AFTERNOON ALLOWING FOR MVFR VISIBILITIES. THE FORECAST ALSO CALLS FOR PREDOMINATELY MVFR CEILINGS THROUGHOUT THE NEXT 24 HOURS BUT DID TRY TO TIME A VFR TIME PERIOD THIS EVENING. THE BETTER CHANCE FOR HEAVIER SNOWFALL WILL ARRIVE OVERNIGHT AFTER 6Z. FOR THIS FORECAST WILL CONTINUE THE 3-4SM MENTION WITH THE LACK OF CONFIDENCE IN OVERALL TIMING. WINDS WILL REMAIN LIGHT AND SOUTHERLY IN DIRECTION THROUGHOUT THE PERIOD. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON... HEAVY FREEZING SPRAY WARNING...LHZ361-LHZ362-LHZ363-LHZ462-LHZ463- LHZ464...FROM 7 PM SATURDAY TO 7 PM SUNDAY. GALE WARNING...LHZ361-LHZ362-LHZ363-LHZ421-LHZ422-LHZ441-LHZ442- LHZ443-LHZ462-LHZ463-LHZ464...FROM 7 PM SATURDAY TO 7 PM SUNDAY. LAKE ST CLAIR... GALE WARNING...FROM 7 PM SATURDAY TO 7 PM SUNDAY. MI WATERS OF LAKE ERIE... GALE WARNING...FROM 7 PM SATURDAY TO 7 PM SUNDAY. && $$ SHORT TERM...CB LONG TERM....SC MARINE.......SC AVIATION.....CB YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE). mi AREA FORECAST DISCUSSION...UPDATE NATIONAL WEATHER SERVICE MARQUETTE MI 1225 PM EST FRI FEB 8 2008 UPDATE AVIATION... ...BLIZZARD CONDITIONS POSSIBLE IN NORTHWEST FLOW SNOWBELTS THIS WEEKEND... .SYNOPSIS... 08Z WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS SHOWED BROAD TROUGHING COVERING MUCH OF NORTH AMERICA. WITHIN THIS TROUGH...FEATURES TO NOTE FOR THIS FORECAST INCLUDE A WEAK SHRTWV TROUGH OVER THE NORTHERN PLAINS...A SHRTWV TROUGH OVER UT/CO...AND A POTENT SHRTWV TROUGH DROPPING SE INTO CENTRAL BRITISH COLUMBIA NORTH OF A 140 KT JET AT 200MB MOVING ACROSS VANCOUVER ISLAND. THE SHRTWV TROUGH OVER THE NORTH PLAINS...COMBINED WITH SOME WEAK ISENTROPIC LIFT ON THE 290-300K SURFACES HAS PRODUCED WIDESPREAD MID AND HIGH CLOUDS OVER MN AND THE DAKOTAS PER IR IMAGERY. BELOW THESE HIGHER CLOUDS...11U-3.9U IMAGERY AND SFC OBS DEPICT LOW STRATUS FROM NORTHERN ILLINOIS INTO NW WI AND MUCH OF MN. THESE LOW CLOUDS ARE IN A WEAK MOISTURE ADVECTION SETUP AHEAD OF A 100MB LOW OVER THE DAKOTAS...AND BELOW A SUBSIDENCE INVERSION AROUND 900MB SEEN ON THE 00Z MPX SOUNDING. AIRMASS IS RELATIVELY MILD OVER THE NORTHERN PLAINS AND WESTERN GREAT LAKES COMPARED TO CLIMATOLOGY...WITH READINGS OF -8C AT INL...APX AND MPX. HOWEVER...AS HAS BEEN STATED IN PREVIOUS DISCUSSIONS AND SPS STATEMENTS...THESE READINGS WILL BE TAKING A TUMBLE THIS WEEKEND. UPSTREAM JUST NORTH OF THE POTENT BRITISH COLUMBIA SHRTWV...850MB TEMPS ARE IN THE LOW -30S C (SEE 00Z CYYE OR FORT NELSON BRITISH COLUMBIA SOUNDING). SURFACE TEMPS THERE ALSO REFLECT THE COLD AIR...WITH READINGS IN THE 20S AND 30S BELOW ZERO. UP IN THE YUKON...MAYO (SITE CYMA) IS REPORTING -60F! SURFACE ANALYSIS DEPICTS A 997MB SURFACE LOW ASSOCIATED WITH THIS POTENT SHRTWV JUST TO THE WEST OF EDMONTON ALBERTA...WITH 1030MB HIGH PRESSURE OVER THE YUKON. && .DISCUSSION... MAIN FORECAST CONCERN IS WITH WINDS...TEMPS AND POTENTIAL BLIZZARD CONDITIONS THIS WEEKEND. TODAY...NORTHERN PLAINS SHRTWV TROUGH AND THE OTHER SHRTWV TROUGH IN UT/CO WILL SORT OF CONSOLIDATE AS THEY DROP DOWN INTO THE MID MISSISSIPPI VALLEY BY 00Z. THIS MEANS MUCH OF THE DYNAMICS FOR PRODUCING PCPN WILL STAY AWAY FROM HERE...AND THUS A DRY FORECAST IS INDICATED. HOWEVER...THE MID AND HIGH CLOUDS ARE EXPECTED TO MIGRATE TO THE EAST AS THE AREA OF ISENTROPIC LIFT SHIFTS EAST. IN ADDITION...LOW CLOUDS SITUATED TO OUR SW WILL ADVECT INTO THE CWA THIS MORNING AS 925-950MB WINDS SHIFT TO THE S TO SW. THE INCREASE IN CLOUD COVER THROUGH THE DAY WILL LIKELY KEEP TEMPS FROM GETTING TOO HIGH...BUT GUIDANCE VALUES IN THE MID TO UPPER 20S SEEM REASONABLE GIVEN READINGS TO OUR SW AND SLOW DAYTIME HEATING. TONIGHT...THE CONSOLIDATED SHRTWV TROUGH OVER THE MID-MISSISSIPPI VALLEY IS PROGGED TO LIFT NE INTO LOWER MICHIGAN...RESULTING IN SOME HEIGHT FALLS OVER THE CWA. WITH ISENTROPIC LIFT PERSISTING... ESPECIALLY DURING THE EVENING...WOULD EXPECT THAT A LITTLE SNOW WILL MOVE THROUGH THE CWA. LACK OF SIGNIFICANT MOISTURE AS SEEN ON 00Z SOUNDINGS ACROSS THE PLAINS SUGGESTS ANY AMOUNTS SHOULD BE ON THE LIGHT SIDE. CLOUD COVER ASSOCIATED WITH THE TROUGH MOVING THROUGH WILL HELP KEEP TEMPS UP...AND THUS STAYED ON THE HIGH END OF GUIDANCE. MEANWHILE TO OUR NW...THE POTENT BRITISH COLUMBIA SHRTWV IS PROGGED TO DROP DOWN INTO SOUTHERN MANITOBA BY 12Z SAT...WITH A 996MB LOW MOVING INTO NW ONTARIO AND THE ARCTIC FRONT DRAPED SOUTH THROUGH MPX. SAT...POTENT SHRTWV TROUGH APPEARS AS IF IT WILL BECOME A LITTLE STRONGER DURING THIS DAY AS IT BEGINS A SOUTHEASTWARD APPROACH TOWARDS THE CWA...WITH MODELS ALL SHOWING THE DEVELOPMENT OF A CLOSED LOW CENTER OVER NW ONTARIO AT 500MB. MORE LIGHT SYNOPTIC SNOW IS EXPECTED DUE TO HEIGHT FALLS FROM THIS DEEPENING SHRTWV TROUGH. AS FAR AS THE TIMING OF THE COLD AIR...MODELS REMAIN PRETTY CONSISTENT BOTH WITHIN THEMSELVES AND AMONGST EACH OTHER...WITH ONLY VERY SLIGHT DIFFERENCES (I.E. GFS MOST AGGRESSIVE DRIVING COLD AIR IN COMPARED TO THE NAM/UKMET). AS THE SURFACE LOW MOVES ACROSS NORTHERN ONTARIO TOWARDS THE NORTH SHORE OF LAKE SUPERIOR...THE ARCTIC FRONT IS EXPECTED TO MAKE ITS TREK ACROSS THE CWA. A CONVERGENT SNOW BAND SEEMS LIKELY TO FORM ALONG THIS FRONT AS IT CROSSES WESTERN LAKE SUPERIOR AND PUSHES INTO THE WESTERN U.P.. 850MB TEMPS IN THE LOW -10S C SUGGESTS THAT GOOD DENDRITE PRODUCTION WILL OCCUR...MEANING A BRIEF PERIOD OF HEAVY SNOWFALL RATES. THE BAND WILL FALL APART AS IT MOVES INTO THE CENTRAL U.P.. WIND FLOW TURNING WESTERLY IN THE WAKE OF THE FRONT MIGHT BE ENOUGH TO KEEP ANY LES OUT OF THE NE CWA...EXCEPT FOR RIGHT ALONG THE SHORELINE FROM GRAND MARAIS TO WHITEFISH POINT. WEST WINDS ARE GOOD FOR THE KEWEENAW...AND UNTIL THE FULL ARCTIC AIR COMES IN (NOT INDICATED UNTIL SAT NIGHT)...DENDRITE PRODUCTION FROM LAKE EFFECT SNOW WILL CONTINUE. HOWEVER...THE WEST WINDS ARE QUITE STRONG...AIDED BY RAPID PRESSURE RISES...WHICH MEANS THE DENDRITES WILL BREAK APART AND THUS CREATING SIGNIFICANT REDUCTION IN VISIBILITIES AND LOWERING SNOW TO WATER RATIOS. THE STRONG WIND WILL HELP TO BLOW WESTERN LAKE SUPERIOR LAKE EFFECT BANDS FARTHER INLAND...LIKELY RIGHT ACROSS MARQUETTE COUNTY. IN ADDITION...THIS STRONG WESTERLY WIND DRIVING IN COLDER AIR MEANS A FALLING TEMPERATURE SETUP... ESPECIALLY IN THE AFTERNOON. IWD TEMP COULD FALL INTO THE SINGLE DIGITS BY 00Z. THE BLUSTERY WIND WILL MAKE CONDITIONS FEEL WORSE AS WIND CHILLS DROP. SAT NIGHT INTO SUN...ARCTIC AIRMASS POURS INTO THE CWA. ALL MODELS ARE IN GOOD AGREEMENT INDICATING THE CLOSED 500MB LOW CENTER MOVING ACROSS EASTERN LAKE SUPERIOR SAT NIGHT. SOUTH OF THIS UPPER LOW CENTER...850MB TEMPS ARE PROGGED TO DROP INTO THE -25 TO -30C RANGE BY 12Z SUN ON STIFF NW WINDS. WIND CHILL ADVISORY CRITERIA IS A SURE BET...AND MOST AREAS ALONG THE WISCONSIN BORDER LOOK VERY GOOD FOR REACHING WARNING CRITERIA AS WNW WINDS DRAG COLD AIR IN FROM MN AND NW WI. HAVE ISSUED WIND CHILL WATCHES FOR THE MOST LIKELY CANDIDATES OF GOGEBIC...IRON AND DICKINSON. CONTEMPLATED MENOMINEE...BUT DOWNSLOPING NW WIND KEEPS THE COUNTY WARMER (NOTED IN MOS GUIDANCE) AND THUS HAVE HELD OFF AT THIS POINT. HAVE FOLLOWED LOWER GUIDANCE VALUES FOR TEMPS BOTH SAT NIGHT AND SUN SINCE THE ARCTIC AIRMASS IS MOVING IN SO QUICK THAT IT MAY NOT HAVE TIME TO MODIFY. IN ADDITION TO THE COLD...THE NEXT CONCERNS ARE WIND AND BLOWING SNOW. ALTHOUGH THE 00Z GFS IS THE MOST AGGRESSIVE WITH THE SYSTEM...IT DOES COME BACK INTO ALIGNMENT WITH THE ECMWF/UKMET BY 12Z SUN...BOTH WITH THE TRACK AND AMOUNT OF COLD AIR. EVEN THE WIND FIELDS LOOK SIMILAR. HOWEVER...AM CONCERNED THAT THE LOW TRACK MIGHT BE OFF IN ALL MODELS AS THE SETUP WITH THE UPPER LOW SUGGESTS A MORE LIKELY SFC LOW TRACK ALONG THE LAKE SUPERIOR/ONTARIO SHORELINE. IN FACT...BOTH THE 00Z REGIONAL CANADIAN AND 03Z RUC 13 FROM ESRL INDICATE THIS TRACK. GUSTS FROM THE 03Z RUC 13 SHOW AT 03Z SUN OF 35-40 KT OVER MUCH OF UPPER MI...WITH A CORRIDOR OF 50 KT NEAR PICTURED ROCKS. SINCE THE GFS/ECMWF BOTH SHOW 925MB WINDS INCREASING TO 40-45 KT AND THERE IS NO PROBLEM MIXING THIS DOWN GIVEN THE ARCTIC AIR...THE BLIZZARD WIND SPEED CRITERIA IS EASILY MET. SOUNDINGS FROM THE GFS IN BOTH THE KEWEENAW AND EASTERN U.P. DEPICT A PROFILE VERY FAVORABLE FOR A LOT OF FINE SNOWFLAKES FROM THE LAKE EFFECT. GIVEN THE STRONG WIND... WOULD IMAGINE THAT VISIBILITIES WILL BE GREATLY REDUCED...VERY SIMILAR TO THE PAST BLIZZARD EVENT. THUS HAVE DECIDED TO CHANGE THE WINTER STORM WATCH TO A BLIZZARD WATCH. INCLUDED ONTONAGON COUNTY... AND ALGER INTO LUCE COUNTIES BASED ON THE 00Z GFS/ECMWF/RUC 13 OUTPUT. THE REST OF THE CWA WILL LIKELY NEED WINTER WEATHER OR WIND CHILL ADVISORIES...BUT THOSE ARE USUALLY ISSUED CLOSER TO THE EVENT. CONDITIONS SHOULD GRADUALLY IMPROVE SUNDAY AFTERNOON AS WINDS RELAX DUE TO THE UPPER AND SURFACE LOWS HEADING EAST TOWARDS QUEBEC. SUN NIGHT INTO MON....ECMWF/GFS/UKMET BEGIN TO SHOW DIFFERENCES WITH REGARDS TO HOW QUICK THE UPPER LOW OFF TO THE EAST EJECTS UP TOWARDS NEWFOUNDLAND. THE GFS/UKMET ARE MORE PROGRESSIVE...WHICH ALLOWS FLOW TO TURN ZONAL OVER THE CWA...AND THUS BRINGS MORE MID/HIGH CLOUDS IN DURING THIS PERIOD AND WARMER AIR COMPARED TO THE ECMWF. HAVE WENT WITH A COMPROMISE FOR NOW...WHICH ALLOWS TEMPS TO REALLY COOL OFF SUN NIGHT. IF THE ECMWF IS CORRECT...SOME INLAND LOCATIONS WILL LIKELY DROP TO 20 BELOW ZERO AS THE DRY ARCTIC HIGH CURRENTLY OVER THE YUKON SITS OVERHEAD. NORTHWEST WINDS MEANS A CONTINUATION OF LAKE EFFECT...BUT WITH LOWERING INVERSION HEIGHTS...SNOWFALL AMOUNTS APPEAR TO BE LESS THAN THOSE FOR SAT NIGHT INTO SUN (THOUGH EVEN THOSE ARE NOT TOO MUCH TO WRITE HOME ABOUT GIVEN THE SMALL SNOWFLAKE SIZE). INCREASING CLOUDS SEEM LIKE A GOOD BET ON MONDAY FROM BOTH MODELS...THOUGH. HAVE LOWERED TEMPS SLIGHTLY...AND KEPT IN THE LOW CHANCES OF SNOW IN THE EVENT THE GFS SCENARIO PANS OUT. && .AVIATION (FOR THE 18Z TAF ISSUANCE)... EXPECT VFR CONDITIONS AT SAW TO GIVE WAY TO IFR CIGS/MVFR VSBY TNGT AS PERSISTENT SLY FLOW AHEAD OF WEAK SFC LO MOVING THRU THE UPR MIDWEST GRADUALLY DRAWS MORE MSTR INTO THE AREA. AS THE LO APRCHS LATER TNGT...EXPECT A PD OF LGT SN WITH IFR VSBY/CIGS PREDOMINATING. CONDITIONS WL IMPROVE A BIT ON SAT MRNG...BUT LACK OF SGNFT DRYING IN THE WAKE OF SFC LO SUGS LO CLDS/SOME FOG WL LINGER. AT CMX...MORE IMPRESSIVE LLVL MOISTENING APPEARS WL SLIDE TO THE E...SO LO CLD THERE SHOULD BE MORE TRANSIENT THRU TNGT WITH VFR CIGS PREDOMINATING EVEN IF MVFR CONDITIONS APPEAR FM TIME TO TIME. ALTHOUGH FOG IS LIKELY THERE TNGT...LACK OF LLVL MOISTENING WITH LO/ PCPN SHIELD STAYING TO THE SE AS WELL AS MID CLD DECK SHOULD PREVENT VSBY FM DROPPING TOO FAR. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... NORTHWEST GALES STILL ON TRACK TO SPREAD ACROSS LAKE SUPERIOR SATURDAY AFTERNOON AND SATURDAY EVENING AS AN ARCTIC COLD FRONT SHIFTS ACROSS THE UPPER GREAT LAKES. STORM FORCE WINDS COULD ALSO OCCUR...BUT ENOUGH UNCERTAINTY EXISTS TO KEEP THEM OUT FOR NOW. GALES SHOULD DIMINISH SUNDAY NIGHT AS HIGH PRESSURE RIDGE DRIFTING EAST FROM THE UPPER MISSISSIPPI RIVER VALLEY HELPS WEAKEN THE PRESSURE GRADIENT OVER THE LAKE. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... BLIZZARD WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING FOR MIZ006-007. BLIZZARD WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY AFTERNOON FOR MIZ001>003. WIND CHILL WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING FOR MIZ009>011. LAKE SUPERIOR...NONE. LAKE MICHIGAN...NONE. && $$ SYNOPSIS/DISCUSSION...AJ AVIATION...KC MARINE...DLG mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 432 AM EST FRI FEB 8 2008 ...BLIZZARD CONDITIONS POSSIBLE IN NORTHWEST FLOW SNOWBELTS THIS WEEKEND... .SYNOPSIS... 08Z WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS SHOWED BROAD TROUGHING COVERING MUCH OF NORTH AMERICA. WITHIN THIS TROUGH...FEATURES TO NOTE FOR THIS FORECAST INCLUDE A WEAK SHRTWV TROUGH OVER THE NORTHERN PLAINS...A SHRTWV TROUGH OVER UT/CO...AND A POTENT SHRTWV TROUGH DROPPING SE INTO CENTRAL BRITISH COLUMBIA NORTH OF A 140 KT JET AT 200MB MOVING ACROSS VANCOUVER ISLAND. THE SHRTWV TROUGH OVER THE NORTH PLAINS...COMBINED WITH SOME WEAK ISENTROPIC LIFT ON THE 290-300K SURFACES HAS PRODUCED WIDESPREAD MID AND HIGH CLOUDS OVER MN AND THE DAKOTAS PER IR IMAGERY. BELOW THESE HIGHER CLOUDS...11U-3.9U IMAGERY AND SFC OBS DEPICT LOW STRATUS FROM NORTHERN ILLINOIS INTO NW WI AND MUCH OF MN. THESE LOW CLOUDS ARE IN A WEAK MOISTURE ADVECTION SETUP AHEAD OF A 100MB LOW OVER THE DAKOTAS...AND BELOW A SUBSIDENCE INVERSION AROUND 900MB SEEN ON THE 00Z MPX SOUNDING. AIRMASS IS RELATIVELY MILD OVER THE NORTHERN PLAINS AND WESTERN GREAT LAKES COMPARED TO CLIMATOLOGY...WITH READINGS OF -8C AT INL...APX AND MPX. HOWEVER...AS HAS BEEN STATED IN PREVIOUS DISCUSSIONS AND SPS STATEMENTS...THESE READINGS WILL BE TAKING A TUMBLE THIS WEEKEND. UPSTREAM JUST NORTH OF THE POTENT BRITISH COLUMBIA SHRTWV...850MB TEMPS ARE IN THE LOW -30S C (SEE 00Z CYYE OR FORT NELSON BRITISH COLUMBIA SOUNDING). SURFACE TEMPS THERE ALSO REFLECT THE COLD AIR...WITH READINGS IN THE 20S AND 30S BELOW ZERO. UP IN THE YUKON...MAYO (SITE CYMA) IS REPORTING -60F! SURFACE ANALYSIS DEPICTS A 997MB SURFACE LOW ASSOCIATED WITH THIS POTENT SHRTWV JUST TO THE WEST OF EDMONTON ALBERTA...WITH 1030MB HIGH PRESSURE OVER THE YUKON. && .DISCUSSION... MAIN FORECAST CONCERN IS WITH WINDS...TEMPS AND POTENTIAL BLIZZARD CONDITIONS THIS WEEKEND. TODAY...NORTHERN PLAINS SHRTWV TROUGH AND THE OTHER SHRTWV TROUGH IN UT/CO WILL SORT OF CONSOLIDATE AS THEY DROP DOWN INTO THE MID MISSISSIPPI VALLEY BY 00Z. THIS MEANS MUCH OF THE DYNAMICS FOR PRODUCING PCPN WILL STAY AWAY FROM HERE...AND THUS A DRY FORECAST IS INDICATED. HOWEVER...THE MID AND HIGH CLOUDS ARE EXPECTED TO MIGRATE TO THE EAST AS THE AREA OF ISENTROPIC LIFT SHIFTS EAST. IN ADDITION...LOW CLOUDS SITUATED TO OUR SW WILL ADVECT INTO THE CWA THIS MORNING AS 925-950MB WINDS SHIFT TO THE S TO SW. THE INCREASE IN CLOUD COVER THROUGH THE DAY WILL LIKELY KEEP TEMPS FROM GETTING TOO HIGH...BUT GUIDANCE VALUES IN THE MID TO UPPER 20S SEEM REASONABLE GIVEN READINGS TO OUR SW AND SLOW DAYTIME HEATING. TONIGHT...THE CONSOLIDATED SHRTWV TROUGH OVER THE MID-MISSISSIPPI VALLEY IS PROGGED TO LIFT NE INTO LOWER MICHIGAN...RESULTING IN SOME HEIGHT FALLS OVER THE CWA. WITH ISENTROPIC LIFT PERSISTING... ESPECIALLY DURING THE EVENING...WOULD EXPECT THAT A LITTLE SNOW WILL MOVE THROUGH THE CWA. LACK OF SIGNIFICANT MOISTURE AS SEEN ON 00Z SOUNDINGS ACROSS THE PLAINS SUGGESTS ANY AMOUNTS SHOULD BE ON THE LIGHT SIDE. CLOUD COVER ASSOCIATED WITH THE TROUGH MOVING THROUGH WILL HELP KEEP TEMPS UP...AND THUS STAYED ON THE HIGH END OF GUIDANCE. MEANWHILE TO OUR NW...THE POTENT BRITISH COLUMBIA SHRTWV IS PROGGED TO DROP DOWN INTO SOUTHERN MANITOBA BY 12Z SAT...WITH A 996MB LOW MOVING INTO NW ONTARIO AND THE ARCTIC FRONT DRAPED SOUTH THROUGH MPX. SAT...POTENT SHRTWV TROUGH APPEARS AS IF IT WILL BECOME A LITTLE STRONGER DURING THIS DAY AS IT BEGINS A SOUTHEASTWARD APPROACH TOWARDS THE CWA...WITH MODELS ALL SHOWING THE DEVELOPMENT OF A CLOSED LOW CENTER OVER NW ONTARIO AT 500MB. MORE LIGHT SYNOPTIC SNOW IS EXPECTED DUE TO HEIGHT FALLS FROM THIS DEEPENING SHRTWV TROUGH. AS FAR AS THE TIMING OF THE COLD AIR...MODELS REMAIN PRETTY CONSISTENT BOTH WITHIN THEMSELVES AND AMONGST EACH OTHER...WITH ONLY VERY SLIGHT DIFFERENCES (I.E. GFS MOST AGGRESSIVE DRIVING COLD AIR IN COMPARED TO THE NAM/UKMET). AS THE SURFACE LOW MOVES ACROSS NORTHERN ONTARIO TOWARDS THE NORTH SHORE OF LAKE SUPERIOR...THE ARCTIC FRONT IS EXPECTED TO MAKE ITS TREK ACROSS THE CWA. A CONVERGENT SNOW BAND SEEMS LIKELY TO FORM ALONG THIS FRONT AS IT CROSSES WESTERN LAKE SUPERIOR AND PUSHES INTO THE WESTERN U.P.. 850MB TEMPS IN THE LOW -10S C SUGGESTS THAT GOOD DENDRITE PRODUCTION WILL OCCUR...MEANING A BRIEF PERIOD OF HEAVY SNOWFALL RATES. THE BAND WILL FALL APART AS IT MOVES INTO THE CENTRAL U.P.. WIND FLOW TURNING WESTERLY IN THE WAKE OF THE FRONT MIGHT BE ENOUGH TO KEEP ANY LES OUT OF THE NE CWA...EXCEPT FOR RIGHT ALONG THE SHORELINE FROM GRAND MARAIS TO WHITEFISH POINT. WEST WINDS ARE GOOD FOR THE KEWEENAW...AND UNTIL THE FULL ARCTIC AIR COMES IN (NOT INDICATED UNTIL SAT NIGHT)...DENDRITE PRODUCTION FROM LAKE EFFECT SNOW WILL CONTINUE. HOWEVER...THE WEST WINDS ARE QUITE STRONG...AIDED BY RAPID PRESSURE RISES...WHICH MEANS THE DENDRITES WILL BREAK APART AND THUS CREATING SIGNIFICANT REDUCTION IN VISIBILITIES AND LOWERING SNOW TO WATER RATIOS. THE STRONG WIND WILL HELP TO BLOW WESTERN LAKE SUPERIOR LAKE EFFECT BANDS FARTHER INLAND...LIKELY RIGHT ACROSS MARQUETTE COUNTY. IN ADDITION...THIS STRONG WESTERLY WIND DRIVING IN COLDER AIR MEANS A FALLING TEMPERATURE SETUP... ESPECIALLY IN THE AFTERNOON. IWD TEMP COULD FALL INTO THE SINGLE DIGITS BY 00Z. THE BLUSTERY WIND WILL MAKE CONDITIONS FEEL WORSE AS WIND CHILLS DROP. SAT NIGHT INTO SUN...ARCTIC AIRMASS POURS INTO THE CWA. ALL MODELS ARE IN GOOD AGREEMENT INDICATING THE CLOSED 500MB LOW CENTER MOVING ACROSS EASTERN LAKE SUPERIOR SAT NIGHT. SOUTH OF THIS UPPER LOW CENTER...850MB TEMPS ARE PROGGED TO DROP INTO THE -25 TO -30C RANGE BY 12Z SUN ON STIFF NW WINDS. WIND CHILL ADVISORY CRITERIA IS A SURE BET...AND MOST AREAS ALONG THE WISCONSIN BORDER LOOK VERY GOOD FOR REACHING WARNING CRITERIA AS WNW WINDS DRAG COLD AIR IN FROM MN AND NW WI. HAVE ISSUED WIND CHILL WATCHES FOR THE MOST LIKELY CANDIDATES OF GOGEBIC...IRON AND DICKINSON. CONTEMPLATED MENOMINEE...BUT DOWNSLOPING NW WIND KEEPS THE COUNTY WARMER (NOTED IN MOS GUIDANCE) AND THUS HAVE HELD OFF AT THIS POINT. HAVE FOLLOWED LOWER GUIDANCE VALUES FOR TEMPS BOTH SAT NIGHT AND SUN SINCE THE ARCTIC AIRMASS IS MOVING IN SO QUICK THAT IT MAY NOT HAVE TIME TO MODIFY. IN ADDITION TO THE COLD...THE NEXT CONCERNS ARE WIND AND BLOWING SNOW. ALTHOUGH THE 00Z GFS IS THE MOST AGGRESSIVE WITH THE SYSTEM...IT DOES COME BACK INTO ALIGNMENT WITH THE ECMWF/UKMET BY 12Z SUN...BOTH WITH THE TRACK AND AMOUNT OF COLD AIR. EVEN THE WIND FIELDS LOOK SIMILAR. HOWEVER...AM CONCERNED THAT THE LOW TRACK MIGHT BE OFF IN ALL MODELS AS THE SETUP WITH THE UPPER LOW SUGGESTS A MORE LIKELY SFC LOW TRACK ALONG THE LAKE SUPERIOR/ONTARIO SHORELINE. IN FACT...BOTH THE 00Z REGIONAL CANADIAN AND 03Z RUC 13 FROM ESRL INDICATE THIS TRACK. GUSTS FROM THE 03Z RUC 13 SHOW AT 03Z SUN OF 35-40 KT OVER MUCH OF UPPER MI...WITH A CORRIDOR OF 50 KT NEAR PICTURED ROCKS. SINCE THE GFS/ECMWF BOTH SHOW 925MB WINDS INCREASING TO 40-45 KT AND THERE IS NO PROBLEM MIXING THIS DOWN GIVEN THE ARCTIC AIR...THE BLIZZARD WIND SPEED CRITERIA IS EASILY MET. SOUNDINGS FROM THE GFS IN BOTH THE KEWEENAW AND EASTERN U.P. DEPICT A PROFILE VERY FAVORABLE FOR A LOT OF FINE SNOWFLAKES FROM THE LAKE EFFECT. GIVEN THE STRONG WIND... WOULD IMAGINE THAT VISIBILITIES WILL BE GREATLY REDUCED...VERY SIMILAR TO THE PAST BLIZZARD EVENT. THUS HAVE DECIDED TO CHANGE THE WINTER STORM WATCH TO A BLIZZARD WATCH. INCLUDED ONTONAGON COUNTY... AND ALGER INTO LUCE COUNTIES BASED ON THE 00Z GFS/ECMWF/RUC 13 OUTPUT. THE REST OF THE CWA WILL LIKELY NEED WINTER WEATHER OR WIND CHILL ADVISORIES...BUT THOSE ARE USUALLY ISSUED CLOSER TO THE EVENT. CONDITIONS SHOULD GRADUALLY IMPROVE SUNDAY AFTERNOON AS WINDS RELAX DUE TO THE UPPER AND SURFACE LOWS HEADING EAST TOWARDS QUEBEC. SUN NIGHT INTO MON....ECMWF/GFS/UKMET BEGIN TO SHOW DIFFERENCES WITH REGARDS TO HOW QUICK THE UPPER LOW OFF TO THE EAST EJECTS UP TOWARDS NEWFOUNDLAND. THE GFS/UKMET ARE MORE PROGRESSIVE...WHICH ALLOWS FLOW TO TURN ZONAL OVER THE CWA...AND THUS BRINGS MORE MID/HIGH CLOUDS IN DURING THIS PERIOD AND WARMER AIR COMPARED TO THE ECMWF. HAVE WENT WITH A COMPROMISE FOR NOW...WHICH ALLOWS TEMPS TO REALLY COOL OFF SUN NIGHT. IF THE ECMWF IS CORRECT...SOME INLAND LOCATIONS WILL LIKELY DROP TO 20 BELOW ZERO AS THE DRY ARCTIC HIGH CURRENTLY OVER THE YUKON SITS OVERHEAD. NORTHWEST WINDS MEANS A CONTINUATION OF LAKE EFFECT...BUT WITH LOWERING INVERSION HEIGHTS...SNOWFALL AMOUNTS APPEAR TO BE LESS THAN THOSE FOR SAT NIGHT INTO SUN (THOUGH EVEN THOSE ARE NOT TOO MUCH TO WRITE HOME ABOUT GIVEN THE SMALL SNOWFLAKE SIZE). INCREASING CLOUDS SEEM LIKE A GOOD BET ON MONDAY FROM BOTH MODELS...THOUGH. HAVE LOWERED TEMPS SLIGHTLY...AND KEPT IN THE LOW CHANCES OF SNOW IN THE EVENT THE GFS SCENARIO PANS OUT. && .AVIATION (FOR THE 06Z TAF ISSUANCE)... AT KCMX...AIRMASS MAY BE JUST COLD ENOUGH DURING THE NIGHT TO RESULT IN LAKE EFFECT CLOUD DEVELOPMENT UNDER W TO WSW FLOW. LATEST SATELLITE IMAGERY SUGGESTS SOME CLOUD DEVELOPMENT IS NOW BEGINNING TO OCCUR OVER THE HIGHER TERRAIN OF THE KEWEENAW N OF KCMX. IF LAKE EFFECT CLOUDS DO NOT FULLY DEVELOP...THE POTENTIAL EXISTS FOR SOME RADIATION FOG/STRATUS (MVFR CONDITIONS) TO DEVELOP UNDER GOOD RADIATIONAL COOLING CONDITIONS. SHOULD SEE IMPROVEMENT FOR A WHILE LATE MORNING INTO EARLY AFTN BEFORE CIGS AGAIN FALL TO MVFR AS LOW LEVEL MOISTURE ADVECTS INTO THE AREA FROM THE SW. AT KSAW... GENERALLY RETAINED PREVIOUS FCST OF OPTIMISTIC VFR CONDITIONS UNTIL FRI AFTN. HOWEVER...THERE MAY BE SOME RADIATION FOG/STRATUS DEVELOPMENT (MVFR CONDITIONS) TOWARD DAYBREAK FOR A FEW HRS. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... NORTHWEST GALES STILL ON TRACK TO SPREAD ACROSS LAKE SUPERIOR SATURDAY AFTERNOON AND SATURDAY EVENING AS AN ARCTIC COLD FRONT SHIFTS ACROSS THE UPPER GREAT LAKES. STORM FORCE WINDS COULD ALSO OCCUR...BUT ENOUGH UNCERTAINTY EXISTS TO KEEP THEM OUT FOR NOW. GALES SHOULD DIMINISH SUNDAY NIGHT AS HIGH PRESSURE RIDGE DRIFTING EAST FROM THE UPPER MISSISSIPPI RIVER VALLEY HELPS WEAKEN THE PRESSURE GRADIENT OVER THE LAKE. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... BLIZZARD WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING FOR MIZ006-007. BLIZZARD WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY AFTERNOON FOR MIZ001>003. WIND CHILL WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY MORNING FOR MIZ009>011. LAKE SUPERIOR...NONE. LAKE MICHIGAN...NONE. && $$ SYNOPSIS/DISCUSSION...AJ AVIATION...ROLFSON MARINE...DLG mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1206 PM EST THU FEB 7 2008 .AVIATION...VFR CONDITIONS EXPECTED THROUGH THURSDAY AS DRY AIR INFILTRATES THE REGION. WEAK STORM SYSTEM COULD BRING MVFR OVERCAST ALONG WITH A LIGHT SNOW THREAT LATER THURSDAY EVENING. MSB && .UPDATE...ISSUED 1038 PM EST WED FEB 06 THINGS PRETTY MUCH UNFOLDING AS PLANNED AS STRONG FGEN AND DEFORMATION DYNAMICS (RESPONSIBLE FOR BRINGING SEVERAL INCHES OF SNOW IN WARNED AND ADVISORIES AREAS WITH REPORTS OF 12+ INCHES JUST SOUTH OF OUR CWA) BEGIN TO PUSH SOUTHEAST OUT OF OUR AREA AS MID LEVEL CIRCULATION PIVOTS OUT OF SOUTHEAST MICHIGAN. LATEST RADAR TRENDS CONFIRM LOSS OF DYNAMICS WITH STEADILY SHRINKING SNOW SHIELD ALONG THE M-55 CORRIDOR. BASED OFF RADAR EXTRAPOLATION...SNOW SHOULD CONTINUE TO WEAKEN AND PULL SOUTHEAST...EXITING THE AREA DURING THE EARLY MORNING HOURS. HAVE BEGIN TO TRIM ADVISORY AREA FROM WEST TO EAST AND SEE NO REASON REST OF ADVISORY/WARNINGS WILL NEED TO BE EXTENDED BEYOND 06Z EXPIRATION TIME. FARTHER NORTH...PRONOUNCED LOW AND MID LEVEL DRYING MAKING STEADY SOUTHEAST PROGRESS...WITH SKIES BECOMING CLEAR OVER EASTERN UPPER MICHIGAN. EXPECT THIS TREND TO CONTINUE...WITH IMPROVING CEILINGS SPREADING SOUTH THROUGH THE OVERNIGHT. TEMPERATURE TRENDS THIS EVENING CLOSELY TIED TO CLOUD COVER...WITH READINGS ALREADY APPROACHING THE SINGLE DIGITS NORTH OF THE BRIDGE. LOWS PUSHING THE MID SINGLE DIGITS BELOW ZERO APPEAR A GOOD BET OVER THE TYPICAL COLDER LOCATIONS OF EASTERN UPPER MICHIGAN AND AROUND THE PELLSTON AREA OF NORTHERN LOWER. OTHERWISE...FORECAST LOW IN THE SINGLE DIGITS INTERIOR REGIONS TO LOW TO MID TEENS ALONG COASTAL AREAS APPEARS ON TARGET. UPDATED GRIDS/ZONES/WINTER WEATHER PRODUCTS/AND NEARSHORES OUT SHORTLY. MSB && .PREV DISCUSSION...ISSUED 330 PM EST WED FEB 06 ANOTHER DAY...ANOTHER TOUGH FCST...WITH THE CHALLENGE TONIGHT BEING LINGERING SNOW/AMOUNTS FOLLOWED BY TEMPERATURES...AND ADDITIONAL SMALL PRECIP CHANCES HEADING INTO TOMORROW. EARLY AFTN SUBJECTIVE ANALYSIS SHOWS THE MAIN PLAYER IN THE SHORT TERM...A POTENT CLOSED LOW ADVANCING THRU WESTERN IL AS OF 18Z...WITH HIGHLY DIFLUENT FLOW REGIME AIDING IN STRONG FORCED ASCENT INTO CENTRAL/LOWER MICHIGAN...AND A SUBSEQUENT RAPID UPTICK IN PRECIP COVERAGE THUS FAR TODAY. THIS OVERALL PATTERN WILL CONTINUE THE REMAINDER OF THE AFTN AND INTO TONIGHT AS STACKED SYSTEM SLIDES OVER FAR SOUTHERN MI...WITH AN ELONGATION OF 700-500MB DEFORMATION AXIS COUPLED WITH CONTINUED ISENTROPIC UPGLIDE/MOISTURE ADVECTION INTO RATHER STOUT TROWAL FEATURE SUPPORTING WIDESPREAD SNOW ACRS THE FAR SOUTHERN CWA. TO THE NORTH...PRONOUNCED LOW/MID LEVEL DRYING WORKING ITS WAY SOUTH IN CONJUNCTION WITH STRONG ARCTIC HIGH MOVING THRU ONTARIO...AIDED BY OVERALL SUBSIDENCE REGIME NORTH OF PRIMARY FORCING. WILL CONTINUE THEME OF PREVIOUS FORECASTS THIS EVENING...WITH WIDESPREAD SNOW ACRS THE M-55 CORRIDOR...AND POTENTIALLY A BIT FARTHER NORTH GIVEN LATEST RADAR TRENDS/RUC GUIDANCE...TRANSITIONING TO BASICALLY NOTHING BY LATE TONIGHT AS FORCING HEADS EAST AND WEAK SHORTWAVE RIDGING/SUBSIDENCE OVERTAKES THE AREA. THE HEAVIEST SNOW HAS YET TO FALL ACRS THE SOUTH...AND AS SUCH WILL OBVIOUSLY CONTINUE WITH HEADLINES AS WOULD THINK ANOTHER 3 TO LOCALLY 7 INCHES OF SNOW A GOOD BET OVERNIGHT...AND WILL HAVE TO WATCH POTENTIAL FOR WARNING CRITERIA TO BE MET IN A FEW SPOTS PER OVERALL BANDED LOOK TO UPSTREAM RADARS. TEMPS ARE THE OTHER CONCERN TONIGHT...AS POTENTIAL IS DEFINITELY THERE FOR A VERY COLD NIGHT ACRS THE NORTH GIVEN GOOD DRAINAGE FLOW SETUP PER PLACEMENT OF BUBBLE HIGH OVR SOUTHEAST ONTARIO. SKY COVER REMAINS TRICKY...OWING OBVIOUSLY TO EVENTUAL NORTHWARD EXTENT OF PRECIP/LOW CLOUD SHIELD EARLY TONIGHT. HOWEVER...GUT FEEL IS DRY INTRUSION WILL WIN OUT BY 06-09Z TIMEFRAME ACRS THE NORTHERN HALF OF THE CWA AS UPPER LOW SLIDES BY TO THE SOUTH...SETTING THE STAGE FOR SOME BELOW ZERO NUMBERS IN THE USUAL COLD SPOTS (KPLN/KANJ/KCIU). A QUIET DAY (RELATIVELY SPEAKING) RETURNS FOR TOMORROW AS WEAK SHORTWAVE RIDGING HOLDS THRU MIDDAY...THOUGH BY AFTN APPEARS NEXT IN A SERIES OF WEAK WAVES RIPPLING THRU THE FAST SEMI-ZONAL FLOW WILL MAKE A RUN AT NORTHERN MICHIGAN. MOISTURE WITH THIS FEATURE UNIMPRESSIVE...HOWEVER A RETURN TOWARD WEAK WARM ADVECTION BY AFTN COUPLED WITH AT LEAST SOME RESIDUAL MOISTURE NEARBY FROM CURRENT STORM ARGUES FOR CHANCY TYPE POPS FOR LIGHT SNOW ACRS THE WEST. PRIOR TO THAT TIME...EXPECT THE SUN TO MAKE A RELATIVELY RARE FEBRUARY APPEARANCE WITH DEEP LAYER DRY AIRMASS IN PLACE BEFORE CLDS RETURN BY AFTN. THUS TEMPS MAY SEE A JUMP FOR THE MORNING...SUCH THAT CURRENT READINGS IN THE MID/UPR 20S LOOK GOOD (THOUGH MAY HAVE TO CUT READINGS OVR THE SOUTH PENDING AMOUNT OF FRESH SNOW TONIGHT). LAWRENCE THURSDAY NIGHT AND FRIDAY...WEAK SURFACE RIDGING PUSHES OFF TO THE EAST. BROAD AREA OF LOW LEVEL WAA AND MID LEVEL DPVA AHEAD OF THE 500 MB TROUGH PLUS ASSOCIATED AREA OF ENHANCED MID/UPPER LEVEL MOISTURE WILL SLOWLY LIFT NE INTO MICHIGAN THURSDAY NIGHT AND FRIDAY. OVERALL LIFT IS RELATIVELY WEAK THRU THE PERIOD. MOISTURE IS INITIALLY LACKING...SPECIFICALLY AT MID LEVELS...BUT ENTIRE COLUMN DOES EVENTUALLY MOISTEN BY FRIDAY NIGHT. SOME SW FLOW LAKE ENHANCEMENT IS POSSIBLE...BUT MARGINAL AS 850 MB TEMPS HOLD AROUND -10 C (I.E. DELTA T`S AROUND 10 C). WILL MAINTAIN CHANCE POPS THRU THE PERIOD...HIGHLIGHTING FRIDAY NIGHT FOR THE HIGHEST POTENTIAL ACCUMULATION. MOST LOCATIONS WILL SEE WELL UNDER AN INCH OF NEW SNOW FOR BOTH THURSDAY NIGHT AND FRIDAY...AND AN INCH MAYBE TWO OF NEW SNOW FRIDAY NIGHT. LOW TEMPS BOTH THURSDAY NIGHT AND FRIDAY NIGHT WILL BE IN THE UPPER TEENS TO LOWER 20S. HIGH TEMPS FRIDAY AFTERNOON WILL BE A COUPLE OF DEGREES EITHER SIDE OF 30. SATURDAY THRU WEDNESDAY...VERY ACTIVE "SEE-SAW" TYPE PATTERN ANTICIPATED OVER THE WEEKEND INTO THE FIRST PART OF NEXT WEEK. SURFACE LOW WILL DEPART NRN MICHIGAN ON SATURDAY...OPENING THE DOOR TO STRONG/RAPID CAA SATURDAY NIGHT. ECMWF SHOWS 850 MB TEMPS DROPPING FROM AROUND -9 C AT 00Z SUNDAY TO -26 C BY 12Z SUNDAY. WINDS SHIFT TO THE NW SATURDAY NIGHT AND REMAIN IN THAT GENERAL VCNTY ALL OF SUNDAY AND INTO MONDAY...SETTING THE STAGE FOR A 36 TO 48 HR LONG LAKE EFFECT EVENT. PRIMARY LIMITATION WILL BE THE VERY COLD TEMPS AS 850 MB TEMPS HOLD IN THE NEGATIVE LOW TO MID 20S THRU THE ENTIRE EVENT. WINDS WILL ALSO BE FAIRLY STRONG DURING THE ONSET OF CAA (I.E. ON SUNDAY. WILL NEED TO KEEP AN EYE ON THIS EVENT AS IT DRAWS CLOSER FOR POSSIBLE HEADLINE ISSUES. COLD AIR BEGINS TO MODIFY ON TUESDAY AS A WEAK LOW PRESSURE SYSTEM PASSES TO OUR SOUTH...SERVING MAINLY TO DISRUPT LOW LEVEL WIND TRAJECTORIES AND BY ASSOCIATION... ONGOING LAKE EFFECT EVENT. STRONG WAA IS PROGGED TO TAKE PLACE ON WEDNESDAY. ECMWF WARMS 850 TEMPS FROM -14 C AT 12Z WEDNESDAY TO NEAR +1 C BY 00Z THURSDAY. WHILE THIS COULD VERY WELL BE OVERLY AGGRESSIVE...IT CERTAINLY POINTS TOWARD A SIGNIFICANT WARM-UP DURING THE MIDDLE PART OF NEXT WEEK (THUS THE "SEE-SAW"). OUR FIRST DRY PERIOD OF THE EXTENDED FORECAST WILL BE TUESDAY NIGHT...WITH DRY WX CONTINUING INTO WEDNESDAY AS WAA COMMENCES. && .APX WATCHES/WARNINGS/ADVISORIES... LM...SMALL CRAFT ADVISORY UNTIL 5 AM EST THURSDAY FOR LMZ323-342- 344>346. LH...SMALL CRAFT ADVISORY UNTIL 5 AM EST THURSDAY FOR LHZ347>349. && $$ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 1144 AM CST THU FEB 7 2008 .UPDATE...FOR AVIATION DISCUSSION BELOW && .DISCUSSION.../ISSUED 533 AM CST THU FEB 7 2008/ FORECAST CONCERNS REMAIN ON THE ARCTIC SURGE FOR THE WEEKEND...AND RESULTANT EFFECTS ON TEMPERATURES...WINDS...AND BLOWING SNOW POTENTIAL. AT PRESENT...SURFACE RIDGE AXIS EXTENDS NORTHWARD ACROSS THE FOREAST AREA...WITH TROUGH/FRONTAL BOUNDARY POISED JUST TO THE WEST OVER THE EASTERN DAKOTAS. SURGE OF WARM ADVECTION AHEAD OF THE TROUGH HAS LED TO DEVELOPMENT OF LOW STRATUS DECK AND PATCHY FOG...SOME OF IT DENSE...OVER SOUTH CENTRAL AND WESTERN MINNESOTA. NARROW BAND OF LIGHT SNOW ALONG THE TROUGH HAS BEEN DETERIORATING EARLY THIS MORNING AS IT PUSHES FURTHER EAST TOWARD MINNESOTA... DUE TO WEAKENING FORCING ALONG THE BOUNDARY. RUC ISENTROPIC ANALYSES SHOW THAT MAIN AREA OF UPLIFT/CONDENSATION PRESSURE DEFICITS MOVES NORTH OF THE FORECAST AREA ACROSS NORTHERN MINNESOTA...SO HAVE DROPPED PRECIP CHANCES TODAY IN FAVOR OF A MENTION OF FLURRIES. HAVE ALSO INSERTED A MENTION OF PATCHY FOG IN THE MORNING IN ROUGHLY THE WESTERN HALF OF THE AREA. HIGH TEMPERATURES SHOULD SHOW LITTLE CHANGE FROM YESTERDAYS...EXCEPT IN THE WEST AND SOUTH...WHERE A 5 TO 7 DEGREE JUMP APPEARS REASONABLE. CLIPPER SYSTEM DROPS THROUGH THE DAKOTAS AND INTO WESTERN/CENTRAL MINNESOTA ON FRIDAY. 280/285K ISENTROPIC SURFACES DEPICT BLOSSOMING REGION OF LOW CONDENSATION PRESSURE DEFICITS AND LIFT OVER PRIMARILY THE EASTERN HALF OF THE FORECAST AREA DURING THE AFTERNOON TOMORROW AS A POTENT SHORTWAVE INTERACTS WITH THE SURFACE TROUGH AND WEAK AREA OF MID LEVEL FRONTOGENESIS DEVELOPS. AMOUNTS LOOK LIGHT...ALTHOUGH UP TO AN INCH MAY FALL TO THE NORTHEAST OF THE I-94 CORRIDOR IN EASTERN MINNESOTA AND ACROSS WEST CENTRAL WISCONSIN. THE SIGNIFICANT CHANGE IN THE WEATHER LOOKS TO AFFECT THE REGION BEGINNING EARLY SATURDAY MORNING. MODELS VERY CONSISTENT IN THE DEVELOPMENT OF A POTENT SURFACE LOW OVER FAR SOUTHERN CANADA/NORTHERN MINNESOTA FRIDAY NIGHT AND SATURDAY...AS A DEEPENING UPPER TROUGH/POTENTIAL VORTICITY ANOMALY RACE SOUTHEASTWARD. MINNESOTA/WISCONSIN WILL BE ON THE NORTH SIDE OF A 150 KT UPPER JET...WITH A POTENTIAL VORTICITY ANOMALY THAT EXTENDS TO ABOUT 650/700 MB. BOTH THE GFS/NAM DEPICT 6 HOUR SURFACE PRESSURE RISES OF AT LEAST 15 MB BEHIND THE ATTENDANT COLD FRONT. ALL OF THIS POINTS TOWARD A VERY WINDY DAY ON SATURDAY AND INTO SATURDAY NIGHT FOR THE ENTIRE FORECAST AREA. AT THIS POINT...HAVE GONE WITH MAXIMUM WIND SPEEDS IN THE 30 KT RANGE...WITH 40 TO 45 KT GUSTS...ESPECIALLY IN THE FAVORED AREAS ALONG THE MINNESOTA RIVER VALLEY...AND THE I-90 CORRIDOR. AS THE TROUGH SWINGS THROUGH...MOST LIKELY AREAS TO RECEIVE SNOW LOOK TO BE TO THE NORTHEAST OF THE I-94 CORRIDOR...ALTHOUGH CHANCES OF SNOW STILL EXIST ACROSS THE REMAINDER OF THE FORECAST AREA...AHEAD OF THE MAIN BLAST OF COLD ADVECTION ACCOMPANYING THE FRONT. IF ANY SNOW IS ABLE TO ACCUMULATE FROM THE FRIDAY SYSTEM...OR FROM THIS ONE...THE VERY WINDY CONDITIONS COULD RESULT IN GROUND BLIZZARD CONDITIONS ACROSS PARTS OF THE AREA. AT THIS POINT...HAVE HIT THE BLOWING SNOW POTENTIAL FAIRLY STRONGLY IN THE GRIDS...USING DEFINITE WORDING IN WEST CENTRAL MINNESOTA IN THE MORE OPEN AREAS. THIS WILL HAVE TO BE WATCHED CLOSELY BY LATER SHIFTS FOR POSSIBLE HEADLINES...BUT AT THIS TIME...WE WILL JUST MENTION IT HERE...IN THE GRIDS...AND THE HWO/WEATHER STORY GRAPHIC. TEMPERATURES WILL TAKE A SIGNIFICANT PLUNGE AS 850 MB TEMPERATURES PLUNGE TO -30C OR LESS ACROSS PARTS OF THE AREA. TIMING THE TEMPERATURE PLUNGE WILL BE DIFFICULT...BUT HAVE LARGELY GONE WITH A NON DIURNAL TREND FOR SATURDAY...WITH HIGHS OCCURRING VERY NEAR THE 12-15Z TIME FRAME...SIMILAR TO THE LAST ARCTIC PLUNGE WE HAD BACK IN LATE JANUARY. HAVE ALSO SHOWN A VERY STRONG GRADIENT IN FRIDAY NIGHT LOWS/SATURDAY HIGHS FROM WEST TO EAST ACROSS THE FORECAST AREA. TEMPERATURES ON SATURDAY NIGHT SHOULD PLUNGE INTO THE DOUBLE DIGIT BELOW ZERO RANGE. WITH WINDS REMAINING UP THROUGH SATURDAY NIGHT...WE WILL MOST LIKELY BE LOOKING AT WIND CHILL ADVISORIES...IF NOT WARNINGS...FOR LATE SATURDAY AND SATURDAY NIGHT...SOMETHING ELSE TO MENTION IN THE HWO/WEATHER STORY. DISCREPANCIES EXIST BETWEEN THE GFS/ECMWF IN HOW LONG THE COLD TEMPERATURES WILL HANG AROUND...BUT HAVE FAVORED THE ECMWF...KEEPING THE COLD AROUND A LITTLE LONGER. TEMPERATURES ON SUNDAY MAY NOT REACH THE ZERO DEGREE MARK...BUT DO NOT HAVE THE CONFIDENCE TO DEPICT BELOW ZERO HIGHS ACROSS THE WHOLE FORECAST AREA AT THIS TIME. HAVE GONE CLOSE THOUGH. WARM ADVECTION RETURNS FOR SUNDAY NIGHT/MONDAY AS THE ARCTIC HIGH PUSHES AWAY...BRINGING A CHANCE OF SNOW TO THE AREA FOR EARLY NEXT WEEK...AND A REBOUND IN TEMPERATURES ON MONDAY AFTERNOON. && .AVIATION.../18Z TAF ISSUANCE/ WEAK WARM FRONT ACROSS CENTRAL MN MOVING EAST. ASSOCIATED IFR CIGS WITH A FEW FLURRIES MAINLY OVER WESTERN WI. EXPECT FLURRIES TO END BY EARLY EVENING. MVFR/IFR CIGS WILL CONTINUE WITH SCT BREAKS. NEXT LOW APPROACHES FROM THE DAKOTAS TOMORROW. MORE WDSPRD IFR CONDS WILL MOVE IN FROM THE WEST BEGINNING LATE TONIGHT. HINTED AT LIGHT SNOW/FLURRIES BEGINNING FRI MORNING OVER MN LOCATIONS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ KAT/KFM mn AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 533 AM CST THU FEB 7 2008 .UPDATE... SENT OUT A QUICK UPDATE HALF AN HOUR AGO TO ADDRESS FOG SPREADING A LITTLE FARTHER TO THE EAST THAN INITIALLY EXPECTED...PER CURRENT SATELLITE TRENDS/SURFACE OBSERVATIONS/RUC13 RELATIVE HUMIDITY PROGS. THINKING IS THAT FOG WILL LIFT SOMEWHAT BY MID MORNING...WITH DECK BEING QUITE THIN...PER 12Z RAOB DATA FROM KMPX. ALSO ADDED 12Z AVIATION DISCUSSION BELOW. && .DISCUSSION... FORECAST CONCERNS REMAIN ON THE ARCTIC SURGE FOR THE WEEKEND...AND RESULTANT EFFECTS ON TEMPERATURES...WINDS...AND BLOWING SNOW POTENTIAL. AT PRESENT...SURFACE RIDGE AXIS EXTENDS NORTHWARD ACROSS THE FOREAST AREA...WITH TROUGH/FRONTAL BOUNDARY POISED JUST TO THE WEST OVER THE EASTERN DAKOTAS. SURGE OF WARM ADVECTION AHEAD OF THE TROUGH HAS LED TO DEVELOPMENT OF LOW STRATUS DECK AND PATCHY FOG...SOME OF IT DENSE...OVER SOUTH CENTRAL AND WESTERN MINNESOTA. NARROW BAND OF LIGHT SNOW ALONG THE TROUGH HAS BEEN DETERIORATING EARLY THIS MORNING AS IT PUSHES FURTHER EAST TOWARD MINNESOTA... DUE TO WEAKENING FORCING ALONG THE BOUNDARY. RUC ISENTROPIC ANALYSES SHOW THAT MAIN AREA OF UPLIFT/CONDENSATION PRESSURE DEFICITS MOVES NORTH OF THE FORECAST AREA ACROSS NORTHERN MINNESOTA...SO HAVE DROPPED PRECIP CHANCES TODAY IN FAVOR OF A MENTION OF FLURRIES. HAVE ALSO INSERTED A MENTION OF PATCHY FOG IN THE MORNING IN ROUGHLY THE WESTERN HALF OF THE AREA. HIGH TEMPERATURES SHOULD SHOW LITTLE CHANGE FROM YESTERDAYS...EXCEPT IN THE WEST AND SOUTH...WHERE A 5 TO 7 DEGREE JUMP APPEARS REASONABLE. CLIPPER SYSTEM DROPS THROUGH THE DAKOTAS AND INTO WESTERN/CENTRAL MINNESOTA ON FRIDAY. 280/285K ISENTROPIC SURFACES DEPICT BLOSSOMING REGION OF LOW CONDENSATION PRESSURE DEFICITS AND LIFT OVER PRIMARILY THE EASTERN HALF OF THE FORECAST AREA DURING THE AFTERNOON TOMORROW AS A POTENT SHORTWAVE INTERACTS WITH THE SURFACE TROUGH AND WEAK AREA OF MID LEVEL FRONTOGENESIS DEVELOPS. AMOUNTS LOOK LIGHT...ALTHOUGH UP TO AN INCH MAY FALL TO THE NORTHEAST OF THE I-94 CORRIDOR IN EASTERN MINNESOTA AND ACROSS WEST CENTRAL WISCONSIN. THE SIGNIFICANT CHANGE IN THE WEATHER LOOKS TO AFFECT THE REGION BEGINNING EARLY SATURDAY MORNING. MODELS VERY CONSISTENT IN THE DEVELOPMENT OF A POTENT SURFACE LOW OVER FAR SOUTHERN CANADA/NORTHERN MINNESOTA FRIDAY NIGHT AND SATURDAY...AS A DEEPENING UPPER TROUGH/POTENTIAL VORTICITY ANOMALY RACE SOUTHEASTWARD. MINNESOTA/WISCONSIN WILL BE ON THE NORTH SIDE OF A 150 KT UPPER JET...WITH A POTENTIAL VORTICITY ANOMALY THAT EXTENDS TO ABOUT 650/700 MB. BOTH THE GFS/NAM DEPICT 6 HOUR SURFACE PRESSURE RISES OF AT LEAST 15 MB BEHIND THE ATTENDANT COLD FRONT. ALL OF THIS POINTS TOWARD A VERY WINDY DAY ON SATURDAY AND INTO SATURDAY NIGHT FOR THE ENTIRE FORECAST AREA. AT THIS POINT...HAVE GONE WITH MAXIMUM WIND SPEEDS IN THE 30 KT RANGE...WITH 40 TO 45 KT GUSTS...ESPECIALLY IN THE FAVORED AREAS ALONG THE MINNESOTA RIVER VALLEY...AND THE I-90 CORRIDOR. AS THE TROUGH SWINGS THROUGH...MOST LIKELY AREAS TO RECEIVE SNOW LOOK TO BE TO THE NORTHEAST OF THE I-94 CORRIDOR...ALTHOUGH CHANCES OF SNOW STILL EXIST ACROSS THE REMAINDER OF THE FORECAST AREA...AHEAD OF THE MAIN BLAST OF COLD ADVECTION ACCOMPANYING THE FRONT. IF ANY SNOW IS ABLE TO ACCUMULATE FROM THE FRIDAY SYSTEM...OR FROM THIS ONE...THE VERY WINDY CONDITIONS COULD RESULT IN GROUND BLIZZARD CONDITIONS ACROSS PARTS OF THE AREA. AT THIS POINT...HAVE HIT THE BLOWING SNOW POTENTIAL FAIRLY STRONGLY IN THE GRIDS...USING DEFINITE WORDING IN WEST CENTRAL MINNESOTA IN THE MORE OPEN AREAS. THIS WILL HAVE TO BE WATCHED CLOSELY BY LATER SHIFTS FOR POSSIBLE HEADLINES...BUT AT THIS TIME...WE WILL JUST MENTION IT HERE...IN THE GRIDS...AND THE HWO/WEATHER STORY GRAPHIC. TEMPERATURES WILL TAKE A SIGNIFICANT PLUNGE AS 850 MB TEMPERATURES PLUNGE TO -30C OR LESS ACROSS PARTS OF THE AREA. TIMING THE TEMPERATURE PLUNGE WILL BE DIFFICULT...BUT HAVE LARGELY GONE WITH A NON DIURNAL TREND FOR SATURDAY...WITH HIGHS OCCURRING VERY NEAR THE 12-15Z TIME FRAME...SIMILAR TO THE LAST ARCTIC PLUNGE WE HAD BACK IN LATE JANUARY. HAVE ALSO SHOWN A VERY STRONG GRADIENT IN FRIDAY NIGHT LOWS/SATURDAY HIGHS FROM WEST TO EAST ACROSS THE FORECAST AREA. TEMPERATURES ON SATURDAY NIGHT SHOULD PLUNGE INTO THE DOUBLE DIGIT BELOW ZERO RANGE. WITH WINDS REMAINING UP THROUGH SATURDAY NIGHT...WE WILL MOST LIKELY BE LOOKING AT WIND CHILL ADVISORIES...IF NOT WARNINGS...FOR LATE SATURDAY AND SATURDAY NIGHT...SOMETHING ELSE TO MENTION IN THE HWO/WEATHER STORY. DISCREPANCIES EXIST BETWEEN THE GFS/ECMWF IN HOW LONG THE COLD TEMPERATURES WILL HANG AROUND...BUT HAVE FAVORED THE ECMWF...KEEPING THE COLD AROUND A LITTLE LONGER. TEMPERATURES ON SUNDAY MAY NOT REACH THE ZERO DEGREE MARK...BUT DO NOT HAVE THE CONFIDENCE TO DEPICT BELOW ZERO HIGHS ACROSS THE WHOLE FORECAST AREA AT THIS TIME. HAVE GONE CLOSE THOUGH. WARM ADVECTION RETURNS FOR SUNDAY NIGHT/MONDAY AS THE ARCTIC HIGH PUSHES AWAY...BRINGING A CHANCE OF SNOW TO THE AREA FOR EARLY NEXT WEEK...AND A REBOUND IN TEMPERATURES ON MONDAY AFTERNOON. && .AVIATION.../12Z TAF ISSUANCE/ DIFFICULT SET OF TAFS...ESPECIALLY IN THE SHORT TERM. IFR STRATUS DECK INVADING THE RGN ON THE BACKSIDE OF SFC RDG...WELL HANDLED BY RUC13 LO LVL RH ANALYSES AT LEAST IN PLACEMENT...WITH ABOUT A 2 HR LAG ON SPEED OF THE DECK. MSP/STC/RNH SHUD BE IN THE IFR CIGS FOR MUCH OF THE MRNG...WITH RWF BREAKING OUT NOT LONG AFTER TAF ISSUANCE. EAU WILL SEE THE DECK FROM MID MRNG THRU MID AFTN. VSBYS WILL ALSO BE REDUCED TO IFR IN THE DECK FOR THE MOST PART. WINDS SHUD BACK TO THE E AND SE THIS EVE AND OVRNGT...WHICH WOULD FAVOR A RETURN OF LOW CIGS/VSBYS...ESPECIALLY WITH THE ABNORMALLY WARM/MOIST SFC CONDITIONS EXPECTED TNGT...AND THE ONGOING WARM ADVECTION AHD OF NEXT SFC LO. HAVE PUT SOME IFR CIGS AND IFR/MVFR VSBYS IN AT ALL SITES EXCEPT MSP...AS ELECTED TO KEEP THEM MVFR FOR THE TIME BEING. SOMETHING TO MONITOR ON FUTURE ISSUANCES. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ KAT mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 255 AM CST THU FEB 7 2008 .DISCUSSION... FORECAST CONCERNS REMAIN ON THE ARCTIC SURGE FOR THE WEEKEND...AND RESULTANT EFFECTS ON TEMPERATURES...WINDS...AND BLOWING SNOW POTENTIAL. AT PRESENT...SURFACE RIDGE AXIS EXTENDS NORTHWARD ACROSS THE FOREAST AREA...WITH TROUGH/FRONTAL BOUNDARY POISED JUST TO THE WEST OVER THE EASTERN DAKOTAS. SURGE OF WARM ADVECTION AHEAD OF THE TROUGH HAS LED TO DEVELOPMENT OF LOW STRATUS DECK AND PATCHY FOG...SOME OF IT DENSE...OVER SOUTH CENTRAL AND WESTERN MINNESOTA. NARROW BAND OF LIGHT SNOW ALONG THE TROUGH HAS BEEN DETERIORATING EARLY THIS MORNING AS IT PUSHES FURTHER EAST TOWARD MINNESOTA... DUE TO WEAKENING FORCING ALONG THE BOUNDARY. RUC ISENTROPIC ANALYSES SHOW THAT MAIN AREA OF UPLIFT/CONDENSATION PRESSURE DEFICITS MOVES NORTH OF THE FORECAST AREA ACROSS NORTHERN MINNESOTA...SO HAVE DROPPED PRECIP CHANCES TODAY IN FAVOR OF A MENTION OF FLURRIES. HAVE ALSO INSERTED A MENTION OF PATCHY FOG IN THE MORNING IN ROUGHLY THE WESTERN HALF OF THE AREA. HIGH TEMPERATURES SHOULD SHOW LITTLE CHANGE FROM YESTERDAYS...EXCEPT IN THE WEST AND SOUTH...WHERE A 5 TO 7 DEGREE JUMP APPEARS REASONABLE. CLIPPER SYSTEM DROPS THROUGH THE DAKOTAS AND INTO WESTERN/CENTRAL MINNESOTA ON FRIDAY. 280/285K ISENTROPIC SURFACES DEPICT BLOSSOMING REGION OF LOW CONDENSATION PRESSURE DEFICITS AND LIFT OVER PRIMARILY THE EASTERN HALF OF THE FORECAST AREA DURING THE AFTERNOON TOMORROW AS A POTENT SHORTWAVE INTERACTS WITH THE SURFACE TROUGH AND WEAK AREA OF MID LEVEL FRONTOGENESIS DEVELOPS. AMOUNTS LOOK LIGHT...ALTHOUGH UP TO AN INCH MAY FALL TO THE NORTHEAST OF THE I-94 CORRIDOR IN EASTERN MINNESOTA AND ACROSS WEST CENTRAL WISCONSIN. THE SIGNIFICANT CHANGE IN THE WEATHER LOOKS TO AFFECT THE REGION BEGINNING EARLY SATURDAY MORNING. MODELS VERY CONSISTENT IN THE DEVELOPMENT OF A POTENT SURFACE LOW OVER FAR SOUTHERN CANADA/NORTHERN MINNESOTA FRIDAY NIGHT AND SATURDAY...AS A DEEPENING UPPER TROUGH/POTENTIAL VORTICITY ANOMALY RACE SOUTHEASTWARD. MINNESOTA/WISCONSIN WILL BE ON THE NORTH SIDE OF A 150 KT UPPER JET...WITH A POTENTIAL VORTICITY ANOMALY THAT EXTENDS TO ABOUT 650/700 MB. BOTH THE GFS/NAM DEPICT 6 HOUR SURFACE PRESSURE RISES OF AT LEAST 15 MB BEHIND THE ATTENDANT COLD FRONT. ALL OF THIS POINTS TOWARD A VERY WINDY DAY ON SATURDAY AND INTO SATURDAY NIGHT FOR THE ENTIRE FORECAST AREA. AT THIS POINT...HAVE GONE WITH MAXIMUM WIND SPEEDS IN THE 30 KT RANGE...WITH 40 TO 45 KT GUSTS...ESPECIALLY IN THE FAVORED AREAS ALONG THE MINNESOTA RIVER VALLEY...AND THE I-90 CORRIDOR. AS THE TROUGH SWINGS THROUGH...MOST LIKELY AREAS TO RECEIVE SNOW LOOK TO BE TO THE NORTHEAST OF THE I-94 CORRIDOR...ALTHOUGH CHANCES OF SNOW STILL EXIST ACROSS THE REMAINDER OF THE FORECAST AREA...AHEAD OF THE MAIN BLAST OF COLD ADVECTION ACCOMPANYING THE FRONT. IF ANY SNOW IS ABLE TO ACCUMULATE FROM THE FRIDAY SYSTEM...OR FROM THIS ONE...THE VERY WINDY CONDITIONS COULD RESULT IN GROUND BLIZZARD CONDITIONS ACROSS PARTS OF THE AREA. AT THIS POINT...HAVE HIT THE BLOWING SNOW POTENTIAL FAIRLY STRONGLY IN THE GRIDS...USING DEFINITE WORDING IN WEST CENTRAL MINNESOTA IN THE MORE OPEN AREAS. THIS WILL HAVE TO BE WATCHED CLOSELY BY LATER SHIFTS FOR POSSIBLE HEADLINES...BUT AT THIS TIME...WE WILL JUST MENTION IT HERE...IN THE GRIDS...AND THE HWO/WEATHER STORY GRAPHIC. TEMPERATURES WILL TAKE A SIGNIFICANT PLUNGE AS 850 MB TEMPERATURES PLUNGE TO -30C OR LESS ACROSS PARTS OF THE AREA. TIMING THE TEMPERATURE PLUNGE WILL BE DIFFICULT...BUT HAVE LARGELY GONE WITH A NON DIURNAL TREND FOR SATURDAY...WITH HIGHS OCCURRING VERY NEAR THE 12-15Z TIME FRAME...SIMILAR TO THE LAST ARCTIC PLUNGE WE HAD BACK IN LATE JANUARY. HAVE ALSO SHOWN A VERY STRONG GRADIENT IN FRIDAY NIGHT LOWS/SATURDAY HIGHS FROM WEST TO EAST ACROSS THE FORECAST AREA. TEMPERATURES ON SATURDAY NIGHT SHOULD PLUNGE INTO THE DOUBLE DIGIT BELOW ZERO RANGE. WITH WINDS REMAINING UP THROUGH SATURDAY NIGHT...WE WILL MOST LIKELY BE LOOKING AT WIND CHILL ADVISORIES...IF NOT WARNINGS...FOR LATE SATURDAY AND SATURDAY NIGHT...SOMETHING ELSE TO MENTION IN THE HWO/WEATHER STORY. DISCREPANCIES EXIST BETWEEN THE GFS/ECMWF IN HOW LONG THE COLD TEMPERATURES WILL HANG AROUND...BUT HAVE FAVORED THE ECMWF...KEEPING THE COLD AROUND A LITTLE LONGER. TEMPERATURES ON SUNDAY MAY NOT REACH THE ZERO DEGREE MARK...BUT DO NOT HAVE THE CONFIDENCE TO DEPICT BELOW ZERO HIGHS ACROSS THE WHOLE FORECAST AREA AT THIS TIME. HAVE GONE CLOSE THOUGH. WARM ADVECTION RETURNS FOR SUNDAY NIGHT/MONDAY AS THE ARCTIC HIGH PUSHES AWAY...BRINGING A CHANCE OF SNOW TO THE AREA FOR EARLY NEXT WEEK...AND A REBOUND IN TEMPERATURES ON MONDAY AFTERNOON. && .AVIATION.../06Z TAF ISSUANCE/ TRICKY FORECAST OVERNIGHT WITH BROAD HIGH PRESSURE OVERHEAD AND PATCHY AREAS OF FOG DEVELOPING AND LOW STRATUS CONTINUING TO FILL THE SKIES OVER SOUTHWEST MINNESOTA JUST SOUTHWEST OF KRWF. EXPECT THAT THE LOW STRATUS WILL MAKE SOME NORTHEASTWARD PROGRESS OVER THE NEXT SEVERAL HOURS AS LOW LEVEL WINDS ABOVE THE SFC START TO INCREASE FROM THE WSW. WOOD LAKE PROFILER STILL SHOWS CALM WINDS AT 925 MB ABUT EXPECT THIS TO BEGIN TO INCREASE. LOW LEVEL MOISTURE AXIS DOES APPEAR TO EXTEND NORTHWARD INTO CENTRAL MN BUT IS NOT ENOUGH TO GENERATE CLOUDS YET. IFR CONDITIONS MAY REACH KRWF IN THE NEXT FEW HOURS WITH POTENTIAL FOR MVFR CIGS TO DEVELOP TOWARDS KSTC AND KMSP LATER TONIGHT. HAVE ALSO INCLUDED FOG TO VARYING DEGREES AT THE SITES WITH HIGH PRESSURE BUT PINNING DOWN HOW LOW AND HOW LONG IT WILL LAST IS DIFFICULT. LOW PRESSURE TROUGH MOVING EASTWARD ACROSS THE DAKOTAS IS SENDING SOME MID LEVEL CLOUD COVER INTO WESTERN MINNESOTA AND THIS WILL CONTINUE. LIGHT SNOW ALSO BEING REPORTED WITH SOME MVFR VIS RESTRICTIONS FOR A BRIEF TIME. EXPECT KAXN AND KSTC TO HAVE THE BEST CHANCE FOR LIGHT SNOW WITH THE BAND REACHING KAXN AROUND 10Z OR SO. SYSTEM LOSES PUNCH AS IT MOVES EAST BUT SOME FLURRIES OR BRIEF LIGHT SNOW MAY AFFECT ALL SITES BUT EXPECT LITTLE IF ANY VIS REDUCTION OUTSIDE OF KAXN AND KSTC AREAS. WINDS REMAIN LIGHT THROUGH THE PERIOD WITH A TREND TO THE SOUTHWEST. CLOUD COVERAGE THURSDAY ALSO PROBLEMATIC BUT EXPECT A MIX OF MVFR AND VFR CIGS WITH POSSIBLE CLEARING WINDOW BEHIND THE PASSING TROUGH. ANOTHER TROUGH QUICKLY SENDS MID AND HIGH CLOUDS BACK OVER THE AREA LATE THURSDAY AFTERNOON AND THURSDAY EVENING. ..MDB.. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ KAT/MDB mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON MS 945 PM CST THU FEB 7 2008 .DISCUSSION...SATELLITE IMAGERY/RUC ANALYSIS SHOWS AXIS OF UPPER TROUGH MOVING INTO WESTERN ALABAMA ALREADY. SURFACE ANALYSIS HAS THE WEAKENING ASSOCIATED LOW OVER GREENWOOD. THIS LOW WILL CONTINUE TO WEAKEN AND SHIFT EAST TONIGHT. NO PRECIPITATION BUT SOME MID LEVEL CLOUDS WERE NOTED WITH THE LOW IN OUR NORTHERN COUNTIES. A FEW GUSTS WERE STILL BEING REPORTED BEHIND THE COLD FRONT ALONG THE MISSISSIPPI RIVER BUT THESE SHOULD BECOME LIGHTER AS THE FRONT MOVES INTO CENTRAL MISSISSIPPI. SOUTHERLY WINDS AHEAD OF THE FRONT HAVE HELD TEMPERATURES AND DEW POINTS UP IN OUR SOUTHWEST. HAVE BUMPED UP FORECAST LOWS A FEW DEGREES THERE AND ADJUSTED TEMP CURVES. VERY LITTLE CLOUD COVER IS EXPECTED OVER THE SOUTHERN TWO THIRDS OF THE CWFA THE REMAINDER OF THE NIGHT. UPDATES HAVE BEEN POSTED. && .AVIATION...A FEW WIND GUSTS WERE NOTED EARLIER IN THE WEST ASSOCIATED WITH THE DRY COLD FRONT. THE WINDS HAVE BECOME LIGHTER DURING THE LAST HOUR AND WILL CONTINUE TO BECOME LIGHTER THE REMAINDER OF THE NIGHT. ELSE...VFR CONDITIONS WILL BE PREVALENT AT ALL TAF SITES FOR THE NEXT 24 HOURS. && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ 22 ms AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 1041 AM MST THU FEB 7 2008 .UPDATE... HOW MUCH SNOW AND HOW STRONG OF WINDS CONTINUE TO BE THE PROBLEM OF THE DAY. UPPER LEVEL TROF APPROACHING FROM THE WEST WITH WINDS INCREASING OVER THE ENTIRE AREA THROUGH THE DAY AND INTO THE NIGHT. GOOD SNOW AMOUNTS OVER THE WESTERN AND SOUTHWESTERN MOUNTAINS WITH PASSES BEING AFFECTED BY SNOW AND WINDS. HAVE CANCELLED SNOW AND BLOWING SNOW ADVISORIES AND HAVE ISSUED THROUGH THE WINTER STORM WARNING OVER THE SOUTHWEST AND PORTIONS OF CENTRAL MONTANA FOR THE REST OF TODAY AND TONIGHT. HIGH WIND WATCH FOR TONIGHT HAS A GOOD CHANCE OF BEING A WARNING ON THIS AFTERNOON PACKAGE. CAMP && AVIATION... UPDATED 1739Z. A STRONG WEATHER SYSTEM WILL BE MOVING THROUGH THE AREA TODAY. STRONG AND GUSTY WINDS WILL BE WIDESPREAD ACROSS THE AREA...GUSTS TO 70 KTS EXPECTED NEAR MOUNTAINS...50 KTS POSSIBLE AT TIMES ACROSS THE PLAINS. IFR CONDITIONS ARE EXPECTED OVER THE ROCKIES DUE TO SNOW...BLOWING SNOW AND WINDY CONDITIONS. SNOW WILL DEVELOP EAST OF THE ROCKIES AND LOCAL MVFR CONDITIONS ARE POSSIBLE DUE TO SNOW AND BLOWING SNOW. WINDS WILL WEAKEN OVER NIGHT BUT REMAIN BREEZY THROUGH THE NEXT 24 HOURS. && .PREV DISCUSSION... (ISSUED 450 AM MST THU FEB 7 2008) FOR THE REMAINDER OF THIS WEEK AND SATURDAY...VERY ENERGETIC...MOIST...PROGRESSIVE...NORTHWESTERLY FLOW PATTERN ALOFT WILL AFFECT THE REGION. MOUNTAIN SNOW SHOWERS WILL BE LIKELY THROUGH THE PERIOD...WITH SCATTERED SNOW SHOWERS OVER THE PLAINS. AN ARCTIC COLD FRONT PLUNGES SOUTHWARDS FRIDAY NIGHT...WITH MORE SNOW SHOWERS ALONG WITH COLDER TEMPERATURES IN CENTRAL AND NORTH CENTRAL MONTANA. BEFORE THAT TIME...TEMPERATURES WILL REMAIN ABOVE SEASONAL AVERAGES. A DETAILED FORECAST RATIONALE BEHIND THE 3-DAY FORECAST/HEADLINE PLAN IS PROVIDED BELOW. COHEN FRIDAY NIGHT THROUGH MONDAY NIGHT...ARCTIC FRONT WILL CONTINUE MOVING SOUTH FRIDAY NIGHT BUT IT LOOKS LIKE IT WILL NOT MAKE IT TO FAR SW MT. LOWERED TEMPERATURES OVER THE NORTHERN PLAINS. QUESTION THEN BECOMES HOW QUICKLY THE ARCTIC AIRMASS RETREATS. IT SHOULD BE OUT OF THE FORECAST AREA BY MONDAY BUT MAIN PROBLEM TIME FRAME WILL BE SUNDAY WITH SOME MODELS HAVING THE ARCTIC AIR OUT OF THE PLAINS AND OTHERS KEEPING IT OVER THE PLAINS. DECIDED TO BE SOMEWHAT AGGRESSIVE IN MOVING IT OUT SO HAVE IT OUT OF THE EAST SLOPES ON SUNDAY BUT WILL KEEP IT OVER HILL AND BLAINE COUNTIES. THE FLOW ALOFT WILL BE OUT OF THE NORTHWEST FROM FRIDAY NIGHT THROUGH MONDAY NIGHT AND FAIRLY MOIST. MOISTURE FRIDAY NIGHT WILL INTERACT WITH THE DEEPENING ARCTIC AIRMASS OVER THE PLAINS TO PRODUCE SNOW AND HAVE RAISED POPS TO THE LIKELY CATEGORY EXCEPT OVER FAR SW MT AND THE NE ZONES. MOIST FLOW SHOULD CONTINUE OVER THE WESTERN MOUNTAINS THROUGH MUCH OF THE WEEKEND SO HAVE RAISED POPS THERE. BLANK WEDNESDAY AND THURSDAY...EXTENDED MODELS CONTINUE TO AGREE WITH A PACIFIC TROUGH MOVING INTO THE REGION MID WEEK. TROUGH IS EXPECTED TO MOVE THROUGH THE WESTERN MOUNTAINS INTO THE CENTRAL PLAINS DURING THE PERIOD. A CHANCE FOR SCATTERED SNOW SHOWERS FOR THE MOUNTAINS AND THE PLAINS. THIS TROUGH WILL MOVE THROUGH THE REGION AT A FAIRLY QUICK PACE AS ANOTHER PACIFIC DISTURBANCE SETS UP FOR THE WEEKEND. SAUCIER ============================================================== DETAILED 3-DAY FORECAST RATIONALE...AND DISCUSSION OF THE CURRENT HEADLINES (HEADLINE SUMMARY IS PROVIDED AT THE END OF THIS PRODUCT)... AT PRESENT...A MID LEVEL TROUGH AND ASSOCIATED 70 KT 500 MB JET STREAK ARE APPROACHING THE AREA...WITH DEEP MOIST ASCENT FOR SNOW SHOWERS OVER THE ROCKY MOUNTAIN FRONT...AND CENTRAL AND SOUTHWEST MOUNTAINS OF MONTANA. WEST NORTHWESTERLY WINDS AT 700 MB WILL CONTINUE TO INCREASE OVER 55 KTS THROUGH THE DAY...BRINGING THE THREAT TO STRONG WINDS TO MUCH OF THE REGION. THINGS GET VERY INTERESTING BY THIS AFTERNOON OVER PORTIONS OF CENTRAL AND SOUTHWEST MONTANA...AS 500 MB JET STRENGTHENS TO OVER 80 KTS AND LIFTS NORTHWARD...AND A 700 MB JET OF 60 TO 70 KTS NOSES INTO CENTRAL AND SOUTHWEST MONTANA. THE 700 MB JET IS NOTED TO BE NORTHWESTERLY...WHICH DOES NOT TYPICALLY LEND ITSELF TO BRINGING HIGH WINDS TO CENTRAL AND SOUTHWEST MONTANA IN THE ABSENCE OF OTHER FACTORS. HOWEVER...INGREDIENTS ARE COMING TOGETHER FOR A HIGH WIND THREAT OVER A NARROW CORRIDOR OF COUNTIES IN SOUTHWEST AND CENTRAL MONTANA FROM 11 AM THIS MORNING THROUGH 5 PM MST THIS AFTERNOON. THE AFOREMENTIONED LOW/MID LEVEL JET CORE WILL INTERACT WITH LOW LEVEL SUBSIDENCE AS EVIDENT IN ETA-BUFKIT SOUNDINGS AT HELENA...AT THE SAME TIME THAT MIXING HEIGHTS...UP TO 4000 FEET ARE MAXIMIZED. MID LEVEL SUBSIDENCE ALSO MAKES AN APPEARANCE OVER THAT REGION DOWNSTREAM OF THE NEXT RIDGE ALOFT. THUS...IT IS BECOMING LIKELY THAT WINDS FROM THAT LOW/MID LEVEL JET CORE WILL MIX DOWN TO THE SURFACE SOMETIME BETWEEN 11 AM AND 5 PM MST TODAY IN PORTIONS OF SW/CENTRAL MONTANA. THUS...BETWEEN THOSE HOURS...THE SNOW AND BLOWING SNOW ADVISORY ABOVE 5500 FEET IS TEMPORARILY UPGRADED TO A WINTER STORM WARNING ABOVE 5500 FEET...AND A HIGH WIND WARNING HAS ALSO BEEN ISSUED FOR ELEVATIONS BELOW 5500 FEET. THIS TEMPORARY UPGRADE/ISSUANCE APPLIES TO CENTRAL AND SOUTHERN LEWIS AND CLARK...JUDITH BASIN...JEFFERSON... BROADWATER...AND MEAGHER COUNTIES ONLY. FOR BEAVERHEAD...MADISON...GALLATIN...AND CASCADE COUNTIES...THE SNOW AND BLOWING SNOW ADVISORY REMAINS IN TACT FROM 5 AM THIS MORNING TO 11 PM MST TONIGHT AT ELEVATIONS ABOVE 5500 FEET. OVER THE PLAINS TODAY...WHILE LEE TROUGHING IN MONTANA AND ASSOCIATED DOWNSLOPE BREEZY WINDS WILL KEEP TEMPERATURES ABOVE SEASONAL AVERAGES AGAIN TODAY...A REGION OF ISENTROPIC LIFT NOTED AT 305K WILL OCCUR FOR MUCH OF THE DAY OVER NORTH CENTRAL MONTANA...WHICH WILL COMBINE WITH FAVORABLE MID LEVEL ASCENT FOR SCATTERED LIGHT SNOW SHOWERS THERE. RUC IS PICKING UP WELL ON THIS PRECIP CHANCE...WHICH IS MAXIMIZED BETWEEN HAVRE AND LEWISTOWN. AS ALL THIS IS OCCURRING...THE POLAR JET STREAM WILL CONTINUE TO INTENSIFY AS IT LIFTS NORTHWARD...YIELDING A 500 MB JET OF OVER 100 KT BY LATE TONIGHT...FURTHER ENHANCING THE 700 AND 850 MB FLOW. WHILE A BRIEF LULL IN THE PRECIP WILL OCCUR TONIGHT AND FRIDAY...MORE WIDESPREAD HIGH WINDS WILL BECOME OF INCREASING CONCERN OVER THE PLAINS...ESPECIALLY AS SYNOPTIC SUBSIDENCE WORKS ITS WAY INTO THE REGION DOWNSTREAM OF YET ANOTHER RIDGE. THUS...A HIGH WIND WATCH HAS BEEN POSTED FOR LATE TONIGHT THROUGH FRIDAY FOR MUCH OF THE FORECAST AREA. WITH THE POTENTIAL FOR MOUNTAIN SNOW...AND POTENTIAL SNOW DUE TO ISENTROPIC LIFT OVER THE PLAINS... THE HIGH WIND EMPHASIS MAY BECOME MORE OF A WINTER WEATHER EMPHASIS IN FUTURE FORECASTS. TEMPERATURES ABOVE SEASONAL AVERAGES WILL OCCUR ON FRIDAY...WITH DOWNSLOPE WINDS AND JET STREAM MOVEMENT NORTHWARD. THE WINTER STORM WARNING CONTINUES THROUGH FRIDAY AFTERNOON FOR THE ROCKY MOUNTAIN FRONT WITH CONTINUOUS HIGH WIND AND STEADY SNOWFALL LIKELIHOOD. THEN FRIDAY NIGHT...A STRONG COLD FRONT PLUNGES SOUTHWARD ACROSS PORTIONS OF THE AREA AS A 1040 MB SURFACE HIGH BUILDS SOUTHEASTWARD OUT OF ALBERTA. SURFACE CONVERGENCE AHEAD OF THIS FRONT COMBINED WITH CONTINUED JET SUPPORT WILL YIELD SNOW SHOWERS OVER MUCH OF THE REGION FROM FRIDAY NIGHT THROUGH SATURDAY. WITH THE FRONT STALLING OVER CENTRAL MONTANA BEFORE SLOWLY RETREATING NORTHWARD AS A WARM FRONT LATE SATURDAY...OVERRUNNING PRECIPITATION WILL BE POSSIBLE...ESPECIALLY IF THE COLD POOL APPEARS TO BECOME MORE STEEP. COLDER CONDITIONS WITH NORTHERLY WINDS ARE EXPECTED OVER NORTH CENTRAL MONTANA ON SATURDAY...WITH A SURFACE TROUGH OVER SOUTHWEST MONTANA PROMOTING SOUTHWESTERLY WINDS AND TEMPERATURES IN THE 20S IN SOUTHWEST MONTANA. COHEN && .PRELIMINARY POINT TEMPS/POPS... GTF 39 25 35 -3 / 20 10 40 60 CTB 35 22 31 -14 / 30 10 40 60 HLN 35 24 32 16 / 60 30 60 60 BZN 38 19 33 17 / 60 40 50 50 WEY 22 9 20 8 / 90 60 70 80 DLN 32 16 31 17 / 70 40 50 40 HVR 38 18 29 -16 / 40 20 40 50 LWT 36 21 32 0 / 30 30 40 60 && .TFX WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 11 PM MST THIS EVENING FOR MTZ008-012- 014-015-050-052>055. HIGH WIND WATCH FROM THIS EVENING THROUGH FRIDAY AFTERNOON FOR MTZ010-012>014-044>046-049>054. WINTER STORM WARNING UNTIL 5 PM MST FRIDAY FOR MTZ009-048. && $$ SHORT TERM...CAMP/COHEN LONG TERM...BLANK/SAUCIER AVIATION...ZELZER WEATHER.GOV/GREATFALLS mt AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 450 AM MST THU FEB 7 2008 UPDATED AVIATION SECTION .DISCUSSION... FOR THE REMAINDER OF THIS WEEK AND SATURDAY...VERY ENERGETIC...MOIST...PROGRESSIVE...NORTHWESTERLY FLOW PATTERN ALOFT WILL AFFECT THE REGION. MOUNTAIN SNOW SHOWERS WILL BE LIKELY THROUGH THE PERIOD...WITH SCATTERED SNOW SHOWERS OVER THE PLAINS. AN ARCTIC COLD FRONT PLUNGES SOUTHWARDS FRIDAY NIGHT...WITH MORE SNOW SHOWERS ALONG WITH COLDER TEMPERATURES IN CENTRAL AND NORTH CENTRAL MONTANA. BEFORE THAT TIME...TEMPERATURES WILL REMAIN ABOVE SEASONAL AVERAGES. A DETAILED FORECAST RATIONALE BEHIND THE 3-DAY FORECAST/HEADLINE PLAN IS PROVIDED BELOW. COHEN FRIDAY NIGHT THROUGH MONDAY NIGHT...ARCTIC FRONT WILL CONTINUE MOVING SOUTH FRIDAY NIGHT BUT IT LOOKS LIKE IT WILL NOT MAKE IT TO FAR SW MT. LOWERED TEMPERATURES OVER THE NORTHERN PLAINS. QUESTION THEN BECOMES HOW QUICKLY THE ARCTIC AIRMASS RETREATS. IT SHOULD BE OUT OF THE FORECAST AREA BY MONDAY BUT MAIN PROBLEM TIME FRAME WILL BE SUNDAY WITH SOME MODELS HAVING THE ARCTIC AIR OUT OF THE PLAINS AND OTHERS KEEPING IT OVER THE PLAINS. DECIDED TO BE SOMEWHAT AGGRESSIVE IN MOVING IT OUT SO HAVE IT OUT OF THE EAST SLOPES ON SUNDAY BUT WILL KEEP IT OVER HILL AND BLAINE COUNTIES. THE FLOW ALOFT WILL BE OUT OF THE NORTHWEST FROM FRIDAY NIGHT THROUGH MONDAY NIGHT AND FAIRLY MOIST. MOISTURE FRIDAY NIGHT WILL INTERACT WITH THE DEEPENING ARCTIC AIRMASS OVER THE PLAINS TO PRODUCE SNOW AND HAVE RAISED POPS TO THE LIKELY CATEGORY EXCEPT OVER FAR SW MT AND THE NE ZONES. MOIST FLOW SHOULD CONTINUE OVER THE WESTERN MOUNTAINS THROUGH MUCH OF THE WEEKEND SO HAVE RAISED POPS THERE. BLANK WEDNESDAY AND THURSDAY...EXTENDED MODELS CONTINUE TO AGREE WITH A PACIFIC TROUGH MOVING INTO THE REGION MID WEEK. TROUGH IS EXPECTED TO MOVE THROUGH THE WESTERN MOUNTAINS INTO THE CENTRAL PLAINS DURING THE PERIOD. A CHANCE FOR SCATTERED SNOW SHOWERS FOR THE MOUNTAINS AND THE PLAINS. THIS TROUGH WILL MOVE THROUGH THE REGION AT A FAIRLY QUICK PACE AS ANOTHER PACIFIC DISTURBANCE SETS UP FOR THE WEEKEND. SAUCIER ============================================================== DETAILED 3-DAY FORECAST RATIONALE...AND DISCUSSION OF THE CURRENT HEADLINES (HEADLINE SUMMARY IS PROVIDED AT THE END OF THIS PRODUCT)... AT PRESENT...A MID LEVEL TROUGH AND ASSOCIATED 70 KT 500 MB JET STREAK ARE APPROACHING THE AREA...WITH DEEP MOIST ASCENT FOR SNOW SHOWERS OVER THE ROCKY MOUNTAIN FRONT...AND CENTRAL AND SOUTHWEST MOUNTAINS OF MONTANA. WEST NORTHWESTERLY WINDS AT 700 MB WILL CONTINUE TO INCREASE OVER 55 KTS THROUGH THE DAY...BRINGING THE THREAT TO STRONG WINDS TO MUCH OF THE REGION. THINGS GET VERY INTERESTING BY THIS AFTERNOON OVER PORTIONS OF CENTRAL AND SOUTHWEST MONTANA...AS 500 MB JET STRENGTHENS TO OVER 80 KTS AND LIFTS NORTHWARD...AND A 700 MB JET OF 60 TO 70 KTS NOSES INTO CENTRAL AND SOUTHWEST MONTANA. THE 700 MB JET IS NOTED TO BE NORTHWESTERLY...WHICH DOES NOT TYPICALLY LEND ITSELF TO BRINGING HIGH WINDS TO CENTRAL AND SOUTHWEST MONTANA IN THE ABSENCE OF OTHER FACTORS. HOWEVER...INGREDIENTS ARE COMING TOGETHER FOR A HIGH WIND THREAT OVER A NARROW CORRIDOR OF COUNTIES IN SOUTHWEST AND CENTRAL MONTANA FROM 11 AM THIS MORNING THROUGH 5 PM MST THIS AFTERNOON. THE AFOREMENTIONED LOW/MID LEVEL JET CORE WILL INTERACT WITH LOW LEVEL SUBSIDENCE AS EVIDENT IN ETA-BUFKIT SOUNDINGS AT HELENA...AT THE SAME TIME THAT MIXING HEIGHTS...UP TO 4000 FEET ARE MAXIMIZED. MID LEVEL SUBSIDENCE ALSO MAKES AN APPEARANCE OVER THAT REGION DOWNSTREAM OF THE NEXT RIDGE ALOFT. THUS...IT IS BECOMING LIKELY THAT WINDS FROM THAT LOW/MID LEVEL JET CORE WILL MIX DOWN TO THE SURFACE SOMETIME BETWEEN 11 AM AND 5 PM MST TODAY IN PORTIONS OF SW/CENTRAL MONTANA. THUS...BETWEEN THOSE HOURS...THE SNOW AND BLOWING SNOW ADVISORY ABOVE 5500 FEET IS TEMPORARILY UPGRADED TO A WINTER STORM WARNING ABOVE 5500 FEET...AND A HIGH WIND WARNING HAS ALSO BEEN ISSUED FOR ELEVATIONS BELOW 5500 FEET. THIS TEMPORARY UPGRADE/ISSUANCE APPLIES TO CENTRAL AND SOUTHERN LEWIS AND CLARK...JUDITH BASIN...JEFFERSON... BROADWATER...AND MEAGHER COUNTIES ONLY. FOR BEAVERHEAD...MADISON...GALLATIN...AND CASCADE COUNTIES...THE SNOW AND BLOWING SNOW ADVISORY REMAINS IN TACT FROM 5 AM THIS MORNING TO 11 PM MST TONIGHT AT ELEVATIONS ABOVE 5500 FEET. OVER THE PLAINS TODAY...WHILE LEE TROUGHING IN MONTANA AND ASSOCIATED DOWNSLOPE BREEZY WINDS WILL KEEP TEMPERATURES ABOVE SEASONAL AVERAGES AGAIN TODAY...A REGION OF ISENTROPIC LIFT NOTED AT 305K WILL OCCUR FOR MUCH OF THE DAY OVER NORTH CENTRAL MONTANA...WHICH WILL COMBINE WITH FAVORABLE MID LEVEL ASCENT FOR SCATTERED LIGHT SNOW SHOWERS THERE. RUC IS PICKING UP WELL ON THIS PRECIP CHANCE...WHICH IS MAXIMIZED BETWEEN HAVRE AND LEWISTOWN. AS ALL THIS IS OCCURRING...THE POLAR JET STREAM WILL CONTINUE TO INTENSIFY AS IT LIFTS NORTHWARD...YIELDING A 500 MB JET OF OVER 100 KT BY LATE TONIGHT...FURTHER ENHANCING THE 700 AND 850 MB FLOW. WHILE A BRIEF LULL IN THE PRECIP WILL OCCUR TONIGHT AND FRIDAY...MORE WIDESPREAD HIGH WINDS WILL BECOME OF INCREASING CONCERN OVER THE PLAINS...ESPECIALLY AS SYNOPTIC SUBSIDENCE WORKS ITS WAY INTO THE REGION DOWNSTREAM OF YET ANOTHER RIDGE. THUS...A HIGH WIND WATCH HAS BEEN POSTED FOR LATE TONIGHT THROUGH FRIDAY FOR MUCH OF THE FORECAST AREA. WITH THE POTENTIAL FOR MOUNTAIN SNOW...AND POTENTIAL SNOW DUE TO ISENTROPIC LIFT OVER THE PLAINS... THE HIGH WIND EMPHASIS MAY BECOME MORE OF A WINTER WEATHER EMPHASIS IN FUTURE FORECASTS. TEMPERATURES ABOVE SEASONAL AVERAGES WILL OCCUR ON FRIDAY...WITH DOWNSLOPE WINDS AND JET STREAM MOVEMENT NORTHWARD. THE WINTER STORM WARNING CONTINUES THROUGH FRIDAY AFTERNOON FOR THE ROCKY MOUNTAIN FRONT WITH CONTINUOUS HIGH WIND AND STEADY SNOWFALL LIKELIHOOD. THEN FRIDAY NIGHT...A STRONG COLD FRONT PLUNGES SOUTHWARD ACROSS PORTIONS OF THE AREA AS A 1040 MB SURFACE HIGH BUILDS SOUTHEASTWARD OUT OF ALBERTA. SURFACE CONVERGENCE AHEAD OF THIS FRONT COMBINED WITH CONTINUED JET SUPPORT WILL YIELD SNOW SHOWERS OVER MUCH OF THE REGION FROM FRIDAY NIGHT THROUGH SATURDAY. WITH THE FRONT STALLING OVER CENTRAL MONTANA BEFORE SLOWLY RETREATING NORTHWARD AS A WARM FRONT LATE SATURDAY...OVERRUNNING PRECIPITATION WILL BE POSSIBLE...ESPECIALLY IF THE COLD POOL APPEARS TO BECOME MORE STEEP. COLDER CONDITIONS WITH NORTHERLY WINDS ARE EXPECTED OVER NORTH CENTRAL MONTANA ON SATURDAY...WITH A SURFACE TROUGH OVER SOUTHWEST MONTANA PROMOTING SOUTHWESTERLY WINDS AND TEMPERATURES IN THE 20S IN SOUTHWEST MONTANA. COHEN && .AVIATION... UPDATED 1150Z. A SIGNIFICANT WEATHER SYSTEM WILL BE MOVING THROUGH THE FORECAST AREA TODAY. FEEL FAIRLY CONFIDENT ABOUT THE ASSOCIATED COLD FRONTAL TIMING. EXPECT THE FRONT TO GO THROUGH KCTB AROUND 16Z...KGTF AND KHLN NR 18Z...KHVR BY 20Z AND KLWT BY 21Z. GUSTY SOUTHWEST WINDS AHEAD OF THE FRONT WILL SHIFT TO THE WEST OR EVEN NORTHWEST BEHIND THE FRONT. THERE WILL BE A THREAT OF WIND GUSTS TO 50KTS EVEN IN THE VALLEYS AND PLAINS NEAR AND BEHIND THE COLD FRONT WITH THE EXCEPTION OF KHVR. THERE IS SOME QUESTION ABOUT THE WINDS AT KCTB BEHIND THE COLD FRONT AS SOME GUIDANCE SUGGESTS WINDS BECOME NORTHWEST 10 TO 15KTS WHILE OTHER GUIDANCE SUGGESTS WEST TO NORTHWEST WINDS WITH STRONGER WIND SPEEDS. HAVE OPTED TO LEAN MORE TOWARDS THE LATTER. BESIDES STRONG AND GUSTY WINDS...AVIATION INTERESTS WILL HAVE TO CONTEND WITH VFR CONDITIONS SUDDENLY DROPPING TO MVFR AND IFR CONDITIONS WITH BANDS OF SNOW ASSOCIATED WITH THE WEATHER SYSTEM. EXPECT FAIRLY WIDESPREAD MOUNTAIN OBSCUREMENT. CONDITIONS SHOULD IMPROVE SOMEWHAT TONIGHT. HOWEVER STRONG WINDS OF 40 TO 50KTS WITH LOCAL GUSTS TO 70KTS WILL DEVELOP ALONG THE ROCKY MOUNTAIN FRONT WITH CONTINUED MOUNTAIN OBSCUREMENT. && .PRELIMINARY POINT TEMPS/POPS... GTF 39 25 35 -3 / 20 10 40 60 CTB 37 22 31 -14 / 40 10 40 60 HLN 35 24 32 16 / 70 30 60 60 BZN 36 19 33 17 / 80 40 50 50 WEY 21 9 20 8 / 100 60 70 80 DLN 32 16 31 17 / 90 40 50 40 HVR 38 18 29 -16 / 40 20 40 50 LWT 36 21 32 0 / 50 30 40 60 && .TFX WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING FROM 11 AM THIS MORNING TO 5 PM MST THIS AFTERNOON FOR ELEVATIONS BELOW 5500 FEET IN CENTRAL AND SOUTHERN LEWIS AND CLARK...JUDITH BASIN...JEFFERSON...BROADWATER...AND MEAGHER COUNTIES. SNOW AND BLOWING SNOW ADVISORY FROM 5 AM TO 11 AM MST THIS MORNING FOR ELEVATIONS ABOVE 5500 FEET IN CENTRAL AND SOUTHERN LEWIS AND CLARK...JUDITH BASIN...JEFFERSON...BROADWATER...AND MEAGHER COUNTIES. SNOW AND BLOWING SNOW ADVISORY FROM 5 PM THIS AFTERNOON TO 11 PM MST THIS EVENING FOR ELEVATIONS ABOVE 5500 FEET IN CENTRAL AND SOUTHERN LEWIS AND CLARK...JUDITH BASIN...JEFFERSON...BROADWATER...AND MEAGHER COUNTIES. WINTER STORM WARNING FROM 11 AM THIS MORNING TO 5 PM MST THIS AFTERNOON FOR ELEVATIONS ABOVE 5500 FEET IN CENTRAL AND SOUTHERN LEWIS AND CLARK...JUDITH BASIN...JEFFERSON...BROADWATER...AND MEAGHER COUNTIES. HIGH WIND WATCH FROM THIS EVENING THROUGH FRIDAY AFTERNOON FOR ALL ELEVATIONS IN PORTIONS OF CENTRAL...NORTH CENTRAL...AND SOUTHWEST MONTANA. SNOW AND BLOWING SNOW ADVISORY FROM 5 AM EARLY THIS MORNING TO 11 PM MST THIS EVENING FOR ELEVATIONS ABOVE 5500 FEET IN CASCADE...BEAVERHEAD...MADISON...AND GALLATIN COUNTIES. WINTER STORM WARNING UNTIL 5 PM MST FRIDAY FOR THE ROCKY MOUNTAIN FRONT. && $$ SHORT TERM...COHEN LONG TERM...BLANK/SAUCIER AVIATION...MPJ WEATHER.GOV/GREATFALLS mt AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 349 AM MST THU FEB 7 2008 .DISCUSSION... FOR THE REMAINDER OF THIS WEEK AND SATURDAY...VERY ENERGETIC...MOIST...PROGRESSIVE...NORTHWESTERLY FLOW PATTERN ALOFT WILL AFFECT THE REGION. MOUNTAIN SNOW SHOWERS WILL BE LIKELY THROUGH THE PERIOD...WITH SCATTERED SNOW SHOWERS OVER THE PLAINS. AN ARCTIC COLD FRONT PLUNGES SOUTHWARDS FRIDAY NIGHT...WITH MORE SNOW SHOWERS ALONG WITH COLDER TEMPERATURES IN CENTRAL AND NORTH CENTRAL MONTANA. BEFORE THAT TIME...TEMPERATURES WILL REMAIN ABOVE SEASONAL AVERAGES. A DETAILED FORECAST RATIONALE BEHIND THE 3-DAY FORECAST/HEADLINE PLAN IS PROVIDED BELOW. COHEN FRIDAY NIGHT THROUGH MONDAY NIGHT...ARCTIC FRONT WILL CONTINUE MOVING SOUTH FRIDAY NIGHT BUT IT LOOKS LIKE IT WILL NOT MAKE IT TO FAR SW MT. LOWERED TEMPERATURES OVER THE NORTHERN PLAINS. QUESTION THEN BECOMES HOW QUICKLY THE ARCTIC AIRMASS RETREATS. IT SHOULD BE OUT OF THE FORECAST AREA BY MONDAY BUT MAIN PROBLEM TIME FRAME WILL BE SUNDAY WITH SOME MODELS HAVING THE ARCTIC AIR OUT OF THE PLAINS AND OTHERS KEEPING IT OVER THE PLAINS. DECIDED TO BE SOMEWHAT AGGRESSIVE IN MOVING IT OUT SO HAVE IT OUT OF THE EAST SLOPES ON SUNDAY BUT WILL KEEP IT OVER HILL AND BLAINE COUNTIES. THE FLOW ALOFT WILL BE OUT OF THE NORTHWEST FROM FRIDAY NIGHT THROUGH MONDAY NIGHT AND FAIRLY MOIST. MOISTURE FRIDAY NIGHT WILL INTERACT WITH THE DEEPENING ARCTIC AIRMASS OVER THE PLAINS TO PRODUCE SNOW AND HAVE RAISED POPS TO THE LIKELY CATEGORY EXCEPT OVER FAR SW MT AND THE NE ZONES. MOIST FLOW SHOULD CONTINUE OVER THE WESTERN MOUNTAINS THROUGH MUCH OF THE WEEKEND SO HAVE RAISED POPS THERE. BLANK WEDNESDAY AND THURSDAY...EXTENDED MODELS CONTINUE TO AGREE WITH A PACIFIC TROUGH MOVING INTO THE REGION MID WEEK. TROUGH IS EXPECTED TO MOVE THROUGH THE WESTERN MOUNTAINS INTO THE CENTRAL PLAINS DURING THE PERIOD. A CHANCE FOR SCATTERED SNOW SHOWERS FOR THE MOUNTAINS AND THE PLAINS. THIS TROUGH WILL MOVE THROUGH THE REGION AT A FAIRLY QUICK PACE AS ANOTHER PACIFIC DISTURBANCE SETS UP FOR THE WEEKEND. SAUCIER ============================================================== DETAILED 3-DAY FORECAST RATIONALE...AND DISCUSSION OF THE CURRENT HEADLINES (HEADLINE SUMMARY IS PROVIDED AT THE END OF THIS PRODUCT)... AT PRESENT...A MID LEVEL TROUGH AND ASSOCIATED 70 KT 500 MB JET STREAK ARE APPROACHING THE AREA...WITH DEEP MOIST ASCENT FOR SNOW SHOWERS OVER THE ROCKY MOUNTAIN FRONT...AND CENTRAL AND SOUTHWEST MOUNTAINS OF MONTANA. WEST NORTHWESTERLY WINDS AT 700 MB WILL CONTINUE TO INCREASE OVER 55 KTS THROUGH THE DAY...BRINGING THE THREAT TO STRONG WINDS TO MUCH OF THE REGION. THINGS GET VERY INTERESTING BY THIS AFTERNOON OVER PORTIONS OF CENTRAL AND SOUTHWEST MONTANA...AS 500 MB JET STRENGTHENS TO OVER 80 KTS AND LIFTS NORTHWARD...AND A 700 MB JET OF 60 TO 70 KTS NOSES INTO CENTRAL AND SOUTHWEST MONTANA. THE 700 MB JET IS NOTED TO BE NORTHWESTERLY...WHICH DOES NOT TYPICALLY LEND ITSELF TO BRINGING HIGH WINDS TO CENTRAL AND SOUTHWEST MONTANA IN THE ABSENCE OF OTHER FACTORS. HOWEVER...INGREDIENTS ARE COMING TOGETHER FOR A HIGH WIND THREAT OVER A NARROW CORRIDOR OF COUNTIES IN SOUTHWEST AND CENTRAL MONTANA FROM 11 AM THIS MORNING THROUGH 5 PM MST THIS AFTERNOON. THE AFOREMENTIONED LOW/MID LEVEL JET CORE WILL INTERACT WITH LOW LEVEL SUBSIDENCE AS EVIDENT IN ETA-BUFKIT SOUNDINGS AT HELENA...AT THE SAME TIME THAT MIXING HEIGHTS...UP TO 4000 FEET ARE MAXIMIZED. MID LEVEL SUBSIDENCE ALSO MAKES AN APPEARANCE OVER THAT REGION DOWNSTREAM OF THE NEXT RIDGE ALOFT. THUS...IT IS BECOMING LIKELY THAT WINDS FROM THAT LOW/MID LEVEL JET CORE WILL MIX DOWN TO THE SURFACE SOMETIME BETWEEN 11 AM AND 5 PM MST TODAY IN PORTIONS OF SW/CENTRAL MONTANA. THUS...BETWEEN THOSE HOURS...THE SNOW AND BLOWING SNOW ADVISORY ABOVE 5500 FEET IS TEMPORARILY UPGRADED TO A WINTER STORM WARNING ABOVE 5500 FEET...AND A HIGH WIND WARNING HAS ALSO BEEN ISSUED FOR ELEVATIONS BELOW 5500 FEET. THIS TEMPORARY UPGRADE/ISSUANCE APPLIES TO CENTRAL AND SOUTHERN LEWIS AND CLARK...JUDITH BASIN...JEFFERSON... BROADWATER...AND MEAGHER COUNTIES ONLY. FOR BEAVERHEAD...MADISON...GALLATIN...AND CASCADE COUNTIES...THE SNOW AND BLOWING SNOW ADVISORY REMAINS IN TACT FROM 5 AM THIS MORNING TO 11 PM MST TONIGHT AT ELEVATIONS ABOVE 5500 FEET. OVER THE PLAINS TODAY...WHILE LEE TROUGHING IN MONTANA AND ASSOCIATED DOWNSLOPE BREEZY WINDS WILL KEEP TEMPERATURES ABOVE SEASONAL AVERAGES AGAIN TODAY...A REGION OF ISENTROPIC LIFT NOTED AT 305K WILL OCCUR FOR MUCH OF THE DAY OVER NORTH CENTRAL MONTANA...WHICH WILL COMBINE WITH FAVORABLE MID LEVEL ASCENT FOR SCATTERED LIGHT SNOW SHOWERS THERE. RUC IS PICKING UP WELL ON THIS PRECIP CHANCE...WHICH IS MAXIMIZED BETWEEN HAVRE AND LEWISTOWN. AS ALL THIS IS OCCURRING...THE POLAR JET STREAM WILL CONTINUE TO INTENSIFY AS IT LIFTS NORTHWARD...YIELDING A 500 MB JET OF OVER 100 KT BY LATE TONIGHT...FURTHER ENHANCING THE 700 AND 850 MB FLOW. WHILE A BRIEF LULL IN THE PRECIP WILL OCCUR TONIGHT AND FRIDAY...MORE WIDESPREAD HIGH WINDS WILL BECOME OF INCREASING CONCERN OVER THE PLAINS...ESPECIALLY AS SYNOPTIC SUBSIDENCE WORKS ITS WAY INTO THE REGION DOWNSTREAM OF YET ANOTHER RIDGE. THUS...A HIGH WIND WATCH HAS BEEN POSTED FOR LATE TONIGHT THROUGH FRIDAY FOR MUCH OF THE FORECAST AREA. WITH THE POTENTIAL FOR MOUNTAIN SNOW...AND POTENTIAL SNOW DUE TO ISENTROPIC LIFT OVER THE PLAINS... THE HIGH WIND EMPHASIS MAY BECOME MORE OF A WINTER WEATHER EMPHASIS IN FUTURE FORECASTS. TEMPERATURES ABOVE SEASONAL AVERAGES WILL OCCUR ON FRIDAY...WITH DOWNSLOPE WINDS AND JET STREAM MOVEMENT NORTHWARD. THE WINTER STORM WARNING CONTINUES THROUGH FRIDAY AFTERNOON FOR THE ROCKY MOUNTAIN FRONT WITH CONTINUOUS HIGH WIND AND STEADY SNOWFALL LIKELIHOOD. THEN FRIDAY NIGHT...A STRONG COLD FRONT PLUNGES SOUTHWARD ACROSS PORTIONS OF THE AREA AS A 1040 MB SURFACE HIGH BUILDS SOUTHEASTWARD OUT OF ALBERTA. SURFACE CONVERGENCE AHEAD OF THIS FRONT COMBINED WITH CONTINUED JET SUPPORT WILL YIELD SNOW SHOWERS OVER MUCH OF THE REGION FROM FRIDAY NIGHT THROUGH SATURDAY. WITH THE FRONT STALLING OVER CENTRAL MONTANA BEFORE SLOWLY RETREATING NORTHWARD AS A WARM FRONT LATE SATURDAY...OVERRUNNING PRECIPITATION WILL BE POSSIBLE...ESPECIALLY IF THE COLD POOL APPEARS TO BECOME MORE STEEP. COLDER CONDITIONS WITH NORTHERLY WINDS ARE EXPECTED OVER NORTH CENTRAL MONTANA ON SATURDAY...WITH A SURFACE TROUGH OVER SOUTHWEST MONTANA PROMOTING SOUTHWESTERLY WINDS AND TEMPERATURES IN THE 20S IN SOUTHWEST MONTANA. COHEN && .AVIATION... NORTHWEST FLOW ALOFT CONTINUES OVER THE FORECAST AREA TONIGHT THROUGH THURSDAY EVENING. ABUNDANT MOISTURE WILL BRING WIDESPREAD SNOW AND OBSCURATIONS TO THE MOUNTAINS NEAR THE CONTINENTAL DIVIDE AND IN SOUTHWEST MONTANA. KBZN IS STILL EXPECTED TO RECEIVE MVFR CONDITIONS IN LIGHT SNOW FROM AROUND 10Z THROUGH 20Z. MODELS ARE STILL UNCLEAR WHETHER KHLN WILL SEE MVFR CONDITIONS AT THIS TIME...BUT FEEL CHANCE OF LOW CEILINGS AND SNOW SHOWERS OCCURRING HAS INCREASED TO 40 PERCENT FROM 09Z ONWARD. BIGGEST CHANGE IN TAF FORECASTS HAS BEEN TO LOWER CEILINGS TO MVFR AND MENTION VCSH AT KHVR AND KLWT AROUND 15Z NORTH AND 19Z SOUTH. MODEL GUIDANCE AND BUFKIT PROFILES ARE SHOWING A SURGE OF LOW LEVEL MOISTURE ON THE WESTERN EDGE OF THE SURFACE LOW PRESSURE SYSTEM. THIS SYSTEM MOVES RAPIDLY EAST THURSDAY EVENING FOR IMPROVING CONDITIONS. MPJ && .PRELIMINARY POINT TEMPS/POPS... GTF 39 25 35 -3 / 20 10 40 60 CTB 37 22 31 -14 / 40 10 40 60 HLN 35 24 32 16 / 70 30 60 60 BZN 36 19 33 17 / 80 40 50 50 WEY 21 9 20 8 / 100 60 70 80 DLN 32 16 31 17 / 90 40 50 40 HVR 38 18 29 -16 / 40 20 40 50 LWT 36 21 32 0 / 50 30 40 60 && .TFX WATCHES/WARNINGS/ADVISORIES... HIGH WIND WARNING FROM 11 AM THIS MORNING TO 5 PM MST THIS AFTERNOON FOR ELEVATIONS BELOW 5500 FEET IN CENTRAL AND SOUTHERN LEWIS AND CLARK...JUDITH BASIN...JEFFERSON...BROADWATER...AND MEAGHER COUNTIES. SNOW AND BLOWING SNOW ADVISORY FROM 5 AM TO 11 AM MST THIS MORNING FOR ELEVATIONS ABOVE 5500 FEET IN CENTRAL AND SOUTHERN LEWIS AND CLARK...JUDITH BASIN...JEFFERSON...BROADWATER...AND MEAGHER COUNTIES. SNOW AND BLOWING SNOW ADVISORY FROM 5 PM THIS AFTERNOON TO 11 PM MST THIS EVENING FOR ELEVATIONS ABOVE 5500 FEET IN CENTRAL AND SOUTHERN LEWIS AND CLARK...JUDITH BASIN...JEFFERSON...BROADWATER...AND MEAGHER COUNTIES. WINTER STORM WARNING FROM 11 AM THIS MORNING TO 5 PM MST THIS AFTERNOON FOR ELEVATIONS ABOVE 5500 FEET IN CENTRAL AND SOUTHERN LEWIS AND CLARK...JUDITH BASIN...JEFFERSON...BROADWATER...AND MEAGHER COUNTIES. HIGH WIND WATCH FROM THIS EVENING THROUGH FRIDAY AFTERNOON FOR ALL ELEVATIONS IN PORTIONS OF CENTRAL...NORTH CENTRAL...AND SOUTHWEST MONTANA. SNOW AND BLOWING SNOW ADVISORY FROM 5 AM EARLY THIS MORNING TO 11 PM MST THIS EVENING FOR ELEVATIONS ABOVE 5500 FEET IN CASCADE...BEAVERHEAD...MADISON...AND GALLATIN COUNTIES. WINTER STORM WARNING UNTIL 5 PM MST FRIDAY FOR THE ROCKY MOUNTAIN FRONT. && $$ SHORT TERM...COHEN LONG TERM...BLANK/SAUCIER AVIATION...MPJ WEATHER.GOV/GREATFALLS mt AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BUFFALO NY 749 AM EST FRI FEB 8 2008 .SYNOPSIS... UNEVENTFUL WEATHER TODAY AND EARLY TONIGHT WILL GIVE WAY TO MORE INTERESTING CONDITIONS OVER THE WEEKEND AS SNOW SHOWERS WILL ONCE AGAIN BECOME QUITE COMMON. THE RETURN TO SNOWY CONDITIONS WILL BE ACCOMPANIED BY A BLAST OF ARCTIC AIR WHICH WILL KEEP US ON THE COLD SIDE OF NORMAL FROM SUNDAY THROUGH AT LEAST TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... NEVER TRUST WARM ADVECTION. A GOOD RULE FOR METEOROLOGISTS TO LIVE BY. THE WARM ADVECTION AHEAD OF A FLAT OHIO VALLEY RIDGE HAS SHOWN TO BE A LITTLE STRONGER THAN ORIGINALLY FORECAST. WIDESPREAD LIGHT SNOW HAS BROKEN OUT ACROSS THE WESTERN COUNTIES EARLY THIS MORNING...WITH 06Z NAM/WRF AND GFS MODELS ALONG WITH THE 09Z RUC13 GUIDANCE PACKAGE SUPPORTING THE MORE WIDESPREAD SNOW DEVELOPMENT. WHILE SNOWFALL AMOUNTS ARE STILL EXPECTED TO BE INSIGNIFICANT AT AN INCH OR SO FOR MOST AREAS...HAVE RAISED POPS TO CATEGORICAL ACROSS THE WESTERN COUNTIES WITH HIGH CHC EAST OF LK ONTARIO. THESE CHANGES HAVE BEEN REFLECTED IN THE UPDATED GRIDS AND ALPHA- NUMERIC PRODUCTS...INCLUDING THE WRITTEN ZONES. TEMPERATURES TODAY WILL CLIMB TO NEAR NORMAL LEVELS...WHICH AT THIS POINT IN THE SEASON RANGE FROM THE MID 30S ACROSS THE BULK OF THE REGION TO THE LOWER 30S EAST OF LAKE ONTARIO. FOR TONIGHT...WEAK RIDGING WILL CROSS THE REGION DURING THE EVENING HOURS THEN MORE SIGNIFICANT WAMR ADVECTION WILL BECOME ESTABLISHED OVERNIGHT IN ADVANCE OF A POTENT SHORTWAVE LIFTING OUT OF THE OHIO VALLEY. THE STRONGER ISENTROPIC UPGLIDE WILL SET THE STAGE FOR AT LEAST SCATTERED SNOW SHOWERS ACROSS THE REGION BY DAYBREAK WITH A LIKELIHOOD OF SNOW SHOWERS OVER THE FAR WESTERN COUNTIES. POPS WERE TAKEN FROM A BLEND OF THE 21Z SREF AND 00Z GFS MODEL RUNS. THE NAM/WRF SOLUTION APPEARED TO BE A LOW OUTLIER. ACCUMULATIONS BY DAYBREAL WILL RANGE FROM A COATING/HALF INCH OVER THE FINGER LAKES REGION TO AN INCH OR TWO NEAR LAKE ERIE. THE ONSET OF THIS NEXT ROUND OF SNOW SHOWERS WILL BE ACCOMPANIED BY MILDER THAN NORMAL TEMPERATURES AS THE WAA SOUTHERLY FLOW WILL KEEP TEMPS GENERALLY IN THE 20S (TEENS EAST OF LK ONT). THESE READINGS WILL BE SOME 6 TO 10 DEG F ABOVE NORMAL. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... THIS PERIOD WILL PROVE TO BE VERY ACTIVE AS A VIGOROUS SHORTWAVE WILL DIG FROM THE CANADIAN PRAIRIES ACROSS THE GREAT LAKES REGION TO NEW ENGLAND. THE RESULT WILL BE WIDESPREAD SNOW SHOWERS AND THE RETURN OF SUB-ARCTIC TEMPERATURES. SOME DETAILS... A SHORTWAVE LIFTING OUT OF THE OHIO VALLEY ON SATURDAY WILL CONTINUE TO PROMOTE ENOUGH WARM ADVECTION TO PRODUCE WIDESPREAD SNOW SHOWERS ACROSS THE REGION. THIS WILL BE PUNCTUATED BY THE PASSAGE OF A PACIFIC BASED COLD FRONTAL BOUNDARY IN THE AFTERNOON. THE LIFT IN THE LOWER LEVELS WILL BE ENHANCED BY SOME JET INDUCED LIFT...AS A 140 KT H25 JET WILL BE RACING ACROSS THE MIDDLE ATLANTIC STATES. POPS FROM THE THREE MAIN OPERATIONAL GUIDANCE PACKAGES SUGGEST HIGH LIKELY TO MINIMAL CAT (70 TO 80) POPS SHOULD BE USED...BUT GIVEN THE DYNAMICS IN PLACE CANNOT SEE WHY WE CANNOT BE AGGRESSIVE AND USE 100 POPS TO COVER THE EVENT. WHILE THERE SHOULD BE LITTLE DOUBT OF AT LEAST A LITTLE SNOW... THE WARM ADVECTION WILL LIEKYL SEND SFC TEMPS INTO THE UPPER 30S TO NEAR 40 IN MOST AREAS. THIS WILL LIMIT SNOWFALL AMOUNTS WITH JUST AN INCH OR TWO ANTICIPATED FOR THE BULK OF THE REGION. A STRONG SHORTWAVE WILL THEN DIVE TO THE SOUTHEAST ACROSS THE UPPER GREAT LAKES SATURDAY NIGHT. THIS WILL SEND A DEEPENING SFC REFLECTION ACROSS UPPER ONTARIO WITH ITS ASSOCIATED ARCTIC COLD FRONT TAKING AIM ON OUR REGION. CURRENT GFS GUIDANCE SUGGESTS THAT THE FRONT CROSS THE WESTERN COUNTIES DURING THE WEE HOURS OF THE MORNING THEN ACROSS THE EASTERN LAKE ONTARIO REGION SHORTLY AFTER DAYBREAK. WHILE FAIRLY WIDESPREAD SNOW SHOWERS SHOULD BE FOUND ACROSS THE REGION SATURDAY NIGHT IN ADVANCE OF THE ARCTIC COLD FRONTAL PASSAGE...THERE COULD BE A BURST OF SNOW RIGHT ALONG THE FRONT ALONG WITH A RUMBLE OF THUNDER. THIS CAN BE BETTER DEFINED AS THE TIMING AND STRENGTH OF THE FRONT BECOMES NAILED DOWN...BUT PATTERN RECOGNITION AND UNSEASONABLY STRONG LAPSE RATES SUGGEST THAT CONVECTION WILL HAVE TO BE CONSIDERED. CAT POPS WILL BE USED FOR THIS PERIOD. FOR SUNDAY...THE DEEP UPPER LEVEL LOW WILL CRUISE ACROSS SOUTHERN ONTARIO TO NEW ENGLAND WHILE ARCTIC AIR WILL POUR OVER THE EASTERN GREAT LAKES. THE CHANCE FOR GENERAL SNOW SHOWERS WILL BE FOUND OVER ALL OF THE REGION AS A RESULT...WITH A VERY COLD (-20C H85) 300-320 FLOW PRODUCING LAKE SNOWS SOUTHEAST OF BOTH LAKES. TEMPERATURES SUNDAY WILL AVERAGE ABOUT 10 TO 15 DEGREES BELOW NORMAL VALUES...WITH MERCURY READINGS BASICALLY REMAINING WITHIN A FEW DEGREES OF THE PREVIOUS OVERNIGHT LOWS. THIS WILL TRANSLATE INTO TEMPS IN THE TEENS AND 20S FOR THE REGION SUNDAY WITH STRONG WEST TO NORTHWEST WINDS GENERATING WIND CHILLS IN THE SINGLE DIGITS. SPEAKING OF THE WINDS...AVERAGE SPEEDS OF 25 TO 40 MPH CAN BE EXPECTED SUNDAY. THIS WILL BE CLOSE TO ADVISORY CRITERIA...SO STAY TUNED. THE PRESSURE GRAIDENT WILL RELAX SUNDAY NIGHT...BUT THE CONTINUED FEED OF COLD -20C H85 AIR OVRE THE LAKES WILL KEEP THE LAKE SNOWS IN PLACE SOUTH OF BUFFALO AND WATERTOWN. && .LONG TERM /MONDAY THROUGH THURSDAY/... AFTER A QUICK SHOT OF ARCTIC AIR THIS UPCOMING WEEKEND...A PACIFIC-BASED FLOW LOOKS TO BECOME REESTABLISHED ACROSS THE CONUS EARLY NEXT WEEK. AS A RESULT...LAKE SNOWS ONGOING AT THE START OF THE PERIOD SHOULD GRADUALLY WIND DOWN MONDAY INTO MONDAY EVENING AS TEMPERATURES ALOFT WARM AND LAKE-AIR DELTA T`S DROP BELOW CRITICAL VALUES. THEREAFTER...OUR ATTENTION WILL SHIFT BACK TO THE SYNOPTIC SCALE FOR THE REMAINDER OF THE PERIOD. WHILE DIFFERENCES IN TIMING PERSIST...THE MEDIUM RANGE MODEL GUIDANCE STILL SUGGESTS THAT THE NEXT UPPER TROUGH WILL APPROACH THE AREA TUESDAY...WITH AN ASSOCIATED SURFACE WAVE/FRONT LIFTING INTO THE AREA TUESDAY AND TUESDAY NIGHT ALONG WITH A MODEST AREA OF PRECIPITATION. THIS COULD BE A TRICKY PERIOD AS FAR AS PRECIPITATION TYPE IS CONCERNED...AS THERE MAY BE ENOUGH WARM AIR ADVECTION ALOFT AND LINGERING COLD AIR NEAR THE SURFACE TO RESULT IN SOME MIXED PRECIPITATION. FOR NOW...HAVE KEPT THINGS IN THE FORM OF SNOW AS PER CONTINUITY...THOUGH THIS WILL HAVE TO BE WATCHED. AFTER THE PASSAGE OF THE INITIAL LOW ON WEDNESDAY...A SECONDARY WAVE OF LOW PRESSURE SHOULD DEVELOP AND MOVE NORTHEAST ALONG THE INITIAL FRONTAL BOUNDARY...THOUGH MOST OF ITS EFFECTS WILL LIKELY STAY SOUTH AND EAST OF THE FORECAST AREA. IN ITS WAKE...HIGH PRESSURE WILL BUILD EAST ACROSS THE GREAT LAKES REGION THURSDAY AND PROVIDE THE AREA WITH DRY UNEVENTFUL WEATHER. IN GENERAL...TEMPERATURES LOOK TO BE WELL BELOW SEASONAL NORMALS AT THE START OF THE PERIOD...BEFORE GRADUALLY WARMING BACK TO NEAR NORMAL BY THE END OF THE WEEK. && .AVIATION /13Z FRIDAY THROUGH TUESDAY/... A WEAK TROUGH WILL SLOWLY PASS ACROSS THE AREA FROM SOUTHWEST TO NORTHEAST THROUGH EARLY THIS EVENING...RESULTING IN A PERIOD OF LIGHT SNOW. GENERALLY SPEAKING...CIGS WILL REMAIN VFR AND VSBYS WILL BE MVFR TO VFR TODAY...THOUGH POCKETS OF IFR CIGS/VSBYS WILL BE POSSIBLE ACROSS PARTS OF THE WESTERN SOUTHERN TIER. IMPROVEMENT TO VFR VSBYS AND MVFR/VFR CEILINGS IS THEN EXPECTED BEHIND THE TROUGH TONIGHT. LOOKING FURTHER AHEAD...ANOTHER SYSTEM WILL BRING ANOTHER CHANCE FOR SOME LIGHT SNOW AND IFR/MVFR CONDITIONS SATURDAY AND SATURDAY NIGHT. && .MARINE... HIGH PRESSURE RIDGED ACROSS THE LOWER LAKES WILL SLOWLY DRIFT EAST TO NEW ENGLAND TODAY AND TONIGHT...AND WILL ACT TO KEEP RELATIVELY LIGHT WINDS/MINIMAL WAVES IN PLACE THROUGH TONIGHT. LOW PRESSURE APPROACHING OVER THE WEEKEND WILL THEN RESULT IN INCREASING WINDS...WITH GALES A DISTINCT POSSIBILITY FOLLOWING THE PASSAGE OF AN ARCTIC COLD FRONT LATE SATURDAY NIGHT/EARLY SUNDAY MORNING. && .HYDROLOGY... FLOOD WARNING REMAINS IN EFFECT ALONG THE ALLEGHENY RIVER AT OLEAN BUT HAS BEEN CANCELED FOR SALAMANCA AS THE RIVER HAS FALLEN BELOW FLOOD STAGE THERE. THE RIVER HAS CRESTED AT OLEAN BUT IS STILL ABOVE FLOOD STAGE AND WILL CONTINUE TO SLOWLY FALL THROUGH TODAY. SEE LATEST FLOOD STATEMENT FOR FURTHER DETAILS. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...NONE. && $$ SYNOPSIS...RSH NEAR TERM...RSH SHORT TERM...RSH LONG TERM...JJR AVIATION...JJR MARINE...JJR HYDROLOGY... ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND FORKS ND 924 PM CST FRI FEB 8 2008 .UPDATE... HUGE CHALLENGE TONIGHT IS HOW WILL WINDS RESPOND LATE TONIGHT BEHIND COLD FRONT AND HOW LOW WILL VSBY GET IN BLOWING SNOW LATE TONIGHT INTO SATURDAY. MORE AND MORE AFTER LOOKING AT DATA UPSTREAM WOULD APPEAR WIND SPEEDS BEHIND COLD FRONT APPEAR LESS THAN EXPECTED. RUC AND 00Z NAM DOES SHOW MORE 40-45 KTS AT 850 MB BEHIND THE FRONT 12Z-18Z A TAD LOWER THAN PREV RUNS. GOOD PRESSURE RISE BEHIND IT WITH 8 MB/3 HR...BUT THIS IS SLIGHTLY LOWER THAN MODELS SHOWED 24 HOURS AGO. UPSTREAM OBS SHOW SUSTAINED 27-31 KTS WITH GUSTS TO 35-37KTS AT TIMES...BUT UPSTREAM VSBYS IN BLOWING SNOW AT ESTEVAN AND REGINA HAVE NOT BEEN TOO IMPRESSIVE...BRIEFLY TO 1/2 TO 3/4SM FOR 1-3 HOUR PERIOD. IN ADDITION...SNOW BAND MOVING INTO DVL AREA IS AHD OF FRONT AND WIND SHIFT WITH OBS AND RADAR INDICATING LITTLE FALLING SNOW BEHIND THE FRONT IN THE WIND AREA. SNOW BAND IS PRETTY NARROW PRODUCING ONE QUARTER TO ONE HALF INCH IN MINOT AREA. MODELS DO CONTINUE TO INDICATE SNOW UPSTREAM IN THE YORKTON SASK AREA MAY YET WRAP SOUTHWARD AROUND SFC LOW AS IT MOVES EAST OF WINNIPEG LATE TONIGHT INTO FAR NE ND/NW MN. THUS BEST CHC OF 1-2 INCHES IS FAR NRN VALLEY...SO DID EXPAND BLIZZARD WARNING INTO THAT AREA. ALSO THIS AREA HAS 10-15 SNOWPACK. FOR THE REST OF THE AREA...INCL GRAND FORKS-FARGO NEW SNOW UNDER AN INCH (LIKELY UNDER A HALF INCH) AND WITH FREQUENT WIND SPEEDS OVER 35 MPH NOT EXTREMELY PROLONGUED FEEL MORE OF AN ADVISORY SITUATION FOR BLOWING SNOW IN OPEN COUNTRY VERSUS A BLIZZARD. TIME WILL TELL. TWEEKED TEMPS A BIT IN WCNTRL MN BUT OTHERWISE NO CHANGES. WILL LET LATER SHIFTS HANDLE TRANSITION TO WIND CHILL HEADLINES WHICH WILL BE NEEDED ONCE ANY BLOWING SNOW ISSUES ARE DONE. && .AVIATION... WIDESPREAD LOW MVFR AND SPOTTY IFR CIGS OVER FAR ERN ND INTO MN WILL STAY PUT UNTIL FRONT ARRIVES...WHICH WILL BE NR 08Z-09Z AT GFK...10-11Z AT FAR...AND 12Z OR SO AT BJI. NORTHWEST WINDS SATURDAY 25-35KTS WITH A FEW HIGHER GUSTS. COULD GET THOSE MVFR CIGS WITH SUSPENDED BLOWING SNOW ON SATURDAY IN ERN ND. && .PREV DISCUSSION... /ISSUED 249 PM CST FRI FEB 8 2008/ SHORT TERM...CHALLENGE DEALS WITH HEADLINES...POSSIBLE BLIZZARD CONDITIONS. 12Z MODELS INITIALIZED WITH MINIMAL ERRORS. MODELS SIMILAR WITH UNFOLDING SCENARIO...WITH GFS/ECMWF A BIT STRONGER. WILL LEAN TOWARD MOST CONSISTENT GFS/ECMWF. TIMING IS A BIT SLOWER...AND THAT WILL BE THE MAIN CHANGE TO FORECAST THINKING. GIVEN CURRENT OBS AND MODEL GUIDANCE...EXPECT COLD FRONT TO BE ENTERING THE W FA JUST BEFORE 06Z...VALLEY BY 09Z...AND E FA BY 12Z. STRONG WIND INDICATORS REMAIN IDEAL. STRONG COLD AIR ADVECTION WILL BE PRESENT THROUGH MID-DAY ON SATURDAY AS 850MB TEMPS DROP 26 DEGREES IN 12 HOURS. 925MB-850MB WINDS WILL BE UNIDIRECTIONAL AT 45KTS-55KTS THROUGH MID-DAY SATURDAY. 15MB/6HR PRESSURE RISE MAXIMUM WILL PROPAGATE ACROSS THE FA FROM W-E ON SAT. THINK STRONGEST CORE (50KNTS-55KTS) OF 850MB WINDS WILL BE ACROSS THE W FA...45KT-50KT SPEEDS OVER THE VALLEY...40KT-45KT SPEEDS E OF THE VALLEY. EXPECT RAPID INCREASE IN SPEEDS WITH FROPA AND STRONG GUSTS. THE GUSTS SHOULD REMAIN...AND THINK SUSTAINED WIND SPEEDS WILL MAXIMIZE WITH PASSAGE OF MAXIMUM PRESSURE RISE (SAT MORNING/EARLY AFTERNOON). WILL MAINTAIN 30-40MPH SUSTAINED WINDS WITH GUSTS TO 50 MPH (25-35MPH WITH GUSTS TO 45MPH EAST OF THE VALLEY). FROPA SHOULD BE ACCOMPANIED BY A BAND OF AT LEAST MODERATE (POSSIBLY HEAVY) SNOWFALL. CURRENT CANADIAN RADAR INDICATES A BAND OF SNOWFALL ASSOCIATED WITH FRONT...AND STRENGTHENING. MODELS INDICATE LOW-MID LEVEL FRONTOGENESIS ASSOCIATED WITH THE FRONT TO STRENGTHEN A BIT MORE. MODELS ALSO INDICATE WEAK 700MB CAPE JUST AHEAD OF THE FRONT...SO THINK A BRIEF (2-3 HOUR) PERIOD OF MODERATE TO HEAVY SNOWFALL LIKELY. WILL GO WITH 1-3 INCHES NEW SNOWFALL GIVEN FAST PROPAGATION. 2 OR 3 INCHES OF SNOW IN 1-3 HOURS COMBINED WITH WINDY CONDITIONS WOULD CAUSE NEAR BLIZZARD CONDITIONS. SYSTEM IS STILL DEVELOPING AND CROSSING THE ROCKIES AT THIS TIME. ALTHOUGH CONFIDENCE WITH THE SYSTEM IS FAIRLY STRONG...SOME QUESTIONS ABOUT WIND SPEEDS ALOFT...SNOW AMTS...AND TIMING/PATH OF MAXIMUM PRESSURE RISE STILL REMAIN. MOST CONFIDENT GOING WITH BLIZZARD WARNING ACROSS A DVL TO VALLEY CITY CORRIDOR AND WILL ISSUE. THIS AREA RECEIVED MOST SNOWFALL THIS PAST WEEK (3-6 INCHES) AND STRONGEST CORE OF 850MB WIND SPEEDS WILL BE ACROSS THIS AREA. WILL KEEP REMAINDER OF BLIZZARD WATCH. WOULD LIKE TO SEE SYSTEM CROSS THE ROCKIES AND DEVELOP FOR ANOTHER FEW HOURS IN ORDER TO GAIN SOME ADDITIONAL CONFIDENCE. ALSO...WOULD LIKE TO SEE HOW SNOW BAND DEVELOPS...AS THIS WILL BE A LIKELY INDICATOR FOR BLIZZARD WARNING VS. WINTER WX ADVISORY CONDITIONS FOR LOCATIONS WHICH HAVE RECEIVED LITTLE OR NO SNOWFALL (S VALLEY INTO WC MN) THIS PAST WEEK. A DECISION ABOUT WHAT TO DO WITH THIS WATCH SHOULD BE MADE BY THIS EVENING. WILL ISSUE A WINTER WX ADVISORY ACROSS THE FAR EASTERN FA. MODERATE TO HEAVY BAND OF SNOW ALONG WITH INCREASING WINDS WILL CAUSE SOME VSBY PROBLEMS...AND WIND CHILL VALUES WILL REACH ADVISORY CRITERIA ON SATURDAY. DANGEROUS WIND CHILL VALUES BELOW -40F ARE AN ADDITIONAL CONCERN INTO SATURDAY/SATURDAY NIGHT. WILL MENTION THIS IN THE PRODUCTS...BUT WANT TO KEEP BLIZZARD THE MAIN FOCUS OF HEADLINES (WILL NOT ISSUE ADDITIONAL WIND CHILL HEADLINES AT THIS TIME). HIGH PRESSURE MOVES ACROSS THE FA ON SUNDAY...TEMPERATURES BELOW NORMAL. NEXT CHANCE FOR SNOW SUNDAY NIGHT AND INTO MONDAY AS NEXT SYSTEM PASSES THROUGH. AT THIS TIME...MAYBE A COUPLE INCHES NEW SNOWFALL EXPECTED. LONG TERM (TUE-FRI)...LONG RANGE MODELS SHOW SIMILAR TRANSITION FROM A MORE ZONAL 500MB FLOW TO MORE AMPLIFICATION BY THE END OF THE EXTENDED FORECAST...BUT DO HAVE SOME TIMING DIFFERENCES ON TROF PASSAGES. INITIAL 500MB TROF AND SURFACE FRONT PASS ON TUE...SO KEPT CHANCE FOR SNOW IN THE FORECAST. WITH MORE SHORTWAVES MOVING THROUGH THE UPPER LEVEL FLOW AND RAPID SURFACE SYSTEM TRANSITIONS...COULD SEE ANOTHER CHANCE OF SNOW ON WED AND WED NIGHT. THEN...A SURFACE HIGH DOMINATES MUCH OF THE REMAINDER OF THE WORK WEEK...SO KEPT FORECAST DRY. AS FAR AS TEMPS...LOOK FOR THEM TO MODERATE TO NEAR NORMAL. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...WINTER WEATHER ADVISORY FROM 3 AM TO 6 PM CST SATURDAY FOR NDZ027-029-030-039-049-052-053. BLIZZARD WARNING UNTIL 6 PM CST SATURDAY FOR NDZ006-007-014-015- 024-026-028-038-054. BLIZZARD WARNING FROM 3 AM TO 6 PM CST SATURDAY FOR NDZ008-016. MN...WINTER WEATHER ADVISORY FROM 3 AM TO 6 PM CST SATURDAY FOR MNZ001>003-005-008-013>015-029. WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM CST SATURDAY FOR MNZ006-009-016-017-022>024-027-028-030>032-040. BLIZZARD WARNING FROM 3 AM TO 6 PM CST SATURDAY FOR MNZ004-007. && $$ RIDDLE nd AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE GRAND FORKS ND 1105 AM CST FRI FEB 8 2008 .DISCUSSION...MAIN CONCERN TODAY IS WITH BLIZZARD WATCH. NEAR TERM...AREAS OF FOG THROUGHOUT THE REGION WITH INCREASING SFC DEW POINTS AND LIGHT WINDS. MOST OF THE REGION HAS VSBY ABOVE 1SM...BUT ISOLD LOCATIONS NEAR ZERO. MENTIONED AREAS OF FOG THROUGH EARLY AFTERNOON. 12Z MODELS COMING IN SLOWER WITH ARRIVAL OF COLD FRONT. STRONG WIND INDICATORS STILL SUGGEST EXPECTED WIND SPEEDS. QPF LOOKS A BIT MORE...AND CONFIDENCE INCREASING THAT IT WILL SNOW. ADJUSTED POPS/WX ACCORDINGLY. OTHERWISE...NO REAL CHANGES NEEDED TO POSSIBLE BLIZZARD CONDITIONS...JUST NEED TO DELAY TIMING OF THE BLIZZARD WATCH. && .AVIATION...IFR CONDITIONS ACROSS MUCH OF THE REGION. HARD TO SEE MOVEMENT WITH HIGHER CLOUDS OBSCURING LOWER CLOUDS ON FOG LOOP. WINDS EXPECTED TO SHIFT TO THE SOUTHWEST THIS AFTERNOON AT AND SHOULD ADVECT LOWER CLOUDS TO THE EAST. && .PREV DISCUSSION... /ISSUED 430 AM CST FRI FEB 8 2008/ DISCUSSION...TODAY THROUGH MON MORNING UPPER LEVEL TROUGH WAS OVER THE RED RIVER VALLEY THIS MORNING AND WAS PRODUCING SOME LIGHT SNOW. AREA RADARS SHOWING LIGHT SNOW ALONG THE ND/MB BORDER MOVING SOUTHEAST ABOUT 15 KNOTS. WILL ADD LOW POPS ALONG THE BORDER THIS MORNING. RUC VERIFIED THE BEST WITH AREA VAD WINDS COMPARED WITH THE GFS AND NAM AND WILL BE USED IN SHORT TERM. STRONG SHORT WAVE AND COLD FRONT EXPECTED TO MOVE THROUGH TONIGHT. SHOWALTER INDEX GETS DOWN TO +2 TONIGHT AHEAD OF THE FRONT. UPPER LEVEL JET DIVES ON THE WEST SIDE OF THE UPPER TROUGH. WILL KEEP BLIZZARD WATCH IN EFFECT WITH LIGHT SNOW EXPECTED TO FALL AHEAD OF FRONTAL PASSAGE THEN STRONG WINDS TO FOLLOW WHICH SHOULD CREATE BLOWNG SNOW AND POOR VISIBILITIES. EXTENDED...MON AND TUE RETURN FLOW EXPECTED TO OCCUR MON AND MON NIGHT. APPROACHING TROUGH WILL PRODUCE LIGHT SNOW. WILL KEEP POPS AS IS FOR MON AND MON NIGHT. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...BLIZZARD WATCH FROM LATE TONIGHT THROUGH SATURDAY AFTERNOON FOR NDZ008-016-027-029-030-038-039-049-052-053. BLIZZARD WATCH FROM 9 PM CST THIS EVENING THROUGH SATURDAY AFTERNOON FOR NDZ006-007-014-015-024-026-028-054. MN...BLIZZARD WATCH FROM LATE TONIGHT THROUGH SATURDAY AFTERNOON FOR MNZ005-008-013>016-022-023-027-028-030-031-040. BLIZZARD WATCH FROM LATE TONIGHT THROUGH SATURDAY AFTERNOON FOR MNZ001>004-007-029. && $$ TG nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND FORKS ND 430 AM CST FRI FEB 8 2008 .DISCUSSION...TODAY THROUGH MON MORNING UPPER LEVEL TROUGH WAS OVER THE RED RIVER VALLEY THIS MORNING AND WAS PRODUCING SOME LIGHT SNOW. AREA RADARS SHOWING LIGHT SNOW ALONG THE ND/MB BORDER MOVING SOUTHEAST ABOUT 15 KNOTS. WILL ADD LOW POPS ALONG THE BORDER THIS MORNING. RUC VERIFIED THE BEST WITH AREA VAD WINDS COMPARED WITH THE GFS AND NAM AND WILL BE USED IN SHORT TERM. STRONG SHORT WAVE AND COLD FRONT EXPECTED TO MOVE THROUGH TONIGHT. SHOWALTER INDEX GETS DOWN TO +2 TONIGHT AHEAD OF THE FRONT. UPPER LEVEL JET DIVES ON THE WEST SIDE OF THE UPPER TROUGH. WILL KEEP BLIZZARD WATCH IN EFFECT WITH LIGHT SNOW EXPECTED TO FALL AHEAD OF FRONTAL PASSAGE THEN STRONG WINDS TO FOLLOW WHICH SHOULD CREATE BLOWNG SNOW AND POOR VISIBILITIES. EXTENDED...MON AND TUE RETURN FLOW EXPECTED TO OCCUR MON AND MON NIGHT. APPROACHING TROUGH WILL PRODUCE LIGHT SNOW. WILL KEEP POPS AS IS FOR MON AND MON NIGHT. && .AVIATION... IFR CONDITIONS WERE GENERALLY SOUTH OF A LINE FROM BJI TO FAR TO OAKES ND. MVFR CONDITIONS WERE SOUTH OF LINE FROM SOUTH OF BDE TO GFK TO NEAR DAZEY ND. HARD TO SEE MOVEMENT WITH HIGHER CLOUDS OBSCURING LOWER CLOUDS ON FOG LOOP. RUC MODEL HAD THE BEST HANDLE ON RH FIELDS. WINDS EXPECTED TO SHIFT TO THE SOUTHWEST LATER THIS MORNING AT GFK AND SHOULD ADVECT LOWER CLOUDS TO THE EAST. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...BLIZZARD WATCH FROM FRIDAY EVENING THROUGH SATURDAY AFTERNOON FOR NDZ006>008-014>016-024-026>030-038-039-049-052>054. MN...BLIZZARD WATCH FROM LATE TONIGHT THROUGH SATURDAY AFTERNOON FOR MNZ005-008-013>016-022-023-027-028-030-031-040. BLIZZARD WATCH FROM THIS EVENING THROUGH SATURDAY AFTERNOON FOR MNZ001>004-007-029. && $$ HOPPES nd AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE GRAND FORKS ND 839 PM CST THU FEB 7 2008 .UPDATE... 500 MB SHORT WAVE IN MONTANA WITH ACCOMPANIED SFC LOW AND WEAK TROUGH IN ERN MT WILL MOVE EAST INTO ERN ND BY 12Z. RADARS AND OBS INDICATE SPOTTY LIGHT -SN. WIDESPREAD MID AND HIGH LEVEL MOISTURE OVER THE AREA AND THIS WILL CONTINUE TONIGHT. IN ADDITION AREA OF LOW CLOUDS WHICH WERE FROM WATERTOWN SD TO ALEXANDRIA TO STAPLES MN AT 4 PM IS MOVING SLOWLY NORTHWARD MAINLY ACROSS MN WITH NRN EDGE HANGING NR A FERGUS FALLS-WADENA LINE. RUC13 INDICATES LOWER LEVEL MOISTURE WILL SLOWLY MOVE NORTH OVERNIGHT..MAINLY AFFECTING VALLEY EASTWARD. WITH ALL THESE CLOUDS AND LIGHT SOUTH WIND TONIGHT DECIDED TO UP TEMPS SOME...MOST PRONOUNCED IN THE NRN VALLEY...WITH MOST SITES IN THE 10-15 RANGE FOR LOWS. NO CHANGES BEYOND TONIGHT. && .PREV DISCUSSION... /ISSUED 251 PM CST THU FEB 7 2008/ SHORT TERM...TONIGHT THROUGH SUNDAY... A CLASSIC ARCTIC OUTBREAK REMAINS IN THE WORKS FRI NIGHT AND THE POTENTIAL FOR A GROUND BLIZZARD DURING THAT PERIOD REMAINS AT THE FOREFRONT OF THE FCST. THE 12Z NAM IS A BIT FASTER WITH THE FROPA THAN ITS GFS AND ECMWF COUNTERPARTS...BUT THE GAP IS NARROW AND WITH NO SHORTAGE OF CAA A SLIGHTLY FASTER SOLUTION IS REASONABLE. MODELS HAVE BACKED OFF JUST SLIGHTLY ON THE CORE OF STRONGEST SFC-850MB WINDS 06-18Z SAT...AND SHIFTED THEM INTO THE NRN RRV. OF COURSE...THE DIFFERENCE BETWEEN 45KTS AND 55KTS OF WIND IN THE MIXED LAYER MAY NOT MEAN MUCH...ESPECIALLY SINCE WE STILL FAVOR THE STRONGER GFS. THE BLIZZARD WATCH WILL BE CONTINUED EXACTLY AS INHERITED AS THE TIMING LOOKS WELL IN HAND. WE WILL EVENTUALLY REQUIRE HEADLINES FURTHER INTO MN FROM KBDE-KBJI /LIKELY SOME TYPE OF ADVZY...FOLLOWED BY WIND CHILL WARNING/ BUT THE RISK OF BLIZZARD CRITERIA BEING MET THERE IS LOW ENOUGH TO REFRAIN FROM A WATCH. A WEAK LEAD S/W WILL PASS JUST TO OUR SOUTH TONIGHT. PLENTY OF CLOUDS UPSTREAM SO IF WE CAN GET THRU THE EVE WITHOUT FALLING TOO MUCH...THEN WARM MODEL SFC TEMPS ARE REASONABLE. THIS S/W LACKS DEEP LAYER MOISTURE OR ASCENT...BUT SFC-850MB FLOW TURNS SLY AND AS THE NOCTURNAL INVERSION SETS UP WE SHOULD DEVELOP A STRATUS DECK ACROSS A GOOD CHUNK OF THE FA BY 12-15Z FRI. NAM PROG SOUNDINGS ARE PARTICULARLY MOIST IN THE BNDRY LAYER...BUT EVEN THE GFS BUFR SOUNDINGS SUGGEST SOME RISK OF -FZDZ FRI MORNING SINCE SATURATION DOES NOT EXTEND COLDER THAN -10 C. BUFKIT TOOLS ARE NOT EXCITED ABOUT THIS...SO WE WILL STOP SHORT OF INCLUDING THIS IN THE FCST AT THIS POINT. SOMETHING TO KEEP AN EYE ON THOUGH. THE ARCTIC FRONT SHOULD SURGE INTO THE KDVL BASIN 00-03Z SAT AND INTO THE VALLEY NEAR 06Z SAT. THE 12Z GFS CONTINUES TO PEG 15MB/6HR PRESSURE RISES DROPPING RIGHT INTO THE VALLEY SO THERE WILL BE A NOTABLE AGEOSTROPHIC COMPONENT TO THE WINDS...WHICH THE GFS PEGS AT 40-45KTS NEAR THE TOP OF THE MIXED LAYER AT 900MB. DRASTIC CAA WITH 850MB TEMPS DROPPING TO -32 C IN THE NRN FA BY 12Z SAT...SO THERE IS MORE THAN ENOUGH MOMENTUM TRANSFER TO DRIVE SIGNIFICANT SFC WINDS. A MORE NRLY LOW LVL FLOW WOULD ENHANCE THE WINDS MORE YET...BUT AT THIS JUNCTURE WE SEEM SET ON A BIT OF A CROSS-VALLEY FLOW. WE DO HAVE 1-3 INCHES OF FRESH SNOW OVER MUCH OF THE AREA...WTIH EVEN GREATER AMOUNTS NEAR EDDY/NELSON COUNTIES. ALWAYS A BIT OF CONCERN THAT WARMING IN THE FRONTAL ZONE WILL BE SIG ENOUGH TO PUT SOME CRUST ON THE SNOW...BUT AT THIS POINT THAT IS NOT EXPECTED. BESIDES...WITH THIS MUCH CAA THE RECENT SNOW WOULD BREAK LOOSE ANYWAY. THE BIG QUESTION MARK FOR MEETING BLIZZARD CRITERIA WILL BE WHETHER -SN WILL FALL WITH THE WINDS. THE NAM REMAINS RATHER DRY...BUT GIVEN PROPENSITY FOR RECENT ARCTIC FRONTS TO DROP SOME -SN WE WILL LEAN IN THE DIRECTION OF THE MORE MOIST GFS. QG FORCING IS FAVORABLE IN THE FRONTOGENETICAL ZONE... AND PWATS NEAR 0.30 INCHES SHOULD GIVE US A FEW-HOUR PERIOD OF -SN WITH 1-2 INCHES ACCUMULATION. THIS WOULD BE ENOUGH TO DROP VIS DOWN TO 1/4SM OR LESS IN OPEN COUNTRY...PARTICULARLY SINCE PERCEIVED VIS WILL BE LOWER AT NIGHT ALREADY. IF THE TREND OF THE 12Z NAM/GFS/ECMWF IS CORRECT...THE BEST CHANCE OF MEETING BLIZZARD CRITERIA MAY BE NEAR AND NORTH OF A KDVL-KGFK-KROX LINE. HOWEVER... WE WOULD NOT BE SURPRISED TO SEE THE CORE OF THE STRONGER WINDS SHIFT BACK A BIT FURTHER WEST...SO THERE REMAIN SOME QUESTIONS TO ANSWER ABOUT THIS EVENT. THE GOING WATCH HANDLES ALL OF THIS FOR NOW. CERTAINLY IT SEEMS THAT AT LEAST SOME PART OF THE FA WILL SEE GROUND BLIZZARD CONDITIONS. DEEP LAYER RH SHOULD RAPIDLY DECREASE 12-21Z SAT AS ARCTIC AIR DEEPENS. THE LOW LVL GRADIENT REMAINS TIGHT AND WE RETAIN 30-40KTS OF WIND UP TO 900MB. AS THE -SN QUICKLY EXITS WITH THE FRONT...OUR HAZARD WILL TRANSITION TO WIND CHILLS. WE WILL STRESS THIS DANGER IN OUR GOING STATEMENTS...BUT AT SOME POINT A WIND CHILL WARNING WILL BE REQUIRED. THE ARCTIC AIR IS QUICK TO MOVE EAST AS ANOTHER S/W ENTERS THE NRN ROCKIES...BUT EVEN IF 1000-500MB THICKNESSES AND 925-850MB TEMPS COME UP SAT NIGHT...THE SFC RIDGE AXIS WILL DOMINATE SFC COOLING. WE DROPPED LOWS A FEW MORE DEG F AND ARE THUS UNDERCUTTING GUIDANCE SOME 5 DEG F SAT NIGHT. THE LOW/MID LVL BAROCLINIC ZONE TIGHTENS SIGNIFICANTLY SUN AS THE S/W WORKS EAST. THIS WILL SET THE STAGE FOR ISENTROPIC LIFT...AND IN FACT BOTH THE NAM AND GFS SHOW CONDENSATION PRESSURE DEFICITS UNDER 10MB AFT 18Z SUN TO THE WEST OF THE RRV. WE WILL INTRODUCE SOME -SN CHANCES... THOUGH THERE IS SOME UNCERTAINTY HOW QUICKLY WE WILL BE ABLE TO SATURATE. LONG TERM...MONDAY THROUGH THURSDAY... AN ACTIVE...PROGRESSIVE NORTHERN STREAM SHOULD STEER PARADE OF S/W`S ACROSS NORTHERN CONUS THROUGH PERIOD. DUE TO DEGREE OF MOISTURE AND FAST NATURE TO SYSTEMS EXPECT NO SIGNIFICANT QPF/SNOW EVENTS. AFTER BITTERLY COLD WEEKEND EXPECT COMMENCEMENT OF MODERATING TREND IN TEMPS WITH VALUES REACHING NEAR NORMAL VALUES BY MID WEEK. AVIATION... EXPECT AN INCREASE IN LOW/MID LEVEL MOISTURE FROM WEST TO EAST THIS EVENING INTO FRIDAY. FORECAST SOUNDINGS DO SHOW DEEPENING OF MOISTURE COLUMN ON FRIDAY AHEAD OF LOW CENTER AND ATTENDANT STRONG ARCTIC FRONT LATER IN THE DAY. WE COULD WELL SEE A LOW STRATUS DECK WITH IFR CIGS TAKE SHAPE LATE TONIGHT INTO FRI. THERE IS ALSO SOME RISK OF LOWER VIS IN BR WITH THIS SCENARIO. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...BLIZZARD WATCH FROM FRIDAY EVENING THROUGH SATURDAY AFTERNOON FOR NDZ006>008-014>016-024-026>030-038-039-049-052>054. MN...BLIZZARD WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY AFTERNOON FOR MNZ005-008-013>016-022-023-027-028-030-031-040. BLIZZARD WATCH FROM FRIDAY EVENING THROUGH SATURDAY AFTERNOON FOR MNZ001>004-007-029. && $$ RIDDLE/SCHULTZ nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CLEVELAND OH 928 PM EST FRI FEB 8 2008 .SYNOPSIS... WEAK LOW PRESSURE WILL MOVE ACROSS NORTHERN LOWER MICHIGAN OVERNIGHT. A WARM FRONT AHEAD OF THE LOW WILL MOVE INTO NORTHERN OHIO...FOLLOWED BY A WEAK COLD FRONT DURING THE LAKE MORNING AND AFTERNOON. LOW PRESSURE WILL DEEPEN OVER THE GREAT LAKES SATURDAY AND DRAG AN ARCTIC COLD FRONT THROUGH THE REGION. ARCTIC HIGH PRESSURE WILL BUILD IN FROM THE WEST SUNDAY AND MONDAY. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... ON THE EDGE ON WHAT TO DO WITH PRECIP TYPE TONIGHT. LIGHT SNOW CURRENTLY FALLING OVER NORTHERN IL AND MOVING THIS WAY. LATEST RUC AND 18Z GFS AND NAM CONTINUE TO SHOW SUB ZERO TEMPS AT 850 MB ALL NIGHT. BUT...BUFKIT SOUNDINGS SHOWING A GOOD PUSH OF WARMER AIR IN THE BOUNDARY LAYER OVERNIGHT. HAD HOPED TO BE ABLE TO PICK ONE PRECIP TYPE FOR THE UPDATE...BUT THAT UNFORNATELY WON`T BE HAPPENING. SURFACE TEMPS DROPPED A DEG OR TWO MOST AREAS AFTER DARK AND NOW HAVE STALLED OUT. THEY WILL LIKELY REBOUND UPWARD A DEGREE OR TWO BY MORNING...HOPEFULLY...OR WE`LL HAVE TO WORRY ABOUT FREEZING PRECIP. SO IN SUMMARY...WILL HAVE TO CONTINUE WITH RA OR SN LIKELY WEST. PRECIP SHOULD NOT GET TO NE OH AND NW TILL 09Z OR SO AND THINK PRECIP THESE AREAS SHOULD BE MAINLY SNOW. WILL HOWEVER KEEP A MENTION OF RA JUST IN CASE. LITTLE IF ANY ACCUMULATION. WILL WORD FOR MAINLY STEADY TEMPS OVERNIGHT. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... SATURDAY MORNING WILL BEGIN WITH A WARM FRONT BISECTING THE AREA FROM NORTHWEST TO SOUTHEAST AND A WEAK COLD FRONT ENTERING FROM THE WEST. TEMPERATURES ALOFT AND AT THE SURFACE WILL BE MARGINAL FOR SNOW SO WILL HAVE TO BEGIN WITH A MIX...FOLLOWED BY A CHANGE TO RAIN FOR MUCH OF THE DAY AS TEMPERATURES MOVE INTO THE UPPER 30S OR LOWER 40S. COLD ADVECTION INCREASES IN THE WEST HOWEVER BY MID AFTERNOON AND WHILE THE ACTUAL CHANCE FOR PRECIP WILL LIKELY BE LOW IN THE WEST BY AFTERNOON THE TYPE WILL BE SNOW. REAL FUN WILL BEGIN SATURDAY NIGHT. AN ARCTIC FRONT IS STILL ON SCHEDULE FOR SATURDAY NIGHT. BY 00Z SAT 850MB TEMPS ON THE NAM SUGGEST A MIX IS POSSIBLE WHILE THE GFS IS A FEW DEGREES COLDER AND ALL SNOW. WILL SIDE HERE WITH THE GFS AND LEAVE OUT ANY MIX STARTING OUT THE EVENING FORECAST. COLD FRONT SWINGS IN QUICK AND BY 06Z FRONT APPEARS TO BE NEAR A HZY-CAK LINE. WOULD EXPECT A BURST OF SNOW WITH THE FRONT AND BOTH THE GFS AND NAM SHOW UVV DURING THE FIRST HALF OF THE NIGHT. LOTS OF DRY AIR HOWEVER MOVES IN FROM THE WEST BEHIND THE FRONT. ON BALANCE WILL GO WITH CHC POPS IN THE SOUTHWEST AND MOVE TO LIKELY ACROSS THE NORTH AND EAST WHERE MOISTURE IS BETTER. DOWN WINDS OF THE LAKE WILL GO WITH CATEGORICAL POPS. LOTS OF ICE ON THE LAKE WHICH WILL CUT DOWN ON ACCUMS. SUNDAY HIGH PRESSURE...DRY AIR AND VEERING WINDS MOVE IN QUICK WHICH SHOULD BEGIN TO SHUT OFF THE LAKE. WILL BEGIN WITH LIKELY POPS BUT WILL CUT BACK TO CHC IN THE AFTERNOON. SUNDAY NIGHT WILL CONTINUE WITH CHC POPS ACROSS THE SNOW BELT. MAY NEED A WIND CHILL ADVISORY FOR SATURDAY NIGHT AND SUNDAY WILL CONTINUE TO WATCH THIS. && .LONG TERM /MONDAY THROUGH FRIDAY/... SOME LINGERING LAKE EFFECT SNOW SHOWERS POSSIBLE ON MONDAY MAINLY IN THE MORNING. SHOULD BE VERY LIMITED WITH LACK OF MOISTURE AND LOWERING INVERSION BY THIS TIME. COLD AIR FROM THE ARCTIC BLAST LINGERS MONDAY BUT THEN TEMPERATURES WARMUP SLIGHTLY FOR MID WEEK. WARM FRONT MONDAY NIGHT FOLLOWED BY WEAK COLD FRONT TUESDAY WILL BRING SOME PRECIP TO THE AREA. ECMWF AND GFS FAIRLY CLOSE ON TIMING OF THIS SYSTEM THOUGH GFS LITTLE WARMER...AND TYPE OF PRECIP WITH BOTH MODELS ON EDGE BETWEEN RAIN/SNOW. THEREFORE WILL SHOW CHANCE OF RAIN/SNOW FOR MUCH OF THE AREA TUESDAY. THEN CHANGE BACK TO SNOW SHOWERS TUESDAY NIGHT AND WEDNESDAY WITH LINGERING PRECIP BEHIND THE COLD FRONT. GFS AND ECMWF BEGIN TO DIFFER SIGNIFICANTLY AT END PERIOD. ECMWF SHOWING RIDGE ACROSS THE AREA THURSDAY KEEPING LOW WELL OFF TO THE SOUTHEAST AND OFF THE COAST WITH GFS KEEPING TROF BACK INTO THE AREA WITH THE LOW A LITTLE FURTHER BACK TO THE WEST. WENT WITH DRY WEATHER WITH AT LEAST NARROW RIDGE OVER THE AREA. THEN BROUGHT COLD FRONT THROUGH FRIDAY WITH SNOW SHOWERS. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... VFR CONDITIONS WILL GIVE WAY TO MVFR/IFR CONDITIONS IN SNOW AS THE FIRST OF TWO COLD FRONTS MOVES THROUGH THE AREA. SOME QUESTIONS TO THE PRECIPITATION TYPE BUT IT SEEMS LIKE FOR MOST OF THE FORECAST AREA IT SHOULD BE SNOW. THE PRECIPITATION SHOULD LAST ABOUT 6 TO 8 HOURS. VFR CONDITIONS WILL TRY TO RETURN AFTER THE SNOW ENDS AND SOUTHWEST WINDS WILL BE GUSTY. .OUTLOOK... ARCTIC FRONT WILL MOVE THROUGH SATURDAY NIGHT WITH WIND GUSTS TO 45 KNOTS AND MVFR AND IFR CONDITIONS IN SNOW SHOWERS. ON SUNDAY MVFR/IFR IN SNOW SHOWERS MAINLY EAST OF CLE...ELSEWHERE MVFR CEILINGS WILL BECOME VFR. HIGH PRESSURE AND VFR BUILDING IN SUNDAY NIGHT AND CONTINUING THROUGH MONDAY AS THE HIGH MOVES EAST. COLD FRONT WILL BE MOVING IN ON TUESDAY WITH NON VFR CONDITIONS. NORTHWEST FLOW ON WEDNESDAY WILL HAVE SOME SNOW SHOWERS WITH MVFR CONDITIONS. HIGH PRESSURE AND VFR BUILDING INTO THE REGION LATE WEDNESDAY. && .MARINE... GALE WARNING ISSUED FOR SATURDAY NIGHT. THE GALE FORCE WINDS WILL SPREAD VERY QUICKLY. WILL HAVE TO MONITOR THE THREAT FOR LOW WATER ON THE WEST END OF THE LAKE. LIGHT SOUTHERLY FLOW TONIGHT WILL TURN MORE SOUTHWESTERLY AND BEGIN TO PICK UP DURING THE DAY SATURDAY AFTER AN INITIAL FRONT PASSES. THE ARCTIC COLD FRONT WILL ARRIVE SATURDAY NIGHT AND WITH IT WINDS WILL QUICKLY PICK UP TO WEST GALES. LOW WATER ADVISORY CRITERIA LIKELY TO DEVELOP ON THE WEST END. BROUGHT WINDS UP TO 45 KNOT GALES...AND 50 KNOT STORMS COULD BE A POSSIBILITY. HIGH PRESSURE TO PASS OVERHEAD ON MONDAY AND WINDS WILL LIGHTEN UP QUICKLY AND BRING THEM AROUND TO THE SOUTHWEST. A LITTLE BIT BETTER AGREEMENT FOR TUESDAY WITH LOW PRESSURE TAKING A RUN TOWARD THE LOWER GREAT LAKES AND REDEVELOPING ALONG THE EAST COAST. HIGH PRESSURE FOLLOWS FOR THURSDAY. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...GALE WARNING FROM 7 PM SATURDAY TO 10 PM EST SUNDAY FOR LEZ061- 142>149-162>169. && $$ SYNOPSIS...TK NEAR TERM...KUBINA SHORT TERM...TK LONG TERM...RANDEL AVIATION...KIELTYKA MARINE...KIELTYKA/OUDEMAN oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ABERDEEN SD 920 PM CST THU FEB 7 2008 .UPDATE... SFC LOW PRESSURE CURRENTLY LOCATED IN WRN ND WITH SFC TROF LOCATED JUST WEST OF THE MO RIVER. MODELS STILL SHOW SFC TROF DRIFTING SLOWLY EAST OVERNIGHT. AREA OF LOW CLOUDS/FOG HAS STALLED OVER THE FAR ERN CWA...AND MODEL BL RH PLOTS SUGGEST THAT THEY WILL STAY IN THROUGH THE NIGHT. LATEST RUC/NAM12 QPF ANALYS SUGGESTS THAT LITTLE IF ANY SNOW WILL FALL OVERNIGHT. CURRENT 20% LIGHT SNOW STILL WORKS FOR THE OVERNIGHT. CURRENT ZONES LOOK IN FAIR TO GOOD SHAPE AND NO NEED TO REISSUE ATTM. UPDATED AVIATION DISCUSSION BELOW. && .PREV DISCUSSION... .SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT TWO SHORT WAVES AND ASSOCIATED SURFACE LOW PRESSURE AREAS WILL BE AFFECTING OUR CWA THROUGH THE SHORT TERM. THE FIRST WAVE AND SURFACE LOW WILL BE TRAVERSING ACROSS THE NORTHERN PLAINS TONIGHT AND EARLY FRIDAY. THE LOW CLOUDS FROM WATERTOWN SOUTH HAVE NOT MOVED MUCH TODAY AND EXPECT THEY WILL PROBABLY REMAIN IN INTO THE EARLY EVENING HOURS. OTHERWISE...WITH SOUTH WINDS UNDER 10 MPH ALONG WITH HIGH LOW LEVEL RH...SOME FOG COULD FORM IN THE WATERTOWN AREA TONIGHT. MID AND HIGH LEVEL CLOUDS WILL CONTINUE SPREADING QUICKLY OVER ALL OF THE CWA THIS AFTERNOON AND EVENING WITH SHORT WAVE TROUGH MOVING IN. RADARS AND SURFACE OBS NORTHWEST OF OUR CWA SHOW SOME WEAK ECHOES ALONG WITH SOME LIGHT SNOW/FLURRIES WITH THE SHORT WAVE MOVING IN. KEPT IN THE SLIGHT CHANCE POP AS ONLY EXPECT A TRACE TO A FEW TENTHS OF AN INCH SNOW ACCUMULATION AND IT SHOULD BE LOW ON WATER EQUIVALENT. THE BIG THING WITH THIS SYSTEM WILL BE THE WARMER AIR THAT WILL BE MOVING INTO THE WESTERN CWA FROM MONTANA AND WYOMING ON WEST WINDS LATER TONIGHT. THUS...LOWS TONIGHT WILL LIKELY BE THIS EVENING AND THEN STEADY OR RISE WITH PACIFIC FRONT COMING THROUGH. THE WINDS WONT TURN TO THE WEST UNTIL FRIDAY ACROSS FAR NORTHEAST SD AND WEST CENTRAL MN. FRIDAY WILL HAVE WEST TO NORTHWEST WINDS ACROSS THE CWA WITH HIGHS MOSTLY IN THE 30S AND LOWER 40S. MAY SEE STRONGER WINDS ALONG WITH WARMER TEMPERATURES ACROSS THE BAREGROUND AREAS OF CENTRAL AND NORTH CENTRAL SD ON FRIDAY. THE MODELS HAVE SLOWED UP A BIT WITH THE ARCTIC FRONT COMING THROUGH ALONG WITH THE STRENGTH OF THE WINDS FOR FRIDAY AND SATURDAY. THUS...FRIDAY NIGHT`S LOWS AND SATURDAY`S HIGHS WILL BE TRICKY. THE LOW FRIDAY NIGHT WILL LIKELY COME LATE WITH THE FRONTAL PASSAGE AFTER MIDNIGHT AND CAA KICKING IN. THE HIGH SATURDAY WILL PROBABLY BE EARLY AS CAA INCREASES AND TEMPERATURES REMAIN STEADY OR FALL LATE IN THE MORNING AND IN THE AFTERNOON. STRONG NORTHWEST WINDS ARE STILL EXPECTED LATER FRIDAY NIGHT AND SATURDAY. THERE IS ANOTHER CHANCE OF LIGHT SNOW AGAIN FRIDAY NIGHT ACROSS THE AREA. WITH THE CURRENT SNOW COVER ALONG WITH SOME ADDITIONAL LIGHT SNOW ACCUMULATIONS POSSIBLE TONIGHT AND FRIDAY NIGHT...AREAS OF BLOWING SNOW MAY BE A PROBLEM LATE FRIDAY NIGHT AND SATURDAY. ALSO...WIND CHILLS WILL FALL FOR LATE FRIDAY NIGHT AND SATURDAY. MAY HAVE TO ISSUE AT LEAST A WIND CHILL ADVISORY FOR SATURDAY IN LATER FORECAST. WILL SEE ABOUT THE BLOWING SNOW AND REDUCED VISIBILITIES. SUNDAY NIGHT SHOULD BE VERY COLD AS SURFACE HIGH PRESSURE RIDGING BUILDS OVER THE AREA. CLOUDS WILL MOVE OUT WITH WINDS DECREASING FOR OVERNIGHT LOWS MAINLY IN THE TEENS TO AROUND 20 BELOW ZERO. .LONG TERM...SUNDAY THROUGH THURSDAY. WILL BEGIN PERIOD KNEE DEEP IN ARCTIC AIR WITH H85 TEMPERATURES AT/BELOW -25C ACROSS THE EASTERN THIRD OF THE CWA. COLD AIR ADVECTION CONTINUES THROUGH MUCH OF THE DAY...WITH H85 TEMPERATURES NEARLY STATIC TILL WARM AIR ADVECTION REGIME DEVELOPS BY 00Z. DESPITE WARMER AIR ALOFT...EASTERN THIRD OF THE CWA LIKELY TO DECOUPLE...SO WILL EXPECT SOME TEMPERATURE FALL BEFORE LEVELING OFF. WARM AIR ADVECTION REGIME THROUGH MOST OF MONDAY AHEAD OF CLIPPER SYSTEM. GFS/ECMWF ARE IN GOOD AGREEMENT AT THIS POINT WITH LOW TRACKING ACROSS THE CWA...AND A BROAD AREA OF LOW LEVEL FRONTOGENISIS/BAROCLINICITY TO SUPPORT SNOW. MODELS INDICATE UPPER RIDGE DEVELOPS ACROSS REGION TUESDAY...ALTHOUGH THERE IS SOME DISPARITY IN THE STRENGTH OF WARM AIR ADVECTION THAT FOLLOWS WEDNESDAY. ECMWF STRONGEST WITH H85 TEMPS ABOVE 0C BY 12Z WEDNESDAY. MODELS DIVERGE RAPIDLY THURSDAY WITH UPPER LEVEL FEATURES...HOWEVER THERE IS SOME INDICATION FOR A CANADIAN AIRMASS TO DRIFT ACROSS THE REGION FOR THURSDAY/FRIDAY...THOUGH THIS AIRMASS IS MILD COMPARED TO LAST COUPLE OF EVENTS. && .AVIATION... SFC TROF SLIDING EAST ACROSS REGION TONIGHT WILL BRING CLOUDY SKIES TO THE AREA. IFR CIGS/VSBYS EXPECTED FOR KATY TAF SITE THROUGH 12Z AS LOW CLOUDS/FOG REMAIN OVER SITE. SOME ISOLD/SCT 200-800 FOOT CLOUDS MAY ADVECT INTO KABR AREA AFT 09Z...BUT NOT EXPECTED TO BECOME A CEILING. FURTHER WEST...VFR CONDS EXPECTED THROUGH 10Z FOR KMBG AND KPIR BEFORE MVFR CIGS MOVE IN AFT 10Z. ISOLD/SCT POCKETS OF LIGHT SNOW ARE ALSO POSSIBLE...WITH LITTLE IMPACT EXPECTED FOR THE AVIATION COMMUNITY. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ UPDATE...HINTZ SHORT TERM...MOHR LONG TERM...CONNELLY AVIATION...HINTZ WEATHER.GOV/ABERDEEN sd AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 1025 AM CST THU FEB 7 2008 .DISCUSSION... LOW CLOUDS AND FOG TRAPPED IN BOUNDARY LAYER BELOW 925 MB FM JAMES VALLEY EWD THRU SWRN MN AND NWRN IA...WILL BE SLOW TO BREAK UP FM W TO E IN CWA THIS AFTN...AND MAY NOT BREAK AT ALL EAST OF I29. INVERSION WILL HANG TOUGH UNDER WEAK SFC RDGG AND SFC WINDS RETURNING TO MORE SLY THRU EVE. SO LWRD HIGHS ABOUT 5 DEG ESP IN TRAPPED LWR ELEVATIONS. WILL ALSO HAVE TO WORRY ABOUT SOME DENSE FOG PERSISTING FM NWRN IA TO SRN PART OF SWRN MN THRU AFTN AND TNGT. RYRHOLM && .AVIATION... IFR CIGS AND AREAS OF IFR VSBYS IN FOG EAST OF LN FM HON TO YKN... IMPROVING TO MVFR MOST PLACES WEST OF I29 BY 21Z...BUT PERSISTING FM MUCH OF NWRN IA AND SRN PART OF SWRN MN THRU 12Z. && .PREV DISCUSSION... TODAY...SFC TROF CURRENTLY LOCATED BETWEEN THE JAMES RIVER VALLEY AND CHAMBERLAIN WL SLOWLY WORK ITS WAY EWD. THE QUESTION IS HOW FAR IT WL GET BEFORE STALLING AND WASHING OUT. 00Z NAM AND GFS WERE MOVG THE SFC TROF THRU NEARLY ALL OF THE FA...ALBEIT SLOWLY. HOWEVER A QUICK GLANCE AT THE 06Z NAM AND RUC SHOWS IT STALLING AROUND THE I 29 CORRIDOR BY MIDDAY. SO THAT BEARS WATCHING...ALTHOUGH WINDS WL BE PRETTY LIGHT TODAY. BUT WHAT A STALLING LOW LEVEL TROF WL DO...IS NOT ALLOW THE LOW CLOUDS TO USHER OUT OF OUR ERN FA BECAUSE WINDS WL STAY SLY OVR THE ERN HALF OF OUR FA. THEREFORE SKY CONDS MAY STAY MOSTLY CLOUDY THROUGHOUT THE DAY OVER A GOOD CHUNK OF OUR EAST. MAY HAVE TO UPDATE THESE WINDS BEFORE LEAVING THIS MORNING. OTHERWISE... ASSOCIATED BAND OF FLURRIES IS HAVING TROUBLE REACHING THE GROUND EARLY THIS MORNING. THAT SAID...DECIDED TO KEEP THE MENTION OF SOME FLURRIES THRU THE ERN HALF OF THE FA THIS MORNING AS THE LIGHT ECHOES ARE HARD TO IGNORE...AND THE ERN FA IS WELL PLACED IN THE LEFT EXIT RGN OF A JET STREAK. CHANGED HIGH TEMPS LITTLE TODAY...JUST WARMED THEM UP EVERY SO SLIGHTLY GIVEN THE LATEST NAM/GFS H925 TEMPS. TONIGHT AND FRIDAY...SFC WINDS WL COME AROUND TO THE S OR SE AHEAD OF A DEVELOPING SFC TROF TO THE WEST OF THE FA...SO THIS HAS SOME FOG CONCERNS DEVELOPING ESP IF THE STRATUS DOES NOT CLEAR OUT OF OUR ERN FA TODAY. THIS SFC TROF IS ASSOCIATED WITH A MID LVL FEATURE OF MODERATE INTENSITY. ATTM...IT APPEARS THAT THERE COULD BE A BIT OF MEASURABLE SNOW OVER MUCH OF OUR SRN FA AS THE PROFILE SATURATES UP BLO H5. STRONG ISENTROPIC LIFT IS NOTED...ESP AROUND 285K PER THE GFS WHICH DIVES SEWD FM SW SD TO ERN NEB AS THE NIGHT PROGRESSES... FOLLOWING THE JET MAX AS IT ALSO MOVES SWD. THEREFORE SOME DECENT LIFT IS FOUND ACROSS THE SRN HALF OF THE FA. DUE TO THE RETURN FLOW AND INCREASING CLOUD COVER...LOW TEMPS SHOULD BE FAIRLY MILD TONIGHT FOR THIS TIME OF YEAR. THE MID LVL WAVE EXITS THE ERN FA FRIDAY MORNING TAKING THE -SN CHCS WITH IT. HOWEVER INTERESTINGLY...THE SFC TROF AND ASSOCIATED SFC LOW PRESSURE USHERS UP STRONG WAA WITH IT THRU THE ERN FA LASTING THRU FRIDAY AFTERNOON. THEREFORE DECIDED TO KEEP A VERY SMALL CHC FOR -SN IN OUR FAR ERN FA WITH THE SFC WIND SHIFT FRIDAY AFTERNOON...ALTHOUGH IT WOULD PROBABLY ONLY OCCUR IN THE EARLY AFTERNOON. THEN THE FUN BEGINS AS FRIDAY NIGHT PROGRESSES...LASTING INTO SATURDAY AS AN ARCTIC BLAST MOVES INTO THIS AREA. LATEST MODEL RUNS HAVE SLOWED DOWN THE LEADING EDGE OF THE ARCTIC FRONT A BIT FOR LATE FRIDAY NIGHT. HOWEVER MOST GUIDANCE READINGS STILL LOOK TOO WARM AS THEY USUALLY HANDLE LOW LEVEL ARCTIC AIR POORLY. THIS ARCTIC FRONT WL COME THRU LIKE A TON OF BRICKS...WITH VERY STRONG WAA AND MIXING TO AROUND H9 POST FRONTAL. THIS WL USHER DOWN SOME VERY STRONG WINDS ALOFT. FUTURE FORECASTS FOR SATURDAY WILL PROBABLY NEED SOME WIND CHILL ADVISORIES FM ABOUT I 90 NWD...AND MAYBE WIND ADVISORIES SOUTH OF I 90. OUR FAR SWRN FA MAY ESCAPE THE STRONGEST WINDS WITH A SLIGHTLY BAGGIER SFC PRS GRAD AND LESS WINDS OFF THE SFC. OBVIOUSLY TEMPS WL NOT REBOUND ON SATURDAY...EXCEPT MAYBE IN OUR FAR SW CORNER. INDICATIONS SAT NIGHT ARE THAT SKIES WL CLEAR ALLOWING COLD OVERNIGHT LOWS. THE EXCEPTION MAY BE OUR SW CORNER WHO COULD STAY MOSTLY CLOUDY MOST OF THE NIGHT ALONG THE STRONG H85 BAROCLINIC ZONE. SLOW WAA BEGINS TO RETURN FM W TO E OVR THE FA ON SUNDAY. BUT WITH THE LIGHT WINDS THRU THE ERN FA...TEMPS WL GRUDGINGLY MOVE UPWARD. BUT STRONG WAA IS NOTED SUNDAY NIGHT SO LOWS MAY NOT DROP OFF THAT MUCH FROM SUNDAY HIGHS. DECIDED TO INCLUDE A SMALL POP THRU THE FA ON MONDAY. BOTH THE ECMWF AND GFS SHOW ANOTHER MID LVL WAVE MOVG RAPIDLY THRU THIS AREA. HOWEVER THE GFS ALSO BRINGS ANOTHER ARCTIC INTRUSION DOWN WITH IT MONDAY NIGHT...WHICH WAS NOT BACKED UP BY THE ECMWF. THEREFORE LEFT TEMPS ALONE EARLY NEXT WEEK. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. $$ MJF/LIEBL sd AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 455 AM CST THU FEB 7 2008 .DISCUSSION... TODAY...SFC TROF CURRENTLY LOCATED BETWEEN THE JAMES RIVER VALLEY AND CHAMBERLAIN WL SLOWLY WORK ITS WAY EWD. THE QUESTION IS HOW FAR IT WL GET BEFORE STALLING AND WASHING OUT. 00Z NAM AND GFS WERE MOVG THE SFC TROF THRU NEARLY ALL OF THE FA...ALBEIT SLOWLY. HOWEVER A QUICK GLANCE AT THE 06Z NAM AND RUC SHOWS IT STALLING AROUND THE I 29 CORRIDOR BY MIDDAY. SO THAT BEARS WATCHING...ALTHOUGH WINDS WL BE PRETTY LIGHT TODAY. BUT WHAT A STALLING LOW LEVEL TROF WL DO...IS NOT ALLOW THE LOW CLOUDS TO USHER OUT OF OUR ERN FA BECAUSE WINDS WL STAY SLY OVR THE ERN HALF OF OUR FA. THEREFORE SKY CONDS MAY STAY MOSTLY CLOUDY THROUGHOUT THE DAY OVER A GOOD CHUNK OF OUR EAST. MAY HAVE TO UPDATE THESE WINDS BEFORE LEAVING THIS MORNING. OTHERWISE... ASSOCIATED BAND OF FLURRIES IS HAVING TROUBLE REACHING THE GROUND EARLY THIS MORNING. THAT SAID...DECIDED TO KEEP THE MENTION OF SOME FLURRIES THRU THE ERN HALF OF THE FA THIS MORNING AS THE LIGHT ECHOES ARE HARD TO IGNORE...AND THE ERN FA IS WELL PLACED IN THE LEFT EXIT RGN OF A JET STREAK. CHANGED HIGH TEMPS LITTLE TODAY...JUST WARMED THEM UP EVERY SO SLIGHTLY GIVEN THE LATEST NAM/GFS H925 TEMPS. TONIGHT AND FRIDAY...SFC WINDS WL COME AROUND TO THE S OR SE AHEAD OF A DEVELOPING SFC TROF TO THE WEST OF THE FA...SO THIS HAS SOME FOG CONCERNS DEVELOPING ESP IF THE STRATUS DOES NOT CLEAR OUT OF OUR ERN FA TODAY. THIS SFC TROF IS ASSOCIATED WITH A MID LVL FEATURE OF MODERATE INTENSITY. ATTM...IT APPEARS THAT THERE COULD BE A BIT OF MEASURABLE SNOW OVER MUCH OF OUR SRN FA AS THE PROFILE SATURATES UP BLO H5. STRONG ISENTROPIC LIFT IS NOTED...ESP AROUND 285K PER THE GFS WHICH DIVES SEWD FM SW SD TO ERN NEB AS THE NIGHT PROGRESSES... FOLLOWING THE JET MAX AS IT ALSO MOVES SWD. THEREFORE SOME DECENT LIFT IS FOUND ACROSS THE SRN HALF OF THE FA. DUE TO THE RETURN FLOW AND INCREASING CLOUD COVER...LOW TEMPS SHOULD BE FAIRLY MILD TONIGHT FOR THIS TIME OF YEAR. THE MID LVL WAVE EXITS THE ERN FA FRIDAY MORNING TAKING THE -SN CHCS WITH IT. HOWEVER INTERESTINGLY...THE SFC TROF AND ASSOCIATED SFC LOW PRESSURE USHERS UP STRONG WAA WITH IT THRU THE ERN FA LASTING THRU FRIDAY AFTERNOON. THEREFORE DECIDED TO KEEP A VERY SMALL CHC FOR -SN IN OUR FAR ERN FA WITH THE SFC WIND SHIFT FRIDAY AFTERNOON...ALTHOUGH IT WOULD PROBABLY ONLY OCCUR IN THE EARLY AFTERNOON. THEN THE FUN BEGINS AS FRIDAY NIGHT PROGRESSES...LASTING INTO SATURDAY AS AN ARCTIC BLAST MOVES INTO THIS AREA. LATEST MODEL RUNS HAVE SLOWED DOWN THE LEADING EDGE OF THE ARCTIC FRONT A BIT FOR LATE FRIDAY NIGHT. HOWEVER MOST GUIDANCE READINGS STILL LOOK TOO WARM AS THEY USUALLY HANDLE LOW LEVEL ARCTIC AIR POORLY. THIS ARCTIC FRONT WL COME THRU LIKE A TON OF BRICKS...WITH VERY STRONG WAA AND MIXING TO AROUND H9 POST FRONTAL. THIS WL USHER DOWN SOME VERY STRONG WINDS ALOFT. FUTURE FORECASTS FOR SATURDAY WILL PROBABLY NEED SOME WIND CHILL ADVISORIES FM ABOUT I 90 NWD...AND MAYBE WIND ADVISORIES SOUTH OF I 90. OUR FAR SWRN FA MAY ESCAPE THE STRONGEST WINDS WITH A SLIGHTLY BAGGIER SFC PRS GRAD AND LESS WINDS OFF THE SFC. OBVIOUSLY TEMPS WL NOT REBOUND ON SATURDAY...EXCEPT MAYBE IN OUR FAR SW CORNER. INDICATIONS SAT NIGHT ARE THAT SKIES WL CLEAR ALLOWING COLD OVERNIGHT LOWS. THE EXCEPTION MAY BE OUR SW CORNER WHO COULD STAY MOSTLY CLOUDY MOST OF THE NIGHT ALONG THE STRONG H85 BAROCLINIC ZONE. SLOW WAA BEGINS TO RETURN FM W TO E OVR THE FA ON SUNDAY. BUT WITH THE LIGHT WINDS THRU THE ERN FA...TEMPS WL GRUDGINGLY MOVE UPWARD. BUT STRONG WAA IS NOTED SUNDAY NIGHT SO LOWS MAY NOT DROP OFF THAT MUCH FROM SUNDAY HIGHS. DECIDED TO INCLUDE A SMALL POP THRU THE FA ON MONDAY. BOTH THE ECMWF AND GFS SHOW ANOTHER MID LVL WAVE MOVG RAPIDLY THRU THIS AREA. HOWEVER THE GFS ALSO BRINGS ANOTHER ARCTIC INTRUSION DOWN WITH IT MONDAY NIGHT...WHICH WAS NOT BACKED UP BY THE ECMWF. THEREFORE LEFT TEMPS ALONE EARLY NEXT WEEK. && .AVIATION... CEILINGS TO VARY GREATLY AROUND THE AREA TODAY. FOR HON...MVFR CEILINGS WILL GIVE WAY TO MOSTLY CLEAR SKIES THIS MORNING. FARTHER EAST IFR CEILING ARE LIKELY NEAR AND EAST OF FSD THROUGH MUCH OF THE MORNING...BUT SHOULD SCATTER OUT IN THE AFTERNOON. TOWARDS SUX...LOW LEVEL MOISTURE WILL REMAIN IN PLACE THROUGH MOST OF THE DAY... PRODUCING PERSISTANT IFR CEILINGS AND SOME REDUCED VISIBILITIES FROM FOG. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. $$ MJF/LIEBL sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NASHVILLE TN 929 AM CST THU FEB 7 2008 .UPDATE...BASED ON LATEST RUC`S HANDLING OF NORTHERN CLOUDS, AND THE FACT THAT THE BROAD 850 THERMAL TROF NEVER REALLY PASSES EAST OF OUR FORECAST AREA TODAY, WILL UPDATE TO GO FOR MOSTLY CLOUDY SKIES AND SLIGHTLY COOLER MAX TEMPERATURES THAN PREVIOUSLY FORECAST. MIGHT EVEN HAVE TO DEAL WITH STUBBORN CLOUDS IN TONIGHT`S FORECAST OVER SOME NORTEHRN AREAS. HOWEVER, WE`LL CROSS THAT BRIDGE A LITTLE LATER TODAY. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 19 tn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 923 PM CST FRI FEB 8 2008 .UPDATE...IR SATELLITE SHOWS MID LEVEL TROUGH AXIS MOVING THROUGH THE AREA ATTM...HOWEVER THE SFC REFLECTION/WEAK FRONTAL BOUNDARY IS LAGGING BEHIND AND IS ALONG A ROCKSPRINGS TO NACOGDOCHES LINE. DWPT DEPRESSIONS ARE LOWEST ALONG THE IMMEDIATE COAST AND 3-5 DEGREES GENERALLY EAST OF I-37. THUS EXPECT RADIATION FOG TO DEVELOP IN THESE AREA AFTER MIDNIGHT. LATEST RUC FORECAST BRINGS THE FRONT TO A COTULLA TO PORT LAVACA LINE BY DAYBREAK. THIS WOULD FOCUS THE FOG TO THE SOUTH OF THIS BOUNDARY. THE FRONT WASHES OUT OVER THE AREA ON SATURDAY AS THE SFC RIDGE SLIDES QUICKLY EAST INTO LOUISIANA. IF DWPTS SURGE MUCH ABOVE THE MID 60S...SEA FOG WILL BE BACK ALONG THE IMMEDIATE COAST ON SATURDAY. ZONES ARE IN GOOD SHAPE. NO CHANGES NEEDED. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 53 76 59 70 62 / 0 0 10 10 10 VICTORIA 47 74 50 67 55 / 0 0 10 10 10 LAREDO 55 84 58 78 63 / 0 0 10 10 10 ALICE 50 79 56 73 60 / 0 0 10 10 10 ROCKPORT 56 71 58 67 61 / 0 0 10 10 10 COTULLA 46 81 54 75 60 / 0 0 10 10 10 KINGSVILLE 51 78 57 72 61 / 0 0 10 10 10 NAVY CORPUS 59 69 60 69 63 / 0 0 10 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ JM/75...SHORT TERM TM/95...AVIATION tx AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX 850 AM CST FRI FEB 8 2008 .UPDATE... HAVE UPDATED THE FORECAST TO INCLUDE HIGH WIND CRITERIA IN THE GUADALUPE AND DAVIS MOUNTAINS. SUSTAINED WINDS TO NEAR 40 MPH WITH GUSTS TO NEAR 65 AND 70 MPH HAVE BEEN REPORTED AT MOUNT LOCKE IN THE DAVIS MOUNTAINS AS WELL AS AT THE BOWL IN THE GUADALUPE MOUNTAINS. HAVE THE HIGH WIND WARNING IN EFFECT UNTIL 08/20Z FOR THESE LOCATIONS...WITH THE HIGH WINDS EXPECTED MAINLY IN THE HIGHER ELEVATIONS ABOVE 5000 FEET. REMAINDER OF PRODUCTS OUT SHORTLY. /13/ && .PREV DISCUSSION... /ISSUED 709 AM CST FRI FEB 8 2008/ UPDATE... AFTER MUCH DISCUSSION...HAVE DECIDED TO GO WITH A RED FLAG WARNING FOR THE GUADALUPE MOUNTAINS...SOUTHEAST NEW MEXICO PLAINS... PERMIAN BASIN...UPPER TRANS PECOS...VAN HORN AREA AND DAVIS MOUNTAINS FROM 11 AM UNTIL 5 PM CST. FIRST...MODEL DEWPOINTS ARE TO HIGH THIS MORNING ACROSS THE CWA AND FURTHER NORTH OVER THE EASTERN NEW MEXICO PLAINS AND THE TEXAS PANHANDLE. WHEN NORTHWEST WINDS INCREASE LATER...THE DOWNSLOPE WINDS SHOULD DRY/WARM THE AIR FURTHER. SECONDLY...MODELS ARE UNDERESTIMATING WIND SPEEDS. 12Z SOUNDINGS AT KAMA AND KMAF INDICATED WINDS ABOVE THE SURFACE WERE STRONGER THAN PROGS...EXCEPT MAYBE THE RUC. THE H5 HEIGHT GRADIENT IS PROGGED TO BE PRETTY TIGHT OVER THE AREA TODAY TOO. AS THE SURFACE PRESSURE GRADIENT INCREASES OVER THE AREA THIS AFTERNOON...SEVERAL LOCATIONS WILL BE AT OR ABOVE 20 MPH FOR SEVERAL HOURS. WIND SPEEDS SHOULD DECREASE BY LATE AFTERNOON AS THE SURFACE PRESSURE GRADIENT SLACKENS. WILL SEND UPDATED PRODUCTS SHORTLY. PREV DISCUSSION... /ISSUED 528 AM CST FRI FEB 8 2008/ AVIATION... PACIFIC FRONT WILL MOVE THROUGH THE TAF SITES THIS MORNING WITH WEST WINDS OF AROUND 10 MPH SHIFTING TO THE NORTHWEST AND INCREASING GENERALLY TO 15 TO 25 MPH. WINDS WILL DIMINISH BY LATE THIS AFTERNOON. VFR CONDITIONS EXPECTED THROUGH THE FORECAST CYCLE. 12 PREV DISCUSSION... /ISSUED 408 AM CST FRI FEB 8 2008/ DISCUSSION... A BROAD UPPER TROUGH WILL ENCOMPASS THE EASTERN CONUS THROUGH SATURDAY BEFORE UPPER RIDGING OVER THE WEST COAST FLATTENS AND EXPANDS EAST. THE FLOW ALOFT WILL AMPLIFY EARLY NEXT WEEK WITH THE NEXT UPPER TROUGH POSSIBLY DEEPENING ENOUGH TO AFFECT THE AREA TUESDAY. NOT A LOT OF AGREEMENT AMONGST MEDIUM RANGE MODELS WITH THIS TROUGH THOUGH. AMPLIFIED FLOW ALOFT WILL THEN PREVAIL THROUGH MUCH OF NEXT WEEK. A LEE TROUGH OVER THE AREA THIS MORNING WILL TRAVERSE THE AREA AS A COLD FRONT PUSHES SOUTH INTO THE CWA. TEMPERATURES WILL BE FAIRLY WARM THOUGH AS MOST OF THE COOLER AIR WILL SLIDE EAST OF THE AREA AND DOWNSLOPE NORTHWEST WINDS WILL AID WARMING. HAVE GONE ON THE HIGH SIDE OF MODEL GUIDANCE OFFERINGS. SAID WINDS WILL BE AT OR ABOVE 20 MPH FOR A PERIOD OF TIME THIS MORNING AND EARLY AFTERNOON...BUT A RED FLAG WARNING WILL NOT BE ISSUED DESPITE DRY AIR ENCOMPASSING THE CWA. IT APPEARS THE BEST WINDS WILL OCCUR BEFORE RH/S BOTTOM OUT. FIRE WEATHER CONCERNS WILL STILL BE ELEVATED AREAWIDE DUE TO THE DRY STATE OF FUELS...SO WILL HIGHLIGHT IN THE HWO. THE DRY AIR WILL REMAIN OVER THE AREA THROUGH SATURDAY...WHICH WILL TRANSLATE INTO FAIRLY CHILLY TEMPERATURES SATURDAY MORNING AS GOOD RADIATIONAL COOLING CONDITIONS WILL PREVAIL TONIGHT. TEMPERATURES WILL REBOUND SATURDAY AS UPPER RIDGING BUILDS OVER THE AREA. LOW LEVEL MOISTURE WILL SPREAD INTO THE EASTERN CWA SATURDAY NIGHT... THEN STAY OVER THESE AREAS THROUGH MONDAY. ALTHOUGH DRIER AIR WILL STILL ENCOMPASS MUCH OF THE WESTERN THIRD OR SO OF THE CWA DURING THIS TIME...WEAKER WINDS ALOFT WILL NEGATE FIRE WEATHER CONCERNS FOR MOST OF THIS TIME. THERE IS SOME HOPE OF RAIN FROM SUNDAY NIGHT THROUGH TUESDAY...BUT MAINLY FROM THE BIG BEND REGION ACROSS THE LOWER TRANS PECOS. THE SCANT CHANCES IN THE FORECAST WILL DEPEND ON HOW MUCH UPPER FLOW AMPLIFIES. OTHERWISE...A COLD FRONT IS EXPECTED TUESDAY...WITH ABOVE NORMAL TEMPERATURES EXPECTED PRIOR TO...AND AFTER TUESDAY. FIRE WEATHER... DRY AIR WILL CONTINUE TO ENCOMPASS SOUTHEAST NEW MEXICO AND WEST TEXAS THROUGH SATURDAY. 20 FOOT WIND SPEEDS WILL EXCEED 20 MPH FOR AWHILE TODAY OVER PORTIONS OF THE GUADALUPE MOUNTAINS...SOUTHEAST NEW MEXICO PLAINS...VAN HORN AREA...UPPER TRANS PECOS...PERMIAN BASIN AND WESTERN LOW ROLLING PLAINS. SINCE MINIMUM RH/S WILL BE BELOW 15 PERCENT THESE AREAS...WILL ISSUE A RED FLAG WARNING FROM 11 AM UNTIL 5 PM CST. WIND SPEEDS WILL NOT BE AS STRONG ELSEWHERE. RECOVERY TONIGHT IS EXPECTED TO BE POOR TO FAIR IN MOST LOCATIONS WITH AFTERNOON RH/S SATURDAY DROPPING BELOW 15 PERCENT IN MOST LOCATIONS. 20 FOOT WIND SPEEDS SATURDAY ARE EXPECTED TO REMAIN BELOW 20 MPH MOST LOCATIONS...SO A FIRE WEATHER WATCH IS NOT IN THE OFFING. RECOVERY SATURDAY NIGHT WILL BE FAIR TO GOOD MOST LOCATIONS. && .MAF WATCHES/WARNINGS/ADVISORIES... NM...RED FLAG WARNING FROM 10 AM THIS MORNING TO 4 PM MST THIS AFTERNOON FOR THE FOLLOWING ZONES...GUADALUPE MOUNTAINS NP/LINCOLN NF/LNZ...SOUTHEAST PLAINS/BLM ROSWELL/LNZ. HIGH WIND WARNING FROM 7 AM THIS MORNING TO 1 PM MST THIS AFTERNOON FOR THE FOLLOWING ZONES...GUADALUPE MOUNTAINS OF EDDY COUNTY. TX...RED FLAG WARNING FROM 11 AM CST /10 AM MST/ THIS MORNING TO 5 PM CST /4 PM MST/ THIS AFTERNOON FOR THE FOLLOWING ZONES... ANDREWS...BORDEN...CRANE...DAVIS/APACHE MOUNTAINS AREA... DAWSON...ECTOR...GAINES...GLASSCOCK...GUADALUPE MOUNTAINS... HOWARD...LOVING...MARTIN...MIDLAND...MITCHELL...REAGAN... REEVES COUNTY AND UPPER TRANS PECOS...SCURRY...UPTON...VAN HORN AND HIGHWAY 54 CORRIDOR...WARD...WINKLER. HIGH WIND WARNING FROM 8 AM CST /7 AM MST/ THIS MORNING TO 2 PM CST /1 PM MST/ THIS AFTERNOON FOR THE FOLLOWING ZONES... DAVIS/APACHE MOUNTAINS AREA...GUADALUPE MOUNTAINS. && $$ 13 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX 709 AM CST FRI FEB 8 2008 .UPDATE... AFTER MUCH DISCUSSION...HAVE DECIDED TO GO WITH A RED FLAG WARNING FOR THE GUADALUPE MOUNTAINS...SOUTHEAST NEW MEXICO PLAINS... PERMIAN BASIN...UPPER TRANS PECOS...VAN HORN AREA AND DAVIS MOUNTAINS FROM 11 AM UNTIL 5 PM CST. FIRST...MODEL DEWPOINTS ARE TO HIGH THIS MORNING ACROSS THE CWA AND FURTHER NORTH OVER THE EASTERN NEW MEXICO PLAINS AND THE TEXAS PANHANDLE. WHEN NORTHWEST WINDS INCREASE LATER...THE DOWNSLOPE WINDS SHOULD DRY/WARM THE AIR FURTHER. SECONDLY...MODELS ARE UNDERESTIMATING WIND SPEEDS. 12Z SOUNDINGS AT KAMA AND KMAF INDICATED WINDS ABOVE THE SURFACE WERE STRONGER THAN PROGS...EXCEPT MAYBE THE RUC. THE H5 HEIGHT GRADIENT IS PROGGED TO BE PRETTY TIGHT OVER THE AREA TODAY TOO. AS THE SURFACE PRESSURE GRADIENT INCREASES OVER THE AREA THIS AFTERNOON...SEVERAL LOCATIONS WILL BE AT OR ABOVE 20 MPH FOR SEVERAL HOURS. WIND SPEEDS SHOULD DECREASE BY LATE AFTERNOON AS THE SURFACE PRESSURE GRADIENT SLACKENS. WILL SEND UPDATED PRODUCTS SHORTLY. && .PREV DISCUSSION... /ISSUED 528 AM CST FRI FEB 8 2008/ AVIATION... PACIFIC FRONT WILL MOVE THROUGH THE TAF SITES THIS MORNING WITH WEST WINDS OF AROUND 10 MPH SHIFTING TO THE NORTHWEST AND INCREASING GENERALLY TO 15 TO 25 MPH. WINDS WILL DIMINISH BY LATE THIS AFTERNOON. VFR CONDITIONS EXPECTED THROUGH THE FORECAST CYCLE. 12 PREV DISCUSSION... /ISSUED 408 AM CST FRI FEB 8 2008/ DISCUSSION... A BROAD UPPER TROUGH WILL ENCOMPASS THE EASTERN CONUS THROUGH SATURDAY BEFORE UPPER RIDGING OVER THE WEST COAST FLATTENS AND EXPANDS EAST. THE FLOW ALOFT WILL AMPLIFY EARLY NEXT WEEK WITH THE NEXT UPPER TROUGH POSSIBLY DEEPENING ENOUGH TO AFFECT THE AREA TUESDAY. NOT A LOT OF AGREEMENT AMONGST MEDIUM RANGE MODELS WITH THIS TROUGH THOUGH. AMPLIFIED FLOW ALOFT WILL THEN PREVAIL THROUGH MUCH OF NEXT WEEK. A LEE TROUGH OVER THE AREA THIS MORNING WILL TRAVERSE THE AREA AS A COLD FRONT PUSHES SOUTH INTO THE CWA. TEMPERATURES WILL BE FAIRLY WARM THOUGH AS MOST OF THE COOLER AIR WILL SLIDE EAST OF THE AREA AND DOWNSLOPE NORTHWEST WINDS WILL AID WARMING. HAVE GONE ON THE HIGH SIDE OF MODEL GUIDANCE OFFERINGS. SAID WINDS WILL BE AT OR ABOVE 20 MPH FOR A PERIOD OF TIME THIS MORNING AND EARLY AFTERNOON...BUT A RED FLAG WARNING WILL NOT BE ISSUED DESPITE DRY AIR ENCOMPASSING THE CWA. IT APPEARS THE BEST WINDS WILL OCCUR BEFORE RH/S BOTTOM OUT. FIRE WEATHER CONCERNS WILL STILL BE ELEVATED AREAWIDE DUE TO THE DRY STATE OF FUELS...SO WILL HIGHLIGHT IN THE HWO. THE DRY AIR WILL REMAIN OVER THE AREA THROUGH SATURDAY...WHICH WILL TRANSLATE INTO FAIRLY CHILLY TEMPERATURES SATURDAY MORNING AS GOOD RADIATIONAL COOLING CONDITIONS WILL PREVAIL TONIGHT. TEMPERATURES WILL REBOUND SATURDAY AS UPPER RIDGING BUILDS OVER THE AREA. LOW LEVEL MOISTURE WILL SPREAD INTO THE EASTERN CWA SATURDAY NIGHT... THEN STAY OVER THESE AREAS THROUGH MONDAY. ALTHOUGH DRIER AIR WILL STILL ENCOMPASS MUCH OF THE WESTERN THIRD OR SO OF THE CWA DURING THIS TIME...WEAKER WINDS ALOFT WILL NEGATE FIRE WEATHER CONCERNS FOR MOST OF THIS TIME. THERE IS SOME HOPE OF RAIN FROM SUNDAY NIGHT THROUGH TUESDAY...BUT MAINLY FROM THE BIG BEND REGION ACROSS THE LOWER TRANS PECOS. THE SCANT CHANCES IN THE FORECAST WILL DEPEND ON HOW MUCH UPPER FLOW AMPLIFIES. OTHERWISE...A COLD FRONT IS EXPECTED TUESDAY...WITH ABOVE NORMAL TEMPERATURES EXPECTED PRIOR TO...AND AFTER TUESDAY. FIRE WEATHER... DRY AIR WILL CONTINUE TO ENCOMPASS SOUTHEAST NEW MEXICO AND WEST TEXAS THROUGH SATURDAY. 20 FOOT WIND SPEEDS WILL EXCEED 20 MPH FOR AWHILE TODAY OVER PORTIONS OF THE GUADALUPE MOUNTAINS...SOUTHEAST NEW MEXICO PLAINS...VAN HORN AREA...UPPER TRANS PECOS...PERMIAN BASIN AND WESTERN LOW ROLLING PLAINS. SINCE MINIMUM RH/S WILL BE BELOW 15 PERCENT THESE AREAS...WILL ISSUE A RED FLAG WARNING FROM 11 AM UNTIL 5 PM CST. WIND SPEEDS WILL NOT BE AS STRONG ELSEWHERE. RECOVERY TONIGHT IS EXPECTED TO BE POOR TO FAIR IN MOST LOCATIONS WITH AFTERNOON RH/S SATURDAY DROPPING BELOW 15 PERCENT IN MOST LOCATIONS. 20 FOOT WIND SPEEDS SATURDAY ARE EXPECTED TO REMAIN BELOW 20 MPH MOST LOCATIONS...SO A FIRE WEATHER WATCH IS NOT IN THE OFFING. RECOVERY SATURDAY NIGHT WILL BE FAIR TO GOOD MOST LOCATIONS. && .MAF WATCHES/WARNINGS/ADVISORIES... NM...RED FLAG WARNING FROM 10 AM THIS MORNING TO 4 PM MST THIS AFTERNOON FOR THE FOLLOWING ZONES...GUADALUPE MOUNTAINS NP/LINCOLN NF/LNZ...SOUTHEAST PLAINS/BLM ROSWELL/LNZ. TX...RED FLAG WARNING FROM 11 AM CST /10 AM MST/ THIS MORNING TO 5 PM CST /4 PM MST/ THIS AFTERNOON FOR THE FOLLOWING ZONES... ANDREWS...BORDEN...CRANE...DAVIS/APACHE MOUNTAINS AREA... DAWSON...ECTOR...GAINES...GLASSCOCK...GUADALUPE MOUNTAINS... HOWARD...LOVING...MARTIN...MIDLAND...MITCHELL...REAGAN... REEVES COUNTY AND UPPER TRANS PECOS...SCURRY...UPTON...VAN HORN AND HIGHWAY 54 CORRIDOR...WARD...WINKLER. && $$ 12/67 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX 911 AM CST THU FEB 7 2008 .UPDATE... HIGH WIND WARNING FOR DAVIS MOUNTAINS HAS EXPIRED. THE WIND AT MOUNT LOCKE HAS FALLEN TO AROUND 10 MPH SO WILL NOT EXTEND THE WARNING. ELSEWHERE ACROSS THE AREA A COLD FRONT HAS PUSHED THROUGH MOST OF THE REGION THIS MORNING WITH A NORTH WIND PICKING UP BEHIND IT. EXPECT OCCASIONAL GUSTS THROUGH MIDDAY UNTIL THE PRESSURE GRADIENT RELAXES. && .PREV DISCUSSION... /ISSUED 606 AM CST THU FEB 7 2008/ AVIATION... FAST MOVING COLD FRONT WILL BRING INCREASED NORTHWEST TO NORTH WINDS ACROSS THE REGION THIS MORNING. WINDS MAY BECOME SUSTAINED NEAR 20 KNOTS WITH GUSTS TO 30 KNOTS AT THE KMAF TERMINAL FOR A BRIEF PERIOD. THE FRONT WILL QUICKLY PUSH SOUTHEAST ACROSS THE STATE...AND WINDS SHOULD GRADUALLY BECOME WESTERLY ACROSS MOST LOCATIONS DURING THE AFTERNOON...THEN SOUTHWEST THIS EVENING. GENERALLY CLEAR SKIES/VFR CONDITIONS TODAY AND TONIGHT. PREV DISCUSSION... /ISSUED 529 AM CST THU FEB 7 2008/ DISCUSSION... WEATHER OBSERVATIONS ACROSS THE HIGHER ELEVATIONS OF THE DAVIS MOUNTAINS CONTINUE TO SHOW MARGINAL HIGH WINDS CONTINUE EARLY THIS MORNING. TAKING A LOOK AT THE RUC13 AND NAM12 MODELS...700MB WINDS FROM THE NORTHWEST REMAIN AT OR JUST ABOVE 40KTS THROUGH ROUGHLY 15Z. GIVEN CURRENT OBSERVATIONS AND MODEL DATA...WE HAVE OPTED TO EXTEND THE HIGH WIND WARNING FOR THE DAVIS MOUNTAINS UNTIL 15Z. ELSEWHERE...A COLD FRONT LOCATED ALONG A JAYTON TO GAIL TO GUADALUPE MOUNTAINS LINE WILL CONTINUE TO PUSH SOUTHEAST ACROSS THE REGION. WINDS BEHIND THE FRONT HAVE BEEN GUSTY GIVEN 5MB/3 HOUR PRESSURE RISES ACROSS THE PANHANDLE. THESE PRESSURE RISES SHOULD CONTINUE TO TRACK SOUTHEAST ALONG THE RED RIVER...THUS THE STRONGER GUSTS BEHIND THE FRONT WILL STAY GENERALLY NORTH OF A TATUM NEW MEXICO TO BIG SPRING LINE THIS MORNING. DESPITE THE COLD FRONT MOVING THROUGH...WE CAN STILL EXPECT NEAR NORMAL TEMPERATURES TODAY GIVEN A DRY AIRMASS AND PLENTY OF INSOLATION. FOR TOMORROW...THE CURRENT PATTERN APPEARS TO REPEAT ITSELF. A MID- LEVEL SHORTWAVE TROUGH WILL MOVE INTO THE NORTHERN PANHANDLE BY EARLY TOMORROW MORNING. THIS WILL AID IN SENDING ANOTHER WEAK FRONT/WIND SHIFT INTO THE REGION TOMORROW MORNING. LITTLE COOLING IS EXPECTED BEHIND THE FRONT...AND GIVEN 850MB WARMING...WE WILL CONTINUE THE CURRENT FORECAST OF ABOVE NORMAL TEMPERATURES ON FRIDAY. CONTINUED ABOVE NORMAL TEMPERATURES FOR SATURDAY AS EAST TO SOUTHEAST SURFACE WINDS BEGIN TO ORGANIZE LATE IN THE DAY. SURFACE WINDS INCREASE OUT OF THE SOUTH TO SOUTHEAST ON SUNDAY...SIGNALING AN INCREASE IN LOW-LEVEL MOISTURE. MEANWHILE...WEAK MID-LEVEL CYCLONIC FLOW TRIES TO ORGANIZE OVER THE BAJA PENINSULA...WITH MID AND UPPER LEVEL MOISTURE INCREASING FROM SOUTH TO NORTH ON SUNDAY. THE MEDIUM RANGE MODELS SUGGEST A SERIES OF WEAK MID-LEVEL DISTURBANCES WILL MOVE OUT OF MEXICO INTO WEST TEXAS SUNDAY THROUGH EARLY NEXT WEEK. LOW-LEVEL MOISTURE CONTINUES TO INCREASE THROUGH THE MENTIONED PERIOD...AND WE WILL CONTINUE TO MAINTAIN A VERY LOW CHANCE OF RAIN SHOWERS ACROSS THE STOCKTON PLATEAU AND BIG BEND REGION THROUGH MONDAY NIGHT. RAIN CHANCES CREEP NORTHWARD INTO THE LOWER TRANS PECOS ON TUESDAY AS A COLD FRONT MOVES INTO THE REGION. UNCERTAINTY BETWEEN THE GFS AND ECMWF CONTINUES INTO THE MIDDLE OF NEXT WEEK...WITH THE LATEST MEX GUIDANCE TRENDING MUCH LOWER WITH POPS. FOR NOW...WE WILL CONTINUE THE CURRENT FORECAST...WHICH CALLS FOR A SLIGHT CHANCE OF RAIN SHOWERS ACROSS THROUGH WEDNESDAY...MAINLY ACROSS THE SOUTHEASTERN PORTION OF THE CWA. FIRE WEATHER... A COLD FRONT WILL PUSH ACROSS THE FIRE WEATHER OUTLOOK AREA TODAY. 20 FT WINDS WILL SHIFT TO THE NORTHWEST/NORTH BEHIND THIS FRONT...WITH SUSTAINED SPEEDS BETWEEN 15 AND 20 MPH POSSIBLE NORTH OF INTERSTATE 20 UNTIL AROUND MID MORNING. WINDS SHOULD GRADUALLY BACK TO THE WEST BY THIS AFTERNOON AS THE SURFACE LOW MOVES TOWARD THE ARKLATEX REGION. THE STRONGEST WINDS DURING THE AFTERNOON WILL LIKELY AFFECT THE GUADALUPE AND DAVIS MOUNTAINS...WHERE WESTERLY 20 FT WIND SPEEDS OF 20-30 MPH...WITH GUSTS NEAR 40 MPH WILL BE POSSIBLE. SUSTAINED SPEEDS NEAR 20 MPH ARE ALSO POSSIBLE ACROSS THE ADJACENT EDDY/REEVES COUNTY PLAINS. VERY DRY AIR WILL REMAIN IN PLACE...WITH RELATIVE HUMIDITY LIKELY DROPPING BETWEEN 10 AND 15 PERCENT ACROSS MOST LOCATIONS. RED FLAG CONDITIONS MAY BE BRIEFLY MET ACROSS THE GUADALUPE AND DAVIS MOUNTAINS AND THE ADJACENT PLAINS AREAS OF EDDY/CULBERSON/REEVES COUNTIES FOR 1-2 HOURS THIS AFTERNOON. THINK THE DURATION WILL BE BRIEF ENOUGH...AND AREA SHOULD BE SMALL ENOUGH TO PRECLUDE A RED FLAG WARNING ISSUANCE...BUT WILL CONTINUE TO HIGHLIGHT DRY AND BREEZY CONDITIONS IN THE FIRE WEATHER PLANNING FORECAST. LIKE YESTERDAY...CAUTION IS VERY MUCH ADVISED WHEN WORKING WITH FLAMMABLE MATERIALS OUTDOORS TODAY. && .MAF WATCHES/WARNINGS/ADVISORIES... NM...NONE. TX...NONE. && $$ tx AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX 606 AM CST THU FEB 7 2008 .AVIATION... FAST MOVING COLD FRONT WILL BRING INCREASED NORTHWEST TO NORTH WINDS ACROSS THE REGION THIS MORNING. WINDS MAY BECOME SUSTAINED NEAR 20 KNOTS WITH GUSTS TO 30 KNOTS AT THE KMAF TERMINAL FOR A BRIEF PERIOD. THE FRONT WILL QUICKLY PUSH SOUTHEAST ACROSS THE STATE...AND WINDS SHOULD GRADUALLY BECOME WESTERLY ACROSS MOST LOCATIONS DURING THE AFTERNOON...THEN SOUTHWEST THIS EVENING. GENERALLY CLEAR SKIES/VFR CONDITIONS TODAY AND TONIGHT. && .PREV DISCUSSION... /ISSUED 529 AM CST THU FEB 7 2008/ DISCUSSION... WEATHER OBSERVATIONS ACROSS THE HIGHER ELEVATIONS OF THE DAVIS MOUNTAINS CONTINUE TO SHOW MARGINAL HIGH WINDS CONTINUE EARLY THIS MORNING. TAKING A LOOK AT THE RUC13 AND NAM12 MODELS...700MB WINDS FROM THE NORTHWEST REMAIN AT OR JUST ABOVE 40KTS THROUGH ROUGHLY 15Z. GIVEN CURRENT OBSERVATIONS AND MODEL DATA...WE HAVE OPTED TO EXTEND THE HIGH WIND WARNING FOR THE DAVIS MOUNTAINS UNTIL 15Z. ELSEWHERE...A COLD FRONT LOCATED ALONG A JAYTON TO GAIL TO GUADALUPE MOUNTAINS LINE WILL CONTINUE TO PUSH SOUTHEAST ACROSS THE REGION. WINDS BEHIND THE FRONT HAVE BEEN GUSTY GIVEN 5MB/3 HOUR PRESSURE RISES ACROSS THE PANHANDLE. THESE PRESSURE RISES SHOULD CONTINUE TO TRACK SOUTHEAST ALONG THE RED RIVER...THUS THE STRONGER GUSTS BEHIND THE FRONT WILL STAY GENERALLY NORTH OF A TATUM NEW MEXICO TO BIG SPRING LINE THIS MORNING. DESPITE THE COLD FRONT MOVING THROUGH...WE CAN STILL EXPECT NEAR NORMAL TEMPERATURES TODAY GIVEN A DRY AIRMASS AND PLENTY OF INSOLATION. FOR TOMORROW...THE CURRENT PATTERN APPEARS TO REPEAT ITSELF. A MID- LEVEL SHORTWAVE TROUGH WILL MOVE INTO THE NORTHERN PANHANDLE BY EARLY TOMORROW MORNING. THIS WILL AID IN SENDING ANOTHER WEAK FRONT/WIND SHIFT INTO THE REGION TOMORROW MORNING. LITTLE COOLING IS EXPECTED BEHIND THE FRONT...AND GIVEN 850MB WARMING...WE WILL CONTINUE THE CURRENT FORECAST OF ABOVE NORMAL TEMPERATURES ON FRIDAY. CONTINUED ABOVE NORMAL TEMPERATURES FOR SATURDAY AS EAST TO SOUTHEAST SURFACE WINDS BEGIN TO ORGANIZE LATE IN THE DAY. SURFACE WINDS INCREASE OUT OF THE SOUTH TO SOUTHEAST ON SUNDAY...SIGNALING AN INCREASE IN LOW-LEVEL MOISTURE. MEANWHILE...WEAK MID-LEVEL CYCLONIC FLOW TRIES TO ORGANIZE OVER THE BAJA PENINSULA...WITH MID AND UPPER LEVEL MOISTURE INCREASING FROM SOUTH TO NORTH ON SUNDAY. THE MEDIUM RANGE MODELS SUGGEST A SERIES OF WEAK MID-LEVEL DISTURBANCES WILL MOVE OUT OF MEXICO INTO WEST TEXAS SUNDAY THROUGH EARLY NEXT WEEK. LOW-LEVEL MOISTURE CONTINUES TO INCREASE THROUGH THE MENTIONED PERIOD...AND WE WILL CONTINUE TO MAINTAIN A VERY LOW CHANCE OF RAIN SHOWERS ACROSS THE STOCKTON PLATEAU AND BIG BEND REGION THROUGH MONDAY NIGHT. RAIN CHANCES CREEP NORTHWARD INTO THE LOWER TRANS PECOS ON TUESDAY AS A COLD FRONT MOVES INTO THE REGION. UNCERTAINTY BETWEEN THE GFS AND ECMWF CONTINUES INTO THE MIDDLE OF NEXT WEEK...WITH THE LATEST MEX GUIDANCE TRENDING MUCH LOWER WITH POPS. FOR NOW...WE WILL CONTINUE THE CURRENT FORECAST...WHICH CALLS FOR A SLIGHT CHANCE OF RAIN SHOWERS ACROSS THROUGH WEDNESDAY...MAINLY ACROSS THE SOUTHEASTERN PORTION OF THE CWA. FIRE WEATHER... A COLD FRONT WILL PUSH ACROSS THE FIRE WEATHER OUTLOOK AREA TODAY. 20 FT WINDS WILL SHIFT TO THE NORTHWEST/NORTH BEHIND THIS FRONT...WITH SUSTAINED SPEEDS BETWEEN 15 AND 20 MPH POSSIBLE NORTH OF INTERSTATE 20 UNTIL AROUND MID MORNING. WINDS SHOULD GRADUALLY BACK TO THE WEST BY THIS AFTERNOON AS THE SURFACE LOW MOVES TOWARD THE ARKLATEX REGION. THE STRONGEST WINDS DURING THE AFTERNOON WILL LIKELY AFFECT THE GUADALUPE AND DAVIS MOUNTAINS...WHERE WESTERLY 20 FT WIND SPEEDS OF 20-30 MPH...WITH GUSTS NEAR 40 MPH WILL BE POSSIBLE. SUSTAINED SPEEDS NEAR 20 MPH ARE ALSO POSSIBLE ACROSS THE ADJACENT EDDY/REEVES COUNTY PLAINS. VERY DRY AIR WILL REMAIN IN PLACE...WITH RELATIVE HUMIDITY LIKELY DROPPING BETWEEN 10 AND 15 PERCENT ACROSS MOST LOCATIONS. RED FLAG CONDITIONS MAY BE BRIEFLY MET ACROSS THE GUADALUPE AND DAVIS MOUNTAINS AND THE ADJACENT PLAINS AREAS OF EDDY/CULBERSON/REEVES COUNTIES FOR 1-2 HOURS THIS AFTERNOON. THINK THE DURATION WILL BE BRIEF ENOUGH...AND AREA SHOULD BE SMALL ENOUGH TO PRECLUDE A RED FLAG WARNING ISSUANCE...BUT WILL CONTINUE TO HIGHLIGHT DRY AND BREEZY CONDITIONS IN THE FIRE WEATHER PLANNING FORECAST. LIKE YESTERDAY...CAUTION IS VERY MUCH ADVISED WHEN WORKING WITH FLAMMABLE MATERIALS OUTDOORS TODAY. && .MAF WATCHES/WARNINGS/ADVISORIES... NM...NONE. TX...HIGH WIND WARNING FROM 5 AM TO 9 AM CST THIS MORNING FOR THE FOLLOWING ZONES...DAVIS/APACHE MOUNTAINS AREA. && $$ 21/06 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX 529 AM CST THU FEB 7 2008 .DISCUSSION... WEATHER OBSERVATIONS ACROSS THE HIGHER ELEVATIONS OF THE DAVIS MOUNTAINS CONTINUE TO SHOW MARGINAL HIGH WINDS CONTINUE EARLY THIS MORNING. TAKING A LOOK AT THE RUC13 AND NAM12 MODELS...700MB WINDS FROM THE NORTHWEST REMAIN AT OR JUST ABOVE 40KTS THROUGH ROUGHLY 15Z. GIVEN CURRENT OBSERVATIONS AND MODEL DATA...WE HAVE OPTED TO EXTEND THE HIGH WIND WARNING FOR THE DAVIS MOUNTAINS UNTIL 15Z. ELSEWHERE...A COLD FRONT LOCATED ALONG A JAYTON TO GAIL TO GUADALUPE MOUNTAINS LINE WILL CONTINUE TO PUSH SOUTHEAST ACROSS THE REGION. WINDS BEHIND THE FRONT HAVE BEEN GUSTY GIVEN 5MB/3 HOUR PRESSURE RISES ACROSS THE PANHANDLE. THESE PRESSURE RISES SHOULD CONTINUE TO TRACK SOUTHEAST ALONG THE RED RIVER...THUS THE STRONGER GUSTS BEHIND THE FRONT WILL STAY GENERALLY NORTH OF A TATUM NEW MEXICO TO BIG SPRING LINE THIS MORNING. DESPITE THE COLD FRONT MOVING THROUGH...WE CAN STILL EXPECT NEAR NORMAL TEMPERATURES TODAY GIVEN A DRY AIRMASS AND PLENTY OF INSOLATION. FOR TOMORROW...THE CURRENT PATTERN APPEARS TO REPEAT ITSELF. A MID- LEVEL SHORTWAVE TROUGH WILL MOVE INTO THE NORTHERN PANHANDLE BY EARLY TOMORROW MORNING. THIS WILL AID IN SENDING ANOTHER WEAK FRONT/WIND SHIFT INTO THE REGION TOMORROW MORNING. LITTLE COOLING IS EXPECTED BEHIND THE FRONT...AND GIVEN 850MB WARMING...WE WILL CONTINUE THE CURRENT FORECAST OF ABOVE NORMAL TEMPERATURES ON FRIDAY. CONTINUED ABOVE NORMAL TEMPERATURES FOR SATURDAY AS EAST TO SOUTHEAST SURFACE WINDS BEGIN TO ORGANIZE LATE IN THE DAY. SURFACE WINDS INCREASE OUT OF THE SOUTH TO SOUTHEAST ON SUNDAY...SIGNALING AN INCREASE IN LOW-LEVEL MOISTURE. MEANWHILE...WEAK MID-LEVEL CYCLONIC FLOW TRIES TO ORGANIZE OVER THE BAJA PENINSULA...WITH MID AND UPPER LEVEL MOISTURE INCREASING FROM SOUTH TO NORTH ON SUNDAY. THE MEDIUM RANGE MODELS SUGGEST A SERIES OF WEAK MID-LEVEL DISTURBANCES WILL MOVE OUT OF MEXICO INTO WEST TEXAS SUNDAY THROUGH EARLY NEXT WEEK. LOW-LEVEL MOISTURE CONTINUES TO INCREASE THROUGH THE MENTIONED PERIOD...AND WE WILL CONTINUE TO MAINTAIN A VERY LOW CHANCE OF RAIN SHOWERS ACROSS THE STOCKTON PLATEAU AND BIG BEND REGION THROUGH MONDAY NIGHT. RAIN CHANCES CREEP NORTHWARD INTO THE LOWER TRANS PECOS ON TUESDAY AS A COLD FRONT MOVES INTO THE REGION. UNCERTAINTY BETWEEN THE GFS AND ECMWF CONTINUES INTO THE MIDDLE OF NEXT WEEK...WITH THE LATEST MEX GUIDANCE TRENDING MUCH LOWER WITH POPS. FOR NOW...WE WILL CONTINUE THE CURRENT FORECAST...WHICH CALLS FOR A SLIGHT CHANCE OF RAIN SHOWERS ACROSS THROUGH WEDNESDAY...MAINLY ACROSS THE SOUTHEASTERN PORTION OF THE CWA. && .FIRE WEATHER... A COLD FRONT WILL PUSH ACROSS THE FIRE WEATHER OUTLOOK AREA TODAY. 20 FT WINDS WILL SHIFT TO THE NORTHWEST/NORTH BEHIND THIS FRONT...WITH SUSTAINED SPEEDS BETWEEN 15 AND 20 MPH POSSIBLE NORTH OF INTERSTATE 20 UNTIL AROUND MID MORNING. WINDS SHOULD GRADUALLY BACK TO THE WEST BY THIS AFTERNOON AS THE SURFACE LOW MOVES TOWARD THE ARKLATEX REGION. THE STRONGEST WINDS DURING THE AFTERNOON WILL LIKELY AFFECT THE GUADALUPE AND DAVIS MOUNTAINS...WHERE WESTERLY 20 FT WIND SPEEDS OF 20-30 MPH...WITH GUSTS NEAR 40 MPH WILL BE POSSIBLE. SUSTAINED SPEEDS NEAR 20 MPH ARE ALSO POSSIBLE ACROSS THE ADJACENT EDDY/REEVES COUNTY PLAINS. VERY DRY AIR WILL REMAIN IN PLACE...WITH RELATIVE HUMIDITY LIKELY DROPPING BETWEEN 10 AND 15 PERCENT ACROSS MOST LOCATIONS. RED FLAG CONDITIONS MAY BE BRIEFLY MET ACROSS THE GUADALUPE AND DAVIS MOUNTAINS AND THE ADJACENT PLAINS AREAS OF EDDY/CULBERSON/REEVES COUNTIES FOR 1-2 HOURS THIS AFTERNOON. THINK THE DURATION WILL BE BRIEF ENOUGH...AND AREA SHOULD BE SMALL ENOUGH TO PRECLUDE A RED FLAG WARNING ISSUANCE...BUT WILL CONTINUE TO HIGHLIGHT DRY AND BREEZY CONDITIONS IN THE FIRE WEATHER PLANNING FORECAST. LIKE YESTERDAY...CAUTION IS VERY MUCH ADVISED WHEN WORKING WITH FLAMMABLE MATERIALS OUTDOORS TODAY. && .PRELIMINARY POINT TEMPS/POPS... BIG SPRING TX 58 37 69 36 / 0 0 0 0 CARLSBAD NM 63 37 70 35 / 0 0 0 0 DRYDEN TX 66 38 75 41 / 0 0 0 0 FORT STOCKTON TX 64 39 73 40 / 0 0 0 0 GUADALUPE PASS TX 57 37 64 41 / 0 0 0 0 HOBBS NM 59 33 67 31 / 0 0 0 0 MARFA TX 59 28 67 31 / 0 0 0 0 MIDLAND INTL AIRPORT TX 59 36 68 36 / 0 0 0 0 ODESSA TX 58 37 68 36 / 0 0 0 0 WINK TX 63 35 73 34 / 0 0 0 0 && .MAF WATCHES/WARNINGS/ADVISORIES... NM...NONE. TX...HIGH WIND WARNING FROM 4 AM TO 9 AM CST THIS MORNING FOR THE FOLLOWING ZONES...DAVIS/APACHE MOUNTAINS AREA. && $$ 21/06 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 250 AM MST SAT FEB 9 2008 .DISCUSSION...WATER VAPOR/RUC ANALYSIS WAS INDICATING NORTHWEST MID/UPPER FLOW OVER THE CENTRAL HIGH PLAINS AS A SHORTWAVE TROUGH DIGS INTO THE UPPER MISSISSIPPI VALLEY/GREAT LAKES REGION EARLY THIS MORNING. AT THE SURFACE...AN ARCTIC COLD FRONT WAS ANALYZED OVER THE NORTHERN PLAINS STATES WITH STRONG CAA EVIDENT BY SFC TEMPERATURES IN THE -10 TO -30 DEGREE RANGE ACROSS PORTIONS OF ALBERTA/SASKATCHEWAN ADVECTING SOUTHEAST TOWARDS THE NORTHERN PLAINS EARLY THIS MORNING. TEMPERATURES SHOULD BEGIN TO REBOUND TODAY IN WESTERLY LOW LEVEL DOWNSLOPE AHEAD OF THE CONTINENTAL ARCTIC AIRMASS...HOWEVER TRENDED COOLER WITH WIDESPREAD SNOW EXPECTED TO IMPACT MIXING ONCE AGAIN TODAY. BOTH NAM/GFS APPEAR IN REASONABLE AGREEMENT WITH ARCTIC COLD FRONT BACKING INTO THE AREA TONIGHT RAISING CONCERNS FOR FOG/FREEZING DRIZZLE ALONG LEADING EDGE OF ARCTIC AIRMASS. BOTH NAM/GFS POINT SOUNDINGS SUGGEST A CONSIDERABLE DEPTH OF SATURATION GRADUALLY SUPPORTING SOME FLURRIES ACROSS THE NORTHEAST ZONES WHERE THE SHALLOW COLD LAYER WILL APPROACH -10C ALLOWING THE INTRODUCTION OF ICE/FLURRIES TOWARD MORNING. RELUCTANT TO WARM TEMPERATURES MUCH ON SUNDAY WITH ARCTIC AIRMASS ENTRENCHED ACROSS MUCH OF THE AREA. HIGHS MAY STRUGGLE TO CLIMB INTO THE 20S ACROSS THE EASTERN ZONES WHILE THE WESTERN ZONES MAY BEGIN TO MIX OUT AS SOUTHERLY FLOW RETURNS. A FEW FLURRIES WILL BE POSSIBLE IN THE MORNING...HOWEVER INCREASING CHANCES FOR INSOLATION ACROSS THE WEST WILL RESULT IN A DECENT DIURNAL CLIMB WITH HIGHS REACHING THE UPPER 30S. MONDAY...SOME WARMING WILL BE POSSIBLE EARLY IN THE PERIOD AS A PRE-FRONTAL TROUGH ADDS A WESTERLY COMPONENT TO THE LOW LEVEL FLOW...HOWEVER ANY WARMING WILL BE SHORT-LIVED AS ANOTHER COLD FRONT ARRIVES LATE IN THE PERIOD. TRENDED HIGHS DOWN SLIGHTLY AND INCREASED POPS AS A PROGRESSIVE SHORTWAVE TROUGH APPROACHES THE AREA. ADDED A SLIGHT CHANCE FOR LIGHT SNOW ACROSS THE WESTERN ZONES MONDAY EVENING AND EXPANDED AN AREA OF FLURRIES EAST INTO PORTIONS OF WESTERN KANSAS/EXTREME SOUTHWEST NEBRASKA. PRECIPITATION IS EXPECTED TO REMAIN LIGHT GIVEN LIMITED MOISTURE/PROGRESSIVE TROUGH. && .AVIATION...VFR CONDITIONS WILL PREVAIL THROUGH 03-05Z ON TUE WITH CIGS LOWERING FROM NORTHEAST TO SOUTHWEST AS AN ARCTIC COLD FRONT BACKS INTO THE AREA. IFR/LIFR CONDITIONS ARE EXPECTED ALONG LEADING EDGE OF ARCTIC AIRMASS IN LOW CIGS/AREAS OF FZDZ AND BR/FG. MVFR CONDITIONS WILL RETURN AFTER 13-15Z ON TUE. .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$ MCGUIRE ks AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 1226 AM EST SAT FEB 9 2008 UPDATED AVIATION DISCUSSION FOR 06Z TAFS .UPDATE (ISSUED AT 1008 PM EST)... FCST FOR THE OVERNIGHT APPEARS TO BE IN GOOD SHAPE. WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A SHORTWAVE OVER THE UPPER AND MID MISSISSIPPI VALLEY. PCPN ASSOCIATED WITH THIS SYSTEM HAS BEEN GRADUALLY INCREASING IN COVERAGE THIS EVENING. PER 00Z RUC... ISENTROPIC ASCENT ON THE 285K THETA SFC IS BEING MAXIMIZED IN ERN WI AND THAT IS WHERE RADARS SHOW THE BEST RADAR RETURNS. ANOTHER ARC OF -SN HAS BEEN GRADUALLY INCREASING ACROSS CNTRL WI JUST N OF VORT MAX TRACK (DEFORMATION ZONE). TRACK OF SHORTWAVE AND ISENTROPIC ASCENT PER 00Z RUC AND EXTRAPOLATION OF -SN CURRENTLY OVER WI SUGGEST ROUGHLY THE SE HALF OF THE FCST AREA WILL SEE SOME -SN OVERNIGHT. MOST PERSISTENT -SN WILL BE TOWARD LAKE MICHIGAN WHERE BEST ISENTROPIC ASCENT WILL OCCUR. INHERITED FCST HAS THIS COVERED WELL. LOOKS LIKE ABOUT 1 TO 1.5 INCHES SHOULD COVER SNOW AMOUNTS CLOSE TO LAKE MICHIGAN. && .PREV DISCUSSION (ISSUED AT 355 PM EST)... ...BLIZZARD CONDITIONS POSSIBLE IN NORTHWEST FLOW SNOWBELTS SATURDAY EVENING INTO SUNDAY... SYNOPSIS... 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A SPLIT FLOW ACRS NAMERICA WITH TROFFING IN THE ARCTIC AND POLAR BRANCHES CENTERED NEAR HUDSON BAY/THE MS RIVER VALLEY. POLAR BRANCH SHRTWV NOTED MOVING INTO WI SUPPORTING AN AREA OF -SN FM CNTRL MN INTO NW WI WHERE MOIST 12Z MPX SDNG SUGS ATMOSPHERE IS SATURATED ENUF TO SUPPORT PCPN. EARLIER TAMDAR SDNG FM SAW SHOWED A VERY DRY LYR BTWN H9-7...SO LTL GOING ON LOCALLY WITH WEAK RDG OVHD...JUST SOME MID AND HI CLD NOTED ASSOCIATED WITH THE SHRTWV TO THE SW. FARTHER UPSTREAM...A MORE POTENT SHRTWV NOTED DIGGING INTO BRITISH COLUMBIA. H3 WIND SPEEDS APRCHG 150KT NOTED WITHIN UPR JET CORE ACCOMPANYING THIS SYS AND ORIENTED ALG SHARP GRADIENT OF H3 HGT RISES. SHORT TERM (TONIGHT AND SATURDAY)... MAIN FORECAST CONCERN TNGT IS POTENTIAL SN ASSOCIATED WITH SHRTWV NOW DRIFTING THRU THE UPR MIDWEST. FOCUS FOR SAT SHIFTS TO TIMING/ IMPACT OF POTENT SHRTWV NOW OVER BRITISH COLUMBIA...SPECIFICALLY SN/AND ONSET OF POTENTIALLY BLIZZARD CONDITIONS AT LEAST OVER THE W. FOR TNGT INTO SAT MRNG...LO PRES OVER THE UPR MIDWEST FCST TO DRIFT INTO NRN LK MI BY 12Z SAT. ISENTROPIC LIFT/MOISTENING ON THE 280-285K SFCS (H65-8) FCST TO IMPACT MAINLY THE SE HALF OF THE CWA IN ADVANCE OF THIS LO. SINCE THERE MAY ALSO BE SOME MOISTENING OFF LI MI...OPTED TO BUMP UP POPS TO LIKELY NEAR THE LK MI SHORE FM LATE TNGT INTO SAT MRNG BEFORE THE SFC LO/ISENTROPIC LIFT TRACKS TO THE NE AND A WEAK RDG AXIS MOVES OVHD IN ITS WAKE. 1-2G/KG SPECIFIC HUMIDITY NOTED IN THE H7-75 LYR...SO EXPECT AS MUCH AS 2 INCHES OF SN TO FALL DURING THE 9 HR PD OF PCPN IN THIS AREA. EXPECT LTL SN TO THE NW WITH RDG AXIS BTWN LO PRES AREA AND APRCHG COLD FNT ASSOCIATED WITH BRITISH COLUMBIA SHRTWV. ON SAT AFTN...GUIDANCE HAS TRENDED A BIT SLOWER WITH ARRIVAL OF BRITISH COLUMBIA SHRTWV AND ARCTIC FNT...WHICH NOW LOOKS TO REACH IWD JUST ARND 19Z AND THEN P53-ESC ARND 00Z. SHARP PRES RISE/CAD BEHIND THE BNDRY IN CONCERT WITH 45KT WINDS IN THE MIXED LYR WHERE LAPSE RATES WL BE ENHANCED BY THE STRONG CAD SUG SUBSTANTIAL MIXING TO THE SFC...SO LOOK FOR GUSTY WINDS/BLSN TO DVLP QUICKLY AFT FROPA AS TEMPS FALL. ATMOSPHERE WL BE RATHER DRY (PWAT AOB 0.25 INCH)...SO A WHOLE LOT OF SN NOT ON TAP WITH QUICK MOVING FNT EVEN THOUGH VIGOROUS 12Z HR H5 HGT FALLS UP TO 100M/DIFFLUENT UPR FLOW WL TEND TO SQUEEZE OUT THE MEAGER MSTR AVBL. THERE WL BE SOME ENHANCEMENT OVER THE HIER TERRAIN OF THE W...WHERE A COUPLE OF INCHES WL LIKELY FALL BEFORE 24Z. LONG TERM (SATURDAY NIGHT THROUGH NEXT FRIDAY)... LOW PRESSURE SHIFTS JUST NORTH OF SAULT STE MARIE SATURDAY EVENING LEAVING 25-30MB PRESSURE GRADIENT ACROSS NORTHERN UPR MI AND LK SUPERIOR. STRONG BURST OF 20-30MPH WITH GUSTS TO 45 MPH WINDS IN WAKE OF ARCTIC FRONT (AIDED BY 10MB/6HR PRESSURE RISE) SHOULD SWEEP INTO THE EASTERN CWA BY LATE EVENING. AFTERWARD...STRONG WINDS THROUGH THE NIGHT ARE A FUNCTION OF TIGHT PRESSURE GRADIENT MAINTAINING THROUGH 12Z SUN. H95-H85 WINDS FM WEST TO NORTHWEST ALLOW MOST CONCENTRATED CONVERGENCE AND LK EFFECT SNOW SHOWERS TO MOVE INTO ONTONAGON TO BEGIN THE EVENING AND IN THE SNOWBELTS EAST OF MUNISING AFTER LATE SAT EVENING. H85 TEMPS LOWERING BLO -20C IN THE MIXED LAYER LEAD TO VERY SMALL SNOWFLAKE SIZE WHICH WON`T BE SUITABLE FOR LARGE ACCUMS...BUT WILL BE VERY EFFICIENT IN YIELDING SEVERELY REDUCED VSBY OVER KEWEENAW PENINSULA INTO ONTONAGON COUNTY AND IN ALGER THROUGH LUCE COUNTIES IN THE NE CWA. A CONCERN ON KEWEENAW IS A MORE WNW WIND DIRECTION WHICH MAY SHUT OFF THE MORE CONCENTRATED SNOW SHOWERS NORTH OF CALUMET AFTER THE INITIAL SURGE OF SNOW/WIND EARLY SATURDAY EVENING DUE TO SHADOW FM ISLE ROYALE. AREAS WHERE THE MAX LIFT IS PRESENT IN THE -12C TO -18C (BETTER SNOW GROWTH) LAYER ALSO INDICATE THIS TREND WITH MAXIMUM VALUES OVR ONTONAGON AND ALGER/LUCE COUNTIES. SINCE AM NOT QUITE SURE HOW KEWEENAW COUNTY WILL WORK OUT AFTER THE EVENING FOR THE MEETING OF BLIZZARD CONDITIONS WILL OPT TO KEEP BLIZZARD WATCH GOING. PREVIOUS SET TIMES FOR THE BLIZZARD WATCHES LOOKED FINE. ISSUED A WINTER STORM WATCH FOR SOUTHERN HOUGHTON AND NORTHERN SCHOOLCRAFT ZONES DUE TO STRONG WINDS BLOWING THE LK EFFECT SNOW BANDS FARTHER INLAND/SIGNIFICANT BLOWING SNOW AND VERY LOW WIND CHILLS. SPEAKING OF THE WIND CHILLS ADDED MENOMINEE AND DELTA INTO THE GOING WIND CHILL WATCH. EVENTUALLY SOME TYPE OF HEADLINE...BE IT WIND CHILL ADVY OR WINTER WEATHER ADVY (SNOW/BLSN/WIND CHILL COMBO)...WILL BE NEEDED FOR ALL REMAINING AREAS OF THE CWA SATURDAY NIGHT INTO SUNDAY. LOW PRESSURE SYSTEM EXITS INTO QUEBEC BY LATE SUNDAY WITH LK EFFECT SNOW AND SOME BLOWING SNOW DIMINISHING OVER THE NW SNOW BELTS BY SUNDAY EVENING. WINDS BECOME VARIABLE SUNDAY NIGHT AWAY FM THE NW WINDS CLOSER TO LAKE SUPERIOR AND THIS SHOULD ALLOW FOR PARTIAL CLEARING AND PLUMMETING TEMPS OVR WEST INTERIOR. FOLLOWING HPC PREFERENCE OF ECMWF IN THE UPCOMING WEEK RESULTS IN WEAK LOW PRESSURE WITH SOME LIGHT SNOW AFFECTING GREAT LAKES MON-TUE. HIGHEST CHANCES IN THE CWA APPEAR OVR SOUTHERN SECTIONS. ANOTHER LOW PRESSURE SYSTEM AFFECTS THE REGION ON THU. GFS MORE EMPHATIC IN BRINGING ANOTHER SHOT OF ARCTIC AIR BY LATE WEEK BUT ECMWF NOT AS AMPLIFIED. CONFIDENCE IN EXTENDED NOT HIGH AS THERE ARE SIGNIFICANT DISAGREEMENTS BTWN THE GFS AND ECMWF AND ENSEMBLES NOT POINTING TO ANY ONE DIRECTION EITHER. TEMPS NEAR CLIMO/HPC GUIDANCE ARE PREFERRED FOR NOW. && .AVIATION (FOR THE 06Z TAF ISSUANCE)... AT KCMX...FOR MOST OF THE NIGHT...EXPECT VFR CONDITIONS TO LINGER. MVFR CIGS AND POSSIBLY MVFR VIS IN FOG SHOULD DEVELOP TOWARD DAYBREAK...BUT MORE LIKELY SAT MORNING AS SW WINDS AHEAD OF APPROACHING ARCTIC COLD FRONT ADVECT LOW-LEVEL MOISTURE (WIDESPREAD MVFR CIGS ARE PRESENT OVER MN RIGHT NOW) INTO THE AREA. STRONG/SHARP ARCTIC COLD FRONT PASSING LATE IN THE AFTN SHOULD BRING A DRAMATIC FALL TO VLIFR CONDITIONS IN SN/BLSN. VLIFR CONDITIONS SHOULD THEN PREVAIL WELL BEYOND THIS FCST PERIOD THRU SUN MORNING DUE TO STRONG WNW WINDS AND LAKE EFFECT SNOW/BLSN. AT KSAW...EXPECT VFR CONDITIONS TO GIVE WAY TO MVFR CIGS AND IFR VIS IN -SN/BR OVER THE NEXT FEW HRS AS NRN FRINGE OF -SN ASSOCIATED WITH LOW PRES OVER WI SPREADS NE. CONDITIONS WILL IMPROVE SOME SAT MORNING INTO THE AFTN AS LOW PRES AND PCPN SHIFT E OF THE AREA. VIS WILL TREND VFR...BUT DO NOT EXPECT CIGS TO LIFT ABOVE MVFR. STRONG/SHARP ARCTIC COLD FRONT ARRIVING LATE AFTN/EARLY EVENING WILL DROP VIS TO IFR IN A BRIEF PERIOD OF -SN. MVFR CONDITIONS ARE THEN EXPECTED FOR THE REMAINDER OF SAT EVENING. && .MARINE (FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)... EXPECT NW GALES TO DVLP OVER WRN LK SUP BEHIND STRONG COLD FNT ON SAT AFTN AND THEN OVERSPREAD THE ENTIRE LK BY EARLY EVNG. STORM FORCE WINDS LOOK LIKE A GOOD POSSIBILITY LATER SAT NGT/EARLY SUN IN SHARP CYC NW FLOW BEHIND DEEP LO PRES MOVING INTO SE CAN BEFORE LO MOVES QUICKLY AWAY AND PRES GRADIENT SLACKENS SUN AFTN. RELATIVELY LGT WINDS WL PREVAIL MON THRU WED WITH NEXT DEEPER LO FCST TO TRACK WELL TO THE S EARLY NEXT WEEK. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... BLIZZARD WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY AFTERNOON FOR MIZ001>003. WIND CHILL WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY AFTERNOON FOR MIZ009>013. WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING FOR MIZ085. WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY AFTERNOON FOR MIZ084. BLIZZARD WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING FOR MIZ006-007. LAKE SUPERIOR... GALE WARNING FROM 9 PM SATURDAY TO 6 PM EST SUNDAY FOR LSZ267. GALE WARNING FROM 6 PM SATURDAY TO 6 PM EST SUNDAY FOR LSZ266. GALE WARNING FROM 5 PM SATURDAY TO 4 PM EST SUNDAY FOR LSZ264- 265. GALE WARNING FROM 1 PM SATURDAY TO 10 AM EST SUNDAY FOR LSZ162-263. LAKE MICHIGAN...NONE. && $$ UPDATE...ROLFSON SYNOPSIS/SHORT TERM...KC LONG TERM...JLA AVIATION...ROLFSON MARINE...KC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 1150 PM EST FRI FEB 8 2008 .AVIATION... INCREASING LIFT EAST OF A STRENGTHENING SURFACE LOW LIFTING INTO SOUTHERN WISCONSIN...WILL ALLOW A BAND OF LIGHT SNOW TO OVERSPREAD SOUTHEAST LOWER MICHIGAN THROUGH THE EARLY/MID MORNING HOURS. THIS WILL BRING VISIBILITY DOWN INTO IFR AT TIMES. SNOW WILL QUICKLY TAPER OFF AS AN INITIAL COLD FRONT LIFTS THROUGH BY MID-MORNING. SOUTHWEST WINDS WILL STRENGTHEN DURING AFTERNOON/EVENING BEHIND THIS FRONT... WITH GUSTS OVER 20 KNOTS. ANOTHER BAND OF LGT SNOW WILL ACCOMPANY AN ARCTIC FRONT TOMORROW EVENING...WITH WINDS SHIFTING TOWARD THE WEST AND INTENSIFYING FURTHER TOWARD 06Z. && .PREV DISCUSSION...ISSUED 1055 PM EST FRI FEB 8 2008 UPDATE... SFC LOW BEGINNING TO STRENGTHEN NOW AS IT LIFTS NORTHEAST INTO SOUTHERN WISCONSIN. LATEST SATELLITE DATA AND UPSTREAM OBSERVATIONS DEPICTING THE RESULTANT INCREASE IN LARGE SCALE ACCENT...WITH COOLING CLOUD TOPS AND AN EXPANSION IN LGT PCPN REPORTS ACROSS EASTERN IL. MORE PRONOUNCED WARM AIR ADVECTION IN CLOSER PROXIMITY TO THE SFC FEATURE ALLOWING THE LOW LEVEL THERMAL PROFILE TO WARM ENOUGH FOR ALL RAIN AS FAR NORTH AS EXTREME SOUTHEAST WISCONSIN. THIS REMAINS A CONCERN LOCALLY TONIGHT... MAINLY ACROSS THE SOUTHERN TIER...AS THIS MOISTURE TRANSLATES NORTHEAST INTO THE AREA LATE TONIGHT. SFC TEMPERATURES PER LATEST OBSERVATIONS CONTINUE TO HOVER AROUND FREEZING...WITH LOCATIONS JUST SOUTH INTO THE TOLEDO AREA NOW IN THE 33-35F RANGE. CHECK OF THE LATEST 00Z NAM SOUNDING DATA INDICATES A BOUNDARY LAYER THAT IS AT LEAST MARGINALLY SUPPORTIVE OF RAIN MIX WITH THE SNOW FROM ROUGHLY ANN ARBOR-DETROIT SOUTHWARD. THUS...WILL INTRODUCE A RAIN/SNOW MIX FOR AFTER 09Z ACROSS THIS CORRIDOR. A DEEP SATURATED LAYER AND MODEST FORCING CONTINUES TO SUPPORT ACCUMULATIONS OF 1 TO 2 INCHES BETWEEN ROUGHLY 09-14Z EARLY THIS MORNING...ESPECIALLY FROM I-69 NORTH WHERE THE THERMAL PROFILE WILL CLEARLY REMAIN SUPPORTIVE OF ALL SNOW AND WHERE MORE PRONOUNCED FORCING WILL EXIST. WILL CUT INTO AMOUNTS SLIGHTLY ACROSS THE OHIO BORDER COUNTIES GIVEN THE HIGHER POTENTIAL FOR SOME MIXING BASED ON CURRENT AND UPSTREAM THERMAL TRENDS. PREV DISCUSSION...ISSUED 348 PM EST FRI FEB 8 2008 SHORT TERM...THIS AFTERNOON AND TONIGHT VERY LIGHT SNOW ACTIVITY CONTINUES TO SWEEP ACROSS SOUTHEASTERN MICHIGAN THIS AFTERNOON...WITH CURRENT LOCATION ACROSS THE TRI CITIES AND THUMB. THIS AREA OF SNOW IS ASSOCIATED WITH LIFT ALONG LEADING THETA E BUBBLE AND EMBEDDED SHORTWAVE ENERGY THE RUC HAS A GREAT HANDLE ON. KDTX RADAR IS GIVING THE DRIZZLE LOOK BEHIND THIS SNOW ACTIVITY AND EXPECTING THIS TO CONTINUE WITH THE SATURATED LOWER TROPOSPHERE. HAVE CUT THE POPS THIS EVENING BACK DOWN TO CHANCE AS METARS HAVE BEEN COMING IN ONLY A TRACE. DESPITE TEMPERATURES A TOUCH BELOW FREEZING...NOT EXPECTING ANY LARGE HEADACHES DUE TO FREEZING DRIZZLE AS AREA ROADWAYS SHOULD BE HEAVILY TREATED AND TEMPERATURES SHOULD LARGELY HOLD STEADY JUST UNDER THE FREEZING MARK. DESPITE WEAK CONTINUED WARMING...MODEL GUIDANCE IS BULLISH ON ALL SNOW MENTION LATER TONIGHT IN THE BUFFER SOUNDINGS AND IN AGREEMENT WITH THE AMOUNT OF COLD AIR IN RESIDENCE NORTH OF THE IOWAN SURFACE REFLECTION. TWO WEAK SHORTWAVES...ONE OVER NORTHERN MINNESOTA...THE OTHER OVER CENTRAL PLAINS WILL MERGE OVER MICHIGAN TONIGHT IN QUASI-CONFLUENT FLOW. THIS RESULTS IN A SURFACE LOW TRACK FROM SOUTHERN WISCONSIN...NORTHEASTWARD TO FRANKFORT MICHIGAN BY THE END OF THE PERIOD. AM FAIRLY IMPRESSED WITH THE THERMODYNAMICS OVERNIGHT AS LOW STATIC STABILITY EXISTS FROM 900MB UPWARD. GIVEN MOIST LOWER TROPOSPHERIC ENVIRONMENT...FEEL THERE ARE NO NEGATIVE ISSUES REGARDING MOISTURE. ON THE OTHER HAND...SYNOPTIC SCALE DYNAMICS ARE FAIRLY LACKLUSTER...GIVEN RAGGED APPEARANCE TO MIDLEVEL VORTS...LACK OF ANY OBVIOUS JET DYNAMICS...AND WEAK MODELED FRONTOGENESIS. SO IT APPEARS...FORCING FOR SNOW WILL BE TIED STRICTLY TO 285K ISENTROPIC LIFT/WARM AIR/MOISTURE ADVECTION. WITH THE A LACK OF AN INVERSION...AN EXPECTED SATURATED ATMOSPHERE THROUGH 400MB...THERE IS A GOOD SHOT AT MEASURABLE SNOWFALL. EXPECTATIONS ARE FOR 1 TO 2 INCHES OF ACCUMULATION FOR EVERYONE WITH ISOLATED 3 INCH AMOUNTS (BEST BET UP NORTH CLOSER TO SURFACE LOW). HAVE SLOWED THE ONSET...AFTER 6Z...WITH THE HEAVIEST ACTIVITY FROM 9-12Z. DID DROP LOWS A COUPLE OF DEGREES AS WET BULB PROCESSES SHOULD ALLOW A QUICK DROP IN TEMPS ONCE THE HEAVIER SNOWS MOVE IN...AT OR JUST UNDER 30 DEGREES. LONG TERM...SATURDAY THROUGH FRIDAY THE MAIN FORECAST CONCERN FOR THIS WEEKEND CONTINUES TO BE WITH THE SHOT OF ARCTIC AIR POISED TO INFILTRATE THE GREAT LAKES SATURDAY NIGHT AND SUNDAY AND THE ASSOCIATED STRONG WINDS AND DANGEROUSLY COLD WIND CHILLS. THE UPPER WAVE CURRENTLY OVER BRITISH COLUMBIA IS STILL FORECAST TO RACE INTO THE WESTERN GREAT LAKES BY SATURDAY EVENING PER 12Z MODEL SUITE AND DEVELOP INTO A CUT OFF CIRCULATION BY SUN MORNING. THE ASSOCIATED SURFACE LOW IS FORECAST TO DEEPEN OVER NORTHERN MINNESOTA ON SATURDAY...THEN MERGE WITH THE SURFACE LOW LIFTING ACROSS NORTHERN MICHIGAN SATURDAY EVENING. WEAK SURFACE RIDGING AND MID LEVEL DRYING SHOULD END THE SNOWFALL BY LATE SATURDAY MORNING. LIFT ASSOCIATED WITH THE NEXT UPPER WAVE HOWEVER WILL BRING A QUICK SHOT OF LIFT SATURDAY EVENING...LIKELY LEADING TO BRIEF YET INTENSE BURST OF SNOW SHOWER ACTIVITY. THE COLD FRONT ASSOCIATED WITH THE DEEPENING LOW TO THE NORTHEAST OF THE STATE WILL QUICKLY RACE ACROSS SE MI SATURDAY EVENING. THE 12Z UPPER AIR ANALYSIS SHOWED VERY COLD AIR ACROSS NORTHWEST CANADA. THIS AIRMASS WILL QUICKLY GET ADVECTED INTO THE GREAT LAKES SATURDAY NIGHT IN THE WAKE OF THE SURFACE COLD FRONT. 850 MB TEMPS ARE STILL FORECAST TO DROP FROM AROUND -8C 00Z SUN TO AROUND -25C BY 12Z SUN. A DECENT ISALLOBARIC COUPLET WILL ACCOMPANY THE SURFACE FRONT THROUGH THE STATE SAT EVENING. MODEL CROSS SECTIONS OF POTENTIAL TEMPERATURE AND OMEGA INDICATE A GOOD POTENTIAL FOR DOWNWARD MOMENTUM TRANSPORT WITHIN STRONG MID LEVEL SUBSIDENCE EARLY SUNDAY MORNING...WITH MODEL SOUNDINGS INDICATING THE POTENTIAL FOR 40 TO 45 KNOT WINDS TO MIX DOWN TO THE SURFACE. THUS WIND GUSTS OF 40 TO 50 MPH SEEM LIKELY SATURDAY NIGHT INTO SUNDAY MORNING. THE ARCTIC AIRMASS WILL DROP TEMPS INTO THE SINGLE DIGITS BY SUNDAY MORNING...WITH LITTLE RECOVERY EXPECTED DURING THE AFTERNOON. THESE TEMPS COMBINED WITH THE STRONG WINDS WILL PRODUCE WIND CHILL READINGS OF 10 TO 20 BELOW ZERO THROUGH THE DAY SUNDAY. EXPECT THERE WILL BE SOME BLOWING SNOW. THIS MAY HOWEVER NOT BE TOO SIGNIFICANT A HAZARD GIVEN THE HIGH WATER CONTENT OF THE SNOW PACK. THE UPPER LOW AND ARCTIC AIRMASS ARE EXPECTED TO BE SHORT LIVED IN THIS FAST PROGRESSIVE FLOW. SURFACE HIGH PRESSURE BUILDING INTO THE REGION SUNDAY NIGHT SHOULD STILL HOWEVER ALLOW TEMPS TO DROP BELOW ZERO IN MANY PLACES BEFORE TEMPERATURES BEGIN MODERATING EARLY NEXT WEEK. THE 12Z MODEL SUITE HAVE COME INTO A LITTLE BETTER AGREEMENT WITH RESPECT TO THE NEXT WAVE FORECAST TO AMPLIFY OVER THE PLAINS MONDAY AND MONDAY NIGHT. THE GFS...ECMWF...UKMET AND CANADIAN ALL DEPICT SOME LIFT ASSOCIATED WITH LOW LEVEL WARM AIR ADVECTION MONDAY NIGHT. FAVORABLE ENTRANCE REGION JET DYNAMICS SHOULD ALSO ALLOW SOME MID TROPOSPHERIC FRONTOGENESIS. THUS HAVE INCREASED THE CHANCES OF SNOW MONDAY NIGHT. AT THIS STAGE SOME ACCUMULATIONS...POSSIBLY EVEN ADVISORY CRITERIA...ARE POSSIBLE MONDAY NIGHT. THE GFS AND CANADIAN ARE FARTHER NORTH WITH THE ASSOCIATED SURFACE LOW TUESDAY. GIVEN THE UPPER AIR PATTERN...PREFER THE MORE SOUTHERLY ECMWF TRACK...WHICH KEEPS SOUTHEAST MICHIGAN WITHIN THE COLDER AIR...INDICATING ANY LINGERING PRECIP WILL BE IN THE FORM OF SNOW. TEMPS SHOULD CONTINUE TO MODERATE TO NEAR NORMAL BY MID WEEK AS HEIGHTS BUILD IN THE WAKE OF THE DEPARTING UPPER TROUGH. MARINE... MARINE INTERESTS WILL BE FOCUSED ON THE IMPENDING ARCTIC COLD FRONT PASSAGE SATURDAY NIGHT. DEEPENING LOW PRESSURE TO THE NORTHEAST OF LAKE HURON SUNDAY NIGHT WILL DRIVE THE FRONT THROUGH THE REGION. VERY STRONG COLD AIR ADVECTION BEHIND THIS FRONT...COMBINED WITH A STRENGTHENING PRESSURE GRADIENT WILL LEAD TO GALE FORCE WINDS SATURDAY NIGHT THROUGH THE DAY SUNDAY. GUSTS WILL ACTUALLY APPROACH 45 KNOTS ON THE OPEN WATERS OF LAKE HURON ON SUNDAY. IF CURRENT MODEL TRENDS HOLD...MAY ACTUALLY HAVE TO UPGRADE TO STORM WARNINGS OVER PORTIONS OF LAKE HURON. THIS FRONT WILL USHER IN AN ARCTIC AIRMASS...WHICH WILL LEAD TO SIGNIFICANT FREEZING SPRAY. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON... HEAVY FREEZING SPRAY WARNING...LHZ361-LHZ362-LHZ363-LHZ462-LHZ463- LHZ464...FROM 7 PM SATURDAY TO 7 PM SUNDAY. GALE WARNING...LHZ361-LHZ362-LHZ363-LHZ421-LHZ422-LHZ441-LHZ442- LHZ443-LHZ462-LHZ463-LHZ464...FROM 7 PM SATURDAY TO 7 PM SUNDAY. LAKE ST CLAIR... GALE WARNING...FROM 7 PM SATURDAY TO 7 PM SUNDAY. MI WATERS OF LAKE ERIE... GALE WARNING...FROM 7 PM SATURDAY TO 7 PM SUNDAY. && $$ AVIATION.....MR UPDATE.......MR SHORT TERM...CB LONG TERM....SC MARINE.......SC YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE). mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND FORKS ND 355 AM CST SAT FEB 9 2008 .DISCUSSION... MAIN FORECAST CHALLENGE IS EXTENT AND DURATION OF BLIZZARD FORCE WINDS AND ACCUMULATING SNOW. CURRENT SNOW BAND IS FAIRLY NARROW AS IT MOVES ACROSS ERN ND... AND STRONGEST WINDS ARE BEHIND THE SNOW. SO EXPECTING 3-4 HOUR WORST VSBY CONDITIONS AS BAND TRANSITS THE AREA. HAVE STUCK WITH PREVIOUS PACKAGE AS FOR BLIZZARD VERSUS ADVISORY AREAS. THREAT FOR SUSTAINED LOW VSBYS IS GREATEST WHERE RECENT SNOWPACK WAS MOST BLOWABLE...AND NEW ANOW AMTS ARE EXPECTED TO BE HIGHEST...MAINLY TO WEST AND NORTH OF GFK-FAR. ATTM THE SFC LOW HAS JUST CROSSED INTO NWRN MN WITH THE COLD FRONTAL BAND MOVING INTO AN HALLOCK-GRAND FORKS-VALLEY CITY LINE. RUC AND NAM40 BRING SFC-850 WIND CORE ALG THE ERN ND CORRIDOR THROUGH 15Z... WITH A REDUCTION IN COUPLING AFT 15Z AS THE SYSTEM TRACKS ACROSS NWRN MN. COLD AND DENSE ARCTIC AIR WILL THEN PUSH THROUGH THE AREA THIS AFTERNOON AND CREATE DANGEROUS WIND CHILL CONDITIONS...FIRST IN NERN ND...THEN SPREADING ACROSS THE FA BY THIS EVENING. EXPECT WILL ISSUE A WIND CHILL WARNING LATER TDY TO COVER TONIGHTS EXTREME WIND CHILL CONDITIONS. THE CURRENT BLIZZARD WARNING AND WINTER WX ADVISORIES ALSO CONTAIN HAZARDOUS WIND CHILL CONDITIONS FOR TDY. SUNDAY AND MONDAY...QUITE COLD CONDITIONS WILL PERSIST INTO THE EARLY PART OF THE COMING WEEK. THE NEXT SYSTEM COLD BRING LIGHT SNOW AND A SLIGHT WARMUP IN TEMPERATURES ON MONDAY...REACHING NEAR NORMAL TEMPERATURES ARE EXPECTED BY TUESDAY. LONG TERM (TUE-FRI)...LONG RANGE MODELS SHOW SIMILAR TRANSITION FROM A MORE ZONAL 500MB FLOW TO MORE AMPLIFICATION BY THE END OF THE EXTENDED FORECAST...BUT DO HAVE SOME TIMING DIFFERENCES ON TROF PASSAGES. INITIAL 500MB TROF AND SURFACE FRONT PASS ON TUE...SO KEPT CHANCE FOR SNOW IN THE FORECAST. WITH MORE SHORTWAVES MOVING THROUGH THE UPPER LEVEL FLOW AND RAPID SURFACE SYSTEM TRANSITIONS...COULD SEE ANOTHER CHANCE OF SNOW ON WED AND WED NIGHT. THEN...A SURFACE HIGH DOMINATES MUCH OF THE REMAINDER OF THE WORK WEEK...SO KEPT FORECAST DRY. AS FAR AS TEMPS...LOOK FOR THEM TO MODERATE TO NEAR NORMAL. && .AVIATION... WIDESPREAD LOW MVFR AND SPOTTY IFR CIGS OVER FAR ERN ND INTO MN WILL THROUGH THE MORNING HOURS ACROSS THE FA. CIGS SHOULD LIFT INTO MVFR RANGES IN ERN ND BY LATE FORENOON...WITH PARTIAL CLEARING THROUGH THE AFTERNOON. CLOUDS WILL DIMINISH OVER NWRN MN THIS AFTERNOON AS SFC HIGH PRESSURE SLIDES INTO THE AREA...BEHIND THE FRONT. LOW CLOUDS WILL LIKELY LINGER INTO THE EVENING ACORSS NCNTRL MN. STRONG N-NW WINDS WILL PUSH OVER THE AREA THROUGHOUT THE DAY...WITH SIGNIFICANTLY REDUCED VSBYS IN BLOWING SNOW. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...WINTER WEATHER ADVISORY FROM 3 AM TO 6 PM CST SATURDAY FOR NDZ027-029-030-039-049-052-053. BLIZZARD WARNING UNTIL 6 PM CST SATURDAY FOR NDZ006-007-014-015- 024-026-028-038-054. BLIZZARD WARNING FROM 3 AM TO 6 PM CST SATURDAY FOR NDZ008-016. MN...WINTER WEATHER ADVISORY FROM 3 AM TO 6 PM CST SATURDAY FOR MNZ001>003-005-008-013>015-029. WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM CST SATURDAY FOR MNZ006-009-016-017-022>024-027-028-030>032-040. BLIZZARD WARNING FROM 3 AM TO 6 PM CST SATURDAY FOR MNZ004-007. && $$ GUST/HOPPES/RIDDLE nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 1145 PM CST FRI FEB 8 2008 .AVIATION...WEAK SFC BOUNDARY MAKING VERY SLOW SOUTHWARD PROGRESS AND JUST MOVED THROUGH SAN ANTONIO AND COLLEGE STATION. LATEST MODELS PROG THIS BOUNDARY TO EASE INTO OUR NORTHERN ZONES GENERALLY AROUND 10Z BUT THE PUSH DOESN`T APPEAR STRONG ENOUGH TO COUNTER FOG FORMATION. EXPECT AREAS OF FOG TO FORM BY 9Z AREA WIDE WITH POCKETS OF DENSE FOG LIFR CONDITIONS BETWEEN 10Z-14Z SAT. VFR CONDITIONS WILL PREVAIL FOR THE REMAINDER OF SAT. && .PREV DISCUSSION... /ISSUED 923 PM CST FRI FEB 8 2008/ UPDATE...IR SATELLITE SHOWS MID LEVEL TROUGH AXIS MOVING THROUGH THE AREA ATTM...HOWEVER THE SFC REFLECTION/WEAK FRONTAL BOUNDARY IS LAGGING BEHIND AND IS ALONG A ROCKSPRINGS TO NACOGDOCHES LINE. DWPT DEPRESSIONS ARE LOWEST ALONG THE IMMEDIATE COAST AND 3-5 DEGREES GENERALLY EAST OF I-37. THUS EXPECT RADIATION FOG TO DEVELOP IN THESE AREA AFTER MIDNIGHT. LATEST RUC FORECAST BRINGS THE FRONT TO A COTULLA TO PORT LAVACA LINE BY DAYBREAK. THIS WOULD FOCUS THE FOG TO THE SOUTH OF THIS BOUNDARY. THE FRONT WASHES OUT OVER THE AREA ON SATURDAY AS THE SFC RIDGE SLIDES QUICKLY EAST INTO LOUISIANA. IF DWPTS SURGE MUCH ABOVE THE MID 60S...SEA FOG WILL BE BACK ALONG THE IMMEDIATE COAST ON SATURDAY. ZONES ARE IN GOOD SHAPE. NO CHANGES NEEDED. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 53 76 59 70 62 / 0 0 10 10 10 VICTORIA 47 74 50 67 55 / 0 0 10 10 10 LAREDO 55 84 58 78 63 / 0 0 10 10 10 ALICE 50 79 56 73 60 / 0 0 10 10 10 ROCKPORT 56 71 58 67 61 / 0 0 10 10 10 COTULLA 46 81 54 75 60 / 0 0 10 10 10 KINGSVILLE 51 78 57 72 61 / 0 0 10 10 10 NAVY CORPUS 59 69 60 69 63 / 0 0 10 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ JM/75...SHORT TERM JR/19...LONG TERM tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 231 PM MST SAT FEB 9 2008 .DISCUSSION...FORECAST CONCERNS ARE TEMPERATURES THROUGHOUT THE 7 DAY PERIOD FOLLOWED BY FOG/FREEZING DRIZZLE CHANCES TONIGHT/SUNDAY AND POPS/WX WEDNESDAY NIGHT AND THURSDAY. AT 21Z LEADING EDGE OF ARCTIC AIRMASS WAS LOCATED (PER SURFACE OBS AND 88D REFLECTIVITY) FROM SIDNEY AND IMPERIAL NEBRASKA SOUTHEAST THROUGH THE NORTHEAST CORNER OF RED WILLOW COUNTY AND TO THE EAST OF NORTON KANSAS. TEMPERATURES AHEAD OF THE FRONT (GLD CWA) WELL INTO THE 40S WITH SOME 50S WHILE NORTHEAST OF THE FRONT (BEHIND) TEMPS WERE IN THE 30S QUICKLY DROPPING INTO THE 20S WITH 10 AT VALENTINE AND AINSWORTH. .SHORT TERM (TONIGHT-TUESDAY NIGHT)... TONIGHT-SUNDAY...PER RUC/NAM/GFS BOUNDARY LAYER RH FORECASTS ARCTIC FRONT WILL BACK INTO THE EXTREME EAST/NORTHEAST CORNER OF THE AREA BY 03Z THEN SPREAD WEST INTO THE REMAINING PARTS OF THE AREA THROUGH THE REST OF THE NIGHT. TYPICALLY THE MODELS UNDER DO THE WESTWARD PROGRESSION (AND TODAYS MODELS ARE FURTHER WEST THAN WHAT YESTERDAYS HAD) AND THE SPEED. HAVE USED THE GFS AS A RESULT AS ITS FURTHER WEST FASTER. 18Z NAM JUST COMING IN AND HAS MATCHED UP WITH THE GFS AND RUC NOW IN A QUICKER DETERIORATION OF CONDITIONS. WITH THAT SAID NEXT ISSUE IS CHANCES OF PRECIPITATION. CURRENT OBSERVATIONS IN NEBRASKA ALONG AND BEHIND THE FRONT SHOW SOME LIGHT SNOW AND FOG IN AN AREA OF 700-600 FRONTOGENESIS AND BETTER LOW TO MID LEVEL MOISTURE ABOVE THE COLD AIRMASS. MOST OF THIS MOISTURE REMAINS EAST OF OUR AREA AND GFS QPF POINTS THIS OUT PRETTY WELL. BY 12Z HOWEVER THIS AREA SHIFTS INTO THE CENTER OF THE FORECAST AREA. WITH A LACK OF APPRECIABLE MOISTURE ABOVE THE SHALLOW BOUNDARY LAYER MOISTURE HAVE PULLED FREEZING PRECIPITATION AND EXPANDED THE FOG. WILL BRIEF INCOMING SHIFT TO THE LIGHT FREEZING PRECIPITATION POTENTIAL BUT RIGHT NOW JUST NOT CONFIDENT IN ITS DEVELOPMENT. BY LATE MORNING TEMP/DP SPREADS REMAIN LOW WITH VIS FORECASTS FROM THE NAM SHOWING SOME RESTRICTIONS. WILL ASSUME THE GFS WOULD BE DOING THE SAME BUT FURTHER WEST...HAVE KEPT SOME FOG GOING AS A RESULT. EVEN AFTER 21Z SOME FOG MAY LINGER AND FUTURE SHIFTS WILL NEED TO POSSIBLY ADDRESS IT. IF THE 18Z NAM VERIFIES THE FOG MAY REDEVELOP THROUGH EARLY EVENING IF IT ISNT ALREADY ONGOING LATE IN THE DAY. TEMPERATURES ON SUNDAY WILL BE TRICKY BUT LATEST GUIDANCE IN BETTER AGREEMENT. 850 TEMPS UNMODIFIED (WORKS BEST IN THESE SITUATIONS) SUGGESTS READINGS RANGING FROM THE LOW/MID 20S ACROSS THE EAST TO LOW/MID 30S ACROSS THE WEST. 09Z/15Z SREF 2M TEMPS WITHIN A DEGREE OR TWO OF THIS AS WELL. CURRENT FORECAST HAD THIS WELL IN HAND SO VERY MINOR ADJUSTMENTS MADE. SUNDAY NIGHT-MONDAY NIGHT...LEE TROUGH DEVELOPS SUNDAY NIGHT AHEAD OF APPROACHING FRONT AND UPPER LEVEL TROUGH. AS THE WINDS SHIFT TO THE SOUTHWEST ARCTIC FRONT AND LOW LEVEL CLOUDS WILL MOVE EAST AND OUT OF THE AREA. PREFRONTAL DOWNSLOPE FLOW AND INCREASING CLOUDS WILL DEVELOP AHEAD OF THE FRONT ALLOWING FOR MONDAY AFTERNOON TEMPERATURES TO WARM BACK INTO THE 40S. WILL NEED TO WATCH FOR SOME PRECIP POTENTIAL DURING THE AFTERNOON AS MID LEVEL FRONTOGENESIS WORKS WITH SOME JET DYNAMICS AND MODEST LAPSE RATES BEHIND THE FRONT. RIGHT NOW AM EXPECTING VIRGA GIVEN DRY LEVELS BELOW 700MB. AGAIN...WILL BRIEF INCOMING SHIFT TO THE POSSIBLE NEED FOR POP INTRODUCTION. SHOULD ALSO HAVE SOME BREEZY TO WINDY CONDITIONS BEHIND THE FRONT. PULLED POPS FOR MONDAY NIGHT AS SYSTEM QUICKLY EXITS THE AREA WITH MOISTURE COLUMN DRYING. MAY SEE SOMETHING ACROSS THE FAR SOUTH/SOUTHWEST BUT RIGHT NOW NOT CONFIDENT ENOUGH TO KEEP POPS GOING. TUESDAY-TUESDAY NIGHT...DESPITE 850 TEMPERATURES FALLING SOME 5-10F 2M/MOS GUIDANCE NUMBERS SUGGEST AFTERNOON TEMPS IN THE LOW TO MID 40S. THE NAM IS A LITTLE SLOWER IN MOVING THE REMNANTS OF MONDAYS FRONT OUT OF THE AREA AND AS A RESULT IT ACTUALLY FURTHER COOLS 850 TEMPS. THE ECMWF IS IN BETWEEN THE GFS AND NAM SO A COMPROMISE WILL BE USED WITH MID 40S EXPECTED ACROSS THE AREA. ABOVE NORMAL TEMPS TUESDAY NIGHT AS LEE TROUGH DEVELOPS AND MODIFYING 850 TEMPS MOVE ACROSS THE AREA. .LONG TERM (WEDNESDAY-SATURDAY)... WEDNESDAY...WARM BEFORE THE STORM (OR NEXT ARCTIC FRONT IN THIS CASE) AS UPPER RIDGE AMPLIFIES AHEAD OF A DEVELOPING TROUGH MOVING TOWARD THE INTERMOUNTIN WEST. MAY HAVE QUITE A BIT OF HIGH CLOUDINESS WHICH COULD IMPACT AFTERNOON TEMPERATURE FORECAST. WILL CONTINUE ON THE MILD SIDE PER 850 TEMPS AND PREVIOUS 5 DAY BIAS FROM THE GFS AND GO WITH READINGS IN THE MID TO UPPER 50S. COULD SEE ANOTHER FEW DEGREES ON TOP OF THIS IF THE CLOUDS HOLD OFF AND MORE TYPICAL 850 BIAS DEVELOP. FOR WEDNESDAY NIGHT DIFFERENCES SHOW UP IN THE HANDLING OF THE UPPER LOW AND ITS TROUGH. GFS HAS THE LOW OVER SOUTHERN CALIFORNIA BY 12Z THURSDAY WHILE THE ECMWF HAS IT OVER THE FOUR CORNERS. CANADIAN IN BETWEEN THE TWO. EITHER WAY LOOKS LIKE PRECIP WILL BREAK OUT ACROSS THE NORTHWEST HALF OF THE AREA AROUND OR SHORTLY AFTER MIDNIGHT. USED THE 18Z HPC POP GUIDANCE AS A START AS IT MATCHES PRETTY WELL TO THE QPF OUTPUT FROM THE VARIOUS LONG RANGE MODELS. WEDNESDAY NIGHT-SATURDAY...MEDIUM RANGE MODELS HAVE COME INTO A BIT BETTER AGREEMENT WITH HANDLING OF TROUGH ACROSS SOUTHWEST THROUGH THE PERIOD. GFS...CAN AND ECMWF ALL NOW APPEAR TO BE SIMILAR IN H5 HEIGHT PATTERN BY 00Z FRIDAY...WITH A STRONG CLOSED LOW OVER THE US-MEXICO BORDER. 00Z AND 06Z GFS...ALONG WITH AVAILABLE CANADIAN DATA ALL IN REASONABLE AGREEMENT...AND 00Z GFS ENS MEAN SFC FIELDS SHOW GOOD CONTINUITY IN PLACING SFC HIGH PRESSURE CENTER OVER THE AREA THUR AND ESPECIALLY ON FRIDAY. ALTHOUGH THERE ARE STILL LARGE DIFFERENCES IN TIMING AND MAGNITUDE OF THE COLD AIR...THINK TRENDING TEMPS TOWARD THE MUCH COLDER GFS ENSEMBLE DATA WOULD BE THE WAY TO GO AT THIS POINT. LOWERED TEMPS AROUND 10 DEGREES...AND IF OPERATIONAL GFS VERIFIES TEMPS MAY NEED TO BE LOWERED A LOT MORE. FOR WX...THINGS LOOK RATHER UNSETTLED THROUGH THE PERIOD AS NORTHERN PIECE OF THE TROUGH WILL IMPACT THE AREA THUR-FRI...AND STRONGER CLOSED LOW LOOKS TO LIFT OUT AND IMPACT THE EXTREME SOUTHERN CWA ON SATURDAY. ADDED SOME LOW POPS FOR SNOW...BUT STILL TO MUCH UNCERTAINTY TO TRY TO NAIL DOWN THINGS. && .AVIATION... FOR THE 18Z TAF. VFR CONDITIONS THROUGH THIS AFTERNOON AHEAD OF AN ARCTIC COLD FRONT THAT IS EXPECTED TO REACH THE KMCK TAF SITE EARLY THIS EVENING AND KGLD LATE TONIGHT. CIGS WILL LOWER ALONG THE LEADING EDGE OF THE COLD FRONT TO MVFR/IFR WITH AREAS OF POSSIBLE FREEZING DRIZZLE THROUGH EARLY SUNDAY MORNING. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$ DDT/JRM&DDT/BURTIS ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 1040 AM MST SAT FEB 9 2008 .UPDATE...HAVE RAISED TEMPERATURES FOR TODAY AS WARMING TREND WILL SUPPORT MAX TEMPERATURES TO REACH INTO THE UPPER 40S/LOWER 50S ACROSS MUCH OF THE FORECAST AREA. COLD FRONTAL PASSAGE LOOKS TO PUSH THROUGH MCCOOK EARLY THIS EVENING AND CONTINUE TO BACK SOUTHWEST INTO THE REST OF THE FORECAST AREA LATE TONIGHT. FORECAST IS ON TRACK SO NO OTHER UPDATES WILL BE NEEDED THIS MORNING. && .AVIATION...FOR THE 18Z TAF. VFR CONDITIONS THROUGH THIS AFTERNOON AHEAD OF AN ARCTIC COLD FRONT THAT IS EXPECTED TO REACH THE KMCK TAF SITE EARLY THIS EVENING AND KGLD LATE TONIGHT. CIGS WILL LOWER ALONG THE LEADING EDGE OF THE COLD FRONT TO MVFR/IFR WITH AREAS OF POSSIBLE FREEZING DRIZZLE THROUGH EARLY SUNDAY MORNING. -BURTIS && .PREV DISCUSSION... /ISSUED 250 AM MST SAT FEB 9 2008/ .DISCUSSION...WATER VAPOR/RUC ANALYSIS WAS INDICATING NORTHWEST MID/UPPER FLOW OVER THE CENTRAL HIGH PLAINS AS A SHORTWAVE TROUGH DIGS INTO THE UPPER MISSISSIPPI VALLEY/GREAT LAKES REGION EARLY THIS MORNING. AT THE SURFACE...AN ARCTIC COLD FRONT WAS ANALYZED OVER THE NORTHERN PLAINS STATES WITH STRONG CAA EVIDENT BY SFC TEMPERATURES IN THE -10 TO -30 DEGREE RANGE ACROSS PORTIONS OF ALBERTA/SASKATCHEWAN ADVECTING SOUTHEAST TOWARDS THE NORTHERN PLAINS EARLY THIS MORNING. TEMPERATURES SHOULD BEGIN TO REBOUND TODAY IN WESTERLY LOW LEVEL DOWNSLOPE AHEAD OF THE CONTINENTAL ARCTIC AIRMASS...HOWEVER TRENDED COOLER WITH WIDESPREAD SNOW EXPECTED TO IMPACT MIXING ONCE AGAIN TODAY. BOTH NAM/GFS APPEAR IN REASONABLE AGREEMENT WITH ARCTIC COLD FRONT BACKING INTO THE AREA TONIGHT RAISING CONCERNS FOR FOG/FREEZING DRIZZLE ALONG LEADING EDGE OF ARCTIC AIRMASS. BOTH NAM/GFS POINT SOUNDINGS SUGGEST A CONSIDERABLE DEPTH OF SATURATION GRADUALLY SUPPORTING SOME FLURRIES ACROSS THE NORTHEAST ZONES WHERE THE SHALLOW COLD LAYER WILL APPROACH -10C ALLOWING THE INTRODUCTION OF ICE/FLURRIES TOWARD MORNING. RELUCTANT TO WARM TEMPERATURES MUCH ON SUNDAY WITH ARCTIC AIRMASS ENTRENCHED ACROSS MUCH OF THE AREA. HIGHS MAY STRUGGLE TO CLIMB INTO THE 20S ACROSS THE EASTERN ZONES WHILE THE WESTERN ZONES MAY BEGIN TO MIX OUT AS SOUTHERLY FLOW RETURNS. A FEW FLURRIES WILL BE POSSIBLE IN THE MORNING...HOWEVER INCREASING CHANCES FOR INSOLATION ACROSS THE WEST WILL RESULT IN A DECENT DIURNAL CLIMB WITH HIGHS REACHING THE UPPER 30S. MONDAY...SOME WARMING WILL BE POSSIBLE EARLY IN THE PERIOD AS A PRE-FRONTAL TROUGH ADDS A WESTERLY COMPONENT TO THE LOW LEVEL FLOW...HOWEVER ANY WARMING WILL BE SHORT-LIVED AS ANOTHER COLD FRONT ARRIVES LATE IN THE PERIOD. TRENDED HIGHS DOWN SLIGHTLY AND INCREASED POPS AS A PROGRESSIVE SHORTWAVE TROUGH APPROACHES THE AREA. ADDED A SLIGHT CHANCE FOR LIGHT SNOW ACROSS THE WESTERN ZONES MONDAY EVENING AND EXPANDED AN AREA OF FLURRIES EAST INTO PORTIONS OF WESTERN KANSAS/EXTREME SOUTHWEST NEBRASKA. PRECIPITATION IS EXPECTED TO REMAIN LIGHT GIVEN LIMITED MOISTURE/PROGRESSIVE TROUGH. && .AVIATION...VFR CONDITIONS WILL PREVAIL THROUGH 03-05Z ON TUE WITH CIGS LOWERING FROM NORTHEAST TO SOUTHWEST AS AN ARCTIC COLD FRONT BACKS INTO THE AREA. IFR/LIFR CONDITIONS ARE EXPECTED ALONG LEADING EDGE OF ARCTIC AIRMASS IN LOW CIGS/AREAS OF FZDZ AND BR/FG. MVFR CONDITIONS WILL RETURN AFTER 13-15Z ON TUE. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && MCGUIRE ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 345 PM EST SAT FEB 9 2008 ...BLIZZARD CONDITIONS OVER SNOWBELTS FAVORED BY NORTHWEST WINDS THROUGH SUNDAY... .SYNOPSIS... 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEPENING TROF IN CNTRL NAMERICA WITH VIGOROUS ARCTIC BRANCH SHRTWV MOVING INTO NW MN DRAGGING VERY COLD AIR (12Z H85/5 TEMPS AS LO AS -32C/-43C AT YQD) INTO THE NRN PLAINS. LEADING EDGE OF THIS BITTERLY COLD AIRMASS... WHICH FEATURES SFC TEMPS STRUGGLING TO RISE ABV -20F IN SRN MANITOBA/SASKATCHEWAN EARLY THIS AFTN...IS NOW MOVING INTO ERN MN AND PASSED DLH AT 1845Z. A BAND OF -SHSN IS AHEAD OF THIS BNDRY WITH SFC VSBY VARYING FM 1-3SM. SOME OF THIS -SN HAS MOVED INTO THE WRN ZNS EARLY THIS AFTN. OTRW...SHRTWV/SFC LO THAT DROPPED UP TO 4 INCHES OF SN OVER THE ERN ZNS IS NOW NEAR ANJ. ACCOMPANYING SN HAS PRETTY MUCH ENDED OVER THE ERN ZNS. JUST SOME SCT -SHSN ARE OCCURRING IN THE AXIS BTWN THE LEADING EDGE OF THE SN ASSOCIATED WITH THE ARCTIC FNT AND THE DEPARTING SFC LO. && .SHORT TERM (TONIGHT AND SUNDAY)... LATEST RUC13/NAM12 ARE CONSISTENT SHOWING THE PROGRESSION OF THE ARCTIC FNT ACRS THE FA THIS EVNG AS INCOMING ARCTIC SHRTWV PHASES WITH SYS ASSOCIATED WITH LO NEAR ANJ. WL CARRY SCT-NMRS -SHSN WITH THIS BNDRY...LOWEST POPS OVER THE SCNTRL WITH DOWNSLOPING WLY FLOW. PCPN WL THEN TRANSITION TO PURE LES IN THE NW WIND SN BELTS AS WINDS INCRS QUICKLY TO THE WSW OF DEEPENING SFC LO OVER SE ONTARIO FOLLOWING PHASING OF UPR FEATURES. STRONG WINDS THAT WL REACH STORM FORCE OVER LK SUP WL TEND TO BLOW THE SHSN WELL INLAND. BUT DRY NATURE OF INCOMING AIRMASS AND FALLING H85 TEMPS TO -25C TO -35C OVER THE W BY 12Z SUN THAT WL LIMIT SN GROWTH WL TEND TO CUT LES AMTS...WL USE 1/2 THE LES CHART AMTS TO ESTIMATE LES ACCUMULATIONS (UP TO 3-4 INCHES/12 HRS). AS FOR WINDS...LARGER SCALE MODELS SHOWN NO MORE THAN 40 TO 45 KT WINDS WITHIN MIXED LYR TNGT INTO SUN. HOWEVER...EXPECTED PHASING OF SHRTWVS AS DESCRIBED ABV AND MAGNITUDE OF INCOMING ARCTIC BLAST SUG GUIDANCE MAY BE ON THE LO END. GIVEN EVALUATION OF LOCAL HI WIND CHECKLIST...WHICH SHOWS LO END WRNG EVENT...AND HIGHER WIND SPEEDS SHOWN BY RUC13...MAINTAINED GOING STORM WRNGS ON LK SUP WITH IMPRESSIVE DESTABLIZATION/INCOMING COLD AIR AND RAPID DEEPENING OF LO PRES TO THE E. FINE NATURE OF SN FLAKES/STRONG WINDS WL RESULT IN EXTENSIVE BLSN...SO ISSUED SOME LES/BLSN ADVYS FOR AREAS OVER THE W WHERE STRONG NW WINDS WL BLOW THE SHSN FARTHER INLAND EVEN THOUGH SN AMTS WL BE RELATIVELY LGT. SINCE NAM12/RUC13 SFC TEMPS ARE OFTEN QUITE RELIABLE IN OUTBREAKS OF SHALLOW ARCTIC AIR PER 12Z BIS SDNG/OBSVD TEMPS UPSTREAM...TENDED TO FOLLOW THIS MODEL EXPLICIT GUIDANCE AND GO LOWER THAN MOS FOR LO TEMPS TNGT/HI TEMPS ON SUN. BASED ON THESE LOWER TEMPS THAN PREVIOUS FCST...EXPANDED WIND CHILL WRNG TO INCLUDE SRN CMX/MNM COUNTIES AND INCLUDED SRN SCHOOLCRAFT IN WIND CHILL ADVY. COORDINATED WITH ENVIRONMENT CAN/GRB/APX/DLH/LOT. .LONG TERM (SUNDAY NIGHT THROUGH NEXT SATURDAY)... LOW PRESSURE SYSTEM SLOW TO EXIT DUE TO PHASING MENTIONED ABOVE LEADS TO CONTINUATION OF LK EFFECT SNOW AND BLSN/BLIZZARD CONDITIONS FOR NW FLOW AREAS MOST OF SUN NIGHT. BY LATE NIGHT...MORE SIGNIFICANT BLSN SHOULD BE PINNED TOWARD MORE EXPOSED LK SUPERIOR SHORE...ESPECIALLY EAST OF MUNISING. BY 12Z MON SHOULD BE WITHIN LESS SEVERE LK EFFECT SNOW REGIME. ONSHORE FLOW AND LONGEST OVER WATER FETCH JUSTIFIES LIKELY POPS NEAR LK SUPERIOR EAST OF MUNISING...BUT BY AFTN WITH APPROACH OF SFC RIDGE...WIND FIELDS BECOME MORE NE/E WHICH WILL DIMINISH THE SNOW SHOWERS OVR THE NORTHEAST CWA BUT MAY ALLOW LIGHT SNOW SHOWERS TO PERSIST OVR HIGHER TERRAIN OF NCNTRL UPR MI. ACTIVE PATTERN CONTINUES FOR THE GREAT LAKES REGION REMAINDER OF THE WEEK. MAIN ISSUE IS WHERE EXACT STORM TRACK WILL SET UP. ATTN LATE MON TURNS TO SHORTWAVE DROPPING INTO THE NORTHERN PLAINS. BTWN THE ENDING LK EFFECT AND THICKENING MID CLOUDS WITH THE SYSTEM TEMPS MAY FALL OFF QUICKLY MON EVENING. USED A NON DIURNAL TEMP CURVE TO SHOW TEMPS RISING AFTER MIDNIGHT MON NIGHT. SHORTWAVE EVENTUALLY PHASES WITH ENERGY IN THE SOUTHERN STREAM AND FORMS SFC LOW OVER THE OHIO VALLEY. INVERTED TROF EXTENDS INTO UPR GREAT LAKES AND THIS COULD FOCUS SOME SNOW LATER MONDAY NIGHT INTO TUESDAY...ESPECIALLY OVER THE SOUTHERN AND EASTERN CWA. WAS PLANNING ON A BREAK FOR WED BUT LAST COUPLE RUNS OF ECMWF/GFS TRENDING FARTHER SOUTH WITH NORTHERN STREAM SHORWAVE MOVING ACROSS ONTARIO. INCLUDED SOME POPS OVR LK SUPERIOR INTO NORTHERN UPR MI. MEANWHILE TO THE WEST...EXPECT ANOTHER SHORTWAVE TO ROLL INTO THE NORTHERN PLAINS. UNLIKE THE EARLY WEEK SYSTEM...THIS ONE HAS MORE COLD AIR POURING INTO THE BACK OF THE TROUGH...WHICH WILL ENHANCE THE THERMAL GRADIENT/PCPN INTO THE GREAT LAKES. INCREASED POPS TO HIGH CHANCE AS UKMET/CANADIAN/ECMWF ARE IN GOOD AGREEMENT. GFS SHOWS SIMILAR SETUP BUT IS FARTHER TO THE SOUTH WITH BETTER DYNAMICS. SO...AT THE LEAST...A MODERATE SNOW IS LIKELY SOMEWHERE IN THE NORTHERN GREAT LAKES REGION ON THU. SOME LK EFFECT FOR FRIDAY ON THE BACK SIDE OF THIS SYSTEM THEN WINDS BACK TO THE SOUTH AHEAD OF ANOTHER SOUTHERN STREAM LOW PRESSURE LIFTING TOWARD THE GREAT LAKES. && .AVIATION (FOR THE 18Z TAF ISSUANCE)... CEILING HEIGHTS WILL GRADUALLY GO DOWN THIS AFTERNOON AS SW WINDS PICK UP AHEAD OF THE ARCTIC COLD FRONT MOVING ACROSS MINNESOTA. PLENTY OF MVFR TYPE CIGS EXIST OVER NW WI AND EASTERN MN. THE PASSAGE OF THE ARCTIC COLD FRONT LATE IN THE AFTN SHOULD BRING A DRAMATIC FALL TO VLIFR CONDITIONS IN SN/BLSN. VLIFR CONDITIONS SHOULD THEN PREVAIL THRU SUN MORNING DUE TO STRONG WNW WINDS AND LAKE EFFECT SNOW/BLSN. TRENDED FCST TO HIGHER VSBY BY EARLY SUN AFTERNOON. AT KSAW...LIGHT SNOW SHOWERS ACROSS CENTRAL UPPER MI WILL CONTINUE INTERMITTENTLY THIS AFTERNOON. VISIBLE SATELLITE INDICATES A BRIEF PERIOD OF BROKEN CLOUD COVER THAT LIES BETWEEN THE EXITING LOW OVER NORTHERN LOWER MI AND THE ARCTIC FRONT OVER MN. THE PASSAGE OF THE ARCTIC COLD FRONT LATE THIS AFTN/EARLY EVENING WILL DROP VIS TO IFR IN A BRIEF PERIOD OF -SN. SHIFTED THE ONSET OF THE FRONT BACK ONE HOUR. MVFR CONDITIONS ARE THEN EXPECTED FOR THE REMAINDER OF SAT NIGHT AND SUNDAY MORNING...MOSTLY DUE TO BLOWING SNOW. && .MARINE (FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)... A LOW PRESSURE SYSTEM EXTENDING FROM NORTHWEST ONTARIO TO NORTHERN LOWER MICHIGAN WILL DEEPEN AS IT MOVES JUST SOUTH OF JAMES BAY SUNDAY MORNING. CONTINUED MENTION OF NW STORM FORCE WINDS OVER THE TERRAIN FAVORED E HALF LATE TNGT INTO SUN AFTN WITH STRONG NW CYC FLOW/ IMPRESSIVE DESTABILIZATION. HIGH PRESSURE OVER THE NORTHERN PLAINS AND CANADIAN PRAIRIES SUNDAY MORNING WILL MOVE OVER THE WESTERN GREAT LAKES SUNDAY NIGHT AND MONDAY...RESULTING IN DIMINISHING WINDS. A LOW PRESSURE SYSTEM DEVELOPING OVER THE CENTRAL PLAINS WILL REACH THE EASTERN GREAT LAKES TUESDAY EVENING. A SECOND LOW PRESSURE SYSTEM WILL CROSS NORTHERN ONTARIO TUESDAY NIGHT AND WEDNESDAY. A HIGH PRESSURE AREA WILL MAKE ITS WAY FROM NORTHERN SASKATCHEWAN TO THE NORTHERN PLAINS THURSDAY. RELATIVELY LIGHT WINDS WILL PREVAIL MON THRU THU WITH NEXT SERIES OF LOWS FORECAST TO TRACK FARTHER TO THE SOUTH. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... BLIZZARD WARNING UNTIL 7 PM EST SUNDAY FOR MIZ001>003. BLIZZARD WARNING FROM 10 PM THIS EVENING TO 1 AM EST MONDAY FOR MIZ006-007. WIND CHILL WARNING FROM 2 AM EST /1 AM CST/ TO 11 AM EST /10 AM CST/ SUNDAY FOR MIZ004-005-009>012-084. LAKE EFFECT SNOW AND BLOWING SNOW ADVISORY FROM 7 PM EST /6 PM CST/ THIS EVENING TO 4 PM EST /3 PM CST/ SUNDAY FOR MIZ004- 010-084. WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO 1 AM EST MONDAY FOR MIZ085. LAKE EFFECT SNOW AND BLOWING SNOW ADVISORY UNTIL 3 PM CST SUNDAY FOR MIZ009. WIND CHILL ADVISORY FROM 2 AM TO 12 PM EST SUNDAY FOR MIZ013-014. LAKE SUPERIOR... STORM WARNING FROM 9 PM THIS EVENING TO 4 PM EST SUNDAY FOR LSZ266-267. STORM WARNING FROM 2 AM TO 2 PM EST SUNDAY FOR LSZ264-265. GALE WARNING FROM 7 PM TO 9 PM EST THIS EVENING FOR LSZ267. GALE WARNING UNTIL 9 PM EST THIS EVENING FOR LSZ266. GALE WARNING UNTIL 2 AM EST SUNDAY FOR LSZ264-265. GALE WARNING UNTIL 7 PM EST SUNDAY FOR LSZ162-263. HEAVY FREEZING SPRAY WARNING FROM 10 PM THIS EVENING TO 1 PM EST MONDAY FOR LSZ267. HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 1 PM EST MONDAY FOR LSZ266. HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST MONDAY FOR LSZ264- 265. HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST MONDAY FOR LSZ162-263. LAKE MICHIGAN... GALE WARNING FROM MIDNIGHT TONIGHT TO 3 PM EST SUNDAY FOR LMZ248-250. HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 1 PM EST MONDAY FOR LMZ248-250. && $$ SYNOPSIS/SHORT TERM...KC LONG TERM...JLA AVIATION...MRC MARINE...KC mi