AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 458 AM MST FRI FEB 17 2006 .SHORT TERM... (TODAY AND TONIGHT) ...HEAVY SNOW IN THE SAN JUANS AND AREAS OF LIGHT SNOW ELSEWHERE NEXT 24 HOURS... HAD TO SCRAMBLE A BIT THIS MORNING...AS THE MODELS ALL SHOWED A PRETTY SIGNIFICANT DEVIATION FROM PREVIOUS FORECAST THINKING. APPEARS NOW THAT A SUBTROPICAL JET WILL MAKE A BRIEF CONNECTION WITH THE SAN JUANS TODAY AND TONIGHT BEFORE MOVING EASTWARD. SO... THIS BOOSTS THE EXPECTED SNOWFALL IN THE EASTERN SAN JUANS PRETTY SUBSTANTIALLY NEXT 24 HRS. ENOUGH SO THAT A WINTER STORM WARNING IS NOW IN EFFECT FOR 12+ INCHES BY NOON SATURDAY...MOST OF IT FALLING TODAY AND TONIGHT. ALSO...A SNOW/BLOWING SNOW ADVISORY IS NOW UP FOR THE ZONES ADJACENT TO THE SAN JUANS...WHICH INCLUDES THE LOWER ELEVATIONS OF THE SAN JUANS AND ALSO THE LA GARITAS. THE BIG INSTIGATOR IN THIS CHANGE IS THE BRIEF SUBTROPICAL TAP THAT LOOKED LIKE IT WOULD BE FARTHER EAST IN PREVIOUS RUNS. NOW...IT BLASTS RIGHT INTO THE EASTERN SAN JUANS. ACCORDING TO THE RUC...H5 DEWPOINT DEPRESSIONS OVER ARIZONA AND SOUTHWEST COLORADO ARE ALREADY COMING WAY DOWN. IF THE RUC IS CORRECT (HARD TO TELL FOR SURE WITHOUT A RAOB)...THE H5 TEMP/DEWPOINT DEPRESSION AT FLAGSTAFF HAS DROPPED FROM AROUND 30C AT 00Z FRIDAY TO 2C BY NOW. ALSO...THE RUC INDICATES THIS AREA OF UPPER LEVEL MOISTURE STREAMING INTO SOUTHWEST COLORADO ATTM. KABQ RADAR HAS SHOWN INCREASING RADAR ECHOES ACROSS CENTRAL/NORTHERN NEW MEXICO THROUGH THE NIGHT...NOW REACHING THE SOUTHWEST COLORADO BORDER. THUS FAR...THERE HAVE ONLY BEEN SOME SPOTTY LIGHT PRECIP AMOUNTS REPORTED AT THE SURFACE ACROSS AZ/NM. THE DEEPER MOISTURE MAY BE A WAYS OFF YET...BUT WITH THE 130-140KT JETSTREAM VISIBLE IN SATELLITE PICTURES STREAMING IN FROM THE SUBTROPICS ACROSS BAJA AND AZ...IT CAN GET HERE PRETTY QUICK. ELSEWHERE...WE ARE SEEING ANOTHER NIGHT OF LIGHT SNOWS ALONG THE I- 25 CORRIDOR FROM PUEBLO TO SPRINGS. WATCHING SATELLITE PICTURES AND RADAR LOOPS...IT APPEARS THAT A BRISK UPSLOPE IS COMBINING WITH JUST ENOUGH SEEDING/FORCING FROM THE INCOMING SUBTROPICAL ENERGY TO SQUEEZE OUT SOME LIGHT PRECIPITATION. THE COLD AIRMASS HELPS THIS PROCESS ALONG BY FACILITATING DENDRITE GROWTH. WOULD EXPECT THIS KIND OF ACTIVITY TO CONTINUE OFF-AND-ON TODAY AS SUBTROPICAL MOISTURE CONTINUES TO STREAM OVERHEAD. ACCUMULATIONS SHOULD BE PRETTY LIGHT ALL-IN-ALL...BUT WITH THE VERY COLD AIRMASS IN PLACE...EVEN A LITTLE BIT OF SNOW TURNS THE ROADS WHITE AND CAUSES HAVOC. TEMPERATURES TODAY WILL NOT WARM VERY MUCH. TOO MANY CLOUDS...AND TOO MUCH COLD AIR. SO...HAVE LOWERED TEMPS A LITTLE WITH GENERALLY ONLY 20S ON THE PLAINS TODAY. TONIGHT MAY BRING THE BEST SHOT AT SNOW TO THE EASTERN PLAINS. HAVE BOOSTED POPS TO THE LIKELY CATEGORY ALONG THE I-25 CORRIDOR. A COMBINATION OF OVERRUNNING SUBTROPICAL MOISTURE...COLD SURFACE AIR AND UPSLOPE...SHOULD RESULT IN A FAIRLY BROAD AREA OF LIGHT SNOW OVER THE PLAINS TONIGHT...ESPECIALLY ALONG THE I-25 CORRIDOR. HOWEVER...ACCUMS ARE NOT EXPECTED TO BE REAL GREAT...GENERALLY ONLY IN THE 1 TO 3 INCH RANGE. TEMPS TONIGHT WILL CONTINUE QUITE COLD...WITH GENERALLY SINGLE DIGITS EVERYWHERE. LW .LONG TERM... (SATURDAY THROUGH THURSDAY) METEOROLOGICAL CHALLENGES IN THE LONG TERM APPEAR TO BE POPS...ESPECIALLY FROM SATURDAY INTO TUESDAY AND TEMPERATURES THROUGHOUT THE LONG TERM. LATEST LONGER TERM MODELS INDICATE THAT SOUTHWEST TO ZONAL UPPER FLOW WILL BE IN PLACE SATURDAY THROUGH MONDAY BEFORE UPPER FLOW SHIFTS TO THE NORTHWEST FROM TUESDAY INTO THURSDAY. ANOTHER UPPER DISTURBANCE IS PROJECTED TO IMPACT REGION FROM SUNDAY INTO MONDAY WITH THE HIGHEST POTENTIAL OF ACCUMULATING SNOW OVER PORTIONS OF THE CENTRAL AND WESTERN MOUNTAINS THIS TIME-FRAME. THEN...WITH THE EXCEPTION OF THE CENTRAL MOUNTAINS...A TENDENCY TOWARDS A DRYING TREND IS INDICATED FROM TUESDAY INTO NEXT THURSDAY. COOL AIRMASS/BELOW TO MUCH BELOW CLIMATOLOGICAL AVERAGE TEMPERATURES ARE EXPECTED TO CONTINUE FROM SATURDAY INTO WEDNESDAY...BEFORE MORE AGGRESSIVE WARMING ATTEMPTS TO TAKE HOLD BY NEXT THURSDAY. THANKS TO SURROUNDING OFFICES FOR COORDINATION/COLLABORATION. && .PUB WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 12 PM MST SATURDAY FOR COZ068. SNOW AND BLOWING SNOW ADVISORY UNTIL 12 PM MST SATURDAY FOR COZ066-COZ067. && $$ co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LINCOLN IL 1215 PM CST FRI FEB 17 2006 .DISCUSSION... UPDATED THE FORECAST TODAY TO ELEVATE HIGHS A FEW DEGREES...RANGING FROM THE LOWER 20S NW AT GALESBURG...TO NEAR 35F FAR SE IL NEAR LAWRENCEVILLE. SO MUCH COLDER TODAY WITH PARTLY SUNNY SKIES AND NW WINDS 10 TO 20 MPH. SCATTERED TO BROKEN CUMULUS CLOUDS DEVELOPED LATE THIS MORNING ACROSS CENTRAL IL WITH SKIES BECOMING PARTLY SUNNY BY MIDDAY. TEMPS RANGE FROM 18F FAR NW AT GALESBURG TO 34F FAR SE AT LAWRENCEVILLE WITH NW WINDS 7 TO 15 MPH AND A FEW GUSTS AROUND 20 MPH NW OF THE IL RIVER. NOON SURFACE MAP SHOWS 1051 MB ARCTIC HIGH PRESSURE OVER EASTERN MT AND RIDGING SE INTO THE CENTRAL PLAINS INTO NEBRASKA. THIS VERY STRONG HIGH HAS PUSHED COLD FRONT WELL SE OF IL INTO THE GULF AND ATLANTIC STATES...LEAVING IL BACK IN A COLD CANADIAN AIR MASS. WEAK SHORT WAVE ENERGY OVER THE CENTRAL PLAINS WILL MOVE EAST AND SPREAD MID/HIGH CLOUDS INTO CENTRAL/SE IL THIS AFTERNOON AND EVENING. THESE CLOUDS ALONG WITH SOME LOW CLOUDS TOO AND NW WINDS WILL KEEP TEMPS FROM CLIMBING TOO MUCH MORE...MAYBE A DEGREE OR TWO. RUC AND NAM WEAKEN THE VERY STRONG ARCTIC HIGH PRESSURE A BIT AS IT MOVES TOWARD THE SD/IOWA BORDER EARLY THIS EVENING. THIS HIGH WILL BRING SOME OF THE COLDEST AIR OF THE SEASON TO IL TONIGHT WITH NORTHERN AREAS GETTING A FEW DEGREES BELOW ZERO AND WIND CHILLS OF 10 TO 15 BELOW. A WIND CHILL ADVISORY IS IN EFFECT TONIGHT ACROSS NORTHERN IL...JUST NORTH OF GALESBURG AND HENRY FOR WIND CHILLS OF 20 TO 30 BELOW ZERO. .PREV DISCUSSION... ...WIND CHILLS MAY REACH ADVISORY CRITERIA TONIGHT INTO TOMORROW MORNING OVER NORTHERN AREAS OF THE CWA... OTHERWISE FAIRLY BENIGN ALBEIT COLD WX THROUGH THE WEEKEND AS STRONG CANADIAN HIGH PRESSURE KEEPS PRECIP FROM A COUPLE DISTURBANCES AT BAY JUST TO OUR SOUTH. SHORT TERM...TODAY THROUGH MONDAY... SECONDARY UPPER DISTURBANCE RESPONSIBLE FOR SCATTERED OVERNIGHT FLURRIES HAS PUSHED INTO INDIANA THIS MORNING. STILL SOME LIGHT ECHOES ON RADAR... BUT AS DRIER AND COLDER AIR CONTINUES TO FILTER IN... THE LESS LIKELY ANYTHING WILL REACH THE GROUND. TEMPERATURES HAVE BEEN DROPPING ALL NIGHT... AND WINDS HAVE REMAINED FAIRLY GUSTY ESPECIALLY ACROSS THE EASTERN CWA. WINDS SHOULD LET UP A LITTLE... ESPECIALLY THE GUSTS... GOING INTO THE AFTERNOON AS STRONG LOW MOVES INTO THE SAINT LAWRENCE VALLEY AND GRADIENT OVER THE MIDWEST SLACKENS UP. LOW CLOUDS EXPECTED TO DIMINISH THROUGH THE MID/LATE MORNING HOURS... BUT HIGH CLOUDS WILL BE ON THE INCREASE THROUGH THE DAY. WITH CONTINUED COLD ADVECTION... DO NOT EXPECT TO SEE MUCH RECOVERY IN TEMPS. SOME SITES... ESPECIALLY THOSE IN THE SOUTHEAST MAY SEE TEMPS STEADY OR SLOWLY DECLINING THROUGH THE DAY. HIGH LEVEL MOISTURE WILL STREAM INTO THE AREA THROUGH THE DAY INTO THE EVENING HOURS. NORTHERN EXTENT OF HIGH CLOUDS IS THE BIG QUESTION WHICH WILL HAVE AN IMPACT ON LOW TEMPS TONIGHT INTO TOMORROW MORNING. IT APPEARS THAT UPPER LOW OVER MANITOBA... AND LARGE TROUGH OVER THE NORTHWEST... WILL SLOWLY SLIDE SOUTH AND EAST THROUGH THE DAY... WITH STRONG UPPER JET OVER THE MIDWEST CAUSING HIGH LEVEL MOISTURE TO SHEAR OFF... WITH NORTHERN EXTENT OF HIGH CLOUDS LIKELY SINKING SOUTH ACROSS CENTRAL ILLINOIS DURING THE OVERNIGHT HOURS. WITH STRONG CANADIAN HIGH PRESSURE STILL OFF TO OUR WEST TONIGHT... THERE WILL STILL BE SOME GRADIENT LEFT... WITH NORTHERLY WINDS OF 7-12 KTS POSSIBLE THROUGH TOMORROW MORNING. THIS MAY LIMIT COOLING POTENTIAL BY KEEPING LOW LEVELS SOMEWHAT MIXED. CORE OF COLD AIRMASS SHOULD STILL DEFLECT JUST TO OUR NORTH OVERNIGHT AS WELL. THAT SAID... TEMPS COULD STILL DIP BELOW ZERO ACROSS THE NORTHERN CWA TOMORROW MORNING... ESPECIALLY IF HIGH CLOUDS PRESS SOUTHWARD AFTER MIDNIGHT. ETA MOS GUIDANCE GOES TO -6 FOR GBG TOMORROW MORNING... AND IT AT LEAST ACKNOWLEDGES HIGH CLOUDS THROUGH 06Z. CONSIDERING TEMPS AT OR BELOW ZERO... AND SOME WINDS STILL ABOUT... MUCH OF THE NORTHERN CWA COULD SEE WIND CHILLS DIP TO BELOW ADVISORY CRITERIA /-15F TO -24F/ OVERNIGHT INTO TOMORROW MORNING. WILL LEAVE THE FINAL DECISION FOR POSSIBLE HEADLINES TO THE DAY SHIFT AS THEY WILL HAVE SOME MORE TIME TO ASSESS HIGH CLOUD ISSUE AND ACT FROM THERE. SUNDAY MORNING COULD STILL BE THE COOLEST MORNING TEMPERATURE-WISE AS HIGH PRESSURE SETTLES OVERHEAD... WINDS BECOME LIGHT AND VARIABLE... AND SKIES BECOME MOSTLY CLEAR. WIND CHILLS SHOULD BE LESS OF AN ISSUE. HIGH PRESSURE SINKS OFF TO OUR SOUTHEAST SUNDAY AFTERNOON... ALLOWING FOR A MODERATING TREND TO BEGIN... WITH HIGHS REACHING THE LOWER/MIDDLE 20S BY SUNDAY. IN TERMS OF PRECIP... COLD HIGH PRESSURE SHOULD KEEP PRECIP THREAT SQUASHED TO OUR SOUTH... WITH ONE WEAK SHORTWAVE MOVING ACROSS THE TENNESSEE VALLEY SATURDAY... AND ANOTHER SUNDAY NIGHT INTO MONDAY MORNING. A CLIPPER DROPPING IN JUST NORTH OF LAKE SUPERIOR SUN NIGHT INTO MONDAY MORNING MAY BRING THE THREAT OF SOME FLURRIES ACROSS NORTHERN REACHES OF THE CWA. LOW LEVEL MOISTURE LOOKS RATHER LIMITED FOR ANYTHING SIGNIFICANT. LONG TERM...TUESDAY THROUGH THURSDAY... MODERATING TREND TO CONTINUE THROUGH THE FIRST HALF OF THE WORKWEEK WITH FAIRLY FLAT QUASI-ZONAL FLOW. STILL LOOKS LIKE A LOT OF COLD AIR JUST NORTH OF THE BORDER. NEXT SYSTEM LOOKS POSSIBLE IN THE THU-FRI TIME FRAME... BRINGING A THREAT OF RAIN OR SNOW AND POSSIBLY PULLING DOWN SOME MORE COLDER AIR. FOR NOW... WILL GO WITH JUST A SLIGHT CHANCE OF RAIN OR SNOW ON THURSDAY... KEEPING IT CONFINED TO ONE PERIOD AS SYSTEM LOOKS TO BE A FAST MOVER. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ HUETTL/HARDIMAN il AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE PADUCAH KY 955 PM CST FRI FEB 17 2006 .UPDATE... RADAR SHOWS UPSTREAM ECHOES IN SRN MO/NRN AR NOT YET REACHING GROUND...BUT SOME REPORTS FURTHER WEST INTO NW AR STARTING TO SHOW UP IN NETWORK. TEMP CURVE SHOWS TEMPS NOT DROPPING AS MUCH AS PREVIOUSLY ANTICIPATED...AND INCOMING 00Z MET DATA PICKS UP ON THIS AND SLIGHTLY WARMS GOING AND OVERNIGHT TEMPS...WHICH WE TWEEKED IN GRIDS/ZONES. THIS WL NOT MAKE MUCH DIFFERENCE IN EXPECTED PCPN THOUGH...EXCEPT ALONG AR/TN BORDERS...WHERE 00Z RUC AND NAM SOUNDINGS SHOW PCPN MAY BEGIN AS BRIEF PERIOD OF SLEET IF ANY REACHES THE GROUND PRIOR TO 06Z...CONFIRMED IN BOOTHEEL ALREADY. SINCE SAME SOUNDINGS DONT SHOW LOWER TROP SATURATION TIL AFT 06Z...WE CHOSE TO THROW A MENTION OF THIS INTO THE ZFP BUT RETAIN THE WSW LARGELY AS WRITTEN. SOME CONSIDERATION GIVEN TO SLIGHT EXPANSION NORTHWARD INTO MORE OF SEMO SINCE 00Z GFS TRICKLED IN...BUT 00Z NAM CONTRADICTS...SO WE LEFT IT ALONE AND WILL INCLUDE ON THE BRIEF FOR A CLOSE MONITORING ON THE DEVELOPING PCPN ZONE. LATEST HPC WWD PAINTS SRN FA IN 2-4" SWATH POSSIBLE AND 00Z MODEL QPF SUPPORTS OUR CURRENT 1-3" WORDING GIVEN 15-1 RATIOS. ISOLATED HIGHER AMOUNTS ARE POSSIBLE AND IS LIKEWISE MENTIONED. .SHORT TERM /TONIGHT THROUGH MONDAY/... AS STATED IN PREVIOUS AFD...HAVE SPREAD THE ADVISORY UP A ROW OF COUNTIES ACROSS THE SOUTHERN TIP OF ILLINOIS AND IN WEST KENTUCKY. THE TIMING REMAINS THE SAME...10 PM TO 8 AM. STRATOCU DECK HANGING FAIRLY STRONG ACROSS SOUTHERN ILLINOIS AND SOUTHWEST INDIANA...ELSEWHERE MID AND HIGH CLOUD BEGINNING SPREAD EASTWARD INTO WESTERN ZONES. SHOULD SEE MID AND HIGH CLOUDS INCREASING RAPIDLY ACROSS THE AREA THIS EVENING...AHEAD OF APPROACHING WINTER STORM. MEANWHILE...DECENT NORTH WINDS WILL CONTINUE THROUGH THE NIGHT...BRINGING MUCH COOLER AIRMASS OVER THE REGION. ALOFT...SOME FRONTOGENETICAL FORCING IN THE 800MB TO 700MB LAYER WILL HELP SNOW TO DEVELOP FROM WEST TO EAST LATE THIS EVENING THROUGH THE OVERNIGHT HOURS. MODELS ARE IN DECENT AGREEMENT ON THESE POINTS...BUT QPF IS A DIFFERENT ISSUE. THE 12Z GFS GENERATES UP TO A TENTH OF AN INCH OF QPF IN THE NORTHERN HALF OF THE AREA TONIGHT...WHICH WAS A SIGNIFICANT CHANGE FROM THE PREVIOUSLY DRY RUNS IN THAT AREA. IT APPEARS TO LATCH ON TO SOME MINOR UPPER DIFFLUENCE IN A VERY STRONG UPPER LEVEL JET. THIS SEEMS LIKE A VERY MINOR FEATURE AND THEREFORE I DO NOT HAVE MUCH CONFIDENCE IN THAT SOLUTION...OPTING MORE FOR A MIDDLE OF THE ROAD APPROACH FOR NOW...KEEPING A 50 POP IN THE NORTHERN ZONES FOR TONIGHT. THE 18Z NAM HAS BACKED DOWN ON ITS QPF IN THE FAR SOUTH AND SOUTHWEST...MORE INTO LINE WITH 12Z GFS QPF. GIVEN THE MODEL DISCREPANCIES...DECIDED TO FOLLOW THE HPC QPF AND USE A 15 TO 1 RATIO TO GET SNOW GRIDS. THE MODELS ARE IN AGREEMENT IN HAVING TEMPERATURES WELL INTO THE LOW TO MID 20S DURING THE EVENT...LEADING TO THE HIGHER RATIO. SNOW AMOUNTS WILL RANGE FROM UNDER AN INCH IN THE NORTH TO 1 TO 3 IN THE SOUTHERN HALF OF THE AREA. CATEGORICAL POPS IN THE SOUTH LOOK REASONABLE. ALL 12Z GUIDANCE IN AGREEMENT IN BRINGING A QUICK END TO THE PRECIPITATION IN THE MORNING...AND CLEARING SKIES FROM THE NORTH DURING THE AFTERNOON AND EVENING. MODELS ALSO IN GOOD AGREEMENT IN SHOWING LITTLE REBOUND IN TEMPERATURES SATURDAY...LEADING TO VERY COLD DAY WITH LOWS IN THE UPPER TEENS NORTH TO LOWER 20S SOUTH. THE POTENTIAL SNOW COVER WILL MAKE TEMPERATURES INTO EARLY NEXT WEEK VERY INTERESTING. THE MODELS CONTINUE TO BE DRY OR MOSTLY SO...FOR SUNDAY THROUGH MONDAY. THE GFS CONTINUES TO BRING SOME LIGHT QPF INTO FAR SOUTHERN PORTIONS OF THE AREA SUNDAY NIGHT AND MONDAY...SO KEPT A LOW POP FOR LIGHT SNOW THEN. THE MODELS SEEM TO HAVE FIGURED OUT THAT THE ARCTIC HIGH IS STRONGER THAN PREVIOUSLY THOUGHT AND WILL NOT ALLOW FOR SURFACE PRESSURE FALLS TO OUR EAST...AS PREVIOUSLY ADVERTISED. DO NOT WANT TO PULL ALL MENTION OF THE EVENT AT THIS TIME...GIVEN THE TREND IN THE LAST 24 HOURS ON TONIGHTS EVENT. TEMPERATURES WILL BE BRUTALLY COLD SUNDAY MORNING AS THE SURFACE HIGH SETTLES OVER THE AREA. IT WILL HANG OUT OVER US THROUGH MONDAY. SHOULD SEE SINGLE DIGIT TEMPERATURES SUNDAY MORNING AND HIGHS ONLY IN THE MID 20S SUNDAY AFTERNOON...DESPITE SOME SUNSHINE. WENT WITH THE COOLER MET SUNDAY NIGHT AND UNDERCUT THE 12Z MEX FOR MONDAY. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... NO PRECIPITATION IS EXPECTED MONDAY NIGHT INTO TUESDAY. FOR TUESDAY NIGHT...GFS BRINGS THE 0.01 QPF LINE INTO SOUTHERN PORTIONS OF THE PAH FORECAST AREA. BASED ON THE PLACEMENT OF A STATIONARY FRONT ACROSS THE GULF COAST STATES...LOOKS LIKE ANY PRECIP PRODUCED FROM OVERRUNNING WOULD STAY WELL SOUTH OF OUR REGION...SO KEPT FORECAST DRY. GFS THEN INDICATES A MID TO LATE WEEK PRECIP CHANCE AS THE STATIONARY FRONT LIFTS NORTH AND A COLD FRONT APRROACHES FROM THE NORTHWEST. 06Z GFS WAS MUCH QUICKER WITH THIS SYSTEM THAN THE 12Z...AND THE ECMWF LOOKS MORE SUPPORTIVE OF THE LATER TIMING OF THE 12Z RUN. HOWEVER...DUE TO SUCH DRASTIC TIMING DIFFERENCES...PREFER TO KEEP FORCAST DRY FOR NOW AND WAIT FOR SOME RUN TO RUN CONSISTENCY BEFORE INTRODUCING POPS. BY THURSDAY NIGHT AND FRIDAY...BOTH GFS AND ECMWF SHOW HIGH PRESSURE ACROSS THE REGION. 12Z MEX TRENDING WARMER NEXT FOR NEXT WEEK. OVERALL...WITH A COUPLE OF EXCEPTIONS...WENT A LITTLE BELOW MEX GUIDANCE FOR TEMPS THROUGH THE EXTENDED...PREFERRING A SLOWER MODERATION IN TEMPS DUE TO PRECIP CHANCE UNCERTAINTIES. && .PAH WATCHES/WARNINGS/ADVISORIES... KY...SNOW ADVISORY FROM 10 PM THIS EVENING TO 8 AM CST SATURDAY FOR BALLARD-CALDWELL-HOPKINS-LIVINGSTON-LYON-MCCRACKEN- MUHLENBERG-CALLOWAY-CARLISLE-CHRISTIAN-FULTON-GRAVES-HICKMAN- MARSHALL-TODD-TRIGG. MO...SNOW ADVISORY FROM 10 PM THIS EVENING TO 8 AM CST SATURDAY FOR BUTLER-CARTER-MISSISSIPPI-NEW MADRID-RIPLEY-SCOTT-STODDARD- WAYNE MO. IL...SNOW ADVISORY FROM 10 PM THIS EVENING TO 8 AM CST SATURDAY FOR ALEXANDER-MASSAC-PULASKI. IN...NONE. && $$ ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CARIBOU ME 1026 PM EST FRI FEB 17 2006 .SYNOPSIS...INTESE LOW PRESSURE WILL CONTINUE THROUGH THE MARITIMES OVERNIGHT. STRONG WINDS ARE EXPECTED TO CONTINUE ESPECIALLY OVER NORTHERN AND NORTH CENTRAL AREA BEFORE DIMINISHING AFTER MIDNIGHT. COLD HIGH PRESSURE WILL BUILD SOUTH OF THE REGION LATE SATURDAY INTO SUNDAY. THIS WILL BRING VERY COLD TEMPERATURES AND BRISK CONDITIONS FOR THE WEEKEND. && .SHORT TERM REST OF TONIGHT... WINDS ACROSS COASTAL AND INTERIOR DOWNEAST ARE NOW CONSISTENTLY BELOW HIGH WIND WARNING CRITERIA AND WITH NO ADDITIONAL DAMAGE REPORTS RECEIVED...HAVE DECIDED TO CANCEL THE HIGH WIND WARNING FOR THESE ZONES. WILL CONTINUE THE HIGH WIND WARNING ELSEWHERE UNTIL EXPIRATION AT 2 AM SATURDAY MORNING. && .MARINE... MARINE STORM WARNING REMAINS IN EFFECT UNTIL 1 AM SATURDAY MORNING. && .PREVIOUS DISCUSSION... /ISSUED 338 PM EST FRI FEB 17 2006/ SYNOPSIS...DEEP LOW PRESSURE WILL PASS JUST NORTH OF THE STATE THIS EVENING. A STRONG ARCTIC COLD FRONT ASSOCIATED WITH THIS LOW WILL CROSS THE STATE TONIGHT. STRONG WINDS ARE EXPECTED TO ACCOMPANY THIS FRONT AND PERSIST INTO TONIGHT. COLD HIGH PRESSURE WILL BUILD SOUTH OF THE REGION LATE SATURDAY INTO SUNDAY. THIS WILL BRING VERY COLD TEMPERATURES AND BRISK CONDITIONS FOR THE WEEKEND. SHORT TERM /TONIGHT-SUNDAY/... EXTENDED THE HIGH WIND WARNINGS OUT TO 2 AM SATURDAY MORNING. ADDED WIND CHILL ADVISORY FOR NORTHERN MAINE LATE TONIGHT INTO SATURDAY MORNING. FLOOD STATEMENT OUT AS WELL FOR RAFL & MELTING SNOW ADDING TO SOME ROAD PROBLEMS IN NORTHERN & NORTHEASTERN MAINE. SEE HYDROLOGY SECTION BELOW. LEANED W/WESTA & THE RUC FOR TONIGHT AS THEY APPEARED TO BE HANDLING THINGS QUITE WELL. AFTER THAT LEANED W/THE GFS INTO SUNDAY. LOW PRES RUNNING ACROSS SRN QUEBEC EXPECTED TO MOVE ACROSS FAR NORTHERN MAINE THIS EVENING & THEN INTO THE MARITIMES LATER TONIGHT. WINDS KICKING UP ACROSS DOWNEAST & COASTAL AREAS AHEAD OF PRE-FRONTAL BOUNDARY. EXPECT THESE WINDS TO TRANSLATE INTO CNTL & NORTHERN AREAS THIS EVENING. A BRIEF LULL & THEN WINDS WILL ONCE AGAIN W/CD FROPA. GRADIENT REALLY TIGHTENS BEHIND DEPARTING LOW EARLY TONIGHT. COULD BE LOOKING AT POWER OUTAGES & DAMAGE. RELAXED WINDS AFT 06Z ACROSS DOWNEAST & THE COAST & KEPT THE WINDS GOING ACROSS NORTHERN MAINE. IN ADDITION TO THE WINDS WILL BE THE ARCTIC BLAST COMING IN THIS EVENING INTO TONIGHT W/A FLASH-FREEZE WHICH WILL LEAD TO FURTHER PROBLEMS W/WATER FREEZING UP. EXPECTING A BRIEF PERIOD OF SNOW THIS EVENING MAINLY ACROSS NORTHERN MAINE. THE STRONG WINDS COMBINED W/THE SNOW COULD LEAD TO BRIEF WHITEOUTS. WIND CHILLS WILL GO TO A RANGE OF 25 TO 30 BELOW ACROSS NORTHERN AREAS LATE TONIGHT INTO SATURDAY MORNING. ARCTIC FRONT TO SWING THROUGH THE CWFA EARLY SATURDAY W/SOME SHSN ACTION ACROSS THE NRN & WRN AREAS W/SOME FORCING IN MID-UPPER LEVELS & CAA. KEPTS WINDS UP IN ADVISORY RANGE. MIDNIGHT CREW MADE NEED TO HAVE WIND ADVISORY UP. GRADIENT (LOOSENING) LOOKS TO HANG ON RIGHT INTO SUNDAY. WOULD NOT BE SURPRISED TO SEE WIND CHILL ADVS BACK UP AGAIN SATURDAY NIGHT INTO SUNDAY MORNING. HIGH PRES OVER THE MID-ATLC REGION RIDGES ACROSS THE REGION LATE SUNDAY. LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... WEAK RIDGE CROSSES THE STATE LATE SUNDAY FOLLOW BY A WEAK LOW PRESSURE MONDAY AFTERNOON. HIGH PRESSURE THEN RETURNS TUESDAY. ANOTHER WEAK SHORT WAVE IS EXPECTED TO CROSS THE REGION WEDNESDAY. AN AREA OF LOW PRESSURE IS EXPECTED TO DEVELOP OFF THE MID- ATLANTIC STATES LATE THURSDAY AS ANOTHER LOW MOVES INTO THE GREAT LAKES. BOTH OF THESE SYSTEMS MERGE INTO ONE TO THE EAST OF NEW ENGLAND FRIDAY. HAVE INITIALIZED WIND GRIDS WITH THE 06Z GFS. ALL OTHER GRIDS INITIALIZED WITH HPC DATA. HAVE ADJUSTED COASTAL TEMPERATURES WITH DGEX..THESE INCLUDE TUESDAY NIGHT...WEDNESDAY NIGHT AND MAX TEMPERATURES FOR FRIDAY. FOR MONDAY HAVE LOWERED TEMPERATURES AND DEW POINT DUE TO THE COLD AIR MASS OVER THE FORECAST AREA BASED ON 06Z GFS...ALSO HAVE MADE SOME MINOR CHANGES TO BETTER FIT WITH NEIGHBORING OFFICE. FOR SUNDAY NIGHT THRU MONDAY HAVE CREATED LAND TEMPERATURES...DEW POINTS AND WIND WITH WITH MAV/MET MOS. ALSO FOR SUNDAY NIGHT INTO MONDAY HAVE USED NAM12 FOR THE COASTAL WATERS. AVIATION... WINDS WILL BE THE MAJOR AVIATION ISSUE FOR THE OVERNIGHT PERIOD. WIND AT ALL LOCATIONS WILL BECOME WESTERLY AT 20 TO 30 KTS WITH MUCH HIGHER GUST. AT THIS TIME THE FRONTAL SYSTEM IS MOVING THROUGH NORTHEASTERN MAINE. WITH THE PASSAGE OF THE FRONT SKY COND WILL IMPROVE...BUT SNOW SHOWER AND INCREASING WIND WILL CAUSE CARIBOU AND PRESQUE ISLE TO BE LIFR TO MININUMS THROUGH MOST OF THE OVERNIGHT HOURS WITH LOW VISIBILITY AND CIGS OBSTRUCTED BY SNOW. FOR HOULTON AND BANGOR AT THIS TIME THERE IS NOT STANDING SNOW COVER. ANTICIPATE SNOW SHOWERS FOR HUL BUT VISIBILITY AND CEILINGS WILL BE MVFR IMPROVING TO VFR AFTER MIDNIGHT...AT IN BGR VFR WITH AFTER 00Z. MARINE... WILL GO W/STORM WARNING TIL 1 AM. WILL BOOST UP WIND TO 40 TO 50 KTS EARLY TONIGHT & THEN IT LOOKS LIKE WINDS LET GO SOME AS LLVL JET EXITS INTO THE MARITIMES. DO NOT HAVE A GOOD FEEL ON WINDS OVER THE WATERS W/WLY FLOW. DECIDED TO GO W/SPEEDS NEAR GLW CRITERIA FOR SAT INTO SAT NIGHT. MIDNIGHT CREW WILL NEED TO ASSESS THIS FURTHER W/LATER GUIDANCE. EXTENDED: HAVE POPULATED WIND GRIDS WITH 06Z GFS. WAVE GRIDS CREATED WITH THE 06Z WNA WAVE WATCH. SINCE FORECASTED AND WAVE MODEL WINDS VERY CLOSE HAVE NOT MADE ANY CHANGES TO WAVE MODEL. HYDROLOGY... FLOOD STATEMENT OUT FOR NRN AND NERN MAINE DUE TO RAFL & MELTING SNOW. DITCHES FILLING UP AND SPILLING OVER ONTO SOME ROADS LEADING TO SOME ISSUES. NO ROAD CLOSURES REPORTED ATTM. FFG INDICATES 6 HRLY RAFL JUST UNDER 2.5 INCHES. SO FAR REPORTS COMING IN & MATCHING THIS UP W/STORM TOTAL FROM THE RADAR SHOWS THINGS BELOW GUIDANCE. WILL NEED TO KEEP AN EYE ON THIS SITUATION THIS EVENING. COLDER AIR COMING IN & WINDS PICKING UP SHOULD HELP TO ALLEVIATE ANY FLOODING CONCERNS LATER ON. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...HIGH WIND WARNING FOR MEZ001>006-010-011-031-032 UNTIL 2 AM SATURDAY. ...WIND CHILL ADVISORY FOR MEZ001>006-010 UNTIL 11 AM SATURDAY. MARINE...STORM WARNING FOR ANZ050 UNTIL 1 AM SATURDAY. && $$ UPDATE...FITZSIMMONS SHORT TERM/MARINE...HEWITT LONG TERM/MARINE...MIGNONE AVIATION...NORTON me AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CARIBOU ME 338 PM EST FRI FEB 17 2006 .SYNOPSIS...DEEP LOW PRESSURE WILL PASS JUST NORTH OF THE STATE THIS EVENING. A STRONG ARCTIC COLD FRONT ASSOCIATED WITH THIS LOW WILL CROSS THE STATE TONIGHT. STRONG WINDS ARE EXPECTED TO ACCOMPANY THIS FRONT AND PERSIST INTO TONIGHT. COLD HIGH PRESSURE WILL BUILD SOUTH OF THE REGION LATE SATURDAY INTO SUNDAY. THIS WILL BRING VERY COLD TEMPERATURES AND BRISK CONDITIONS FOR THE WEEKEND. && .SHORT TERM /TONIGHT-SUNDAY/... EXTENDED THE HIGH WIND WARNINGS OUT TO 2 AM SATURDAY MORNING. ADDED WIND CHILL ADVISORY FOR NORTHERN MAINE LATE TONIGHT INTO SATURDAY MORNING. FLOOD STATEMENT OUT AS WELL FOR RAFL & MELTING SNOW ADDING TO SOME ROAD PROBLEMS IN NORTHERN & NORTHEASTERN MAINE. SEE HYDROLOGY SECTION BELOW. LEANED W/WESTA & THE RUC FOR TONIGHT AS THEY APPEARED TO BE HANDLING THINGS QUITE WELL. AFTER THAT LEANED W/THE GFS INTO SUNDAY. LOW PRES RUNNING ACROSS SRN QUEBEC EXPECTED TO MOVE ACROSS FAR NORTHERN MAINE THIS EVENING & THEN INTO THE MARITIMES LATER TONIGHT. WINDS KICKING UP ACROSS DOWNEAST & COASTAL AREAS AHEAD OF PRE-FRONTAL BOUNDARY. EXPECT THESE WINDS TO TRANSLATE INTO CNTL & NORTHERN AREAS THIS EVENING. A BRIEF LULL & THEN WINDS WILL ONCE AGAIN W/CD FROPA. GRADIENT REALLY TIGHTENS BEHIND DEPARTING LOW EARLY TONIGHT. COULD BE LOOKING AT POWER OUTAGES & DAMAGE. RELAXED WINDS AFT 06Z ACROSS DOWNEAST & THE COAST & KEPT THE WINDS GOING ACROSS NORTHERN MAINE. IN ADDITION TO THE WINDS WILL BE THE ARCTIC BLAST COMING IN THIS EVENING INTO TONIGHT W/A FLASH-FREEZE WHICH WILL LEAD TO FURTHER PROBLEMS W/WATER FREEZING UP. EXPECTING A BRIEF PERIOD OF SNOW THIS EVENING MAINLY ACROSS NORTHERN MAINE. THE STRONG WINDS COMBINED W/THE SNOW COULD LEAD TO BRIEF WHITEOUTS. WIND CHILLS WILL GO TO A RANGE OF 25 TO 30 BELOW ACROSS NORTHERN AREAS LATE TONIGHT INTO SATURDAY MORNING. ARCTIC FRONT TO SWING THROUGH THE CWFA EARLY SATURDAY W/SOME SHSN ACTION ACROSS THE NRN & WRN AREAS W/SOME FORCING IN MID-UPPER LEVELS & CAA. KEPTS WINDS UP IN ADVISORY RANGE. MIDNIGHT CREW MADE NEED TO HAVE WIND ADVISORY UP. GRADIENT (LOOSENING) LOOKS TO HANG ON RIGHT INTO SUNDAY. WOULD NOT BE SURPRISED TO SEE WIND CHILL ADVS BACK UP AGAIN SATURDAY NIGHT INTO SUNDAY MORNING. HIGH PRES OVER THE MID-ATLC REGION RIDGES ACROSS THE REGION LATE SUNDAY. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... WEAK RIDGE CROSSES THE STATE LATE SUNDAY FOLLOW BY A WEAK LOW PRESSURE MONDAY AFTERNOON. HIGH PRESSURE THEN RETURNS TUESDAY. ANOTHER WEAK SHORT WAVE IS EXPECTED TO CROSS THE REGION WEDNESDAY. AN AREA OF LOW PRESSURE IS EXPECTED TO DEVELOP OFF THE MID- ATLANTIC STATES LATE THURSDAY AS ANOTHER LOW MOVES INTO THE GREAT LAKES. BOTH OF THESE SYSTEMS MERGE INTO ONE TO THE EAST OF NEW ENGLAND FRIDAY. HAVE INITIALIZED WIND GRIDS WITH THE 06Z GFS. ALL OTHER GRIDS INITIALIZED WITH HPC DATA. HAVE ADJUSTED COASTAL TEMPERATURES WITH DGEX..THESE INCLUDE TUESDAY NIGHT...WEDNESDAY NIGHT AND MAX TEMPERATURES FOR FRIDAY. FOR MONDAY HAVE LOWERED TEMPERATURES AND DEW POINT DUE TO THE COLD AIR MASS OVER THE FORECAST AREA BASED ON 06Z GFS...ALSO HAVE MADE SOME MINOR CHANGES TO BETTER FIT WITH NEIGHBORING OFFICE. FOR SUNDAY NIGHT THRU MONDAY HAVE CREATED LAND TEMPERATURES...DEW POINTS AND WIND WITH WITH MAV/MET MOS. ALSO FOR SUNDAY NIGHT INTO MONDAY HAVE USED NAM12 FOR THE COASTAL WATERS. && .AVIATION... WINDS WILL BE THE MAJOR AVIATION ISSUE FOR THE OVERNIGHT PERIOD. WIND AT ALL LOCATIONS WILL BECOME WESTERLY AT 20 TO 30 KTS WITH MUCH HIGHER GUST. AT THIS TIME THE FRONTAL SYSTEM IS MOVING THROUGH NORTHEASTERN MAINE. WITH THE PASSAGE OF THE FRONT SKY COND WILL IMPROVE...BUT SNOW SHOWER AND INCREASING WIND WILL CAUSE CARIBOU AND PRESQUE ISLE TO BE LIFR TO MININUMS THROUGH MOST OF THE OVERNIGHT HOURS WITH LOW VISIBILITY AND CIGS OBSTRUCTED BY SNOW. FOR HOULTON AND BANGOR AT THIS TIME THERE IS NOT STANDING SNOW COVER. ANTICIPATE SNOW SHOWERS FOR HUL BUT VISIBILITY AND CEILINGS WILL BE MVFR IMPROVING TO VFR AFTER MIDNIGHT...AT IN BGR VFR WITH AFTER 00Z. && .MARINE... WILL GO W/STORM WARNING TIL 1 AM. WILL BOOST UP WIND TO 40 TO 50 KTS EARLY TONIGHT & THEN IT LOOKS LIKE WINDS LET GO SOME AS LLVL JET EXITS INTO THE MARITIMES. DO NOT HAVE A GOOD FEEL ON WINDS OVER THE WATERS W/WLY FLOW. DECIDED TO GO W/SPEEDS NEAR GLW CRITERIA FOR SAT INTO SAT NIGHT. MIDNIGHT CREW WILL NEED TO ASSESS THIS FURTHER W/LATER GUIDANCE. EXTENDED: HAVE POPULATED WIND GRIDS WITH 06Z GFS. WAVE GRIDS CREATED WITH THE 06Z WNA WAVE WATCH. SINCE FORECASTED AND WAVE MODEL WINDS VERY CLOSE HAVE NOT MADE ANY CHANGES TO WAVE MODEL. && .HYDROLOGY... FLOOD STATEMENT OUT FOR NRN AND NERN MAINE DUE TO RAFL & MELTING SNOW. DITCHES FILLING UP AND SPILLING OVER ONTO SOME ROADS LEADING TO SOME ISSUES. NO ROAD CLOSURES REPORTED ATTM. FFG INDICATES 6 HRLY RAFL JUST UNDER 2.5 INCHES. SO FAR REPORTS COMING IN & MATCHING THIS UP W/STORM TOTAL FROM THE RADAR SHOWS THINGS BELOW GUIDANCE. WILL NEED TO KEEP AN EYE ON THIS SITUATION THIS EVENING. COLDER AIR COMING IN & WINDS PICKING UP SHOULD HELP TO ALLEVIATE ANY FLOODING CONCERNS LATER ON. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...HIGH WIND WARNING FOR MEZ001>006-010-011-031-032 UNTIL 2 AM SATURDAY. ...WIND CHILL ADVISORY FOR MEZ001>006-010 FROM 11 PM FRIDAY TO 11 AM SATURDAY. ...HIGH WIND WARNING FOR MEZ015>017-029-030 UNTIL 2 AM SATURDAY. MARINE...STORM WARNING FOR ANZ050 UNTIL 1 AM SATURDAY. && $$ SHORT TERM/MARINE...HEWITT LONG TERM/MARINE...DUDA AVIATION...NORTON me AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAY ME 1212 PM EST FRI FEB 17 2006 .SHORT TERM (REST OF TODAY)... MESOCALE UPDATE... A LINE OF SHALLOW CONVECTION HAS DEVELOPED AHEAD OF THE COLD FRONT (WHICH STILL APPEARS TO BE WEST OF THE CONNECTICUT RIVER...BASED ON THE LEB OBSERVATION). THE MAIN CONVECTION IS CENTERED OVER CARROLL COUNTY AT THIS TIME. WHILE DAMAGING WINDS AND EVEN SMALL HAIL IS POSSIBLE WITH THIS CONVECTION...WILL CONTINUE TO HANDLE THIS AS A HIGH WIND EVENT...RATHER THAN ISSUE SEVERE THUNDERSTORM WARNING. WILL ALSO CONTINUE TO ISSUE SPECIAL WEATHER STATEMENTS TO COVER THE EVENT. AS A HEADS UP...WILL NEED TO CONSIDER WIND CHILL ADVISORIES FOR AT LEAST THE MOUNTAINS BASED ON TEMPERATURE AND WIND FORECASTS. && .PREVIOUS DISCUSSION... (ISSUED 920 AM EST FRI FEB 17 2006) SHORT TERM (REST OF TODAY)... THE ZONE FORECASTS WILL BE UPDATING THIS MORNING TO ACCOUNT FOR TRENDS...BUT NO SIGNIFICANT CHANGES ARE EXPECTED AS WE AWAIT THE WIND EVENT THIS AFTERNOON AND THIS EVENING. CURRENTLY...THE LAST OF THE COLD AIR IS BEING SCOURED OUT OF THE NORTHEAST ZONES AS THE INCREASING GRADIENT ERODES IT FROM THE TOP. ELSEWHERE...THE COLD AIR HAS BEEN COMPLETELY ELIMINATED AT THE SURFACE. THE 12Z GYX SOUNDINGS SHOWS A FAIRLY STRONG INVERSION STILL IN PLACE...BUT SOME LOCATIONS ARE ALREADY STARTING TO GUST TO 35 MPH IN THE SOUTH TO SOUTHWEST FLOW. THE INVERSION IS STILL INTACT AT ALY AS WELL...BUT JUST TO THE WEST THE FRONT IS BREAKING THE INVERSION. WE HAVE NOTED GUSTS TO 67 KT AT ROC AND 54 KT AT SYR SO FAR THIS MORNING...WITH AND JUST BEHIND THE FRONT. IN THE MID LEVELS...THE WATER VAPOR LOOP SHOWS A VERY STRONG SHORT WAVE ACROSS EASTERN PA...WITH RAPID DRYING AND STRONG DOWNWARD VERTICAL VELOCITY. NO SIGNIFICANT CHANGES EXPECTED TO THE FORECAST. MODEL SOUNDINGS STILL SHOW 60 TO 70 KNOTS AVAILABLE IN THE MIXED LAYER ABOUT AN HOUR AHEAD OF THE FRONT...AND CONTINUING BEHIND THE FRONT FOR A FEW HOURS. THE LATEST RUC SOUNDINGS STILL SHOW NEARLY VERTICAL POTENTIAL TEMPERATURE PROFILES WITH THE FRONT...AND WITH THE VERIFICATION TO THE WEST SO FAR THIS MORNING...WILL UP THE MAXIMUM WIND GUSTS TO NEAR 70 MPH. BASED ON THE POTENTIAL AND WHAT HAS ALREADY HAPPENED TO THE WEST THIS MORNING...THE EVENT HAS THE POTENTIAL FOR WIDESPREAD POWER OUTAGES AND TREE DAMAGE. THE UPDATED HIGH WIND WARNING STATEMENT HAS ALREADY BEEN SENT. THE CHANGE TO SNOW IN THE MOUNTAINS OF NORTHERN NEW HAMPSHIRE MAY BE QUITE RAPID WITH CRASHING HEIGHTS AND TEMPERATURES...AND WILL INDICATE THIS IN THE UPDATE. ELSEWHERE...QPF AMOUNTS SHOULD BE LIMITED BY THE QUICK MOVEMENT OF THE FRONT. MARINE... NO SIGNIFICANT CHANGES HERE THIS MORNING. PREVIOUS DISCUSSION... (ISSUED 537 AM EST FRI FEB 17 2006) SHORT TERM (REST OF TODAY THROUGH FRIDAY NIGHT)...QUICK UPDATE WAS TO CANCEL THE WINTER WEATHER ADVISORIES FOR THE MOUNTAINS AND NORTHERNMOST NEW HAMPSHIRE. WARM AIR WILL CONTINUE TO ENTER THE REGION THIS MORNING. WINDS WILL BE ON THE INCREASE. FIRST BAND OF RAIN RACING IN FROM THE WEST EARLY THIS MORNING. ALL HIGH WIND WARNINGS FOR THIS AFTERNOON AND EVENING REMAIN IN PLACE. PREVIOUS DISCUSSION... (ISSUED 248 AM EST FRI FEB 17 2006) SHORT TERM (TODAY THROUGH FRIDAY NIGHT)...WILL LEAVE ADVISORIES IN PLACE FOR THE MOUNTAINS WHICH ARE DUE TO EXPIRE AT 12Z. HIGH WIND WARNINGS WILL REMAIN IN PLACE AND THERE WILL BE NO CHANGES TO THE WIND FORECAST FOR THIS AFTERNOON AND EVENING. EXPECT SOME VERY HIGH WIND GUSTS...MAINLY ALONG AND SHORTLY AFTER THE COLD FROPA. ONLY CHANGES TO THE SHORT TERM ARE TO INCREASE MAX TEMPERATURE FORECAST FOR TODAY AS READINGS ALREADY IN THE 40S AND LOWER 50S ACROSS PORTIONS OF OUR FORECAST AREA. LONG TERM (SATURDAY THROUGH THURSDAY)... THE WEEKEND LOOKS TO HAVE THE COLDEST AIR OF THE SEASON SETTLING OVER THE AREA. CONDITIONS WILL BE DRY. THE PATTERN CONTINUES TO LOOK UNEVENTFUL THROUGH THE WEEK WITH BELOW NORMAL TEMPERATURES GRADUALLY MODERATING MID TO LATE IN THE WEEK. NO MAJOR STORMS ON THE HORIZON THRU NEXT THURSDAY. AVIATION...MAINLY VFR...LOWERING TO IFR THIS MORNING. POSSIBLY A RUMBLE OF THUNDER WITH THE PASSAGE OF THE COLD FRONT. MARINE...STORM WARNINGS REMAIN IN PLACE. NO CHANGES TO FORECAST PHILOSOPHY THIS PACKAGE. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...HIGH WIND WARNING FOR MEZ007>009-012>014-018>028 UNTIL 10 PM FRIDAY. NH...HIGH WIND WARNING FOR NHZ001>010-013-014 UNTIL 10 PM FRIDAY. MARINE...STORM WARNING FOR ANZ150 UNTIL 10 PM FRIDAY. && $$ me AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAY ME 920 AM EST FRI FEB 17 2006 .SHORT TERM (REST OF TODAY)... THE ZONE FORECASTS WILL BE UPDATING THIS MORNING TO ACCOUNT FOR TRENDS...BUT NO SIGNIFICANT CHANGES ARE EXPECTED AS WE AWAIT THE WIND EVENT THIS AFTERNOON AND THIS EVENING. CURRENTLY...THE LAST OF THE COLD AIR IS BEING SCOURED OUT OF THE NORTHEAST ZONES AS THE INCREASING GRADIENT ERODES IT FROM THE TOP. ELSEWHERE...THE COLD AIR HAS BEEN COMPLETELY ELIMINATED AT THE SURFACE. THE 12Z GYX SOUNDINGS SHOWS A FAIRLY STRONG INVERSION STILL IN PLACE...BUT SOME LOCATIONS ARE ALREADY STARTING TO GUST TO 35 MPH IN THE SOUTH TO SOUTHWEST FLOW. THE INVERSION IS STILL INTACT AT ALY AS WELL...BUT JUST TO THE WEST THE FRONT IS BREAKING THE INVERSION. WE HAVE NOTED GUSTS TO 67 KT AT ROC AND 54 KT AT SYR SO FAR THIS MORNING...WITH AND JUST BEHIND THE FRONT. IN THE MID LEVELS...THE WATER VAPOR LOOP SHOWS A VERY STRONG SHORT WAVE ACROSS EASTERN PA...WITH RAPID DRYING AND STRONG DOWNWARD VERTICAL VELOCITY. NO SIGNIFICANT CHANGES EXPECTED TO THE FORECAST. MODEL SOUNDINGS STILL SHOW 60 TO 70 KNOTS AVAILABLE IN THE MIXED LAYER ABOUT AN HOUR AHEAD OF THE FRONT...AND CONTINUING BEHIND THE FRONT FOR A FEW HOURS. THE LATEST RUC SOUNDINGS STILL SHOW NEARLY VERTICAL POTENTIAL TEMPERATURE PROFILES WITH THE FRONT...AND WITH THE VERIFICATION TO THE WEST SO FAR THIS MORNING...WILL UP THE MAXIMUM WIND GUSTS TO NEAR 70 MPH. BASED ON THE POTENTIAL AND WHAT HAS ALREADY HAPPENED TO THE WEST THIS MORNING...THE EVENT HAS THE POTENTIAL FOR WIDESPREAD POWER OUTAGES AND TREE DAMAGE. THE UPDATED HIGH WIND WARNING STATEMENT HAS ALREADY BEEN SENT. THE CHANGE TO SNOW IN THE MOUNTAINS OF NORTHERN NEW HAMPSHIRE MAY BE QUITE RAPID WITH CRASHING HEIGHTS AND TEMPERATURES...AND WILL INDICATE THIS IN THE UPDATE. ELSEWHERE...QPF AMOUNTS SHOULD BE LIMITED BY THE QUICK MOVEMENT OF THE FRONT. && .MARINE... NO SIGNIFICANT CHANGES HERE THIS MORNING. && .PREVIOUS DISCUSSION... (ISSUED 537 AM EST FRI FEB 17 2006) SHORT TERM (REST OF TODAY THROUGH FRIDAY NIGHT)...QUICK UPDATE WAS TO CANCEL THE WINTER WEATHER ADVISORIES FOR THE MOUNTAINS AND NORTHERNMOST NEW HAMPSHIRE. WARM AIR WILL CONTINUE TO ENTER THE REGION THIS MORNING. WINDS WILL BE ON THE INCREASE. FIRST BAND OF RAIN RACING IN FROM THE WEST EARLY THIS MORNING. ALL HIGH WIND WARNINGS FOR THIS AFTERNOON AND EVENING REMAIN IN PLACE. PREVIOUS DISCUSSION... (ISSUED 248 AM EST FRI FEB 17 2006) SHORT TERM (TODAY THROUGH FRIDAY NIGHT)...WILL LEAVE ADVISORIES IN PLACE FOR THE MOUNTAINS WHICH ARE DUE TO EXPIRE AT 12Z. HIGH WIND WARNINGS WILL REMAIN IN PLACE AND THERE WILL BE NO CHANGES TO THE WIND FORECAST FOR THIS AFTERNOON AND EVENING. EXPECT SOME VERY HIGH WIND GUSTS...MAINLY ALONG AND SHORTLY AFTER THE COLD FROPA. ONLY CHANGES TO THE SHORT TERM ARE TO INCREASE MAX TEMPERATURE FORECAST FOR TODAY AS READINGS ALREADY IN THE 40S AND LOWER 50S ACROSS PORTIONS OF OUR FORECAST AREA. LONG TERM (SATURDAY THROUGH THURSDAY)... THE WEEKEND LOOKS TO HAVE THE COLDEST AIR OF THE SEASON SETTLING OVER THE AREA. CONDITIONS WILL BE DRY. THE PATTERN CONTINUES TO LOOK UNEVENTFUL THROUGH THE WEEK WITH BELOW NORMAL TEMPERATURES GRADUALLY MODERATING MID TO LATE IN THE WEEK. NO MAJOR STORMS ON THE HORIZON THRU NEXT THURSDAY. AVIATION...MAINLY VFR...LOWERING TO IFR THIS MORNING. POSSIBLY A RUMBLE OF THUNDER WITH THE PASSAGE OF THE COLD FRONT. MARINE...STORM WARNINGS REMAIN IN PLACE. NO CHANGES TO FORECAST PHILOSOPHY THIS PACKAGE. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...HIGH WIND WARNING FOR MEZ007>009-012>014-018>028 UNTIL 10 PM FRIDAY. NH...HIGH WIND WARNING FOR NHZ001>010-013-014 UNTIL 10 PM FRIDAY. MARINE...STORM WARNING FOR ANZ150 UNTIL 10 PM FRIDAY. && $$ me AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1202 PM EST FRI FEB 17 2006 .UPDATE... CONCERNS ARE STATUS OF HEADLINES FOR HEAVY SNOW AND WIND CHILLS. UPSTREAM POLAR VORTEX FROM WRN ONTARIO AND NRN MN NOW ROTATING OVER WRN LAKE SUPERIOR. VERY COLD BUT RELATIVELY MOIST AND UNSTABLE AIR TO 11 KFT NOTED ON UPSTREAM 12Z KINL SNDG IS INDICATIVE OF AIRMASS ADVECTING OVER LAKE SUPERIOR AT PRESENT. MODELS SHOW STRONG 700-500 MB Q-VECT CONV MOVG OVER THE AREA IN ASSOCATION WITH POLAR VORTEX WHICH HAS HELPED INTENSIFY LES BANDS OVER WRN LAKE SUPERIOR. THERE HAVE SEVERAL REPORTS THIS MORNING OF NEAR TO NEAR ZERO VSBY IN HEAVY SNOW AND BLOWING SNOW FROM ONTONAGON UP THROUGH THE KEWEENAW PENINSULA. APPARENTLY STRONG DYNAMICS AND LOW-LVL CONVERGENCE ASSOC WITH VORTEX HAVE OVERCOME RELATIVELY POOR SNOW GROWTH DUE TO EXTREMELY COLD ARCTIC AMS. GIVEN REPORTS THUS FAR HAVE DECIDED TO DROP SNOW AND BLOWING ADVISORY AND GO WITH A WINTER STORM WARNING FOR HEAVY SNOW/BLOWING SNOW FOR ONT-SOUTHERN HOUGHTON THROUGH TONIGHT AND FOR NORTHERN HOUGHTON AND KEWEENAW THROUGH EARLY SATURDAY AFTERNOON. WOULD NOT BE SURPRISED TO SEE 4 TO LOCALLY 8 INCHES OVER THESE AREAS BY THIS EVENING. SINCE STRONG DYNAMICS AND MOIST/UNSTABLE AIR WILL BE MOVING ACROSS ERN LAKE SUPERIOR THIS AFTERNOON AND THIS EVENING AND GOOD CONVERGENT FLOW WILL CONTINUE ALONG LAKE SUPERIOR SHORE OF ERN ALGER AND NRN LUCE THROUGH SAT MORNING HAVE EXTENDED WINTER STORM WARNING THERE AS WELL. BUMPED UP AMOUNTS TO LOCALLY 8 INCHES TODAY AND LOCALLY 7 INCHES TONIGHT WITH HEAVIEST AMOUNTS ALONG SHORE FROM GRAND MARAIS EASTWARD WHERE LLVL CONVERGENCE WILL BE MAXIMIZED. ISSUED A WIND CHILL ADVISORY FOR GOGEBIC AND IRON COUNTY FOR THE REST OF TODAY. STRONG CAA CAUSING TEMPS TO FALL TO AROUND ZERO OR A FEW DEGREES BLO ZERO AND THIS ALONG WITH W-NW WINDS OF 10 TO 20 MPH HAVE CAUSED WIND CHILL READINGS TO PLUMMET TO 20 BLO ZERO IN SPOTS. WILL LET SNOW/BS ADVISORY EXPIRE FOR GOGEBIC COUNTY BY NOON TODAY AND EXPECT THAT WINTER STORM WARNING FOR NRN SCHOOLCRAFT CAN END AS PLANNED THIS EVENING WITH FLOW BACKING MORE WEST WITH TIME. && .PREV DISCUSSION... MAIN FCST CONCERNS ARE LES/WIND TRENDS AND WIND CHILLS TONIGHT INTO SAT MORNING. WV IMAGERY...00Z RAOBS AND RUC ANALYSIS INDICATED DEPARTING SHRTWV TROF FROM ERN LK SUPERIOR INTO LWR MI WITH MID LVL LOW(POLAR VORTEX) UPSTREAM OVER SRN MANITOBA. AT THE SFC...CYCLONIC NRLY FLOW PREVAILED ACRS THE WRN GRT LAKES BTWN 995 MB LOW PRES OVER W QUEBEC AND A 1052 MB RDG FROM ALBERTA INTO THE NRN PLAINS. VERY COLD AIR WAS SPREADING INTO THE REGION WITH TEMPS IN THE -15 TO -25 RANGE FROM NRN MN INTO SRN MANITOBA. DESPITE THE EXTREMELY DRY COLD AIR...FAIRLY STRONG QVECTOR CONV AHEAD OF THE MID LVL LOW SUPPORTED SOME LIGHT SNOW OVER NRN MN WITH VSBYS TO 3-5SM. IR/WV IMAGERY SHOWED BACK EDGE OF DEEPER MOISTURE WITH DEFORMATION ZONE FROM THE DEPARTING STORM SYSTEM HAD MOVED TO THE E END OF LK SUPERIOR. RADAR INDICATED THAT THE LES BANDS HAVE SLOWLY REALIGNED WITH THE BACKING WINDS TO NNW. SOME ISOLATED 28DBZ RETURNS REMAINED BUT BAND SPACING HAS INCREASED AND MOVEMENT HAS LED TO DIMINISHING SNOWFALL RATES SINCE 06Z. MDLS WERE IN REASONABLY GOOD AGREEMENT THROUGH THE WEEKEND. SO...LEANED TOWARD THE NAM FOR DETAILS WITH LOW LVL FLOW. TODAY...AS THE CORE OF THE COLDER AIR APPROACHES...850 MB TEMPS ARE FCST TO DROP FROM AROUND -20C TO THE -25C TO -30C RANGE BY LATE TODAY. STRONG 850-500 QVECTOR CONV ASSOCIATED WITH THE MID LVL LOW MOVES ACRS LK SUPERIOR BTWN 15Z-21Z WHICH WILL RAISE INVERSION HGTS TO NEAR 10K FT. EVEN THOUGH THE VERY COLD AIR WOULD ORDINARILY BE UNFAVORABLE FOR DECENT SNOWFLAKE GROWTH THE HIGH LAKE INDUCED CAPE...LONGER FETCH AND FCST 950 CONV...PER LAPS WRF AND NAM SHOULD SUPPORT STRONG LES BANDS NEAR LAKE SUPERIOR EAST OF MARQUETTE. ALTHOUGH THE SHIFTING LOCATION OF MAX CONV MAY LIMIT OVERALL SNOW TOTALS...ADDITIONAL AMOUNTS IN THE 3-7 INCH RANGE ARE EXPECTED. SO...WINTER STORM WARNINGS REMAIN IN EFFECT FOR ALGER/LUCE/ N SCHOOLCRAFT. WITH BACKING WINDS...LES OVER THE WEST SHOULD LIFT NORTH OF KIWD AND CONTINUE OVER THE NW CWA. SHORTER FETCH AND VERY COLD/DRY PRFL SHOULD KEEP SNOWFALL TOTALS IN THE 2-5 INCH RANGE. TONIGHT...BACKING WINDS WILL TO WRLY WILL ALLOW VERY COLD AIR OVER NRN MN TO FILTER INTO MUCH OF UPR MI WITHOUT BECOMING MODIFIED OVER THE LAKE. GRADIENT WILL REMAIN TIGHT ENOUGH TO KEEP WINDS AT LEAST IN THE 10 TO 15 MPH RANGE FOR MUCH OF THE NIGHT. UPSTREAM...10-15 KT WINDS PERSISTED FROM ND INTO NW MN WHERE TEMPS HAD FALLEN TO -20 F TO -25 F. EVEN THOUGH SOME INLAND TEMPS MAY FALL OFF TO -15F TO -20F...THAT WOULD ALSO BE WHERE THE RADIATIONAL COOLING AND PREVAILS WITH WEAKER/DECOUPLED WINDS (BLO 10 MPH REQUIRED FOR WIND CHILL HEADLINES). SO...HAVE REMAINED CONSERVATIVE WITH WIND CHILL VALUES. NEVERTHELESS...EXPECT WIND CHILL VALUES AOB -35 OVER SW UPR MI BTWN(BTWN KIWD-KIMT) WITH VALUES IN THE -25 TO -35 RANGE OVER MUCH OF THE REST OF CNTRL UPR MI. BRISK WRLY WINDS WILL KEEP LES/BLSN GOING OVER THE KEWEENAW BUT FALLING INVERSION HGTS TO NEAR 5K FT AND VERY COLD/DRY AIR...LIMITING SNOWFLAKE GROWTH...SHOULD AGAIN KEEP SNOWFALL AMOUNTS IN THE ADVY RANGE (2-5 INCHES). THE NAM HAS REMAINED CONSISTENT IN FEATURING SUBSTANTIAL LOW LVL CONV TOWARD NE LUCE COUNTY WHICH SEEMS PLAUSIBLE GIVEN RESIDUAL HELP FROM MID LVL QVECTOR CONV AND STRENGTH OF LAND BREEZES AND LAKE INDUCED TROFFING WITH SUCH A COLD AIRMASS. HOWEVER...WITH MODEL MAX LOW LVL CONV JUST CLIPPING THE NE LUCE COUNTY AND UNCERTAINTY WHERE ACTUAL HEAVIER SNOWBAND WILL DEVELOP SO THAT THE WARNING WAS NOT EXTENDED AT THIS TIME. SAT INTO SAT NIGHT...LES/BLSN ADVY WAS EXTENDED THROUGH THE PERIOD FOR THE KEWEENAW WITH PERSISTENT WRLY FLOW MAXIMIZING FETCH AND PROVIDING FAVORABLE LOW LVL CONV PATTERN. ANOTHER WEAK SHRTWV FROM NW ONTARIO BRUSHING THE AREA MAY PROVIDE A BOOST TO THE LES SAT WITH BETTER 850-700 MB MOISTURE. CBL WINDS IN THE 20-30 KT RANGE ALSO WILL PRODUCE SIGNIFICANT BLOWING AND DRIFTING IN OPEN AREAS. SUN INTO SUN NIGHT...EXPECT A STRONGER SHRTWV TROF MOVING TOWARD THE WRN LAKES FROM NRN MANITOBA WILL CAUSE WINDS TO BACK SWRLY AND LIFT LES BANDS OFFSHORE OR OVER JUST THE NRN TIP OF THE KEWEENAW. LES POTENTIAL MAY INCREASE AGAIN SUN NIGHT OVER THE KEWEENAW AS THE SHRTWV MOVES THROUGH AND WINDS VEER WNW WHILE 850 MB TEMPS REMAIN NEAR -18C WITH INVERSION HGTS CLIMBING AOA 7K FT(PER GFS). && .MQT WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 6 PM EST THIS AFTERNOON FOR MIZ085. WINTER STORM WARNING UNTIL NOON EST SATURDAY MIZ006-007. LAKE EFFECT SNOW AND BLOWING SNOW ADVISORY FOR MIZ009 UNTIL 12 PM EST. WINTER STORM WARNING FOR MIZ002-084 UNTIL 7 AM EST SATURDAY. WINTER STORM WARNING FOR MIZ001-MIZ003 UNTIL 1 PM EST SATURDAY. WIND CHILL ADVISORY FROM 6 PM EST /5 PM CST/ THIS EVENING TO 12 PM EST /11 AM CST/ SATURDAY FOR MIZ002-MIZ004-MIZ005-MIZ006-MIZ011-MIZ012-MIZ013-MIZ084. WIND CHILL ADVISORY FROM 11 AM EST TODAY TO 6 PM EST TODAY FOR MIZ009-010. WIND CHILL WARNING FROM 5 PM THIS AFTERNOON TO 11 AM CST SATURDAY FOR MIZ009-MIZ010. && $$ VOSS (UPDATE) JLB (PREV DISCUSSION) mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 500 AM EST FRI FEB 17 2006 .DISCUSSION... MAIN FCST CONCERNS ARE LES/WIND TRENDS AND WIND CHILLS TONIGHT INTO SAT MORNING. WV IMAGERY...00Z RAOBS AND RUC ANALYSIS INDICATED DEPARTING SHRTWV TROF FROM ERN LK SUPERIOR INTO LWR MI WITH MID LVL LOW(POLAR VORTEX) UPSTREAM OVER SRN MANITOBA. AT THE SFC...CYCLONIC NRLY FLOW PREVAILED ACRS THE WRN GRT LAKES BTWN 995 MB LOW PRES OVER W QUEBEC AND A 1052 MB RDG FROM ALBERTA INTO THE NRN PLAINS. VERY COLD AIR WAS SPREADING INTO THE REGION WITH TEMPS IN THE -15 TO -25 RANGE FROM NRN MN INTO SRN MANITOBA. DESPITE THE EXTREMELY DRY COLD AIR...FAIRLY STRONG QVECTOR CONV AHEAD OF THE MID LVL LOW SUPPORTED SOME LIGHT SNOW OVER NRN MN WITH VSBYS TO 3-5SM. IR/WV IMAGERY SHOWED BACK EDGE OF DEEPER MOISTURE WITH DEFORMATION ZONE FROM THE DEPARTING STORM SYSTEM HAD MOVED TO THE E END OF LK SUPERIOR. RADAR INDICATED THAT THE LES BANDS HAVE SLOWLY REALIGNED WITH THE BACKING WINDS TO NNW. SOME ISOLATED 28DBZ RETURNS REMAINED BUT BAND SPACING HAS INCREASED AND MOVEMENT HAS LED TO DIMINISHING SNOWFALL RATES SINCE 06Z. MDLS WERE IN REASONABLY GOOD AGREEMENT THROUGH THE WEEKEND. SO...LEANED TOWARD THE NAM FOR DETAILS WITH LOW LVL FLOW. TODAY...AS THE CORE OF THE COLDER AIR APPROACHES...850 MB TEMPS ARE FCST TO DROP FROM AROUND -20C TO THE -25C TO -30C RANGE BY LATE TODAY. STRONG 850-500 QVECTOR CONV ASSOCIATED WITH THE MID LVL LOW MOVES ACRS LK SUPERIOR BTWN 15Z-21Z WHICH WILL RAISE INVERSION HGTS TO NEAR 10K FT. EVEN THOUGH THE VERY COLD AIR WOULD ORDINARILY BE UNFAVORABLE FOR DECENT SNOWFLAKE GROWTH THE HIGH LAKE INDUCED CAPE...LONGER FETCH AND FCST 950 CONV...PER LAPS WRF AND NAM SHOULD SUPPORT STRONG LES BANDS NEAR LAKE SUPERIOR EAST OF MARQUETTE. ALTHOUGH THE SHIFTING LOCATION OF MAX CONV MAY LIMIT OVERALL SNOW TOTALS...ADDITIONAL AMOUNTS IN THE 3-7 INCH RANGE ARE EXPECTED. SO...WINTER STORM WARNINGS REMAIN IN EFFECT FOR ALGER/LUCE/ N SCHOOLCRAFT. WITH BACKING WINDS...LES OVER THE WEST SHOULD LIFT NORTH OF KIWD AND CONTINUE OVER THE NW CWA. SHORTER FETCH AND VERY COLD/DRY PRFL SHOULD KEEP SNOWFALL TOTALS IN THE 2-5 INCH RANGE. TONIGHT...BACKING WINDS WILL TO WRLY WILL ALLOW VERY COLD AIR OVER NRN MN TO FILTER INTO MUCH OF UPR MI WITHOUT BECOMING MODIFIED OVER THE LAKE. GRADIENT WILL REMAIN TIGHT ENOUGH TO KEEP WINDS AT LEAST IN THE 10 TO 15 MPH RANGE FOR MUCH OF THE NIGHT. UPSTREAM...10-15 KT WINDS PERSISTED FROM ND INTO NW MN WHERE TEMPS HAD FALLEN TO -20 F TO -25 F. EVEN THOUGH SOME INLAND TEMPS MAY FALL OFF TO -15F TO -20F...THAT WOULD ALSO BE WHERE THE RADIATIONAL COOLING AND PREVAILS WITH WEAKER/DECOUPLED WINDS (BLO 10 MPH REQUIRED FOR WIND CHILL HEADLINES). SO...HAVE REMAINED CONSERVATIVE WITH WIND CHILL VALUES. NEVERTHELESS...EXPECT WIND CHILL VALUES AOB -35 OVER SW UPR MI BTWN(BTWN KIWD-KIMT) WITH VALUES IN THE -25 TO -35 RANGE OVER MUCH OF THE REST OF CNTRL UPR MI. BRISK WRLY WINDS WILL KEEP LES/BLSN GOING OVER THE KEWEENAW BUT FALLING INVERSION HGTS TO NEAR 5K FT AND VERY COLD/DRY AIR...LIMITING SNOWFLAKE GROWTH...SHOULD AGAIN KEEP SNOWFALL AMOUNTS IN THE ADVY RANGE (2-5 INCHES). THE NAM HAS REMAINED CONSISTENT IN FEATURING SUBSTANTIAL LOW LVL CONV TOWARD NE LUCE COUNTY WHICH SEEMS PLAUSIBLE GIVEN RESIDUAL HELP FROM MID LVL QVECTOR CONV AND STRENGTH OF LAND BREEZES AND LAKE INDUCED TROFFING WITH SUCH A COLD AIRMASS. HOWEVER...WITH MODEL MAX LOW LVL CONV JUST CLIPPING THE NE LUCE COUNTY AND UNCERTAINTY WHERE ACTUAL HEAVIER SNOWBAND WILL DEVELOP SO THAT THE WARNING WAS NOT EXTENDED AT THIS TIME. SAT INTO SAT NIGHT...LES/BLSN ADVY WAS EXTENDED THROUGH THE PERIOD FOR THE KEWEENAW WITH PERSISTENT WRLY FLOW MAXIMIZING FETCH AND PROVIDING FAVORABLE LOW LVL CONV PATTERN. ANOTHER WEAK SHRTWV FROM NW ONTARIO BRUSHING THE AREA MAY PROVIDE A BOOST TO THE LES SAT WITH BETTER 850-700 MB MOISTURE. CBL WINDS IN THE 20-30 KT RANGE ALSO WILL PRODUCE SIGNIFICANT BLOWING AND DRIFTING IN OPEN AREAS. SUN INTO SUN NIGHT...EXPECT A STRONGER SHRTWV TROF MOVING TOWARD THE WRN LAKES FROM NRN MANITOBA WILL CAUSE WINDS TO BACK SWRLY AND LIFT LES BANDS OFFSHORE OR OVER JUST THE NRN TIP OF THE KEWEENAW. LES POTENTIAL MAY INCREASE AGAIN SUN NIGHT OVER THE KEWEENAW AS THE SHRTWV MOVES THROUGH AND WINDS VEER WNW WHILE 850 MB TEMPS REMAIN NEAR -18C WITH INVERSION HGTS CLIMBING AOA 7K FT(PER GFS). && .MQT WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 6 PM EST THIS AFTERNOON FOR MIZ006-MIZ007-MIZ085. LAKE EFFECT SNOW AND BLOWING SNOW ADVISORY FOR MIZ009 UNTIL 12 PM EST. LAKE EFFECT SNOW AND BLOWING SNOW ADVISORY FOR MIZ002 UNTIL 6 AM EST SATURDAY. LAKE EFFECT SNOW AND BLOWING SNOW ADVISORY FOR MIZ001-MIZ003 UNTIL 6 AM EST SUNDAY. WIND CHILL ADVISORY FROM 6 PM EST /5 PM CST/ THIS EVENING TO 12 PM EST /11 AM CST/ SATURDAY FOR MIZ002-MIZ004-MIZ005-MIZ006- MIZ011-MIZ012-MIZ013-MIZ084. WIND CHILL WARNING FROM 5 PM THIS AFTERNOON TO 11 AM CST SATURDAY FOR MIZ009-MIZ010. && $$ JLB mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 849 PM CST FRI FEB 17 2006 .UPDATE... WE EXTENDED OUR WIND CHILL ADVISORY UNTIL 10 AM SATURDAY AFTER REVIEWING EVENING RUC WIND FORECAST IN COMBINATIION WITH ANTICIPATED TEMPERATURES THROUGH NOON SATURDAY. PREVIOUS DISCUSSION .DISCUSSION...TONIGHT THROUGH MONDAY AFTERNOON. BRRRRR...BEST WAY TO DESCRIBE WHAT IS IN STORE FOR MUCH OF THE UPPER MIDWEST TONIGHT. COPIOUS AMOUNTS OF ARCTIC AIR HAVE BEEN FUNNELING INTO THE REGION DURING THE DAY...SETTING US UP FOR FAR AND AWAY THE COLDEST NIGHT OF THE WINTER SEASON...PERIOD. ALTHOUGH 850 MINIMUM TEMPERATURE BULLESEYE PROGGED TO TREK INTO NORTHERN WI TONIGHT...MOST OF CWA STILL LEFT TO DEAL WITH TEMPS BETWEEN MINUS 25 AND MINUS 28. SFC RIDGE AXIS OVER DAKOTAS WILL SAG SOUTH AND EXTEND FROM EASTERN NE TO FAR SOUTHERN MN BY DAWN. ALTHOUGH GRADIENT EXPECTED TO REMAIN FAIRLY HEALTHY ...DECIDED ENOUGH DECOUPLING SHOULD OCCUR AFTER MIDNIGHT TO PULL WIND CHILL ADVISORIES ACROSS MUCH OF REGION. ONLY CAVEAT WOULD BE OUR W CENTRAL WI COUNTIES...WHERE WESTERLY FLOW MAY REMAIN STUBBORNLY ABOVE 10 MPH. MASSIVE 200 KT JET CORE PASSES OVER N IA DURING EVE HOURS...WITH SOME RESIDUAL MID CLOUDS POSSIBLY INTRUDING INTO FAR SOUTHERN CWA. IF THIS OCCURS OVERNIGHT LOWS WILL HAVE TO BE TRIMMED SOMEWHAT. SFC PRESSURE GRADIENT SHOULD INCREASE AFTER SUNRISE...WITH POSSIBLE REISSUANCE OF WIND CHILL ADVISORIES FOR LATE MORNING HOURS. AIRMASS WILL SLOWLY MODERATE ON SATURDAY AND MORE SO ON SUNDAY...AS MID FEBRUARY SUNSHINE REALLY KICKS IN. BY MONDAY GFSLR INDICATING ZONAL WARMER PACIFIC MARITIME FLOW ACROSS THE REGION...FINALLY BRINGING US BACK TO SEASONAL TEMPERATURES. AS THIS OCCURS A FAST MOVING CLIPPER TYPE SYSTEM SWEEPS THROUGH MUCH OF THE NORTHERN PORTION OF MN. ALTHOUGH BEST FORCING CLEARLY SEEN ON GFS 285K ISENTROPIC SFC OVER FAR NORTHERN MINNESOTA...ENOUGH MOISTURE AND WEAK OMEGA IN PLAY FOR CHANCE LIGHT SNOW ACROSS FAR NORTHERN FA BY LATE MONDAY AFTERNOON. LONGER TERM...MONDAY EVENING THROUGH FRIDAY CONSENSUS BETWEEN THE ECMWF...CANADIAN...AND DGEX SUGGESTS KEEPING A DRY FORECAST INTO MID WEEK...ALONG WITH A SLOW WARMING TREND...AS A SERIES OF SURFACE LOWS TRACK TO THE NORTH OF THE FA. A STRONGER WAVE IS ANTICIPATED WEDNESDAY NIGHT AND THURSDAY...BUT LOCATION AND TIMING DIFFER AMONG THE MODELS...SO KEPT LOW CHANCE POPS FOR SNOW IN PLACE. DAY 7 DRY AND COLDER WITH LOWS/HIGHS BELOW CLIMATOLOGY. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...WIND CHILL ADVISORY UNTIL 10 AM CST SATURDAY FOR ANOKA-BENTON- BLUE EARTH-BROWN-CARVER-CHIPPEWA-CHISAGO-DAKOTA-DOUGLAS- FARIBAULT-FREEBORN-GOODHUE-HENNEPIN-ISANTI-KANABEC- KANDIYOHI-LAC QUI PARLE-LE SUEUR-MARTIN-MCLEOD-MEEKER-MILLE LACS-MORRISON-NICOLLET-POPE-RAMSEY-REDWOOD-RENVILLE-RICE- SCOTT-SHERBURNE-SIBLEY-STEARNS-STEELE-STEVENS-SWIFT-TODD- WASECA-WASHINGTON-WATONWAN-WRIGHT-YELLOW MEDICINE COUNTY(IES). WI...WIND CHILL ADVISORY UNTIL 10 AM CST SATURDAY FOR BARRON-CHIPPEWA- DUNN-EAU CLAIRE-PEPIN-PIERCE-POLK-RUSK-ST. CROIX COUNTY(IES). && $$ AZ/JVM/WET mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 935 AM CST FRI FEB 17 2006 .DISCUSSION... WITH MASSIVE SURFACE COLD AIR ADVECTION ACROSS WEST CENTRAL MINNESOTA...PLENTY OF MIXING AND 850 TEMPS IN THE -30 TO -35 RANGE...DECIDED TEMPERATURES IN THIS REGION WILL BE VERY SLOW TO RECOVER...IF AT ALL...PRIOR TO 1 PM. WITH WIND CHILLS STUBBORNLY STAYING IN THE -40 TO -47 DEGREE RANGE...A WIND CHILL WARNING IS NOW IN EFFECT ACROSS THIS REGION UNTIL 1 PM. AFTER THIS TIME FRAME SLIGHT SURFACE TEMPERATURE RECOVERY COUPLED WITH CONTINUED STRONG NW FLOW JUSTIFIES A CONTINUATION OF THE PREVIOUS WIND CHILL ADVISORY UNTIL 5 PM. OTHER THEN THAT NO OTHER CHANGES TO FORECAST NEEDED AT THIS TIME. .PREVIOUS DISCUSSION...TODAY THROUGH SUNDAY NIGHT THE RUC AND NAM MODELS SHOW THE STRONGEST LOW LEVEL COLD ADVECTION MOVING ACROSS OUR COUNTY WARNING AREA EARLY THIS MORNING. OBSERVATIONS SHOW THAT THIS IS ACCOMPANIED BY GUSTS FROM 25 TO 30 MPH...WIND CHILLS FALLING INTO THE WIND CHILL ADVISORY CRITERIA AND AN AREA OF COLD AIR STRATO CUMULUS. LOW LEVEL COLD ADVECTION IS FORECAST TO CONTINUE THROUGH TODAY. NAM DATA ON BUFKIT SUGGESTS THAT BRISK WINDS WILL PERSIST TODAY AND TEMPERATURES WILL RECOVER LITTLE IF AT ALL. THE COLDEST TEMPERATURES ARE EXPECTED TONIGHT AS A SURFACE HIGH PRESSURE RIDGE PASSES JUST SOUTH OF OUR FORECAST AREA. LOW LEVEL WESTERLY WINDS...THROUGH 850 MB...ARE FORECAST TO REMAIN 20 TO 35 KNOTS TONIGHT AND SATURDAY. THESE WINDS ARE EXPECTED TO DECOUPLE THIS EVENING BUT SHOULD BECOME A FACTOR FOR WIND CHILLS AGAIN SATURDAY. AN IMPRESSIVE WESTERLY UPPER LEVEL JET CORE IS FORECAST BY THE GFS MODEL TO REMAIN JUST SOUTH OF THE REGION DURING THIS FORECAST PERIOD. AN ARCTIC AIR MASS IS EXPECTED TO PERSIST ACROSS OUR AREA. IT WILL BE DIFFICULT TO DISPLACE THIS FRIGID AIR MASS. MODEL OUTPUT STATISTICS MAY BE FAST IN MODERATING OUR TEMPERATURES. LONGER TERM...MONDAY THROUGH FRIDAY CONSENSUS BETWEEN THE ECMWF...CANADIAN...AND DGEX SUGGESTS KEEPING A DRY FORECAST INTO MID WEEK...ALONG WITH A SLOW WARMING TREND...AS A SERIES OF SURFACE LOWS TRACK TO THE NORTH OF THE FA. A STRONGER WAVE IS ANTICIPATED WEDNESDAY NIGHT AND THURSDAY...BUT LOCATION AND TIMING DIFFER AMONG THE MODELS...SO KEPT LOW CHANCE POPS FOR SNOW IN PLACE. DAY 7 DRY AND COLDER WITH LOWS/HIGHS BELOW CLIMATOLOGY. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...WIND CHILL ADVISORY UNTIL 5 PM CST THIS AFTERNOON FOR ANOKA-BLUE EARTH-BROWN-CARVER-CHISAGO-DAKOTA-FARIBAULT-FREEBORN- GOODHUE-HENNEPIN-ISANTI-KANABEC-LE SUEUR-MARTIN-MCLEOD- MILLE LACS-NICOLLET-RAMSEY-REDWOOD-RENVILLE-RICE-SCOTT- SHERBURNE-SIBLEY-STEELE-WASECA-WASHINGTON-WATONWAN-WRIGHT- YELLOW MEDICINE COUNTY(IES). WIND CHILL WARNING UNTIL 1 PM CST THIS AFTERNOON FOR BENTON- CHIPPEWA-DOUGLAS-KANDIYOHI-LAC QUI PARLE-MEEKER-MORRISON- POPE-STEARNS-STEVENS-SWIFT-TODD COUNTY(IES). WIND CHILL ADVISORY FROM 1 PM TO 5 PM CST THIS AFTERNOON FOR BENTON-CHIPPEWA-DOUGLAS-KANDIYOHI-LAC QUI PARLE-MEEKER- MORRISON-POPE-STEARNS-STEVENS-SWIFT-TODD COUNTY(IES). WI...WIND CHILL ADVISORY UNTIL 5 PM CST THIS AFTERNOON FOR BARRON- CHIPPEWA-DUNN-EAU CLAIRE-PEPIN-PIERCE-POLK-RUSK-ST. CROIX COUNTY(IES). && $$ AZ/JM mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBUQUERQUE NM 718 AM MST FRI FEB 17 2006 .UPDATE...UPDATED FORECAST TO ADD SNOW ADVYS AND WINTER WX ADVY. && .DISCUSSION...SOUNDER INDICATES CONSIDERABLE MOISTURE BEING DRAWN AROUND AND AHEAD OF THE UPPER TROUGH OFF THE WEST COAST EARLY THIS MORNING. ALSO APPEARS THERE MAY BE A SHORTWAVE OR TWO EMBEDDED IN THE SUBTROPICAL STREAM TO EJECT AHEAD OF THE TROUGH. THE NAM MAY BE OVERDONE IN IT/S SIGNIFICANT INCREASE IN BELOW MOUNTAIN TOP MOISTURE FOR TODAY VERSUS THE GFS. RUC CLOSER TO GFS FOR TODAY. BUT BOTH SHOWN A DEEP LAYER OF MOISTURE AOA THAT LEVEL BY 18Z AND PERSISTING THROUGH MIDNIGHT TONIGHT. WITH THE STRONG SOUTHWEST FLOW ALOFT CONTINUING...H7 50KT FORECAST BY THE GFS THIS AFTERNOON OVER PARTS OF THE EAST AND SOUTH WITH SOMEWHAT LESSER VALUES REMAINDER OF AREA...CONSIDERING POSSIBILITY OF ACCUMULATING SNOWS OVER PORTIONS OF THE WESTERN AND NORTHERN MOUNTAINS AS WELL AS SANDIA/MANZANOS LATER TODAY/THIS EVENING. AT THE SAME TIME...LIGHT SNOW HAS STARTED TO FALL AT CLAYTON...AND WILL SPREAD AT LEAST TOKEN 10 POPS OVER THE EAST TODAY AND TONIGHT FOR THE POSSIBILITY OF A WINTRY MIX OF PCPN. THE STRONG WINDS WILL PERSIST ALOFT THROUGH THE WEEKEND. ALTHOUGH DRY SLOTTING MAY BE A POSSIBILITY FOR PART OF THE FORECAST AREA...THE NORTHWEST AND SOUTH COULD STILL REMAIN UNDER THE MORE SIGNIFICANT MOISTURE. AREAS THAT DON/T SEE CLOUDS MAY DEFINITELY EXPERIENCE MORE WIND. MAY NEED TO UPDATE FORECAST BEFORE 8 AM FOR WINTER WEATHER HIGHLIGHTS. STAY TUNED. && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 44 21 50 25 / 40 40 10 20 GALLUP.......................... 44 18 48 21 / 40 30 10 20 GRANTS.......................... 41 20 47 21 / 40 40 10 20 GLENWOOD........................ 55 26 59 32 / 30 20 10 30 CHAMA........................... 32 14 38 11 / 70 70 50 30 LOS ALAMOS...................... 39 22 46 21 / 40 50 30 30 RED RIVER....................... 30 10 34 7 / 50 60 20 30 TAOS............................ 35 14 41 16 / 50 60 30 30 SANTA FE........................ 38 19 45 22 / 40 50 20 30 SANTA FE AIRPORT................ 41 22 49 25 / 40 40 20 30 ESPANOLA........................ 44 22 49 25 / 40 40 20 30 ALBUQUERQUE HEIGHTS............. 46 30 52 32 / 40 30 10 30 ALBUQUERQUE VALLEY.............. 44 25 53 32 / 40 30 10 30 ALBUQUERQUE FOOTHILLS........... 41 25 48 29 / 40 40 10 30 ALBUQUERQUE WEST MESA........... 46 29 54 31 / 40 40 10 30 SOCORRO......................... 50 30 56 33 / 20 10 10 30 SANDIA PARK/CEDAR CREST......... 41 22 47 24 / 40 40 10 30 MORIARTY/ESTANCIA............... 40 15 44 27 / 30 30 10 30 CARRIZOZO....................... 51 27 50 32 / 10 20 10 30 RUIDOSO......................... 44 28 48 29 / 20 20 10 30 RATON........................... 32 8 36 12 / 30 30 20 20 LAS VEGAS....................... 35 17 38 20 / 50 40 20 30 ROY............................. 31 11 38 19 / 30 30 10 30 CLAYTON......................... 27 6 33 17 / 40 20 10 20 SANTA ROSA...................... 42 19 42 28 / 10 20 10 30 TUCUMCARI....................... 34 15 40 24 / 10 10 10 30 FORT SUMNER..................... 40 22 41 29 / 10 10 20 30 CLOVIS.......................... 34 17 37 25 / 10 10 20 30 PORTALES........................ 38 20 38 26 / 10 10 20 30 ROSWELL......................... 42 26 45 29 / 10 10 20 30 && .ABQ WATCHES/WARNINGS/ADVISORIES... SNOW ADVISORY FROM 11 AM THIS MORNING TO 5 AM MST SATURDAY FOR NMZ002-NMZ004. WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR NMZ005- NMZ006-NMZ007. && $$ nm AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE COLUMBIA SC 1009 PM EST FRI FEB 17 2006 .SHORT TERM (REST OF TONIGHT)... MADE A FEW QUICK ADJUSTMENTS FOR THE OVERNIGHT PERIOD. SATELLITE SHOWS SOME AREAS OF MOSTLY CLEAR SKIES ACROSS THE AREA THIS EVENING...BUT ADDITIONAL CLOUDINESS UPSTREAM HEADING EWD. ALSO ADJUST POPS FOR THE OVERNIGHT. CHANCE FOR MEASURABLE PCPN LOOKS RATHER LOW WITH DEEPEST MOISTURE WELL WWD. ALSO MADE SOME SLIGHT ADJUSTMENTS TO T/TDS THIS EVENING THOUGHOUT THE OVERNIGHT. FORECAST BASICALLY LOOKS ON TRACK FROM LATE TONIGHT INTO SATURDAY. PEEKING AT 00Z NAM40...QPF NOT THAT IMPRESSIVE ON SATURDAY...BUT P-TYPE ISSUES REMAIN ACROSS THE NRN PORTION OF THE CWA. MAIN PROBLEM WILL BE LATER SATURDAY AFTERNOON AND EVENING AS COLD AIR SETTLES SLOWLY SWD. && .PREVIOUS DISCUSSION... (ISSUED 218 PM EST FRI FEB 17 2006) SHORT TERM (TONIGHT THROUGH SUNDAY NIGHT)... COLD FRONT IN THE NORTH CAROLINA MOUNTAINS WILL CONTINUE TO PUSH TO THE SOUTHEAST. LIKE RUC/NAM MODELS TIMING OF COLD FRONT IN AREA AROUND 00Z THIS EVENING. ALL MODELS SHOW AT LEAST WEAK OVERRUNNING MOISTURE TONIGHT AND SATURDAY. WITH THICKENING AND LOWERING CLOUDS OVERNIGHT...WILL INTRODUCE A 30 PERCENT CHANCE OF LIGHT RAIN AFTER MIDNIGHT. THEN WITH THE CONTINUED WEAK WAA AT 850 MB SATURDAY AND GOOD ISENTROPIC LIFT...WILL INCREASE POPS TO LIKELY CATEGORY. TO COMPLICATE MATTERS SATURDAY...THERE WILL BE GOOD CAA BELOW 850 MB AT NEAR 925 MB WHERE BOTH NAM AND GFS ARE SHOWING TEMPS -1C OVER A LAYER OF ABOUT 2-3 THOUSAND OVER THE NORTHERN COUNTIES. LOW TEMPERATURES TONIGHT SHOULD BE THE HIGH TEMPERATURES FOR SATURDAY WITH TEMPERATURES FALLING IN THE AFTERNOON. WILL DROP TEMPS NORTHERN COUNTIES INTO UPPER 30S...MAYBE A FEW MID 30S SATURDAY AFTERNOON. WILL GO RAIN LIKELY EVERYWHERE SATURDAY...BUT WILL ALSO INCLUDE A SLIGHT CHANCE OF SLEET IN THE NORTHERN COUNTIES. WILL HOLD ONTO 30 PERCENT CHANCE OF SAME PRECIPITATION CONFIGURATION FOR EARLY SATURDAY NIGHT UNTIL THE COLD FRONT DRIFTS MORE SOUTHWARD AND THE MOISTURE DECREASES. THEN...THE LOW TEMPERATURES WILL BE REACHED NEAR DAYBREAK SUNDAY...AROUND 30 NORTH...LOWER 30S CENTRAL INCLUDING CAE...AND THE MID 30S IN THE SOUTHERN PART OF THE CWA. PRETTY GOOD IN SITU WEDGE FOR SUNDAY AND SUNDAY NIGHT AS GFS INDICATES WITH POSSIBLE WAVE DEVELOPMENT ON FRONT TO THE SOUTH. EVERYBODY IS BRINGING AT LEAST A CHANCE OF PRECIPITATION BACK IN...ESPECIALLY AFTER MIDNIGHT SUNDAY NIGHT. TIMING OF PRECIP AND TEMPERATURES ARE CRITICAL. DECIDED TO NARROW TIMING OF MENTION OF FREEZING RAIN IN NORTHERN COUNTIES UNTIL 09-12Z IN THE GRIDS...JUST RAIN TO THE SOUTH. WILL GO LOWS NEAR 32 NORTHERN COUNTIES AND IN MID 30S ELSEWHERE. LONG TERM (TUESDAY THROUGH FRIDAY)... STILL A LOT OF UNCERTAINTY IN THE EXTENDED. STAYED CLOSE TO HPC GUIDANCE. HIGH PRESSURE WILL CONTINUE TO SLOWLY BUILD FROM THE NORTH WITH QUASI- STATIONARY FRONT DRAPED ACROSS GA AND SC. GRADUALLY DECREASED POPS EACH DAY FROM HIGH CHANCE TUESDAY TO DRY BY LATE FRIDAY AS ANOTHER COLD FRONT APPROACHING FROM THE WEST AN SWEEPING THROUGH THE AREA FRIDAY. TEMPS WELL BELOW NORMAL TUESDAY AND WEDNESDAY AND NEAR TO ABOVE NORMAL THURSDAY AND FRIDAY. AVIATION... COLD FRONT APPROACHING FROM THE WEST. VFR CONDITIONS THIS AFTERNOON AND EVENING WITH SCT-BKN CLOUDS 4-6 THOUSAND FEET. VSBYS 7 MI OR GREATER. FRONT SLIDES SOUTH OF THE AREA AFTER 00Z AND BECOMES STATIONARY. OVERRUNNING MOISTURE TONIGHT WITH CIGS LOWERING TO 2-3 THOUSAND FEET AND PATCHY LIGHT RAIN LOWERING VSBYS TO 4-5 MILES. AFTER 12Z SATURDAY MORNING CIGS LOWER TO NEAR ONE THOUSAND FEET AND VSBYS NEAR 3 MILES IN MORE WIDESPREAD LIGHT RAIN AND FOG. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$ 77 sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE COLUMBIA SC 218 PM EST FRI FEB 17 2006 .SHORT TERM (TONIGHT THROUGH SUNDAY NIGHT)... COLD FRONT IN THE NORTH CAROLINA MOUNTAINS WILL CONTINUE TO PUSH TO THE SOUTHEAST. LIKE RUC/NAM MODELS TIMING OF COLD FRONT IN AREA AROUND 00Z THIS EVENING. ALL MODELS SHOW AT LEAST WEAK OVERRUNNING MOISTURE TONIGHT AND SATURDAY. WITH THICKENING AND LOWERING CLOUDS OVERNIGHT...WILL INTRODUCE A 30 PERCENT CHANCE OF LIGHT RAIN AFTER MIDNIGHT. THEN WITH THE CONTINUED WEAK WAA AT 850 MB SATURDAY AND GOOD ISENTROPIC LIFT...WILL INCREASE POPS TO LIKELY CATEGORY. TO COMPLICATE MATTERS SATURDAY...THERE WILL BE GOOD CAA BELOW 850 MB AT NEAR 925 MB WHERE BOTH NAM AND GFS ARE SHOWING TEMPS -1C OVER A LAYER OF ABOUT 2-3 THOUSAND OVER THE NORTHERN COUNTIES. LOW TEMPERATURES TONIGHT SHOULD BE THE HIGH TEMPERATURES FOR SATURDAY WITH TEMPERATURES FALLING IN THE AFTERNOON. WILL DROP TEMPS NORTHERN COUNTIES INTO UPPER 30S...MAYBE A FEW MID 30S SATURDAY AFTERNOON. WILL GO RAIN LIKELY EVERYWHERE SATURDAY...BUT WILL ALSO INCLUDE A SLIGHT CHANCE OF SLEET IN THE NORTHERN COUNTIES. WILL HOLD ONTO 30 PERCENT CHANCE OF SAME PRECIPITATION CONFIGURATION FOR EARLY SATURDAY NIGHT UNTIL THE COLD FRONT DRIFTS MORE SOUTHWARD AND THE MOISTURE DECREASES. THEN...THE LOW TEMPERATURES WILL BE REACHED NEAR DAYBREAK SUNDAY...AROUND 30 NORTH...LOWER 30S CENTRAL INCLUDING CAE...AND THE MID 30S IN THE SOUTHERN PART OF THE CWA. PRETTY GOOD IN SITU WEDGE FOR SUNDAY AND SUNDAY NIGHT AS GFS INDICATES WITH POSSIBLE WAVE DEVELOPMENT ON FRONT TO THE SOUTH. EVERYBODY IS BRINGING AT LEAST A CHANCE OF PRECIPITATION BACK IN...ESPECIALLY AFTER MIDNIGHT SUNDAY NIGHT. TIMING OF PRECIP AND TEMPERATURES ARE CRITICAL. DECIDED TO NARROW TIMING OF MENTION OF FREEZING RAIN IN NORTHERN COUNTIES UNTIL 09-12Z IN THE GRIDS...JUST RAIN TO THE SOUTH. WILL GO LOWS NEAR 32 NORTHERN COUNTIES AND IN MID 30S ELSEWHERE. && .LONG TERM (TUESDAY THROUGH FRIDAY)... STILL A LOT OF UNCERTAINTY IN THE EXTENDED. STAYED CLOSE TO HPC GUIDANCE. HIGH PRESSURE WILL CONTINUE TO SLOWLY BUILD FROM THE NORTH WITH QUASI- STATIONARY FRONT DRAPED ACROSS GA AND SC. GRADUALLY DECREASED POPS EACH DAY FROM HIGH CHANCE TUESDAY TO DRY BY LATE FRIDAY AS ANOTHER COLD FRONT APPROACHING FROM THE WEST AN SWEEPING THROUGH THE AREA FRIDAY. TEMPS WELL BELOW NORMAL TUESDAY AND WEDNESDAY AND NEAR TO ABOVE NORMAL THURSDAY AND FRIDAY. && .AVIATION... COLD FRONT APPROACHING FROM THE WEST. VFR CONDITIONS THIS AFTERNOON AND EVENING WITH SCT-BKN CLOUDS 4-6 THOUSAND FEET. VSBYS 7 MI OR GREATER. FRONT SLIDES SOUTH OF THE AREA AFTER 00Z AND BECOMES STATIONARY. OVERRUNNING MOISTURE TONIGHT WITH CIGS LOWERING TO 2-3 THOUSAND FEET AND PATCHY LIGHT RAIN LOWERING VSBYS TO 4-5 MILES. AFTER 12Z SATURDAY MORNING CIGS LOWER TO NEAR ONE THOUSAND FEET AND VSBYS NEAR 3 MILES IN MORE WIDESPREAD LIGHT RAIN AND FOG. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$ 22/07 sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MORRISTOWN TN 920 PM EST FRI FEB 17 2006 .DISCUSSION...CURRENT IR SATELLITE BEGINNING TO SHOW CLOUDS THICKENING OVER MIDDLE TENNESSEE. TEMPERATURES HAVE DROPPED INTO THE LOWER 30S TO LOWER 40S ACROSS THE REGION WITH THE COLDEST TEMPERATURES ACROSS THE NORTHERN PLATEAU AND SOUTHWEST VIRGINIA. PATCHY LIGHT PRECIPITATION HAD DEVELOPED ACROSS EASTERN OKLAHOMA AND SHOULD INCREASE THERE AND OVER ARKANSAS THROUGH LATE EVENING AND THEN SPREAD OR DEVELOP EAST INTO TENNESSEE AROUND MIDNIGHT. LATEST RUC GUIDANCE THROUGH 18/12Z SHOWS SIGNIFICANT PRECIPITATION SPREADING INTO EAST TN AROUND 12Z WHICH IS A LITTLE SLOWER THAN CURRENTLY IN THE GRIDS. ADJUSTED GRIDS TO START POPS A COUPLE HOURS LATER. 18Z GFS STILL INDICATING SNOW ACCUMULATION WILL BE LATE TONIGHT AS TEMPERATURES FALL VERY SLOWLY AS CLOUDS THICKEN AND LOWER. WOULD EXPECT ANY ACCUMULATIONS TONIGHT WILL BE ONLY ON GRASSY SURFACES AND EXPOSED METAL OBJECTS DUE TO WARM GROUND. AM A LITTLE PESSIMISTIC AMOUNTS WILL BE HIGH ENOUGH FOR ADVISORY SOUTHERN AND CENTRAL VALLEYS BUT SINCE PRECIPITATION IS STILL SEVERAL HOURS AWAY WILL LET NEXT SHIFT MAKE ANY AMOUNT CHANGES. WILL UPDATE TO ADJUST NIGHT TIME WORDING. UPDATING TEMPERATURE AND DEW POINT GRIDS AS WELL TO REFLECT CURRENT TRENDS. WSW WILL BE REFRESHED AROUND 11PM. && .MRX WATCHES/WARNINGS/ADVISORIES... NC...WINTER WEATHER ADVISORY FROM 4 AM SATURDAY TO 4 PM SATURDAY FOR THE FOLLOWING ZONES: CHEROKEE...AND CLAY. TN...SNOW ADVISORY FROM 4 AM SATURDAY TO 4 PM SATURDAY FOR THE FOLLOWING ZONES: CAMPBELL...CLAIBORNE...HANCOCK...HAWKINS... MORGAN...NORTHWEST CARTER...NORTHWEST GREENE...SCOTT TN... SULLIVAN...AND WASHINGTON TN. WINTER STORM WARNING FROM 4 AM SATURDAY TO 4 PM SATURDAY FOR THE FOLLOWING ZONES: JOHNSON...SOUTHEAST CARTER...SOUTHEAST...GREENE...AND UNICOI. WINTER WEATHER ADVISORY FROM 4 AM SATURDAY TO 4 PM SATURDAY FOR THE FOLLOWING ZONES: ANDERSON...BLEDSOE...BLOUNT SMOKY MOUNTAINS...BRADLEY...COCKE SMOKY MOUNTAINS...EAST POLK... GRAINGER...HAMBLEN...HAMILTON...JEFFERSON...KNOX...LOUDON... MARION...MCMINN...MEIGS...NW BLOUNT...NORTH SEVIER... NORTHWEST COCKE...NORTHWEST MONROE...RHEA...ROANE... SEQUATCHIE...SEVIER SMOKY MOUNTAINS...SOUTHEAST MONROE... UNION...AND WEST POLK. VA...WINTER STORM WARNING FROM 4 AM SATURDAY TO 4 PM SATURDAY FOR THE FOLLOWING ZONES: LEE...RUSSELL...SCOTT...WASHINGTON...AND WISE. && $$ TD tn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL 922 AM CST SAT FEB 18 2006 .DISCUSSION FOR MORNING UPDATE... 922 AM CST HAVE EXTENDED WIND CHILL ADVISORY A FEW HOURS THOUGH NOON CST. ACARS SOUNDINGS OUT OF KRFD AND KORD THIS MORNING SHOWING INVERSION RIGHT AROUND 950 HPA...WITH TEMPS AROUND A FRIGID -25 C AT THAT LEVEL. RUC/NAM/GFS ALL POINT TOWARD TEMPS HAVING A TOUGH TIME CLIMBING DESPITE PLENTIFUL SUNSHINE TODAY...WITH 950 HPA TEMPS HOLDING AROUND -25 NORTH AND AROUND -20 SOUTHEAST THROUGH EARLY AFTERNOON. THEREFORE HAVE LOWERED MAX TEMPS A FEW DEGREES ESPECIALLY NORTHWEST WHERE STILL HOVERING AROUND -8 F. WIND CHILLS STILL AROUND -25 F ACROSS ADVISORY AREA...AND IN KEEPING WITH UPDATED TEMP FORECAST HAVE EXTENDED WIND CHILL ADVISORY THROUGH NOON CST. ALSO...DESPITE VERY SHORT FETCH...ARCTIC AIR RESULTING IN SNOW SHOWERS OVER EXTREME NORTHEAST LAKE AND NORTHERN PORTER COUNTIES IN IND. HAVE INCREASED SNOW FALL GRIDS TO AROUND 1/2 INCH NORTHERN PORTER CO. RATZER && .DISCUSSION FOR MORNING ZONES/GRIDS... 230 AM CST WIND CHILLS DOWN IN -20 TO -30 RANGE NORTH OF I-80 AS ANTICIPATED. WILL KEEP ADVISORY GOING THRU 9AM THIS MORNING...TEMPS WILL SLOWLY MODERATE THIS MORNING WHILE WIND SPEEDS SLACK OFF WITH ADVANCING HIGH PRESSURE INTO MS VLY. H8 TEMPS AT THEIR LOWEST NOW WITH SOME COMPRESSION WARMING TODAY ABOVE -20. AC/CI SHIELD SLIPPING S AND E TODAY SHUD OPEN UP SKY TO PLENTIFUL SUNSHINE WITH STRONG SUBSIDENCE. HOWEVER EVEN WITH THIS GOING FOR IT...TEMPS NOT LIKELY TO SEE DOUBLE DIGITS IN THE NORTH...ESP RFD AREA WHERE LIGHT SNOW COVER LIKELY TO STILL BE THERE. CLEAR SKIES OVERNIGHT WILL RADIATE HEAT QUICKLY WITH SUBZERO NUMBERS TO RETURN. HOWEVER WINDS SLACKING UNDER HIGH PRESSURE SHUD KEEP WIND CHILLS ABOVE ADVISORY CRITERIA...ALTHO FLIRTING CLOSELY FAR NORTHWEST AROUND RFD TONIGHT. THIS WILL NEED GUARDING TODAY. WINDS BACKING TO LGT SW BY SUN MRNG WITH CONSIDERABLE DAYTIME SUNSHINE TO WARM TEMPS INTO 20S. ANOTHER JET STREAK PASSING BY SUNDAY EVENING WILL BRUSH THE MIDWEST WITH ANOTHER BAND OF AC/CI THRU SUNDAY NIGHT SUPPORTING SOME WEAK MID LVL TROFING. AFTER THIS THE UPPER PATTERN TURNS A LITTLE MORE SW WITH WAA CI HANGING OVER THE REGION THRU THE REST OF THE WEEK. THIS IS ALRIGHT SINCE THIS MEANS TEMPS WILL BE REBOUNDING BACK ABOVE NORMALS BY MIDWEEK. THE NEXT FRONTAL SYSTEM DOESNT MAKE A PASS UNTIL THURSDAY EVENING AND DOESNT COME CLOSE TO THE IMPACT OF THIS LAST EVENT. AM LEAVING IT DRY FOR NOW WITH THIS FRONT...BUT SOME RAIN OR SNOW COULD POSSIBLY SNEAK INTO THE FORECAST BY THAT TIME WITH ANOTHER MASSIVE HIGH PRESSURE RIDGE MOVING IN FOR NEXT WEEKEND. && .AVIATION... 12Z TAFS...QUIET WEATHER EXPECTED THRU THE PERIOD. LAKE EFFECT CLOUDS/SNOW SHOWERS JUST EAST OF GYY. OTHERWISE MID/HIGH LEVEL CLOUDS PUSHING SOUTH WITH SKC EXPECTED THRU SUNDAY MORNING AS STRONG ARCTIC HIGH PRESSURE MOVES ACROSS THE AREA. NW WINDS 10-15 KTS WITH A FEW HIGHER GUSTS THIS MORNING WILL GRADUALLY DIMINISH DURING THE AFTERNOON AND BECOME WESTERLY UNDER 10KTS THIS EVENING. && .LOT WATCHES/WARNINGS/ADVISORIES... .IL...WIND CHILL ADVISORY N OF I-80 THRU MID MRNG TODAY. .IN...WIND CHILL ADVISORY LAKE CNTY THRU MID MRNG TODAY. .LM...SMALL CRAFT ADVISORY IL NEARSHORE THRU 10 AM CST. SMALL CRAFT ADVISORY IN NEARSHORE THRU SUNDAY MORNING. && $$ il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 500 AM EST SAT FEB 18 2006 .DISCUSSION... MAIN FCST CONCERNS ARE LES/WIND TRENDS ALONG WITH WIND CHILLS. WV IMAGERY...00Z RAOBS AND RUC ANALYSIS INDICATED A MID/UPR LVL TROF NE OF LK SUPERIOR LEAVING CONFLUENT WRLY FLOW FROM THE NRN PLAINS TO THE WRN LAKES. STRONG QVECTOR DIV WAS TAKING OVER IN THE WAKE OF THE TROF WITH FALLING INVERSION HGTS LIMITING DEPTH OF THE LES CONVECTION AS IR IMAGERY SHOWED SHRINKING AREA OF COLDER CLOUD TOPS. DEEPER LES VCNTY KERY WITH CONVERGENT SNOWBANDS HAD DIMINISHED TO MORE WIDELY SPACED MULTIPLE WIND PARALLEL BANDS. AT THE SFC...BREEZY WNW WINDS PREVAILED ACRS UPR MI BTWN 1048 MB HIGH PRES OVER IA/NE AND LAKE INDUCED TROF OVER ERN LK SUPERIOR. AS AREA OF CAA AND STRONG 255K-260K ISENTROPIC DESCENT MOVED OFF TO THE EAST...WINDS HAVE DIMINISHED WITH MAINLY 15-25 MPH WINDS OVER THE KEWEENAW AND TO 5 TO 15 MPH OVER MUCH OF INTERIOR CENTRAL UPR MI. HOWEVER...WITH TEMPERATURES IN THE -10 TO -15 RANGE...WIND CHILL VALUES RANGED FROM AROUND -25 TO -43. TODAY...EVEN THOUGH WINDS AND LES INTENSITY HAVE DIMINISHED OVER THE NORTHWEST...EXPECT THAT WITH SMALL SNOWFLAKES IN VERY COLD AIRMASS OVER THE WEST...VSBYS WILL REMAIN POOR. UNFAVORABLE SNOWFLAKE GROWTH AND LOWER INVERSION HGTS TO 4K-5K FT SHOULD ALSO LIMIT ACCUMULATIONS TO 2-5 INCHES DESPITE 850 MB TEMPS AROUND -25C. MDLS ALSO SUGGEST THAT WINDS SHOULD REMAIN MAINLY IN THE 15 TO 25 MPH RANGE WITH SOME 30 MPH GUSTS CLOSER TO THE LAKE SHORE AND DURING THE AFTERNOON WITH DIURNAL HEATING AND GREATER MIXING. SO...LAKE EFFECT SNOW/BLSN ADVY WAS ISSUED IN PLACE OF THE BLIZZARD OR WINTER STORM WARNINGS. OVER THE EAST...THE NAM...WHICH HAS SHOWN DECENT DEPICTION OF LOW LVL WIND FIELDS...SUGGESTS THAT THE 950 MB CONVERGENCE INTO THE NE CWA WILL SHIFT QUICKLY TO THE EAST AS WINDS BACK THIS MORNING. RESULTING 280-290 FLOW BY MIDDAY MAY STILL PUSH SOME LES BANDS INTO LOCATIONS NEAR THE SHORELINE FROM GRAND MARAIS EASTWARD. EVEN WITH BETTER FETCH THAN THE WEST...SHIFTING WINDS/BANDS AND UNFAVORABLE SNOWFLAKE GROWTH PRFL SHOULD LIMIT ADDITIONAL ACCUMULATIONS TO 2-5 INCHES. MID FEBRUARY SUNSHINE WILL BOOST TEMPERATURES BY MIDDAY INTO THE SINGLE DIGITS SO THAT WIND CHILL VALUES WILL MOVE BACK INTO THE ZERO TO -20 RANGE. TONIGHT...WRLY WINDS WILL KEEP LES CONFINED TO THE KEWEENAW WITH ONLY A CHANCE OF ANY SHSN ALONG THE SHORELINE FROM GRAND MARAIS TO TO THE EAST. THE LES/BLSN ADVY CONTINUES AS FAIRLY TIGHT GRADIENT KEEPS WINDS IN THE 15-30 MPH RANGE. AS WAA GETS UNDERWAY WITH THE DEPARTING COLD POOL...MDLS SUGGEST INVERSION HGTS WILL CONTINUE TO FALL AOB 3K FT. SO...EVEN THOUGH THERMAL PROFILE MAY BE A BIT MORE FAVORABLE FOR SNOWFLAKE GROWTH AND MODEST LOW LVL CONV FOCUSES INTO THE NRN KEWEENAW...ADDITIONAL SNOWFALL AMOUNTS SHOULD REMAIN IN THE LOWER ADVY RANGE(1-5 INCHES). WIND CHILL VALUES WILL ALSO FALL THIS EVENING TO VALUES NEAR OR INTO THE ADVY RANGE (BLO -25). HOWEVER...SINCE WINDS MAY BE BLO 10 MPH WITH THE COLDEST AIR TEMPS...CONDITIONS MAY BE MARGINAL FOR AN ADVY. SO...ADDITIONAL WIND CHILL HEADLINES WERE NOT ISSUED WITH THIS PACKAGE. SUNDAY...MDLS SUGGEST NEXT WEAK CLIPPER SHRTWV WILL BRUSH THE WRN LAKES AS IT MOVES THROUGH NRN ONTARIO. EXPECT THAT CBL WINDS MAY BACK A BIT MORE SW THAN MDLS SUGGEST WHICH WOULD PUSH LES BANDS OFFSHORE FROM THE KEWEENAW BY AFTERNOON. SUNDAY NIGHT INTO MON...AS WINDS VEER IN THE WAKE OF THE SHRTWV...MORE FAVORABLE CONVERGENT WRLY FLOW DEVELOPS. ENOUGH INSTABILITY REMAINS WITH 850 MB TEMPS FCST AROUND -16C TO KEEP LIKELY POPS GOING OVER THE NRN KEWEENAW. BY MON WITH WRLY FLOW CONTINUING...MDLS SUGGEST ADDITIONAL SHEARED SHRTWVS MAY MOVE THROUGH THE UPPER LAKES MON THAT WOULD SUPPORT DEEPER MOISTURE AND BETTER LES ENVIRONMENT. && MQT WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL NOON EST TODAY FOR MIZ006-MIZ007. WIND CHILL WARNING UNTIL NOON EST /11 AM CST/ TODAY FOR MIZ002-MIZ004-MIZ005-MIZ009-MIZ010-MIZ011-MIZ012-MIZ013-MIZ084. LAKE EFFECT SNOW AND BLOWING SNOW ADVISORY UNTIL 6 AM EST SUNDAY FOR MIZ001-003. LAKE EFFECT SNOW AND BLOWING SNOW ADVISORY UNTIL NOON EST TODAY FOR MIZ002. WIND CHILL ADVISORY UNTIL NOON EST TODAY FOR MIZ001-MIZ003. WIND CHILL ADVISORY UNTIL NOON EST TODAY FOR MIZ014-MIZ085. && $$ JLB mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 1118 AM EST SAT FEB 18 2006 .SHORT TERM (REST OF TODAY)...UPDATED TO LOWER POPS OVER SRN HALF OF AREA AND ADJUST TEMPS/DEW POINTS PER LATEST OBS. OVERRUNNING PCPN TAKING A LITTLE LONGER TO DEVELOP AND WESTERLY FLOW WILL LIKELY RESULT IN PCPN MAINLY N AND S OF AREA. PCPN WILL TAKE A WHILE TO SATURATE DRY MID AND LOW LAYERS...AND DELAYED BEST CHC UNTIL AFTER 18Z. LATEST ETA12 AND RUC INDICATE VERY LITTLE QPF FOR SRN SECTIONS AND SCALED BACK POPS TO 60 THERE...KEPT 80 OVER N. LATEST FCST SOUNDINGS STILL INDICATE POTENTIAL FOR MIX WITH SLEET OVER NRN HALF OF AREA WITH COLD NOSE AROUND 900 MB. TEMPS WARMED TO AROUND 50 OVE SRN MOST ZONES WITH A FEW HOURS OF SUN THIS MORNING...AND ADJUSTED TEMP GRIDS ACCORDINGLY. EXPECT STEADY TEMPS WITH CLOUDY SKIES EARLY THIS AFTN...THEN FALLING AS PCPN DEVELOPS. && .AVIATION...DELAY OF PRECIP UNTIL THE AFTERNOON AND EVENING HOURS. VFR THROUGH MID AFTERNOON THEN MVFR CONDITIONS BY LATE AFTERNOON AS PRECIP BEGINS TO OVERSPREAD THE AREA. LOCALIZED AREAS OF IFR POSSIBLE THIS EVENING. && .MARINE...LITTLE CHANGES MADE TO CURRENT GRIDS FOR THIS UPDATE. SCA WILL REMAIN IN EFFECT FOR ALL COASTAL WATERS AND THE PAMLICO SOUND TODAY. ALTHOUGH A LULL IN WIND SPEEDS IS OCCURRING THIS MORNING ACROSS MUCH OF THE AREA...MODELS INDICATE STRONG CAA SURGE LATE THIS AFTERNOON INTO THE OVERNIGHT HOURS. WINDS WILL INCREASE OUT OF THE NORTH THIS AFTERNOON WITH SPEEDS 2O TO 25 KT. CURRENT SEAS ARE AROUND 5 FT AT DIAMOND WITH 3 TO 5 FT ELSEWHERE. WAVEWATCH INDICATES AN EASTERLY SWELL DEVELOPING BY LATE AFTERNOON WITH SEAS 4 TO 6 FT MOST AREAS WITH THE EXCEPTION OF THE EXTREME SOUTHERN WATERS WHERE 3 TO 5 FT WILL BE COMMON BY EVENING. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...SMALL CRAFT ADVISORY FOR AMZ135 UNTIL 1 AM SUNDAY. ...SMALL CRAFT ADVISORY FOR AMZ150-152-154 UNTIL 7 PM SUNDAY. ...SMALL CRAFT ADVISORY FOR AMZ156 UNTIL 9 AM SUNDAY. ...SMALL CRAFT ADVISORY FOR AMZ158 UNTIL 7 AM SUNDAY. && $$ JBM/JW nc AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE RALEIGH NC 1109 AM EST SAT FEB 18 2006 .SHORT TERM (REST OF TODAY THROUGH TONIGHT)... MOIST MID-LEVEL FLOW CONTINUES ACROSS CENTRAL NORTH CAROLINA AS COLD AIR CONTINUES TO SEEP SOUTH. IT CERTAINLY HAS BEEN QUITE SOME TIME SINCE THE IR IMAGE HAS SHOWN SUCH COLD AIR FROM THE SURFACE ACROSS THE NORTHERN TIER OF CONUS. FORTUNATELY IN CENTRAL NORTH CAROLINA...TEMPERATURES IN MOST AREAS DURING THE LATE MORNING WERE 40 OR BETTER...EXCEPT IN THE 30S TOWARD THE TRIAD WHERE AREAS OF PRECIPITATION HAD MOVED IN. MORNING GSO SOUNDING WOULD SUPPORT SNOW WITH EVAPORATIVE COOLING...AND THAT IS WHAT HAS TAKEN PLACE THERE DURING THE LATE MORNING HOURS. STRONG TEMPERATURE GRADIENT AT 850MB JUST TO THE NORTH OF THE STATE...WITH TEMPERATURES OVER MUCH OF NORTH CAROLINA AT THAT LEVEL MAINLY AT OR ABOVE 5C. RUC AND NAM SUGGEST COOLING AT 850MB WILL TAKE PLACE OVER CENTRAL NORTH CAROLINA ESPECIALLY AFTER 18Z AS TEMPERATURES AT THAT LEVEL VEER MORE TO THE WEST AND WEST-NORTHWEST. WET-BULB TEMPERATURES AS INDICATED ON MSAS HAVE STRUGGLED TO FALL EXCEPT IN THE IMMEDIATE TRIAD...WITH SOME WARMING ACTUALLY SHOWN OVER THE COASTAL PLAIN AND NEAR THE SOUTH CAROLINA BORDER. A STEADY OR EVEN SLIGHT INCREASE IN LOW- LEVEL THICKNESSES WAS ACTUALLY FORECAST BY THE GFS UNTIL ABOUT 18Z. THIS SHOULD HELP DELAY THE ONSET OF SNOW SOMEWHAT...BUT EVEN WITH THAT...MODEL SOUNDINGS AND PARTIAL THICKNESSES SUPPORT ESSENTIALLY ALL SNOW BY 00Z ACROSS CENTRAL NORTH CAROLINA. BY THE TIME THE AFTERNOON WEARS ON...PASSAGE OF 100KT MID-LEVEL JETLET AND MID-LEVEL VORTICITY SHOWN BETTER AT 700MB THAN 500MB ON THE RUC SUPPORT INCREASING SUBSIDENCE LATE IN THE DAY. THE BEST UPPER DIVERGENCE IS EARLY THIS AFTERNOON...FOLLOWED BY PLUNGING 700MB THETA-E VALUES LATE. OPTED TO INCREASE POPS IN THE NORTHWEST TO CATEGORICAL WHILE DIMINISHING POPS IN THE FAR SOUTHEAST BUT STILL IN THE LIKELY CATEGORY. THERE...QPF MAY BE PRETTY LIGHT. WITH TEMPERATURES ALREADY IN THE MID 30S TOWARD INT AND GSO... ANTICIPATE MINOR ACCUMULATION OF SNOW MAINLY ON GRASSY SURFACES WITH THE LATEST GROUND TEMPERATURES STILL IN THE MID 40S AT HIGH POINT AS OF 1050AM. SHOULD MOSTLY BE LESS THAN AN INCH FROM KHNZ TO KEXX...AND GENERALLY LITTLE OR NO ACCUMULATION SOUTH OF THERE. HIGHS CLOSE TO 50 IN THE FAR SOUTHEAST WITH TEMPERATURES FALLING TO AROUND 40 OR SO EVEN THERE BY DUSK. ANY LIGHT SNOW SHOULD DIMINISH RAPIDLY THIS EVENING AS DRIER AIR MOVES IN QUICKLY. RAISED POPS IN THE EVENING FAR SOUTHEAST FOR EXPECTED LINGERING AREAS OF PRECIPITATION EARLY. THANKS TO ADJACENT OFFICES FOR COLLABORATION THIS MORNING. GRIDDED AND WORDED FORECASTS ALREADY ISSUED. && .PREVIOUS DISCUSSION... (ISSUED 210 AM EST SAT FEB 18 2006) SHORT TERM (TODAY THROUGH MONDAY NIGHT)... ANTECEDENT GROUND CONDITIONS WILL BE VERY WARM...GROUND TEMPS WERE IN THE MID 40S TO LOWER 50S YESTERDAY MORNING BEFORE WE RANG UP ALL THOSE LOWER 70S HIGHS IN THE AFTERNOON. AIR TEMPS WILL REMAIN ABOVE FREEZING...SOOOO...WITHOUT A PRETTY DECENT PRECIP RATE (DISCUSSED BELOW)...WE'RE NOT GOING TO ACCUMULATE ANY SNOW. TODAY...1050 HIGH OVER THE MID WEST WILL BE DOMINATING OUR THERMAL PROFILE WITH ZONAL FLOW ALOFT. NOT AN EASY SCENARIO AS BROAD CORRIDORS OF MIXED PRECIP ARE LIKELY. THE NAM IS HANDLING THE PRECIP BREAKING OUT ACROSS ARKANSAS AND TENNESSEE PRETTY WELL AND WILL LEAN MORE TOWARDS ITS SOLUTION IN THE SHORT TERM. MOST OF OUR LIFT SEEMS TO ORIGINATE IN THE MID LAYERS...WHERE ISENTROPIC LIFT WILL BE STRONGEST FROM 800 TO 750 MB AROUND 15Z IN THE WEST...SHIFTING TO THE EAST BY 18Z THEN VIRTUALLY NON-EXISTENT BY 00Z. MOISTENING THE DRY AIRMASS IN PLACE WILL REQUIRE A SIGNIFICANT PORTION OF OUR LIMITED (.10-.20) QPF. THE NORTHERN HALF OF THE CWFA MAY EXPECT A MIX OF RAIN AND SNOW INITIALLY...BUT ONCE THE THERMAL PROFILE HAS STABILIZED...SNOW WILL BECOME PREDOMINANT BY MID DAY...AND SHOULD BE ENDING AROUND 22Z. NO ACCUMULATION EXPECTED DUE TO THE LIGHT INTENSITY AND WARM ANTECENDENT CONDITIONS. ACROSS THE SOUTH... SOUTHWESTERLY FLOW WILL PRODUCE A WARM NOSE ALOFT...WITH MARGINAL COLD AIR BELOW... EXPECT PREDOMINANT RAIN WHICH WILL BE MIXED AT TIMES WITH SLEET...WITH ANY LINGERING PRECIP THIS EVENING ENDING AS SNOW. DRY TONIGHT AND SUNDAY AS A PORTION OF THE HIGH PINCHES OFF AND THE REALLY COLD AND DRY AIR SETTLES DOWN THE EAST COAST. THE SHORT WAVE SEEN IN YESTERDAYS MODEL RUNS IS STILL ON TRACK TO RACE ACROSS LATE SUNDAY NIGHT INTO MONDAY...BUT MOISTURE ADVECTION WILL BE VERY WEAK AND ISENTROPIC LIMITED IN THE WESTERLY FLOW. ONGOING CHANCE POPS FOR SNOW LOOK OKAY...ALTHOUGH COULD SEE SOME MIXED ACROSS THE FAR SOUTHERN TIER...NOTHING TO GET EXCITED ABOUT GIVEN THE LIGHT AMOUNTS. WILL BE SCALING THE SNOWFALL AMOUNTS IN MY GRIDS BACK TO MATCH MY LOWERED QPF...(0.2" MAX). LONG TERM (TUESDAY THROUGH FRIDAY)... FAST ZONAL FLOW PROJECTED ACROSS CENTRAL NC DURING PERIOD AS NORTHERN STREAM AND SOUTHERN STREAM JUST WEST OF AREA. THIS TYPE OF PATTERN USUALLY MEANS AN UPPER LEVEL WEATHER SYSTEM CROSSING REGION EVERY 36-48 HOURS WITH TEMPS AVERAGING A BIT BELOW NORMAL. CURRENT GRIDS/FORECAST SUPPORTS THIS THINKING WITH A NOMINAL CHANCE OF PRECIP THROUGH PERIOD AND MAX TEMPS 5-8 DEGREES BELOW NORMAL. TEMP PROFILE WILL DETERMINE P-TYPE IN THE MON NIGHT-TUE TIME FRAME AS WELL AS WED INTO THU. CONTINUED SLIGHT TO SMALL CHANCE POPS MON NIGHT THROUGH TUE BUT WENT WITH A MIX MON NIGHT /EARLY TUE ACROSS THE NORTHERN THIRD CWA. KEPT PRECIP MAINLY LIQUID IN THE WED-THU TIME FRAME AS SURFACE WET BULB (PER GFS) REMAIN JUST ABOVE FREEZING. AVIATION... VFR CONDITIONS EXPECTED THROUGH LATE MORNING SATURDAY AS CLOUD BASES GENERALLY REMAIN AOA 5K FT. AN APPROACHING UPPER LEVEL WEATHER SYSTEM WILL CAUSE PRECIP TO DEVELOP ACROSS CENTRAL NC LATE THIS MORNING AND CONTINUE THROUGH MID AFTERNOON THEN DIMINISH BY SUNSET. THE PRECIP MAY BE HEAVY ENOUGH TO SATURATE COLUMN TO GENERATE MVFR CONDITIONS DUE TO CEILINGS. THERE IS THE POTENTIAL FOR POCKETS OF IFR CEILING BUT AGAIN THEY WILL BE ISOLATED. PRECIP EXPECTED TO BE SPOTTY. PRECIP EXPECTED TO START OUT AS A MIX OF RAIN AND SNOW ACROSS THE REGION...THEN GRADUALLY SWITCH TO MAINLY LIGHT SNOW AT THE NORTHERN TERMINALS. DUE TO LIGHT PRECIP INTENSITY...VISIBILITY IN THE PRECIP AREAS SHOULD BE NO WORSE THAN MVFR. RETURN TO VFR CONDITIONS EXPECTED BY 00Z SUN. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...DJF nc AREA FORECAST DISCUSSION...CORRECTED NATIONAL WEATHER SERVICE WAKEFIELD VA 1113 AM EST SAT FEB 18 2006 .SHORT TERM (REST OF TODAY)... LAST FEW RUC MODEL RUNS HAVE DONE A BETTER JOB AT DEPICTING THE LATEST SHORT RANGE RADAR TRENDS. LOW LEVELS HAVE MOISTENED RAPIDLY ACROSS CENTRAL VA AS FRONTOGENETIC BANDS OF SNOW HAVE MOVED IN FROM THE WEST. LATEST RUC SHOWS A POCKET OF STRONG RRQ UPPER JET FORCING (LOW-MID LEVEL FGEN AND QVECTOR CONVERGENCE) COINCIDING WITH THE PRECIP REGION. RAPID MOISTENING OF THE LOW LEVELS IS QUITE NOTEWORTHY CONSIDERING THE WRLY (DOWNSLOPING) LOW LEVEL FLOW AND CONTINUED DRY AIR ADVECTION ON THE SYNOPTIC SCALE (DEVELOPING NRLY ISALLOBARIC COMPONENT). STILL THINK THE DURATION OF PRECIPITATION WILL BE RELATIVELY SHORT-LIVED (2-4 HOURS OF MODERATE/OCCASIONALLY HEAVY SNOW)...AS THE FAVORED RRQ UPPER JET FORCING AND DEEPER MOISTURE SHIFT QUICKLY TO THE EAST. RUC TRENDS CONTINUE TO SUPPORT THE EARLIER NOTION THAT THE BULK OF THE ACTIVITY MAY STAY N OF SOUTHSIDE VA/NRN NC...A BIT CONTRADICTORY TO WHAT WAS NOTED FROM THE GFS/NAM MODEL RUNS YESTERDAY. STILL...GIVEN THE POTENTIAL FOR ACCUMS AROUND 1 INCH... HAVE NEVERTHELESS EXPANDED THE SNOW ADVISORY TO THE VA/NC BORDER. DESPITE THE FACT THAT WE'VE BEEN SO WARM OF LATE (PAVED SURFACE TEMPS ABOVE FREEZING)...A QUICK BURST OF SNOW WOULD MAXIMIZE THE EVAPORATIVE COOLING POTENTIAL NEAR THE SURFACE...ALLOWING TEMPS TO COOL QUICKLY INTO THE LOWER-MID 30S...AND GIVEN THE INTENSITY THEREBY ALLOWING FOR AT LEAST MINOR (UP TO 1") SLUSHY ACCUMS ON THE ROADWAYS. ON GRASSY SURFACES...ANYWHERE FROM 1-3" OF ACCUMULATION IS A GOOD BET...EVEN IN A RELATIVELY SHORT PERIOD OF TIME. F.Y.I...THIS "QUICK BURST" OF SNOW IS REMINISCENT TO THE EVENT LAST JANUARY (2005)...EXCEPT FOR SURFACE TEMPS DURING THE JAN 2005 EVENT WERE IN THE LOWER-MID 20S WHEN THE SNOW BEGAN FALLING. FORTUNATELY...GROUND TEMPS ARE NOT NEARLY AS COLD TODAY...THEREFORE THE IMPACT IN TERMS OF ROADWAY CONDITIONS WILL NOT BE AS SIGNIFICANT. && .PREVIOUS DISCUSSION... (ISSUED 544 AM EST SAT FEB 18 2006) SHORT TERM UPDATE (TODAY)... 06Z MODEL SUITE HAS SHIFTED AXIS OF MID LVL FRONTOGENETIC FORCING A BIT FARTHER NW TO INCLUDE MUCH OF EASTERN VA AND THIS SEEMS TO BE IN LINE WITH LATEST REGIONAL RADAR TRENDS. WILL UPDATE FCST PRODUCTS TO RAISE POPS TO LIKELY AND MENTION LIGHT SNOW ACCUM TO INCLUDE ANOTHER TIER OF COUNTIES TO NW OF CURRENT AREA...WHICH WILL NOW INCLUDE THE RICHMOND METRO. NEW PRODUCTS OUT SHORTLY. PREVIOUS DISCUSSION... (ISSUED 408 AM EST SAT FEB 18 2006) SHORT TERM (TODAY THROUGH SUNDAY)... AREA OF OVERRUNNING PCPN PUSHING EAST ACRS TNVLY ATTM. AS JET STREAK DROPS SE FROM UPR MIDWEST...PCPN WILL SPREAD ACRS SOUTHERN APPALACHIANS IN THE PREDAWN HOURS AND THEN INTO CNTRL/SOUTHERN MID ATLC REGION AFTER DAYBREAK. WILL TAKE A WHILE TO SATURATE LOWER LVLS EAST OF MTNS AND HAVE PUSHED BACK TIMING OF ONSET OF PCPN UNTIL LATE MORN. COLD AIR CONTS TO FEED DOWN EAST OF MTNS BUT RETARDED SOMEWHAT THUS FAR BY THICKENING MID/HIGH LVL CLOUDS. BNDRY LAYER TEMPS STILL RELATIVELY WARM AND EXPECT INITIAL SHOT OF PCPN TO BE RAIN OR RAIN/SNOW MIX. LOW DEW POINTS INDICATE EVAPORATIVE COOLING POTENTIAL AND PCPN SHUD TURN MNLY TO SNOW ONCE PCPN STARTS FALLING A BIT MORE HEAVILY BY MIDDAY OR EARLY AFTN. ACCUM OF SNOW WILL BE DIFFICULT GIVEN THE WARM GROUND BUT ELEVATED AND GRASSY SFCS WHICH RETAIN LESS HEAT MAY BE SUSCEPTIBLE TO SOME MINOR ACCUMS...GENERALLY LESS THAN AN INCH GIVEN THE LIGHT QPF AMOUNTS. PCPN COMES TO AN END AS JET STREAK MOVES OFFSHORE BY LATE AFTN/EARLY EVE. REINFORCING COLD SHOT DROPS THRU TNGT WITH WINDS PICKING BACK UP RESULTING IN WINDS CHILLS IN THE SINGLE DIGITS AND TEENS EARLY SUNDAY MORN. A SUNNY AND VERY COLD START SUNDAY BUT LESSENING WIND AS HIGH PRES BUILDS IN FROM OHVLY. SHUD SEE SOME INCRSG HIGH CLOUDS DUR AFTN AS NEXT SOUTHERN STREAM SYSTEM PUSHES EAST FROM TNVLY. LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)... NEXT SHORT WAVE IN ACTIVE SOUTHERN STREAM BRINGS PCPN CHCS BACK INTO CNRTL/SOUTHERN MID ATLC REGION EARLY THIS FCST PD. LTST MODEL TRENDS SUPRESS PCPN FARTHER SOUTH BUT RELUCTANT TO TOTALLY REMOVE POPS GIVEN THE MODEL DIFFICULTY IN FAST SOUTHERN STREAM FLOW. DID PUSH BACK PCPN TIMING TIL AFTER DAYBREAK MON AND LIMITED TO SLIGHT/LOW CHCS FROM NORTH/SOUTH. PTYPES PROBLEMATIC BUT TEMPERATURE/WET BULB PROFILES SUGGEST MAINLY SNOW AT THE START WITH MIX/CHANGOVER TO RAIN IF ANY PCPN SHOULD OCCUR. LTL CHG MADE AFTER MONDAY FOR NOW GIVEN THE MODEL DIFFICULTY IN HANDLING THE ACTIVE SOUTHERN STREAM. AVIATION... CURRENTLY VFR EARLY THIS MRNG WITH MID TO HIGH CLOUDS ACRS THE AREA. OVERALL CONDS WILL BEGIN TO DETERIORATE LATER THIS MRNG...WITH MVFR VSBY/CIGS POSBL LATE THIS MRNG THRU MID AFTN FOR RAIN IN NC...RAIN/SNOW ELSEWHERE. BECOMES VFR ALL AREAS BY LATE AFTN OR ERLY EVENG AS SKIES CLEAR FROM NW TO SE. WINDS WILL REMAIN GUSTY FROM NNE OVERNGT AT ORF. MARINE... STILL SEEING RESIDUAL SMALL CRAFT ON CTSL WTRS RIGHT NOW...ALTHOUGH EXPECT THIS TO DECREASE OVER NXT FEW HRS. WILL START THE CWF WITH SMALL CRAFT ON COAST...LIKELY BEING ABLE TO DROP IT SHORTLY AFTER SUNRISE. HOWEVER...STRG COLD SURGE LATE AFTN/EVNG WILL INCREASE WINDS AGAIN ALLOWING SMALL CRAFT TO RETURN TO ALL ZONES...LASTING OVERNGT INTO SUNDAY MRNG/ERLY AFTN ON COAST. GENERALLY QUIETER CONDS WITH LIGHTER WINDS SUN NGT INTO NXT WEEK AS WEAK HIGH PRES BLDS INTO MID ATLC. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...SNOW ADVISORY FOR MDZ021>025 UNTIL 7 PM SATURDAY. NC...SNOW ADVISORY FOR NCZ012 UNTIL 7 PM SATURDAY. VA...SNOW ADVISORY FOR VAZ048-049-060>071-079-080 UNTIL 4 PM SATURDAY. ...SNOW ADVISORY FOR VAZ072>078-081>100 UNTIL 7 PM SATURDAY. MARINE...SMALL CRAFT ADVISORY FOR ANZ630-631 FROM 4 PM SATURDAY TO 7 AM SUNDAY. ...SMALL CRAFT ADVISORY FOR ANZ632 FROM 6 PM SATURDAY TO 9 AM SUNDAY. ...SMALL CRAFT ADVISORY FOR ANZ633 FROM 8 PM SATURDAY TO 9 AM SUNDAY. ...SMALL CRAFT ADVISORY FOR ANZ650-652-654-656 FROM 6 PM SATURDAY TO NOON SUNDAY. ...SMALL CRAFT ADVISORY FOR ANZ658 FROM 8 PM SATURDAY TO NOON SUNDAY. && $$ SHORT TERM UPDATE...HURLEY SHORT TERM (TONIGHT-TUE)...CULLEN LONG TERM (WED-SAT)...RUSNAK/HURLEY va AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 1113 AM EST SAT FEB 18 2006 .SHORT TERM (REST OF TODAY)... AST FEW RUC MODEL RUNS HAVE DONE A BETTER JOB AT DEPICTING THE LATEST SHORT RANGE RADAR TRENDS. LOW LEVELS HAVE MOISTENED RAPIDLY ACROSS CENTRAL VA AS FRONTOGENETIC BANDS OF SNOW HAVE MOVED IN FROM THE WEST. LATEST RUC SHOWS A POCKET OF STRONG RRQ UPPER JET FORCING (LOW-MID LEVEL FGEN AND QVECTOR CONVERGENCE) COINCIDING WITH THE PRECIP REGION. RAPID MOISTENING OF THE LOW LEVELS IS QUITE NOTEWORTHY CONSIDERING THE WRLY (DOWNSLOPING) LOW LEVEL FLOW AND CONTINUED DRY AIR ADVECTION ON THE SYNOPTIC SCALE (DEVELOPING NRLY ISALLOBARIC COMPONENT). STILL THINK THE DURATION OF PRECIPITATION WILL BE RELATIVELY SHORT-LIVED (2-4 HOURS OF MODERATE/OCCASIONALLY HEAVY SNOW)...AS THE FAVORED RRQ UPPER JET FORCING AND DEEPER MOISTURE SHIFT QUICKLY TO THE EAST. RUC TRENDS CONTINUE TO SUPPORT THE EARLIER NOTION THAT THE BULK OF THE ACTIVITY MAY STAY N OF SOUTHSIDE VA/NRN NC...A BIT CONTRADICTORY TO WHAT WAS NOTED FROM THE GFS/NAM MODEL RUNS YESTERDAY. STILL...GIVEN THE POTENTIAL FOR ACCUMS AROUND 1 INCH... HAVE NEVERTHELESS EXPANDED THE SNOW ADVISORY TO THE VA/NC BORDER. DESPITE THE FACT THAT WE'VE BEEN SO WARM OF LATE (PAVED SURFACE TEMPS ABOVE FREEZING)...A QUICK BURST OF SNOW WOULD MAXIMIZE THE EVAPORATIVE COOLING POTENTIAL NEAR THE SURFACE...ALLOWING TEMPS TO COOL QUICKLY INTO THE LOWER-MID 30S...AND GIVEN THE INTENSITY THEREBY ALLOWING FOR AT LEAST MINOR (UP TO 1") SLUSHY ACCUMS ON THE ROADWAYS. ON GRASSY SURFACES...ANYWHERE FROM 1-3" OF ACCUMULATION IS A GOOD BET...EVEN IN A RELATIVELY SHORT PERIOD OF TIME. F.Y.I...THIS "QUICK BURST" OF SNOW IS REMINISCENT TO THE EVENT LAST JANUARY (2005)...EXCEPT FOR SURFACE TEMPS DURING THE JAN 2005 EVENT WERE IN THE LOWER-MID 20S WHEN THE SNOW BEGAN FALLING. FORTUNATELY...GROUND TEMPS ARE NOT NEARLY AS COLD TODAY...THEREFORE THE IMPACT IN TERMS OF ROADWAY CONDITIONS WILL NOT BE AS SIGNIFICANT. && .PREVIOUS DISCUSSION... (ISSUED 544 AM EST SAT FEB 18 2006) SHORT TERM UPDATE (TODAY)... 06Z MODEL SUITE HAS SHIFTED AXIS OF MID LVL FRONTOGENETIC FORCING A BIT FARTHER NW TO INCLUDE MUCH OF EASTERN VA AND THIS SEEMS TO BE IN LINE WITH LATEST REGIONAL RADAR TRENDS. WILL UPDATE FCST PRODUCTS TO RAISE POPS TO LIKELY AND MENTION LIGHT SNOW ACCUM TO INCLUDE ANOTHER TIER OF COUNTIES TO NW OF CURRENT AREA...WHICH WILL NOW INCLUDE THE RICHMOND METRO. NEW PRODUCTS OUT SHORTLY. PREVIOUS DISCUSSION... (ISSUED 408 AM EST SAT FEB 18 2006) SHORT TERM (TODAY THROUGH SUNDAY)... AREA OF OVERRUNNING PCPN PUSHING EAST ACRS TNVLY ATTM. AS JET STREAK DROPS SE FROM UPR MIDWEST...PCPN WILL SPREAD ACRS SOUTHERN APPALACHIANS IN THE PREDAWN HOURS AND THEN INTO CNTRL/SOUTHERN MID ATLC REGION AFTER DAYBREAK. WILL TAKE A WHILE TO SATURATE LOWER LVLS EAST OF MTNS AND HAVE PUSHED BACK TIMING OF ONSET OF PCPN UNTIL LATE MORN. COLD AIR CONTS TO FEED DOWN EAST OF MTNS BUT RETARDED SOMEWHAT THUS FAR BY THICKENING MID/HIGH LVL CLOUDS. BNDRY LAYER TEMPS STILL RELATIVELY WARM AND EXPECT INITIAL SHOT OF PCPN TO BE RAIN OR RAIN/SNOW MIX. LOW DEW POINTS INDICATE EVAPORATIVE COOLING POTENTIAL AND PCPN SHUD TURN MNLY TO SNOW ONCE PCPN STARTS FALLING A BIT MORE HEAVILY BY MIDDAY OR EARLY AFTN. ACCUM OF SNOW WILL BE DIFFICULT GIVEN THE WARM GROUND BUT ELEVATED AND GRASSY SFCS WHICH RETAIN LESS HEAT MAY BE SUSCEPTIBLE TO SOME MINOR ACCUMS...GENERALLY LESS THAN AN INCH GIVEN THE LIGHT QPF AMOUNTS. PCPN COMES TO AN END AS JET STREAK MOVES OFFSHORE BY LATE AFTN/EARLY EVE. REINFORCING COLD SHOT DROPS THRU TNGT WITH WINDS PICKING BACK UP RESULTING IN WINDS CHILLS IN THE SINGLE DIGITS AND TEENS EARLY SUNDAY MORN. A SUNNY AND VERY COLD START SUNDAY BUT LESSENING WIND AS HIGH PRES BUILDS IN FROM OHVLY. SHUD SEE SOME INCRSG HIGH CLOUDS DUR AFTN AS NEXT SOUTHERN STREAM SYSTEM PUSHES EAST FROM TNVLY. LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)... NEXT SHORT WAVE IN ACTIVE SOUTHERN STREAM BRINGS PCPN CHCS BACK INTO CNRTL/SOUTHERN MID ATLC REGION EARLY THIS FCST PD. LTST MODEL TRENDS SUPRESS PCPN FARTHER SOUTH BUT RELUCTANT TO TOTALLY REMOVE POPS GIVEN THE MODEL DIFFICULTY IN FAST SOUTHERN STREAM FLOW. DID PUSH BACK PCPN TIMING TIL AFTER DAYBREAK MON AND LIMITED TO SLIGHT/LOW CHCS FROM NORTH/SOUTH. PTYPES PROBLEMATIC BUT TEMPERATURE/WET BULB PROFILES SUGGEST MAINLY SNOW AT THE START WITH MIX/CHANGOVER TO RAIN IF ANY PCPN SHOULD OCCUR. LTL CHG MADE AFTER MONDAY FOR NOW GIVEN THE MODEL DIFFICULTY IN HANDLING THE ACTIVE SOUTHERN STREAM. AVIATION... CURRENTLY VFR EARLY THIS MRNG WITH MID TO HIGH CLOUDS ACRS THE AREA. OVERALL CONDS WILL BEGIN TO DETERIORATE LATER THIS MRNG...WITH MVFR VSBY/CIGS POSBL LATE THIS MRNG THRU MID AFTN FOR RAIN IN NC...RAIN/SNOW ELSEWHERE. BECOMES VFR ALL AREAS BY LATE AFTN OR ERLY EVENG AS SKIES CLEAR FROM NW TO SE. WINDS WILL REMAIN GUSTY FROM NNE OVERNGT AT ORF. MARINE... STILL SEEING RESIDUAL SMALL CRAFT ON CTSL WTRS RIGHT NOW...ALTHOUGH EXPECT THIS TO DECREASE OVER NXT FEW HRS. WILL START THE CWF WITH SMALL CRAFT ON COAST...LIKELY BEING ABLE TO DROP IT SHORTLY AFTER SUNRISE. HOWEVER...STRG COLD SURGE LATE AFTN/EVNG WILL INCREASE WINDS AGAIN ALLOWING SMALL CRAFT TO RETURN TO ALL ZONES...LASTING OVERNGT INTO SUNDAY MRNG/ERLY AFTN ON COAST. GENERALLY QUIETER CONDS WITH LIGHTER WINDS SUN NGT INTO NXT WEEK AS WEAK HIGH PRES BLDS INTO MID ATLC. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...SNOW ADVISORY FOR MDZ021>025 UNTIL 7 PM SATURDAY. NC...SNOW ADVISORY FOR NCZ012 UNTIL 7 PM SATURDAY. VA...SNOW ADVISORY FOR VAZ048-049-060>071-079-080 UNTIL 4 PM SATURDAY. ...SNOW ADVISORY FOR VAZ072>078-081>100 UNTIL 7 PM SATURDAY. MARINE...SMALL CRAFT ADVISORY FOR ANZ630-631 FROM 4 PM SATURDAY TO 7 AM SUNDAY. ...SMALL CRAFT ADVISORY FOR ANZ632 FROM 6 PM SATURDAY TO 9 AM SUNDAY. ...SMALL CRAFT ADVISORY FOR ANZ633 FROM 8 PM SATURDAY TO 9 AM SUNDAY. ...SMALL CRAFT ADVISORY FOR ANZ650-652-654-656 FROM 6 PM SATURDAY TO NOON SUNDAY. ...SMALL CRAFT ADVISORY FOR ANZ658 FROM 8 PM SATURDAY TO NOON SUNDAY. && $$ SHORT TERM UPDATE...HURLEY SHORT TERM (TONIGHT-TUE)...CULLEN LONG TERM (WED-SAT)...RUSNAK/HURLEY va AREA FORECAST DISCUSSION...SHORT TERM UPDATE NATIONAL WEATHER SERVICE WAKEFIELD VA 1110 AM EST SAT FEB 18 2006 .SHORT TERM UPDATE (TODAY)... PAST FEW RUC MODEL RUNS HAVE DONE A BETTER JOB AT DEPICTING THE LATEST SHORT RANGE RADAR TRENDS. LOW LEVELS HAVE MOISTENED RAPIDLY ACROSS CENTRAL VA AS FRONTOGENETIC BANDS OF SNOW HAVE MOVED IN FROM THE WEST. LATEST RUC SHOWS A POCKET OF STRONG RRQ UPPER JET FORCING (LOW-MID LEVEL FGEN AND QVECTOR CONVERGENCE) COINCIDING WITH THE PRECIP REGION. RAPID MOISTENING OF THE LOW LEVELS IS QUITE NOTEWORTHY CONSIDERING THE WRLY (DOWNSLOPING) LOW LEVEL FLOW AND CONTINUED DRY AIR ADVECTION ON THE SYNOPTIC SCALE (DEVELOPING NRLY ISALLOBARIC COMPONENT). STILL THINK THE DURATION OF PRECIPITATION WILL BE RELATIVELY SHORT-LIVED (2-4 HOURS OF MODERATE/OCCASIONALLY HEAVY SNOW)...AS THE FAVORED RRQ UPPER JET FORCING AND DEEPER MOISTURE SHIFT QUICKLY TO THE EAST. RUC TRENDS CONTINUE TO SUPPORT THE EARLIER NOTION THAT THE BULK OF THE ACTIVITY MAY STAY N OF SOUTHSIDE VA/NRN NC...A BIT CONTRADICTORY TO WHAT WAS NOTED FROM THE GFS/NAM MODEL RUNS YESTERDAY. STILL...GIVEN THE POTENTIAL FOR ACCUMS AROUND 1 INCH... HAVE NEVERTHELESS EXPANDED THE SNOW ADVISORY TO THE VA/NC BORDER. DESPITE THE FACT THAT WE'VE BEEN SO WARM OF LATE (PAVED SURFACE TEMPS ABOVE FREEZING)...A QUICK BURST OF SNOW WOULD MAXIMIZE THE EVAPORATIVE COOLING POTENTIAL NEAR THE SURFACE...ALLOWING TEMPS TO COOL QUICKLY INTO THE LOWER-MID 30S...AND GIVEN THE INTENSITY THEREBY ALLOWING FOR AT LEAST MINOR (UP TO 1") SLUSHY ACCUMS ON THE ROADWAYS. ON GRASSY SURFACES...ANYWHERE FROM 1-3" OF ACCUMULATION IS A GOOD BET...EVEN IN A RELATIVELY SHORT PERIOD OF TIME. F.Y.I...THIS "QUICK BURST" OF SNOW IS REMINISCENT TO THE EVENT LAST JANUARY (2005)...EXCEPT FOR SURFACE TEMPS DURING THE JAN 2005 EVENT WERE IN THE LOWER-MID 20S WHEN THE SNOW BEGAN FALLING. FORTUNATELY...GROUND TEMPS ARE NOT NEARLY AS COLD TODAY...THEREFORE THE IMPACT IN TERMS OF ROADWAY CONDITIONS WILL NOT BE AS SIGNIFICANT. && .PREVIOUS DISCUSSION... (ISSUED 408 AM EST SAT FEB 18 2006) SHORT TERM (TODAY THROUGH SUNDAY)... AREA OF OVERRUNNING PCPN PUSHING EAST ACRS TNVLY ATTM. AS JET STREAK DROPS SE FROM UPR MIDWEST...PCPN WILL SPREAD ACRS SOUTHERN APPALACHIANS IN THE PREDAWN HOURS AND THEN INTO CNTRL/SOUTHERN MID ATLC REGION AFTER DAYBREAK. WILL TAKE A WHILE TO SATURATE LOWER LVLS EAST OF MTNS AND HAVE PUSHED BACK TIMING OF ONSET OF PCPN UNTIL LATE MORN. COLD AIR CONTS TO FEED DOWN EAST OF MTNS BUT RETARDED SOMEWHAT THUS FAR BY THICKENING MID/HIGH LVL CLOUDS. BNDRY LAYER TEMPS STILL RELATIVELY WARM AND EXPECT INITIAL SHOT OF PCPN TO BE RAIN OR RAIN/SNOW MIX. LOW DEW POINTS INDICATE EVAPORATIVE COOLING POTENTIAL AND PCPN SHUD TURN MNLY TO SNOW ONCE PCPN STARTS FALLING A BIT MORE HEAVILY BY MIDDAY OR EARLY AFTN. ACCUM OF SNOW WILL BE DIFFICULT GIVEN THE WARM GROUND BUT ELEVATED AND GRASSY SFCS WHICH RETAIN LESS HEAT MAY BE SUSCEPTIBLE TO SOME MINOR ACCUMS...GENERALLY LESS THAN AN INCH GIVEN THE LIGHT QPF AMOUNTS. PCPN COMES TO AN END AS JET STREAK MOVES OFFSHORE BY LATE AFTN/EARLY EVE. REINFORCING COLD SHOT DROPS THRU TNGT WITH WINDS PICKING BACK UP RESULTING IN WINDS CHILLS IN THE SINGLE DIGITS AND TEENS EARLY SUNDAY MORN. A SUNNY AND VERY COLD START SUNDAY BUT LESSENING WIND AS HIGH PRES BUILDS IN FROM OHVLY. SHUD SEE SOME INCRSG HIGH CLOUDS DUR AFTN AS NEXT SOUTHERN STREAM SYSTEM PUSHES EAST FROM TNVLY. LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)... NEXT SHORT WAVE IN ACTIVE SOUTHERN STREAM BRINGS PCPN CHCS BACK INTO CNRTL/SOUTHERN MID ATLC REGION EARLY THIS FCST PD. LTST MODEL TRENDS SUPRESS PCPN FARTHER SOUTH BUT RELUCTANT TO TOTALLY REMOVE POPS GIVEN THE MODEL DIFFICULTY IN FAST SOUTHERN STREAM FLOW. DID PUSH BACK PCPN TIMING TIL AFTER DAYBREAK MON AND LIMITED TO SLIGHT/LOW CHCS FROM NORTH/SOUTH. PTYPES PROBLEMATIC BUT TEMPERATURE/WET BULB PROFILES SUGGEST MAINLY SNOW AT THE START WITH MIX/CHANGOVER TO RAIN IF ANY PCPN SHOULD OCCUR. LTL CHG MADE AFTER MONDAY FOR NOW GIVEN THE MODEL DIFFICULTY IN HANDLING THE ACTIVE SOUTHERN STREAM. AVIATION... CURRENTLY VFR EARLY THIS MRNG WITH MID TO HIGH CLOUDS ACRS THE AREA. OVERALL CONDS WILL BEGIN TO DETERIORATE LATER THIS MRNG...WITH MVFR VSBY/CIGS POSBL LATE THIS MRNG THRU MID AFTN FOR RAIN IN NC...RAIN/SNOW ELSEWHERE. BECOMES VFR ALL AREAS BY LATE AFTN OR ERLY EVENG AS SKIES CLEAR FROM NW TO SE. WINDS WILL REMAIN GUSTY FROM NNE OVERNGT AT ORF. MARINE... STILL SEEING RESIDUAL SMALL CRAFT ON CTSL WTRS RIGHT NOW...ALTHOUGH EXPECT THIS TO DECREASE OVER NXT FEW HRS. WILL START THE CWF WITH SMALL CRAFT ON COAST...LIKELY BEING ABLE TO DROP IT SHORTLY AFTER SUNRISE. HOWEVER...STRG COLD SURGE LATE AFTN/EVNG WILL INCREASE WINDS AGAIN ALLOWING SMALL CRAFT TO RETURN TO ALL ZONES...LASTING OVERNGT INTO SUNDAY MRNG/ERLY AFTN ON COAST. GENERALLY QUIETER CONDS WITH LIGHTER WINDS SUN NGT INTO NXT WEEK AS WEAK HIGH PRES BLDS INTO MID ATLC. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY FOR ANZ658 UNTIL 10 AM SATURDAY. ...SMALL CRAFT ADVISORY FOR ANZ658 FROM 8 PM SATURDAY TO NOON SUNDAY. ...SMALL CRAFT ADVISORY FOR ANZ630-631 FROM 4 PM SATURDAY TO 7 AM SUNDAY. ...SMALL CRAFT ADVISORY FOR ANZ632 FROM 6 PM SATURDAY TO 9 AM SUNDAY. ...SMALL CRAFT ADVISORY FOR ANZ650-652-654-656 FROM 6 PM SATURDAY TO NOON SUNDAY. ...SMALL CRAFT ADVISORY FOR ANZ633 FROM 8 PM SATURDAY TO 9 AM SUNDAY. && $$ SHORT TERM UPDATE...CULLEN va AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 216 PM MST SAT FEB 18 2006 UPDATED TO REMOVE HEADLINES. SIGNIFICANT SNOWFALL HAS ENDED AND WINTER HIGHLIGHTS HAVE EXPIRED. .SHORT TERM (TONIGHT THROUGH MONDAY)...NOT THE MOST STRAIGHT FORWARD SITUATION PRESENTED IN THE SHORT TERM. A DEEP TROUGH OVER THE WESTERN GREAT BASIN WILL SLOWLY FILL AND BE CAUGHT UP IN THE BAROCLINIC ZONE THAT STRETCHES FROM SOUTHERN CA TO MISSOURI. IN THE RUN AND ETA12 IT LOOKS LIKE A MINOR VORT MAX AND JET MAXIMA WILL TRAVEL OVER THE FORECAST AREA. RIGHT NOW ITS HARD TO PICK OUT THESE FEATURES ON SATELLITE. RUC SHOWS A FEW CHANNELED VORT MAXES WITHIN BENEATH THE JET OVER SRN CA. ONE OF THESE COULD DRAG ENOUGH MOISTURE NORTHEAST TO PRODUCE AN INCREASE IN CLOUDS AND SHOWERS. HARD TO PEG WHAT WILL HAPPEN...BUT RIGHT NOW BELIEVE IT'LL BE MAINLY OROGRAPHIC IN NATURE OVER THE HIGHER ELEVATIONS. HAVE DECREASED POPS OVER THE VALLEYS AS A RESULT AND KEPT THE POP RELATIVELY HIGH OVER THE MOUNTAINS. WITH LITTLE REAL DYNAMIC SUPPORT I KEPT THE SNOW AMOUNTS BELOW ADVISORY LEVEL. SUNDAY THROUGH MONDAY: HAVE NOT CHANGED TOO MUCH IN THIS PERIOD. THE MAIN FEATURES...120KT JET ENTRANCE REGION AND WEAK PVA...REMAIN AS CHANNELED VORT MAXES ARE PROJECTED TO RIDE ALONG THE STRONG WSW FLOW ALOFT. MAIN INGREDIENT MISSING FOR A SIGNIFICANT SNOW EVENT IS MOISTURE. ETA AND GFS APPEAR DRIER...ESPECIALLY THE ETA. HAVE LEFT THE POP ABOUT THE SAME...THOUGH TONED DOWN SNOW AMTS A BIT. THE POSSIBILITY FOR HIGHLIGHTS MONDAY REMAINS...BUT NEED TO SEE MORE MOISTURE TO ISSUE A WATCH COMFORTABLY. .LONG TERM (MONDAY NIGHT THROUGH SATURDAY)...MEDIUM RANGE MDLS REMAIN IN DECENT AGREEMENT ON THE SYNOPTIC SCALE. ALTHO GFS SHOWS A MORE AMPLIFIED RIDGE OVER THE WEST COAST FRIDAY THAN THE EC...BUT EXPECT SENSIBLE WX WILL SHOW LITTLE DIFFERENCE. MONDAY NIGHT-TUESDAY...A NORTHWEST FLOW WILL PREVAIL OVER THE NRN PART OF THE CWA MONDAY NIGHT...WHILE A WEAK DEFORMATION ZONE AS DEPICTED BY THE NAM WILL BE OVER THE REMAINDER OF THE CWA. ENOUGH MSTR TO MAINTAIN LOW END SCATTERED POPS MAINLY O/MTNS. LITTLE CHANGE EXPECTED TUESDAY AS UPPER LOW NEAR WRN ARIZONA OPENS AND TRACKS EWRD INTO NEW MEXICO. BEST MSTR HOWEVER REMAINS OVER THE NORTH WHERE SCT POPS CONTINUE. WEDNESDAY-THURSDAY...A NW FLOW WILL PREVAIL OVER OUR CWA AFTER ABOVE MENTIONED TROF PASSAGE. ENOUGH MSTR AND INSTABILITY TO PRODUCE SCATTERED SNOW SHOWERS OVER THE MTNS. FRIDAY-SATURDAY...A STRONG RIDGE BEGINS TO BUILD ALONG THE WEST COAST THEN SHIFT SLOWLY EWRD WITH TIME. THIS WILL BRING DRY AND WARMING CONDITIONS...EXCEPT INVERSION PRONE VALLEYS. && .GJT WATCHES/WARNINGS/ADVISORIES... .CO...NONE. .UT...NONE. && CJC/MC co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LINCOLN IL 1230 PM CST SAT FEB 18 2006 ...WIND CHILL ADVISORY ALLOWED TO EXPIRE AT NOON NORTH OF LINCOLN.... .DISCUSSION... UPDATED THE FORECAST TO ALLOW THE WIND CHILL ADVISORY TO EXPIRE AT NOON ALONG AND NORTH OF A RUSHVILLE TO BLOOMINGTON LINE. WIND CHILLS ACTUALLY GOT AS COLD AS 15 TO 20 BELOW AS FAR SOUTH AS TAYLORVILLE AND MATTOON EARLY THIS MORNING. WIND CHILLS WERE AS COLD AS 20 TO 24 BELOW ZERO FROM LINCOLN NORTH. LIGHT SNOW AND FLURRIES EXIT SE IL FROM I-70 SOUTH BY 9 AM WHILE CLOUDS ALSO DECREASED WITH JUST HIGH CLOUDS ALONG AND SOUTH OF A TAYLORVILLE TO TERRE HAUTE LINE WHERE SKIES WERE MOSTLY SUNNY. SUNNY SKIES NORTH OF THERE. THE MAIN STORY THOUGH IS THE FRIGID AIR MASS WITH LOWS THIS MORNING RANGING FROM 8 BELOW AT GALESBURG AND MINONK TO 9 ABOVE AT FLORA AND LAWRENCEVILLE. TEMPS AT NOON ELEVATED TO AROUND 5F NORTH AND AROUND 13F SE IL. WIND CHILLS RANGE FROM 10 TO 15 BELOW NORTH OF I-70 TO 5 TO 10 BELOW SOUTH OF I-70. NOON SURFACE MAP SHOWS 1046 MB ARCTIC HIGH PRESSURE ALONG THE IA/NE/MO BORDER. RUC AND NAM WEAK HIGH A BIT TO 1040 MB NEAR THE IA/MO/IL BORDER THIS EVENING. THIS WILL ALLOW NW WINDS TO BECOME LIGHT BY THIS EVENING AND CLEAR SKIES. TEMPS SHOULD ONLY CLIMB A FEW MORE DEGREES FOR HIGHS THIS AFTERNOON RANGING FROM 7F FAR NW AT GALESBURG TO 17F OVER SE IL BY LAWRENEVILLE. LOWS TONIGHT COULD BE A FEW DEGREES COLDER THAN THIS MORNING WITH CLEAR SKIES AND LIGHT WINDS. WITH LIGHTER WINDS...WIND CHILLS WILL NOT BE AS COLD AS THIS MORNING...RANGING FROM 5 TO 15 BELOW ZERO...AND COLDEST NORTH. && .PREV DISCUSSION... ALREADY ISSUED WIND CHILL ADVISORY FOR THE NORTHERN THIRD OF THE CWA AS WIND CHILL READINGS RANGE FROM -15 TO -24 DEGREES AND WINDS HAVE NOT LET UP YET. GRADIENT REMAINS TIGHT AS STRONG HI PRSS SITS CENTERED IN EASTERN NEB...AND A SHORT WAVE MOVES ACRS SOUTHERN MO/IL/IND. MODELS IN GOOD AGREEMENT WITH CURRENT SITUATION AND ONLY REAL CONCERN THIS PACKAGE IS TEMPERATURES IN THE SHORT TERM. SHORT TERM...TODAY THROUGH MONDAY... SHORT WAVE MOVING ACRS SRN IL PRODUCING QUITE A BIT OF SNOW IN PARTS OF SRN MO AND SRN IL. SOME FLURRIES HAVE GOTTEN AS FAR NORTH AS UIN AND PPQ IN WESTERN IL AND WILL LIKELY CONTINUE THROUGH THE MORNING HOURS ACRS THE SOUTHERN HALF OF THE CWA. THEREFORE WILL LOOK AT MAKING ADJUSTMENTS TO POP/WX GRIDS FOR THIS MORNING. THIS SHORT WAVE WILL BE ONLY SHOT OF ANY PCPN...AS STRONG COLD HIGH PRSS WILL PUSH EAST INTO THE STATE BY TONIGHT AND BRING THE COLDEST TEMPS OF THE SEASON. THIS HIGH PRSS RIDGE WILL SIT ACRS THE EASTERN AND SOUTHEASTERN HALF OF THE US THROUGH MONDAY AND KEEP ALL PCPN WELL SOUTH OF THE AREA. TEMPS WILL REMAIN WELL BELOW NORMAL NEXT 48 HOURS. 850 TEMPS OF -16 TO -20 WILL SIT OVER THE AREA THROUGH TONIGHT AND THEN WARM SLIGHTLY FOR TOMORROW. THEN HIGH PRSS WILL BECOME MODIFIED ENOUGH TO SEE TEMPS WARM SLIGHTLY BUT STILL REMAIN BELOW NORMAL. HAVE FOLLOWED THE MET FOR HIGHS...EXCEPT IN THE SOUTH WILL LEAN TOWARD MAV. DUE TO LACK OF SNOW COVER ACRS THE AREA FOLLOWED A BLEND OF MAV AND MET FOR LOWS TONIGHT. BLEND OF GUIDANCE ALSO LOOKS BEST FOR REMAINDER OF SHORT TERM PERIODS. LONG TERM...TUESDAY THROUGH FRIDAY... EXTENDED MODELS OF GFS AND ECMWF REMAIN SIMILAR AND ADVERTISE TWO SEPARATE STREAMS IN THE FLOW FOR NEXT WEEK. IL APPEARS TO BE CAUGHT IN THE MIDDLE OF BOTH STREAMS. GFS DOES BRING A COUPLE OF SHORT WAVES THROUGH ON WED AND AGAIN ON THUR. WED SYSTEM HAS NO SFC REFLECTION WHILE THUR SYSTEM DOES HOLD MORE PROMISE. HOWEVER STILL TOO MUCH UNCERTAINTY AND NEED TO WAIT FOR NEW EXTENDED MODEL GUIDANCE. SO WILL KEEP PERIOD DRY AND LET DAY SHIFT MAKE THE CHANGE...IF NECESSARY. GUIDANCE WARMS TEMPS UP TOO QUICKLY ACRS AREA SO HAVE KEPT TEMPS CLOSE TO PREVIOUS FCST...WHICH HAS BEEN TO UNDERCUT GUIDANCE BY SEVERAL DEGREES. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ HUETTL/AUTEN il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CARIBOU ME 1128 AM EST SAT FEB 18 2006 .SYNOPSIS...INTESE LOW PRESSURE WILL CONTINUE THROUGH THE MARITIMES TODAY. GUSTY WINDS ARE EXPECTED TO CONTINUE BEFORE DIMINISHING LATER TODAY. COLD HIGH PRESSURE WILL BUILD SOUTH OF THE REGION THROUGH SUNDAY BRINGING VERY COLD TEMPERATURES AND BRISK CONDITIONS BUT DRY WEATHER FOR THE WEEKEND. && .UPDATE /REST OF TODAY/... UPDATED GRIDS/ZFP TO REMOVE WIND CHILL ADVISORY ACROSS NORTHERN ZONES AS IT IS ALLOWED TO EXPIRE. MIGHJT NEED IT AGAIN TONIGHT. KEPT WIND ADV GOING THROUGH THE AFTERNOON AS WINDS SHOULD COME BACK UP. SATL IMAGERY & RUC SHOWING DISTURBANCE DIVING SEWD ACROSS THE ST. LAWRENCE RIVER TRIGGERING SOME SHSN. DECIDED TO BOOST POPS ACROSS FAR NORTHERN ZONES W/ANY ACCUMULATION ACROSS THE NORTHERN TIP OF ZONES 1 & 2. BUFKIT PROFILES SUPPORT SHSN ACTION & WINDEX CHART POINTS TO THIS ACTIVITY AS WELL W/TEMPERATURE DIFFERENTIAL > 10C & SOME INSTABILITY NOTED. LLVL RH IS THERE AS WELL. ACTIVITY SHOULD DIE DOWN AFT SUNSET. REST OF THE FCST LEFT ALONE. && .MARINE... NO CHGS W/GLW LEFT UP. && .PREVIOUS DISCUSSION... /ISSUED 355 AM EST SAT FEB 18 2006/ SHORT TERM /TODAY THROUGH SUNDAY/... MJR CHANGES PAST 24 HRS AS SHARP COLD FRONT HAS CROSSED THE AREA W/ STRONG WINDS AND PLUNGING TEMPS IN ITS WAKE. ON THE UP SIDE...VERY DRY SUBSIDENT AIR OVERSPREADING THE AREA SO WDSPRD CLDS AND SIGNIFICANT PRECIP A NON FACTOR THRU THE SHORT TERM... SAT PIX AND RADAR DOES SHOW SOME PLUMES OF MOISTURE COMING OFF THE YET OPEN ST LAWRENCE SEAWAY AND STREAMING ACROSS FAR NRN MAINE ATTM. LIKE LAKE EFFECT...VERY COLD AIR CROSSING THIS BODY OF WATER DOES OCNLY PRODUCE SOME NARROW BANDS OF SNOW FOR OUR NRN AREAS AND CAN NOT RULE THIS OUT THIS GO AROUND EITHER. THESE ARE VERY LOCALIZED AND DIFFICULT TO FCST SO WILL COVER W/ NOWCASTS IF THEY OCCUR. THEREFORE...MAIN CONCERN THIS PACKAGE WILL BE WINDS AND COLD TEMPS AS WELL AS WND CHILLS... ALONG THESE LINES...HEALTHY UPPER SHORT WAVE PROGGED TO SWING SE ACROSS THE FA TODAY AND THIS SHOULD HELP SFC PRES GRADIENT WHICH WILL TEMPORARILY RELAX A BIT ERLY TODAY...TO TIGHTEN UP AGAIN LATER ON. FCST WNDS SUPPORT A SOLID WND ADV FOR THE ENTIRE CWA TODAY. HAVE LET THE HGH WND WRNG EXPIRE AND HAVE REPLACED IT W/ A WND ADV WHICH WILL CONT THRU 5 PM TODAY. WNDS AND FCST TEMPS ALSO CONT TO SUPPORT WND CHILL ADV OUR NRN ZNS THRU THE AM HRS. LOOKS LIKE TEMPS AND CONTD BRISK WNDS TONIGHT WILL BRING WND CHILL ADV CRITERIA BACK INTO PLAY AGAIN BUT WILL LET THE DAY SHIFT ADDRESS THESE LATER ISSUES. LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... RATHER TRANQUIL WEATHER PATTERN IN THE LONG TERM WITH NO MAJOR SYSTEMS TO AFFECT THE FORECAST AREA THROUGH AT LEAST THE MIDDLE OF NEXT WEEK. UPPER FLOW BECOMES FAIRLY ZONAL WITH ONLY SOME MINOR SHORT WAVES CROSSING THE REGION THROUGH MID WEEK POSSIBLY BRINGING SOME SNOW SHOWERS OR FLURRIES MAINLY ACROSS THE NORTH. AVIATION... EXPECT MAINLY VFR CONDITIONS TODAY ALTHOUGH THERE COULD BE SOME MVFR THIS MORNING ACROSS NORTHERN TAF SITES DUE TO CEILINGS AND POSSIBLY SOME SCATTERED SNOW SHOWERS. GUSTY WEST WINDS WILL CONTINUE TODAY WITH WIND GUSTS TO AROUND 35-40 KT POSSIBLE. MARINE... LET THE STRM WRNG EXPIRE AS WNDS HAVE BACKED OFF SIGNIFICANTLY... ACTUALLY JUST A BIT BLO GLW ATTM. HOWEVER...WILL GO W/ A GLW THRU TNGT AS ANOTHER RATHER HEALTHY SHORT WAVE XPCTD TO DROP SE ACROSS THE REGION TODAY ENHANCING THE ARCTIC AIR INTRUSION INTO THE AREA AND XPCT WNDS TO INCREASE AGAIN SPCLY LATER ON. CAR WATCHES/WARNINGS/ADVISORIES... ME...WIND ADVISORY FOR MEZ001>006-010-011-015>017-029>032 UNTIL 5 PM SATURDAY. MARINE...GALE WARNING FOR ANZ050 UNTIL MIDNIGHT SUNDAY. $$ && UPDATE...HEWITT/NORTON SHORT TERM/MARINE...KHW LONG TERM/MARINE...DUDA me AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 350 PM EST SAT FEB 18 2006 .DISCUSSION... THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS THE OVERNIGHT WIND CHILLS. WATER VAPOR IMAGERY AND RUC/NAM SHOWING A CLOSED LOW OVER NORTHERN CALIFORNIA. A SHORTWAVE TROUGH EXTENDS FROM THIS LOW EAST INTO NORTH DAKOTA. A DOME OF HIGH PRESSURE IS OVER IOWA. THIS DOME BLANKETS MUCH OF THE UPPER MISSISSIPPI RIVER VALLEY AND THE UPPER GREAT LAKES. ANTI-CYCLONIC FLOW AROUND THIS HIGH IS PRODUCING WINDS AROUND 10 TO 15 KNOTS AND WIND CHILLS ACROSS UPPER MICHIGAN OF -15F TO -25F. STRONG 500MB NVA WILL MOVE ACROSS THE FORECAST AREA OVERNIGHT. THE SURFACE HIGH WILL SLIDE INTO WEST CENTRAL ILLINOIS. THE PERSISTENT ANTI-CYCLONIC FLOW WILL KEEP WINDS FROM THE WEST AROUND 10 KNOTS AROUND THE FORECAST AREA. THIS WILL PRODUCE A LITTLE MIXING AT THE LOW LEVEL...WHICH WILL LIMIT RADIATIONAL COOLING OVERNIGHT. OVERNIGHT LOWS WILL STILL DIP TO -5F TO -10F WHICH WILL THE WINDS AND LOW TEMPERATURES WILL PRODUCE SOME WIND CHILLS BELOW -25F SO WILL PUT IN A WIND CHILL ADVISORY FOR OVERNIGHT. A THERMAL TROUGH WILL SLIDE OVER LAKE SUPERIOR CAUSING A LAKE-850MB DELTA-T OF AROUND 17C. THIS WILL BE CONDUCIVE TO KEEPING SOME LAKE EFFECT SNOW GOING. WITH THE WESTERLY FLOW AND DELTA-T'S LOOKING FOR LES TO CONTINUE OVER THE KEWEENAW PENINSULA AND NORTHERN LUCE AND EASTERN ALGER COUNTIES OVERNIGHT. STRONG WINDS WILL ALSO MIX TO SURFACE OVER LAKE SUPERIOR OVERNIGHT PROMPTING SOME GALE WARNINGS. THE HIGH WILL SETTLE INTO THE MIDDLE MISSISSIPPI RIVER VALLEY WITH THE RIDGE EXTENDING EAST ACROSS THE OHIO RIVER VALLEY. THIS SHOULD KEEP A WESTERN FLOW ACROSS THE FORECAST AREA. THE DELTA-T'S WILL KEEP LAKE EFFECT SNOWS GOING INTO SUNDAY. THE SURFACE RIDGE WILL PERSIST OVER THE OHIO RIVER VALLEY THROUGH SUNDAY NIGHT. MODELS AGREE THAT THE WEAK SHORTWAVE WILL SLIDE OVER NORTHERN LAKE SUPERIOR. THE ASSOCIATED INSTABILITY SHOULD HELP TO KEEP LAKE EFFECT SNOWS GOING. ANOTHER SHORTWAVE WILL MOVE OUT OF THE CENTRAL PLAINS AND STREAM TO THE SOUTH OF THE FORECAST AREA AND SHOULD HAVE LITTLE IF ANY AFFECT ON THE U.P.'S WEATHER. ON MONDAY AND MONDAY NIGHT...THE DEEPER SHORTWAVE WILL SWEEP ACROSS THE FORECAST AREA. THE SURFACE LOW WILL SWEEP OUT OF CENTRAL CANADA THROUGH ONTARIO DRAGGING A COLD FRONT THROUGH THE FORECAST AREA. COLD AIR ADVECTING INTO THE AREA BEHIND THE FRONT WILL SET UP SOME LAKE EFFECT AGAIN ON TUESDAY. GFS/ECMWF SHOWING THE SHORTWAVE THAT STRETCHES FROM LOWER MICHIGAN SOUTHWEST WILL MOVE TO THE EAST COAST AND REMAIN STRETCHES INTO SOUTHWEST CONUS TUESDAY NIGHT. A SHORTWAVE MOVING THROUGH CENTRAL CANADA AS IT SWINGS THROUGH THE BASE OF THE LONGWAVE TROUGH WILL REACH THE U.P. TUESDAY NIGHT NIGHT. THE WEAK SURFACE LOW WILL MOVE INTO JUST NORTH OF CENTRAL LAKE SUPERIOR LEADING A COLD FRONT THROUGH WESTERN U.P. THE SHORTWAVE ENERGY AND ISENTROPIC ASCENT AHEAD OF THE FRONTAL SYSTEM WILL GENERATE A CHANCE OF SNOW SHOWERS ACROSS THE U.P. AS THIS SHORTWAVE RACES EAST...ANOTHER WEAK SHORTWAVE WILL FOLLOW REACHING THE UPPER MISSISSIPPI RIVER VALLEY LATE WEDNESDAY. MEANWHILE...A DEEPER SHORTWAVE WILL SWING INTO EASTERN NORTH DAKOTAS. THE FIRST SHORTWAVE WILL GENERATE MORE SNOW OVER THE NORTHERN U.P. AND LAKE SUPERIOR. DRY AIR FOLLOWING THE COLD SHOULD LIMIT THE AMOUNT OF SNOW. DELTA-T'S WILL BE BORDER LINE FOR THE PRODUCTION OF LES. THUS WILL KEEP A CHANCE OF SNOW GOING MAINLY FOR THE NORTHERN COUNTIES. THE DEEPER SHORTWAVE AND SURFACE LOW WILL SWEEP INTO CENTRAL NORTHERN LAKE SUPERIOR WEDNESDAY NIGHT. THE COLD FRONT WILL SWEEP THROUGH UPPER MICHIGAN. MOISTURE AHEAD OF THE COLD FRONT WILL INCREASE OVER THE AREA. TOGETHER THESE WILL GENERATE A CHANCE OF SNOW OVER THE AREA. THE SHORTWAVE WILL SWEEP THROUGH THE FORECAST AREA ON THURSDAY AS THE SURFACE LOW MOVES FROM LAKE SUPERIOR INTO EAST CENTRAL ONTARIO DRAGGING THE COLD FRONT WITH IT. INSTABILITY ASSOCIATED WITH THE SHORTWAVE AND FRONTAL SYSTEM WILL KEEP A POTENTIAL FOR SNOW GOING. COLD AIR ADVECTING INTO THE AREA BEHIND THE FRONT WILL INCREASE THE POTENTIAL FOR LAKE EFFECT SNOWS ACROSS THE AREA. DRY AIR WILL LIMIT THE AMOUNT OF SNOW. MEANWHILE A LONGWAVE TROUGH WILL DEEPEN OVER HUDSON BAY...AS SURFACE RIDGE BUILDS OVER THE NORTHERN PLAINS. TOGETHER THESE SHOULD DRAW VERY COLD AIR INTO THE AREA NEXT WEEKEND PRODUCING LAKE EFFECT SNOW. GFS SHOWING A THERMAL TROUGH WILL 850MB TEMPERATURES AS LOW AS -21C OVER THE LAKE SUPERIOR. THUS WILL KEEP A MENTION OF LAKE EFFECT SNOWS GOING AS WINDS SHOULD REMAIN OUT OF THE NORTH. && MQT WATCHES/WARNINGS/ADVISORIES... WIND CHILL ADVISORY UNTIL NOON EST/11 AM CST/ SUNDAY FOR MIZ002-MIZ004>MIZ006-MIZ008>MIZ013-MIZ084. LAKE EFFECT SNOW AND BLOWING SNOW ADVISORY UNTIL 6 AM EST SUNDAY FOR MIZ001-MIZ003. GALE WARNING FOR LAKE SUPERIOR. && $$ DLG mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1207 PM EST SAT FEB 18 2006 .UPDATE... STATUS OF HEADLINES ARE MAIN CONCERN. ALLOWED ALL WIND CHILL HEADLINES TO EXPIRE AS TEMPS REBOUNDING WELL THROUGHOUT THE CWA FROM DOUBLE DIGIT BELOW ZERO OVERNIGHT LOWS IN MANY INLAND AREAS. MOST INLAND READINGS IN PAST HOUR WERE 5 BLO ZERO TO ZERO WITH DOWNSLOPING WEST FLOW SHORELINE AREAS ZERO TO 7 ABOVE. ALTHOUGH INCREASING WINDS 15 TO 20 MPH AT SOME SPOTS WITH DIURNAL MIXING MAY KEEP WIND CHILLS HOVERING AROUND 20 BLO MUCH OF AFTERNOON...FELT THIS COULD BE COVERED WELL ENOUGH IN ZFP. BACKING FLOW TO WEST WITH APPROACH OF NEXT CLIPPER OVER SRN CANADA HAS ALLOWED LES BANDS TO LIFT OUT OF ONTONAGON AND SRN HOUGHTON COUNTIES THIS MORNING AND WILL SOON LIFT OUT OF ALGER-LUCE SHORELINE AREAS EARLY THIS AFTERNOON. SO HAVE DROPPED WSW HEADLINES FOR COUNTIES. ONLY HEADLINE STILL IN EFFECT IS LES SNOW/BLOWING SNOW ADVISORY OVER NRN HOUGHTON AND KEWEENAW WHERE VSBYS STILL 1/4SM OR LESS IN SOME AREAS FROM SNOW/BLOWING SNOW. && .PREV DISCUSSION... MAIN FCST CONCERNS ARE LES/WIND TRENDS ALONG WITH WIND CHILLS. WV IMAGERY...00Z RAOBS AND RUC ANALYSIS INDICATED A MID/UPR LVL TROF NE OF LK SUPERIOR LEAVING CONFLUENT WRLY FLOW FROM THE NRN PLAINS TO THE WRN LAKES. STRONG QVECTOR DIV WAS TAKING OVER IN THE WAKE OF THE TROF WITH FALLING INVERSION HGTS LIMITING DEPTH OF THE LES CONVECTION AS IR IMAGERY SHOWED SHRINKING AREA OF COLDER CLOUD TOPS. DEEPER LES VCNTY KERY WITH CONVERGENT SNOWBANDS HAD DIMINISHED TO MORE WIDELY SPACED MULTIPLE WIND PARALLEL BANDS. AT THE SFC...BREEZY WNW WINDS PREVAILED ACRS UPR MI BTWN 1048 MB HIGH PRES OVER IA/NE AND LAKE INDUCED TROF OVER ERN LK SUPERIOR. AS AREA OF CAA AND STRONG 255K-260K ISENTROPIC DESCENT MOVED OFF TO THE EAST...WINDS HAVE DIMINISHED WITH MAINLY 15-25 MPH WINDS OVER THE KEWEENAW AND TO 5 TO 15 MPH OVER MUCH OF INTERIOR CENTRAL UPR MI. HOWEVER...WITH TEMPERATURES IN THE -10 TO -15 RANGE...WIND CHILL VALUES RANGED FROM AROUND -25 TO -43. TODAY...EVEN THOUGH WINDS AND LES INTENSITY HAVE DIMINISHED OVER THE NORTHWEST...EXPECT THAT WITH SMALL SNOWFLAKES IN VERY COLD AIRMASS OVER THE WEST...VSBYS WILL REMAIN POOR. UNFAVORABLE SNOWFLAKE GROWTH AND LOWER INVERSION HGTS TO 4K-5K FT SHOULD ALSO LIMIT ACCUMULATIONS TO 2-5 INCHES DESPITE 850 MB TEMPS AROUND -25C. MDLS ALSO SUGGEST THAT WINDS SHOULD REMAIN MAINLY IN THE 15 TO 25 MPH RANGE WITH SOME 30 MPH GUSTS CLOSER TO THE LAKE SHORE AND DURING THE AFTERNOON WITH DIURNAL HEATING AND GREATER MIXING. SO...LAKE EFFECT SNOW/BLSN ADVY WAS ISSUED IN PLACE OF THE BLIZZARD OR WINTER STORM WARNINGS. OVER THE EAST...THE NAM...WHICH HAS SHOWN DECENT DEPICTION OF LOW LVL WIND FIELDS...SUGGESTS THAT THE 950 MB CONVERGENCE INTO THE NE CWA WILL SHIFT QUICKLY TO THE EAST AS WINDS BACK THIS MORNING. RESULTING 280-290 FLOW BY MIDDAY MAY STILL PUSH SOME LES BANDS INTO LOCATIONS NEAR THE SHORELINE FROM GRAND MARAIS EASTWARD. EVEN WITH BETTER FETCH THAN THE WEST...SHIFTING WINDS/BANDS AND UNFAVORABLE SNOWFLAKE GROWTH PRFL SHOULD LIMIT ADDITIONAL ACCUMULATIONS TO 2-5 INCHES. MID FEBRUARY SUNSHINE WILL BOOST TEMPERATURES BY MIDDAY INTO THE SINGLE DIGITS SO THAT WIND CHILL VALUES WILL MOVE BACK INTO THE ZERO TO -20 RANGE. TONIGHT...WRLY WINDS WILL KEEP LES CONFINED TO THE KEWEENAW WITH ONLY A CHANCE OF ANY SHSN ALONG THE SHORELINE FROM GRAND MARAIS TO TO THE EAST. THE LES/BLSN ADVY CONTINUES AS FAIRLY TIGHT GRADIENT KEEPS WINDS IN THE 15-30 MPH RANGE. AS WAA GETS UNDERWAY WITH THE DEPARTING COLD POOL...MDLS SUGGEST INVERSION HGTS WILL CONTINUE TO FALL AOB 3K FT. SO...EVEN THOUGH THERMAL PROFILE MAY BE A BIT MORE FAVORABLE FOR SNOWFLAKE GROWTH AND MODEST LOW LVL CONV FOCUSES INTO THE NRN KEWEENAW...ADDITIONAL SNOWFALL AMOUNTS SHOULD REMAIN IN THE LOWER ADVY RANGE(1-5 INCHES). WIND CHILL VALUES WILL ALSO FALL THIS EVENING TO VALUES NEAR OR INTO THE ADVY RANGE (BLO -25). HOWEVER...SINCE WINDS MAY BE BLO 10 MPH WITH THE COLDEST AIR TEMPS...CONDITIONS MAY BE MARGINAL FOR AN ADVY. SO...ADDITIONAL WIND CHILL HEADLINES WERE NOT ISSUED WITH THIS PACKAGE. SUNDAY...MDLS SUGGEST NEXT WEAK CLIPPER SHRTWV WILL BRUSH THE WRN LAKES AS IT MOVES THROUGH NRN ONTARIO. EXPECT THAT CBL WINDS MAY BACK A BIT MORE SW THAN MDLS SUGGEST WHICH WOULD PUSH LES BANDS OFFSHORE FROM THE KEWEENAW BY AFTERNOON. SUNDAY NIGHT INTO MON...AS WINDS VEER IN THE WAKE OF THE SHRTWV...MORE FAVORABLE CONVERGENT WRLY FLOW DEVELOPS. ENOUGH INSTABILITY REMAINS WITH 850 MB TEMPS FCST AROUND -16C TO KEEP LIKELY POPS GOING OVER THE NRN KEWEENAW. BY MON WITH WRLY FLOW CONTINUING...MDLS SUGGEST ADDITIONAL SHEARED SHRTWVS MAY MOVE THROUGH THE UPPER LAKES MON THAT WOULD SUPPORT DEEPER MOISTURE AND BETTER LES ENVIRONMENT. && MQT WATCHES/WARNINGS/ADVISORIES... LAKE EFFECT SNOW AND BLOWING SNOW ADVISORY UNTIL 6 AM EST SUNDAY FOR MIZ001-003. && $$ UPDATE (VOSS) PREV DISCUSSION (JLB) mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE COLUMBIA SC 320 PM EST SAT FEB 18 2006 .SHORT TERM (TONIGHT THROUGH MONDAY NIGHT)... NEARLY ZONAL UPPER FLOW TO CONTINUE TONIGHT THROUGH MONDAY NIGHT. SOUTHERN STREAM WILL REMAIN OVER THE SOUTHEAST WITH EMBEDDED RIPPLES. SURFACE COLD TO STATIONARY FRONT SORT OF MEANDERS AROUND DURING THE PERIOD. WEDGE OF COLD AIR WILL ACTUALLY HELP PUSH THE FRONT SOUTHWARD TONIGHT. WILL MENTION A MIXTURE OF RAIN AND SLEET ACROSS THE NORTHERN COUNTIES AS BOTH RUC AND NAM ARE INDICATED H925 MB TEMPERATURES BELOW FREEZING WHILE THE DEEPER MOISTURE HANGS AROUND. AGREE WITH MOS TEMPERATURES IN THE LOWER TO MID 30S TONIGHT AND SUNDAY NIGHT. WILL CONTINUE MENTION OF SOME FREEZING RAIN NORTHERN COUNTIES ALSO MONDAY MORNING. IT DOESN'T APPEAR THAT TEMPERATURES WILL BE NEAR FREEZING LONG ENOUGH AND JUST LIGHT PRECIPITATION WILL CAUSE MANY PROBLEMS MONDAY MORNING. && .LONG TERM (TUESDAY THROUGH SATURDAY)... ZONAL FLOW CONTINUES WITH SOUTHERN STREAM. SHORT WAVE THURSDAY APPEARS TO PUSH WET WEATHER FARTHER SOUTH FRIDAY AND SATURDAY. TEMPERATURES INITIALLY COOL TUESDAY BUT WARM UP BY FRIDAY. && .AVIATION... MOIST WEST FLO ALOFT WL KP CLDS OVR AREA THRU PD. COLD SFC HI CONTS TO BLD OVR AREA. EXPECT CIGS 030-040 AND MID LVL CLDS 080 TO 100 FT THRU PD. VFR VSBYS. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$ 07/07/14 sc AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 1130 AM EST SAT FEB 18 2006 .SHORT TERM (THIS AFTERNOON)... AFTER A BRIEF LULL LATE THIS MORNING...PRECIP WAS MOVING BACK IN FROM THE WEST AHEAD OF A WEAK SHORT WAVE PICKED UP BY THE 12Z AND 15Z RUC. THE WAVE SHOULD MOVE OVERHEAD DURING THE FIRST PART OF THE AFTERNOON ALONG WITH SOME WEAK UPPER DIVERGENCE AS THE RIGHT ENTRANCE REGION OF THE JET REMAINS STRETCHED E-W ACROSS THE SOUTHERN APPALACHIANS. RADAR TRENDS TO THE WEST SUPPORT KEEPING THE CATEGORICAL POP THROUGH THE AFTERNOON ACROSS ALL BUT THE SOUTHEASTERN FRINGE OF THE FORECAST AREA. MEANWHILE...TEMPERATURES SHOULD CONTINUE TO FALL AS COLD ADVECTION CONTINUES. A QUICK LOOK AT THE 12Z RUN OF THE NAM STILL SUPPORTS A CHANGEOVER TO SNOW ACROSS MOST OF THE MOUNTAINS BY 18Z BUT PERHAPS A SLIGHT DELAY ACROSS THE I-40 CORRIDOR UNTIL THE LATE AFTERNOON...HOWEVER THE UPSTATE AND SOUTHERN PIEDMONT ARE EXPECTED TO BE MOSTLY RAIN THROUGH SUNSET. AS FOR THE COLLECTION OF WARNINGS AND ADVISORIES...ALL APPEAR TO BE ON TRACK GENERALLY SPEAKING...ALTHOUGH THE DETAILS ARE NOT WORKING OUT AS FIRST EXPECTED. NO CHANGES ARE ANTICIPATED. THE EVENING PERIOD WILL ALSO BE UPDATED TO RETAIN A CHANCE POP ACROSS THE EASTERN ZONES AND THE MENTION OF MIXED PRECIP WILL BE MOVED TO THAT PERIOD. && .PREVIOUS DISCUSSION... ISSUED AT 315 AM SHORT TERM (TODAY THROUGH MONDAY)... REGIONAL 88D LOOPS INDICATE THAT UPGLIDE PCPN INCREASING UPSTREAM OF THE CWFA ATTM...AND WILL BE OVERSPREADING THE MOUNTAINS LATER THIS MORNING. ACRS THE NC MTNS...THERMAL PROFILES SUPPORT A WINTRY MIX AT THE ONSET...BEFORE A QUICK CHANGE TO ALL SNOW AS THE COLUMN SATURATES. QPF LOOKING A BIT MARGINAL FOR WARNING SNOW ACRS THE NORTHERN MTNS...BUT WILL HOLD ON FOR A LOW END WARNING EVENT FOR MADISON THRU AVERY. CONVERSELY...POSSIBILITY OF HIGHER ELEVATION WARNING SNOW FOR THE SMOKIES LOOKS HIGHER...BUT BULK OF THE SW MTN ZONES SHOULD SEE JUST ADVISORY LEVEL SNOW...AND WILL LEAVE AS IS. THROUGHOUT THE MORNING...IT LOOKS AS IF SNOW LEVELS WILL BE ABOVE THE VALLEY FLOORS FOR AREAS AROUND AND S/SW OF KAVL...SO ACCUMS BECOME INCREASINGLY ELEVATION DEPENDENT ACRS THE SOUTHERN NC MTNS. AS WOULD BE EXPECTED IN THE WEAKLY FORCED AND FAST FLOW WE CURRENTLY FIND OURSELVES UNDER...WAA LIFT DIMINISHES DURING THE AFTERNOON AND DEEPER MOISTURE BAND DEVELOPS EAST OF THE MTNS...SO ANY ADDITIONAL SNOW ACCUMULATION DURING THE AFTERNOON IS EXPECTED TO BE OF A LESSER CONSEQUENCE. BASED ON THE AFOREMENTIONED SCENARIO...HAVE EXPANDED WINTER WX ADVISORY INTO THE SOUTHERN NC MTNS...EMPHASIZING LIGHT ACCUMULATIONS IN THE HIGHER ELEVATIONS. SURGE OF DEEPER RH WILL SPREAD INTO THE FOOTHILLS AND PIEDMONT FROM LATE MORNING INTO THE AFTERNOON...BUT AS THE AFTERNOON WEARS ON... AN INCREASING AMOUNT OF DOWNGLIDE FLOW WILL DEVELOP LIKELY EATING INTO PCPN AMTS EAST OF THE MTNS. NONETHELESS...A PERIOD OF RAIN AND SLEET...PERHAPS ENDING AS PERIODS OF SNOW IS POSSIBLE ALONG THE I-40 CORRIDOR EAST OF THE BLUE RIDGE...AND HAVE EXPANDED WINTER WEATHER ADVISORY INTO THE NORTHERN FTHLS WHERE THE BEST CHANCE FOR AN INCH OR TWO OF ACCUMULATION BEGIN IN THE HIGHER ELEVATIONS. FOR THE REST OF THE CWFA...IT IS LOOKING LIKE HIGH PROBABILITIES FOR A PERIOD OF MAINLY LIGHT PCPN...MIXED WITH SOME SLEET AT THE ONSET...AND ACRS NORTHERN SXNS...ENDING AS A PERIOD OF SNOW WITH LITTLE OR NO ACCUMULATION. FOR TONIGHT...DEEP RH BAND CONTINUES TO GET SHUNTED INTO THE SOUTHERN FRINGES OF THE CWFA EARLY THIS EVENING AND AS THE NIGHT WEARS ON...WE EVEN SEE SOME DEEP LAYER DRYING SPREADING INTO NC. SO...SAVE FOR A PERIOD OF LIGHT WINTRY MIX EARLY ON...THE BULK OF THE PERIOD EXPECTED TO BE DRY. EVEN INTO SUNDAY...WITH CHILLY HIGH PRESSURE IN CONTROL...A DRY FCST WILL CONTINUE...BUT WITH MAX TEMPS SEVERAL CATEGORIES BELOW NORMAL. THE NEXT WEAKLY FORCED IMPULSE/WAA MAX LOOKS TO SPREAD INTO THE CWFA SUNDAY NIGHT INTO MONDAY...AND A ROUND OF LIGHT WINTRY MIX WILL BE POSSIBLE AGAIN. -CSH LONG TERM (MONDAY NIGHT THROUGH FRIDAY)... FRONTAL BOUNDARY WILL REMAIN DRAPED ACROSS THE SRN PERIPHERY OF THE FORECAST AREA THROUGH THE WEEK. WAVES INDUCED BY UPPER JET DYNAMICS WILL RIPPLE EASTWARD ALONG THE BOUNDARY THROUGH THE WEEK...WITH LOW PRES TIMED ABOUT EVERY 36 HOURS TUE THROUGH FRI. THERMAL PROFILES WILL BE EXCEEDINGLY HARD TO PIN DOWN GIVEN THIS PATTERN...BUT WINTRY PRECIP CHANCES WILL REMAIN GREATEST ACROSS THE NRN TIER AND HIGH TERRAIN WITH EACH SYSTEM. THE LATEST GFS HAS VERY SLIGHT THICKNESS WARMING TUE THROUGH FRI...BUT WITH REINFORCING ARCTIC AIR ARRIVING BY NEXT WEEKEND. ONLY MINOR ADJUSTMENTS IN THE TEMPERATURE FIELDS HAVE BEEN MADE FOR THE MEDIUM RANGE...WITH ASSOCIATED ADJUSTMENTS IN THE PRECIPITATION TYPE FIELDS. -HG && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...WINTER STORM WARNING FOR NCZ033-048>050 UNTIL 6 PM SATURDAY. ...WINTER WEATHER ADVISORY FOR NCZ051>053-058-059-062 FROM 6 AM SATURDAY TO 6 PM SATURDAY. SC...NONE. && $$ SHORT TERM (UPDATE)...MOORE sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEMPHIS TN 1031 AM CST SAT FEB 18 2006 .UPDATE...LATEST SURFACE ANALYSIS PLACES COLD FRONT STRETCHING FROM THE FLORIDA PANHANDLE TO THE JUST OFFSHORE OF THE LOUISIANA/MISSSIPPI COASTLINE. TEMPERATURES ACROSS THE MID SOUTH THIS MORNING CONTINUE TO DROP GRADUALLY AS VERY COLD ARCTIC AIR REMAINS JUST TO THE NORTH ACROSS THE UPPER AND MIDDLE MISSISSIPPI RIVER VALLEY WHERE SINGLE DIGIT TO BELOW ZERO READINGS RESIDE. MAIN FOCUS FOR UPDATE THIS MORNING IS HEADLINE ISSUES WITH THE CURRENT WINTER WEATHER EVENT. 88D REGIONAL RADAR CONTINUES TO SHOW PRECIPITATION OCCURING ACROSS MUCH OF THE MID SOUTH...THOUGH RETURNS AND ASOS/AWOS OBSERVATIONS INDICATE VERY LIGHT SNOW ACROSS THE NORTHERN THIRD OF THE FORECAST AREA. AREAS UP TO THE NORTH RECEIVED 2-3 INCHES THUS FAR IN ADDITION TO FREEZING RAIN/SLEET MIXTURE FROM LATE EVENING/OVERNIGHT. FURTHER TO THE SOUTH...ESPECIALLY ALONG THE I-40 CORRIDOR DOWN ACROSS A PORTION OF NORTH MISSISSIPPI FREEZING RAIN AND SLEET HAVE PRIMARILY BEEN THE PRECIPITATION TYPES WITH ROUGHLY AROUND 1/2 INCH OF SLEET THUS FAR. OBSERVATIONS IN THE ICE WARNING AREA HAVE FINALLY SEEN PRECIPITATION CHANGE OVER FROM RAIN TO FREEZING RAIN. 295K SURFACE SHOW ISENTROPIC ASCENT STEADILY DECREASING THIS AFTERNOON WITH SOME RESIDUAL MOISTURE HANGING AROUND. RUC/NAM/GFS SOUNDINGS SHOW PRECIP AS LIGHT SNOW ACROSS THE NORTHERN THIRD...SLEET/SNOW MIXTURE ACROSS THE I-40 CORRIDOR...AND FREEZING RAIN/SLEET MIXTURE NEAR THE SOUTHERN TIER OR TWO OF COUNTIES. PRECIPITATION SHOULD COME TO AN END BY LATE AFTERNOON/EARLY EVENING. ANTICIPATING ONLY MINOR SNOW/ICE/SLEET ACCUMULATIONS AS BEST AS MENTIONED ABOVE BUT WILL DOWNGRADE AREAS ALONG AND SOUTH OF I-40 TO A WINTER WEATHER ADVISORY DUE TO THE LIGHT PRECIPITATION OCCURRING AND THE HAZARDOUS ROAD CONDITIONS FROM EARILER WINTER PRECIPITATION LAST EVENING INTO THIS MORNING. WILL MAKE ANY OTHER ADDITIONAL ADJUSTMENTS AS NECESSARY TO FORECAST BASED ON CURRENT TRENDS. CJC && .PREV DISCUSSION... (ISSUED 358 AM CST SAT FEB 18 2006) DISCUSSION... FORECAST PRETTY MUCH ON TRACK THIS MORNING. FREEZING LINE AT 09Z APPEARS TO BE ALONG A LINE FROM IUKA...TO OXFORD...TO CLARKSDALE. NORTH OF THAT LINE...MIXED PRECIPITATION SEEMS TO BE THE RULE. ONLY REPORT OF SIGNIFICANT SNOW ACCUMULATIONS IN NORTHERN SECTIONS IS A REPORT OF 2-4 INCHES IN NRN DUNKLIN COUNTY MISSOURI...BUT WITH SLEET AND FREEZING RAIN CONTINUING ELSEWHERE. SCATTERED REPORTS OF SLIPPERY ROADS AND SOME ICING OF EXPOSED SURFACES...BUT NO MAJOR PROBLEMS...YET. SHORT TERM (THROUGH MONDAY)... PRECIPITATION SHIELD EXTENDS BACK INTO SE OKLAHOMA AND NW LOUISIANA. HOURLY PRECIP TOTALS AROUND 0.05 INCH LIQUID. EXPECT PRECIPITATION TO OVERSPREAD REMAINDER OF CWA THIS MORNING AND TEMPS IN TUPELO AREA AND POINTS SOUTH SHOULD FALL TO AROUND THE FREEZING MARK. EVENTUALLY WILL SEE FREEZING RAIN IN ICE STORM WARNING AREA. SOME QUESTION WHETHER QPF WILL BE ENOUGH TO ACTUALLY VERIFY WARNINGS...BUT WILL CONTINUE WARNINGS AS PATH OF LEAST REGRET. TEMPERATURES AT 12Z WILL LIKELY BE HIGHS FOR DAYTIME HOURS. MOST PRECIPITATION SHOULD CUT OFF BY 00Z. MAY STILL BE SOME ACROSS SOUTHERN COUPLE OF TIERS OF COUNTIES DURING THE EVENING...BUT THAT PRECIPITATION SHOULD BE LIGHT AND WILL NOT EXTEND WARNINGS FOR NOW. EXPECT OVERNIGHT LOWS TONIGHT TO BE CLOSE TO THE COLDEST READINGS OF THE WINTER. MAY GET A FEW GLIMPSES OF SUNSHINE ON SUNDAY...BUT DO NOT EXPECT HIGH TEMPERATURES TO MAKE IT MUCH PAST FREEZING...IF THAT FAR. ANOTHER WEAK IMPULSE MOVING THROUGH THE FLOW ON SUNDAY NIGHT INTO MONDAY...BUT MOST PRECIPITATION SHOULD REMAIN SOUTH OF OUR AREA. WILL MAINTAIN THE CHANCE POPS WE HAVE GOING. TEMPS SHOULD SNEAK ABOVE FREEZING ON MONDAY. LONG TERM (AFTER MONDAY)... CONSIDERING ISSUES IN SHORT TERM PORTION OF THE FORECAST...AND ATTENTION NEEDED FOR THAT...OPTED NOT TO MAKE SIGNIFICANT CHANGES TO EXTENDED PORTION OF THE FORECAST. TRIED TO KEEP WITHIN RANGES OF NEIGHBORING OFFICES. LONGER RANGE LOOK AT GFS WOULD INDICATE ANOTHER COLD SPELL NEXT WEEKEND. THIS SOLUTION NOT REALLY SUPPORTED BY 00Z ECMWF RUN...SO WILL ALLOW LATER RUNS TO DEFINE WHETHER CHANGES WILL BE NEEDED. && .MEG WATCHES/WARNINGS/ADVISORIES... AR...WINTER WEATHER ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR CRITTENDEN-CROSS-LEE(AR)-PHILLIPS-ST. FRANCIS. MO...NONE. MS...WINTER WEATHER ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR ALCORN- BENTON(MS)-CALHOUN-CHICKASAW-COAHOMA-DESOTO-ITAWAMBA- LAFAYETTE-LEE(MS)-MARSHALL-MONROE-PANOLA-PONTOTOC-PRENTISS- QUITMAN-TALLAHATCHIE-TATE-TIPPAH-TISHOMINGO-TUNICA-UNION- YALOBUSHA. TN...WINTER WEATHER ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR CHESTER-DECATUR-FAYETTE-HARDEMAN-HARDIN-HAYWOOD-HENDERSON- MADISON-MCNAIRY-SHELBY-TIPTON. && $$ tn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BURLINGTON VT 1154 AM EST SAT FEB 18 2006 HAVE OPTED TO UPDATE THE GOING FCST FOR SOME CHANGES TO THE FIRST THREE PERIODS. .SYNOPSIS... HI PRESS RIDGE TO BUILD INTO THE FA TODAY AND TONITE. UPR TROF TO MOVE DOWN ACRS THE FA TODAY AND TONITE AS WELL. .SHORT TERM /REST OF TODAY THROUGH SUNDAY/... 09-12Z RUC13 SHOWS TEMPS TO GET UP INTO THE SINGLE NUMBERS-MID TEENS TODAY WITH NW SFC WINDS AT 10-15G30 KTS. T1MAX TEMPS ARE +5-15F TODAY. FEW TWEAKS TO FIRST PERIOD TEMPS/WINDS BASED ON THIS DATA AND MESONET OBS. RUC SHOWS SKIES TO BECOME MOSUNNY ACRS THE FA TODAY AFTER SOME LINGERING MTN -SHSN EARLY. H85 CAA TO TAKE PLACE ACRS THE FA TODAY...WITH WK WAA TONITE. SOME LOW-LVL MSTR TO AFFECT THE FA THRU TONITE. LOW-LVL LAPSE RATES TO BE HI ACRS THE FA THRU TONITE. PW VALUES ACRS THE FA LOOK TO BE AOB 0.20" THRU TONITE. 88D MOSAIC SHOWS A FEW LT RETURNS ACRS SOME OF THE MTN ZONES ATTM. VIS SAT PIX ALSO SHOW THE MOST AMT OF CLDS ACRS THE MTN ZONES. WILL OPT TO HANG ONTO CLDS/FLURRIES THE LONGEST FOR THE REST OF TODAY ACRS THE MTN ZONES. NOT MUCH IN THE WAY OF WX EXPECTED ACRS THE FA TONITE. LATEST NAM BUFR DATA SHOWS THAT ANY LES SHOULD BE SOUTH OF THE FA THRU TONITE. NEEDED TO EXPAND THE GOING WIND CHILL ADVISORY TO INCLUDE THE ST LAW VLY BASED ON OBSERVED WIND CHILLS THERE RECENTLY. LOWEST WIND CHILLS TO BE EXPERIENCED ACRS THE FA TONITE WITH READINGS IN THE 20S BLW ZERO ACRS MUCH OF THE GOING ADVISORY AREAS. WILL MOST LIKELY KEEP THESE AREAS AS IS FOR THE AFTERNOON PACKAGE. THE CHAMP VLY MAY BRIEFLY TOUCH -20F FOR A TIME TONITE...SO WILL TAKE ANOTHER LOOK AT THAT THIS AFTERNOON AS WELL. ALL FINAL PRODUCTS ALREADY ISSUED. LATER... .HYDROLOGY... 24-HR QPE /THRU 16-17Z TODAY/ LOOKED TO BE BLW 0.25" ACRS THE FA. .PREV DISCUSSION... /ISSUED 452 AM EST SAT FEB 18 2006/ SHORT TERM /TODAY THROUGH MONDAY/... WAVE OF LOW PRESSURE INDUCED BY THE WARM GREAT LAKES...MOVING ALONG SECONDARY FRONT IN EASTERN LAKE ONTARIO EARLY THIS MORNING. THIS LOW HAS ENHANCED LAKE EFFECT SNOWS AND HAS PRODUCED TWO BANDS OF SNOW EARLY THIS MORNING. ONE BAND OFF HURON AND THE SECOND OFF ONTARIO. FLOW IS VEERING TO NORTHWEST AND WILL PUSH THE FRONT AND PRECIPITATION SOUTH EARLY THIS MORNING. AN INCH OR TWO OF SNOW CANT BE RULED OUT BEFORE DAWN. DURING THE DAY...LOW LEVEL MOISTURE AND EXTREME LOW LEVEL LAPSE RATES WILL COMBINE TO PRODUCE SCATTERED SNOW SHOWERS...TAPERING OFF TO FLURRIES WITHOUT MUCH ACCUMULATION. TEMPERATURES WILL FALL THIS MORNING...THEN BECOME STEADY THIS AFTERNOON BEFORE PLUNGING BELOW ZERO TONIGHT. 850 TEMPS -25 TO -28 SHOULD GIVE HIGHS FROM THE SINGLE NUMBERS NORTH TO 20 SOUTH. TONIGHT/S MINS ARE TRICKY DUE TO CLOUD COVER AND WIND FORECAST. MODEL SOUNDINGS SUGGEST SOME MOISTURE REMAINS AND BOUNDARY LAYER REMAINS MIXED TO KEEP THE WINDS GOING. THIS SEEMS REASONABLE WITH LACK OF GOOD DEEP SNOW COVER TO HELP DECOUPLE LOW LEVELS. SUNDAY...BOUNDARY LAYER FLOW STARTS TO BACK TO WESTERLY AND BY THE END OF THE DAY SOME LAKE EFFECT SNOW SHOWERS MAY START DRIFTING BACK ACROSS THE ADIRONDACKS REACHING THE ST. LAWRENCE VALLEY SUNDAY NIGHT. SOME OF THIS COULD REACH FURTHER EAST BY EARLY MONDAY. WEAK TROF MOVES THROUGH THE REGION ON MONDAY WITH A CHANCE OF SNOW SHOWERS. 850 TEMPS AROUND -15C SHOULD BRING MAX TEMPS BACK UP IN THE MID 20S TO NEAR 30. LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... NO CHANGES TO CURRENT EXTENDED FORECAST. BROAD LOW AMPLITUDE TROF ACROSS ERN CANADA WITH EMBEDDED WEAK SHORT WAVES TO BRING CHANCES OF LIGHT SNOW SHOWERS FROM TIME TO TIME THOUGH TIMING UNCERTAIN. TOWARD THE END OF THE WEEK THERE ARE SOME SIGNS OF AMPLIFICATION OF THE ERN TROF AND PERHAPS A BETTER CHANCE AT SOME MORE SIGNIFICANT PRECIPITATION. AVIATION... SECONDARY ARCTIC COLD FRONT APPROACHING THE SAINT LAWRENCE VALLEY IN NORTHERN NEW YORK AT THIS TIME...WITH BANDS OF SNOW SHOWERS AHEAD OF IT. EXPECTING CONDITIONS TO LOWER TO IFR/LIFR IN SNOW SHOWERS THIS MORNING ACROSS NORTHERN NEW YORK AND VERMONT...WITH THE HIGHER TERRAIN OF THE ADIRONDACKS AND THE GREEN MOUNTAINS BECOMING OBSCURED IN CLOUDS AND PRECIPITATION. EXPECT CONDITIONS TO BECOME VFR ACROSS THE REGION BY 18Z. SOME SCATTERED FLURRIES ARE POSSIBLE AFTER 18Z... WITH THE HIGHER TERRAIN OF VERMONT AND NORTHERN NEW YORK OCCASIONALLY OBSCURED IN CLOUDS. .BTV WATCHES/WARNINGS/ADVISORIES... VT...WIND CHILL ADVISORY FOR VTZ003-004-006-016>018 UNTIL 11 AM SUNDAY. ...WIND CHILL ADVISORY FOR VTZ007-008-010-019 UNTIL 11 AM SUNDAY. NY...WIND CHILL ADVISORY FOR NYZ026-027-029>031-034-087 UNTIL 11 AM SUNDAY. && $$ UPDATED SYNOPSIS/SHORT TERM/HYDROLOGY...MURRAY vt