AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 245 PM MDT SUN MAR 23 2008 .SHORT TERM... (TONIGHT AND MONDAY) SHORT TERM CONCERNS INCLUDE TEMPERATURE AND WINDS ALONG WITH THE POTENTIAL FOR CRITICAL FIRE WEATHER CONDITIONS DEVELOPING ACROSS THE SOUTHEAST PLAINS MONDAY AFTERNOON. CURRENT WATER VAPOR IMAGERY AND RUC UPPER AIR ANALYSIS INDICATING DECREASING WEST TO NORTHWEST FLOW ALOFT ACROSS THE REGION AS A STRONG SHORT WAVE TROUGH MOVING ACROSS THE PAC NW COAST IS FLATTENING THE UPPER LEVEL RIDGE BUILDING ACROSS THE GREAT BASIN REGION AND INTO WESTERN COLORADO ATTM. AT THE SFC...LOW LEVEL SOUTH TO SOUTHEAST RETURN FLOW CONTINUES ACROSS THE PLAINS KEEPING CLOUDS BANKED UP ACROSS THE EASTERN SLOPES OF THE RAMPART RANGE ATTM. SATELLITE PICTURES INDICATING SC FIELD SLOWLY DIMINISHING ACROSS THE REST OF THE SE PLAINS WITH GENERALLY CLEAR SKIES OUT WEST. TONIGHT AND MONDAY...MODERATE WESTERLY FLOW ALOFT PROGGED TO CONTINUE ACROSS THE REGION THROUGH THE DAY MONDAY AS PAC NW SHORT WAVE CONTINUES ACROSS THE NORTHERN TIER. ANY CLOUDS ACROSS THE PLAINS WILL CONTINUE TO DIMINISH THROUGH THE EVENING WITH CLEAR SKIES EXPECTED THROUGH THE OVERNIGHT. WITH THE WESTERLY FLOW...WEAK LEE TROUGH TO DEVELOP ACROSS THE I-25 CORRIDOR...AND SHOULD SEE BREEZY CONDITIONS AND WARMING TEMPS THROUGH THE OVERNIGHT ACROSS THE LOWER EASTERN SLOPES. LEE TROUGH MOVES ACROSS THE EASTERN PLAINS MONDAY AFTERNOON IN RESPONSE TO NORTHERN TIER SHORT WAVE...AND WITH MOSTLY SUNNY SKIES PROMOTING GOOD MIXING...SHOULD SEE SOUTH TO SOUTHWEST WINDS OF 15 TO 25 MPH AND DRIER AIR MIXING DOWN ACROSS THE AREA THROUGH THE AFTERNOON. WITH H7 TEMPS PROGGED BETWEEN 0 AND +4C ALONG WITH DOWNSLOPE FLOW...HAVE STAYED CLOSER TO THE WARM SIDE OF GUIDANCE WITH HIGHS IN THE 60S TO LOWER 70S ACROSS THE PLAINS AND IN THE MID 30S TO MID 50S ACROSS THE HIGHER TERRAIN AND HIGH MT VALLEYS. WITH ABOVE NORMAL TEMPERATURES...AFTERNOON HUMIDITIES AT OR BELOW 15 PERCENT AND BREEZY CONDITIONS...COULD SEE A BRIEF PERIOD OF CRITICAL FIRE WEATHER CONDITIONS DEVELOPING ACROSS PORTIONS OF THE EASTERN PLAINS MONDAY AFTERNOON. HOWEVER...HAVE OPTED NOT TO ISSUE ANY HIGHLIGHTS ATTM...AS SET UP LOOKS MARGINAL IN DEVELOPMENT AND DURATION. IF WINDS ARE STRONGER THAN FORECAST...THE MOST LIKELY AREAS OF CRITICAL FIRE WEATHER BEHAVIOR WOULD BE ACROSS BACA...KIOWA...BENT AND PROWERS COUNTIES...WHICH DID NOT RECEIVE AS MUCH PRECIPITATION WITH THIS LAST SYSTEM. -MW .LONG TERM... (TUESDAY THROUGH SUNDAY) ...NEAR CRITICAL FIRE WEATHER CONDITIONS POSSIBLE TUE-THU... ...HIGH TERRAIN SNOW MELT TO CONTINUE THROUGH MUCH OF THE WEEK... TUESDAY...MIDDLE TO UPPER LEVEL WESTERLY FLOW WILL PERSIST ACROSS THE CENTRAL ROCKIES WITH 700MB TEMPERATURES 0C TO +2C OVER THE MOUNTAINS/HIGH VALLEYS TO AROUND +4C ACROSS SOUTHEAST CO. MODELS CONTINUE TO ADVERTISE A SHALLOW WEAK COLD FRONT TO SLIP INTO THE EASTERN CO PLAINS DURING TUESDAY...BUT ITS ONLY AFFECTS WOULD BE TO DROP HIGH TEMPERATURES A FEW DEGREES ACROSS THE FAR SOUTHEASTERN CO PLAINS. MIXING TO 600MB WOULD SUPPORT TEMPERATURES INTO THE 60S TO AROUND 70F ALONG THE I-25 CORRIDOR. ANY "SIGNIFICANT" WINDS... BREEZY TO WINDY...WOULD LIKELY BE ACROSS THE HIGHER TERRAIN. MET MOS IS RELATIVELY TOO STRONG WITH ITS WIND SPEEDS(BIAS) AND OPTED FOR A 50/50 BLEND WITH THE MAV MOS FOR WINDS. WILL PROBABLY NEED ANOTHER DAY FOR FINE FUEL CURING GIVEN LAST NIGHT`S SNOWFALL ACROSS PORTIONS OF SOUTHEAST CO...BUT IT MELTED QUICKLY AND IT DOESN`T TAKE LONG TO DRY OUT THE FINE FUELS(1 HOUR)...WHICH WILL OCCUR MONDAY AND TUESDAY. WEDNESDAY...THIS DAY CONTINUES TO LOOK LIKE THE POSSIBILITY FOR ALL WEATHER CONDITIONS COMING TOGETHER FOR CRITICAL FIRE WEATHER CONCERNS. THE NAM-WRF AND GFS BOTH SUPPORT INCREASE MIDDLE AND MOUNTAIN TOP WIND FLOW...ESPECIALLY BY THE AFTERNOON. SFC/PBL DRYLINE SETS UP ACROSS THE CO/KS BORDER AND SHOULD MIX OUT AND DIURNALLY SHIFT EASTWARD DURING THE DAY AS DRY ADIABATIC MIXING OCCURS WEDNESDAY AFTERNOON. WITH THE MIXING...MIXED LAYER STEEP LAPSE RATES 8.5-9.5 C/KM...AND MUCH DRIER AIR ALOFT...SHOULD SEE SURFACE WINDS INCREASE BY THE AFTERNOON AND EARLY EVENING. 700MB TEMPERATURES ARE PROGGED TO BE +2C TO +4C OVER THE MOUNTAINS/HIGH VALLEYS AND +6C TO +7C ACROSS SOUTHEAST CO. DEEP DRY ADIABATIC MIXING WOULD SUPPORT 70S ACROSS MUCH OF SOUTHEAST CO AND 30S TO 60S ACROSS THE MOUNTAINS/HIGH VALLEYS/RIDGES. ALSO...I WOULDN`T BE SURPRISED TO SEE SURFACE DEW POINTS DROP INTO THE SINGLE DIGITS ALONG THE I-25 CORRIDOR IF THE DEEP MIXING OCCURS. MODEL MOS AND RAW GRIDDED DATA ARE CONSISTENTLY TOO HIGH IN THESE METEOROLOGICAL PATTERNS...SO I DROP DEW POINTS ABOUT 5 DEGREES WEDNESDAY AFTERNOON AND EARLY EVENING. THE BIGGEST QUESTION WILL BE ALL WEATHER FEATURES BECOMING JUXTAPOSED TO SUPPORT CRITICAL FIRE WEATHER CONDITIONS. THE FINER FUELS SHOULD TRYOUT AND THERE IS THE MODERATE DROUGHT OCCURRING ACROSS EASTERN LAS ANIMAS...BENT... PROWERS...AND BACA COUNTIES. HAINES VALUES WILL BE 4-5. DAYTIME HUMIDITY VALUES WILL LIKELY DROP BELOW 20%...BUT WHAT WILL BE THE WINDS. ALREADY HAD SEVERAL GRASSLAND WILDFIRE EVENTS ACROSS PORTIONS OF EAST CENTRAL AND SOUTHEAST CO IN THE LAST COUPLE OF WEEKS. HIGH TERRAIN SNOW MELT WILL LIKELY CONTINUE WITH DAYTIME TEMPERATURES IN THE 30S AND 40S GENERALLY AT AND ABOVE 10K FT MSL. THURSDAY AND FRIDAY...UPPER LEVEL JET STREAM AND JET STREAKS BEGIN TO DROP INTO THE CENTRAL ROCKIES DURING THESE PERIODS. WEDNESDAY NIGHT/THURSDAY MORNING LOW TEMPERATURES WILL BE A BIG CHALLENGE GIVEN THE VIGOROUS WESTERLY FLOW ALOFT. WOULDN`T BE SURPRISED TO SEE SOME WIND GUSTS OF 40-50KTS ACROSS OUR NORTH-SOUTH ORIENTED MOUNTAINS ALONG THE PEAKS AND EASTERN SLOPES. GFS/DGEX/ECMWF CONTINUE TO SUPPORT A COLD FRONT DROPPING THROUGH EASTERN CO THURSDAY. ANY CHANCE FOR PRECIPITATION SHOULD BE ALONG THE CONTINENTAL DIVIDE THURSDAY AND THEN SHIFT EASTWARD INTO THE SOUTHEAST CO PLAINS TOWARDS THE COLD FRONT THURSDAY NIGHT/FRIDAY MORNING. 800-700MB AND 700-600MB LAYER SUPPORTING FRONTOGENETICAL FORCING(IMPLIED UPWARD VERTICAL MOTION) TO DRIVE PRECIPITATION. INITIAL THE SUB- CLOUD LAYER SHOULD SUPPORT MOSTLY RAIN...BUT COULD SWITCH OVER TO A RAIN/SNOW MIX OR ALL SNOW GIVEN THE ELEVATION LATE THURSDAY NIGHT/FRIDAY MORNING. EQUIVALENT POTENTIAL VORTICITY VALUES AROUND OR SLIGHT BELOW 0 PVU SUPPORTS SOME LAYER CONVECTIVE POTENTIAL SUPPORT SOME MODERATE-HEAVIER PRECIPITATION POTENTIAL THURSDAY NIGHT/FRIDAY MORNING. I INCREASED POPS/WX TO "CHANCE" ACROSS OUR EASTERN MOUNTAINS AND I-25 CORRIDOR FOR THURSDAY NIGHT/FRIDAY GIVEN THIS SETUP. THURSDAY`S HIGH TEMPERATURES WILL BE A CHALLENGE ACROSS SOUTHEAST CO GIVEN THE VIGOROUS WESTERLY FLOW AHEAD OF THE COLD FRONT AND COULD SUPPORT A QUICK JUMP INTO THE 60S BEFORE FALLING MIDDLE TO LATE AFTERNOON. TRENDED FRIDAY TEMPERATURES MUCH COOLER THAN PREVIOUS DAYS. SATURDAY AND SUNDAY...ENSEMBLE DATA ARE ALL OVER THE PLACE FOR THE FLOW REGIME ON DAY 6-7. GENERALLY STUCK WITH HPC TEMPERATURES. ANY PRECIPITATION CHANCES WOULD BE ALONG THE CONTINENTAL DIVIDE WITH MUCH LESSER CHANCES EAST OF THE DIVIDE NEXT WEEKEND. METZE && .AVIATION... LOW LEVEL SOUTHERLY FLOW HAS KEPT MVFR AND PATCHY IFR CIGS BANKED UP ACROSS RAMPART RANGE AND KCOS. EXPECTING CLOUDS TO CONTINUE TO DIMINISH THROUGH THE EVENING AS NORTHERLY DRAINAGE FLOWS DEVELOP. EXPECTING VFR CONDITIONS TO PERSIST ACROSS THE REST OF THE AREA THROUGH MONDAY. -MW && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 23/17 co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 417 AM MDT SUN MAR 23 2008 .SHORT TERM... (TODAY AND TONIGHT) MAIN CONCERN IS WHEN WILL THE SNOW SHOWERS END. CURRENTLY...AS OF 2 AM...LIGHT SNOW WAS FALLING ALONG THE I-25 CORRIDOR FROM S OF DENVER TO THE NM BORDER. SOME OF THE LIGHT SNOW EXTENDED E OUT ONTO THE PLAINS. SNOW ACCUMS HAVE BEEN GENERALLY LIGHT WITH AMOUNTS IN THE 1-3" RANGE. WEB CAMS UP IN THE COS AREA SHOW THE INTERSTATE PARTIALLY COVERED WITH LIGHT SNOW. TODAY...AS PER LATEST 06Z NAM AND RUC GUIDANCE..ANY SNOW SHOWERS ALONG THE I-25 CORRIDOR FROM PUB N TO KCOS SHOULD BE ENDING PRIOR TO SUNRISE (~7AM) AT THE LATEST WITH CLOUDS DECREASING SHORTLY THEREAFTER AS MID LVL DRYING ADVECTS INTO SE CO. SOME SNOW SHOWERS MAY LINGER A BIT LATER S OF PUB INTO MID MORNING. BY MID TO LATE MORNING NEARLY ALL AREAS SHOULD SEE MOSTLY SUNNY SKIES WITH MAX TEMPS AROUND 50 (40S KCOS AREA)...30S AND 40S MTNS. TONIGHT...CLEAR SKIES AND COOL TEMPS WITH LOWS IN THE 20S PLAINS AND TEENS MTNS. /HODANISH .LONG TERM...(MONDAY THROUGH SATURDAY) MODELS CONTINUE TO BE FAIRLY STABLE THROUGH THE EXTENDED PERIOD. 00Z OP GFS IS SIMILAR TO ENSEMBLE MEANS...SO HAVE USED THIS RUN GENERALLY FOR FCST DETAILS. THE POLAR JET WILL BE N OF CO...RUNNING THRU NRN WY/SRN MT...THRU WED. AM NOT EXPECTING ANY PRECIP THRU TUE EVE. ZONAL FLOW ALOFT WILL DOMINATE THRU MIDWEEK...LEADING TO DRY AND WARM CONDITIONS OVR THE PLAINS FOR THIS PERIOD. HAVE MAINTAINED ISOLD TO SCT POPS TUE NITE THRU WED OVR THE CONTDVD...ALTHOUGH MOISTURE LOOKS LIMITED AND EVEN THESE LOW POPS MAY BE A BIT GENEROUS. DRY AND BREEZY CONDITIONS WILL CONTINUE THRU TUE AND PEAK ON WED...LEADING TO FIRE WEATHER CONCERNS. DOES NOT LOOK TO BE A CRITICAL FIRE WX SCENARIO AT THIS POINT...AS SFC WINDS DO NOT LOOK PARTICULARLY STRONG AND LOW HUMIDITIES ARE MARGINAL. EXCEPTION MIGHT BE OVR THE EXTREME SE GRASSLANDS WED INTO THU. TONIGHT`S LIGHT SNOW WILL HELP MOISTEN FUELS A BIT OVR MUCH OF SE CO...ALTHOUGH SHORT TERM FUELS WILL NOT TAKE LONG TO DRY OUT. A TROUGH WILL MOVE THROUGH THE ROCKIES LATE WED THRU FRI. THE TROUGH WILL AMPLIFY ON THU...AS A COLD FRONT DROPS THRU ERN CO. STILL SOME UNCERTAINTY AS TO HOW MUCH COLD AIR TO EXPECT AND THE AMT AND LOCATION OF PRECIP TO EXPECT WITH THIS SYSTEM. BEST BET FOR PRECIP APPEARS TO BE THU...WITH THE ARRIVAL OF THE FRONT...SO HAVE INTRODUCED LOW POPS OVR THE PLAINS THIS DAY...AND BOOSTED MTN POPS TO A GOOD CHANCE. ROSE && .AVIATION...MAIN CONCERN IS HOW FAST KCOS WILL CLEAR OUT. GUIDANCE SHOWS WEAK S FLOW DEVELOPING TOWARDS SUNRISE AND THIS MAY KEEP LOW CIGS OVER THE KCOS AREA INTO MID MORNING. ALL GUIDANCE SHOWS THE AREA CLEARING OUT BY MID TO LATE MORNING. AS FOR KPUB...LOW CIGS SHOULD CONTINUE UNTIL AROUND 15Z AND THEN DECREASE THEREAFTER...BECOMING VFR. KALS WILL REMAIN CLEAR THROUGH THE NEXT 24H. /HODANISH && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 34/44 co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 310 PM MDT SAT MAR 22 2008 .SHORT TERM... (TONIGHT AND SUNDAY) SHORT TERM CONCERNS INCLUDE PRECIP CHANCES AND AMOUNTS WITH PASSING SHORT WAVE AND ASSOCIATED COLD FRONT. CURRENT WATER VAPOR IMAGERY AND RUC UPPER AIR ANALYSIS INDICATING INCREASING NORTHWEST FLOW ALOFT ACROSS THE REGION WITH AN EMBEDDED SHORT WAVE AND ASSOCIATED 80+ KT JET CORE MOVING ACROSS SOUTH CENTRAL WYOMING ATTM. AT THE SFC...A BOUNDARY IS CURRENTLY BACKED UP ACROSS THE RAMPART RANGE ACROSS SOUTHEASTERN EL PASO COUNTY AND BACK THROUGH NORTHEAST COLORADO...WITH LATEST MSAS DATA INDICATING 1-2MB PRESSURE FALLS ACROSS THE SOUTHERN I-25 CORRIDOR ATTM. FOR TONIGHT...MODERATE NORTHWEST FLOW EMBEDDED SHORT WAVE ACROSS SOUTH CENTRAL WYOMING CONTINUES ACROSS THE NORTHEASTERN COLORADO WITH SECONDARY SURGE OF COLD AIR MOVING ACROSS THE SOUTHEAST PLAINS OVERNIGHT. UVV ASSOCIATED WITH BOUNDARY AND WEAK ISENTROPIC LIFT HAS ALLOWED FOR SCATTERED TO WIDESPREAD SHOWERS TO DEVELOP ACROSS TELLER AND EL PASO COUNTY LATE THIS MORNING THROUGH THE AFTERNOON. I AM EXPECTING THIS AREA OF PRECIP TO CONTINUE THROUGH THE EARLY EVENING AND THEN BEGIN TO SHIFT SOUTH AND WEST THROUGH THE LATE EVENING AND OVERNIGHT AS SFC-H7 FLOW TURNS MORE EAST TO NORTHEAST BEHIND PASSING SYSTEM. MOISTURE REMAINS LIMITED WITH THIS SYSTEM AND HAVE KEPT SNOW ACCUMULATIONS GENERALLY RANGING BETWEEN 2 TO 6 INCHES ACROSS THE EASTERN MTS WITH 1 TO 4 INCHES ACROSS THE IMMEDIATE ADJACENT PLAINS AND UP TO 1 ELSEWHERE. SUNDAY...WEST TO NORTHWEST FLOW MODERATES THROUGH THE DAY AS FLAT UPPER LEVEL RIDGING BUILDS ACROSS THE GREAT BASIN. EAST TO NORTHEAST LOW LEVEL UPSLOPE FLOW ACROSS THE PLAINS SUNDAY MORNING WILL KEEP LOW CLOUDS ACROSS THE PLAINS THROUGH THE MORNING WITH SOUTHERLY RETURN FLOW DEVELOPING AND CLEARING SKIES EXPECTED THROUGH THE AFTERNOON. HAVE KEPT SLIGHT POPS ACROSS THE SOUTHERN MTS EARLY SUNDAY MORNING FOR ANY LINGERING PRECIP...THOUGH WOULD EXPECT ONLY FLURRIES IF AT ALL. -MW .LONG TERM... (MONDAY THROUGH SATURDAY) ...WARMING TREND FOR NEXT WEEK ON TRACK... ...CRITICAL FIRE WEATHER CONCERNS INCREASING MON THROUGH THU... ...HIGH TERRAIN SNOW MELT SHOULD CONTINUE NEXT WEEK... MONDAY THROUGH WEDNESDAY...WESTERLY FLOW CONTINUES TO BE ADVERTISED ACROSS THE CENTRAL ROCKIES BY ALL OF THE MODELS. VERY LITTLE CHANCE FOR PRECIPITATION...BUT FIRE WEATHER CONCERNS COULD BE ON THE INCREASE...MAINLY ACROSS THE I-25 CORRIDOR AND SOUTHEAST COLORADO PLAINS. 700MB TEMPERATURES WARM TO +2C OVER THE MOUNTAINS/HIGH VALLEYS TO +6 TO +8C OVER THE SOUTHEAST CO PLAINS DURING THE EARLY TO MIDDLE PARTS OF THE WEEK. THIS WOULD PROMOTE HIGH TEMPERATURES IN THE 60S/70S ACROSS SOUTHEAST CO AND 30S TO 50S ACROSS THE MOUNTAINS AND HIGH VALLEYS. THE WARMEST DAYS STILL LOOKS TO BE WEDNESDAY WITH MIDDLE TO UPPER LEVEL WINDS BACKING TO A SOUTHWESTERLY COMPONENT AHEAD OF THE NEXT UPPER LEVEL JET STREAK ENTERING THE GREAT BASIN BY LATE WEDNESDAY. DRYLINE DEVELOPS ALONG CO/KS BORDER WEDNESDAY MORNING...BUT SHOULD MIX OUT WITH THE DEEP "DRY" SOUTHWESTERLY FLOW ENTRAINING INTO THE LOWER TROP/SURFACE. A VERY SHALLOW AND WEAK COLD FRONT CONTINUES TO BE FORECAST ACROSS THE FAR EASTERN CO/WESTERN KS PLAINS LATE MONDAY NIGHT/TUESDAY MORNING AND MIGHT TAKE A FEW DEGREES OFF THE HIGH TEMPERATURES ACROSS THE FAR SOUTHEAST CO PLAINS ON TUESDAY. WITH DAYTIME TEMPERATURES AROUND 10-15 DEGREES ABOVE AVERAGE...DAYTIME HUMIDITY LEVELS LESS THAN 20%...AND BREEZY-WINDY CONDITIONS...THERE IS A POTENTIAL FOR CRITICAL FIRE WEATHER CONDITIONS TO DEVELOP MAINLY ALONG AND EAST OF I-25 CORRIDOR. THERE HAVE ALREADY BEEN A FEW PLAINS GRASSLAND FIRES OCCURRING OVER THE PAST WEEK. CRITICAL FIRE WEATHER CONDITIONS LOOK MARGINAL MONDAY AND TUESDAY WITH WEDNESDAY STILL LOOKING LIKE SEVERE CRITICAL FIRE WEATHER CONDITIONS POSSIBLE BY THE LATE MORNING THROUGH EVENING. MODERATE DROUGHT CONDITIONS CONTINUE ACROSS PORTIONS OF SOUTHEAST CO PLAINS INCLUDING LAS ANIMAS... BENT...PROWERS...AND BACA COUNTIES. THE FINER FUELS...ONE HOUR GRASSES...WEEDS...ETC...ARE STILL DEAD FAIRLY "DRY" DESPITE ANY PRECIPITATION THAT FALLS THIS AFTERNOON AND TONIGHT. HELD OFF ISSUING A FIRE WEATHER WATCH FOR MONDAY GIVEN THE MARGINAL WIND CONDITIONS WHILE ALL THE OTHER PARAMETERS WOULD EXIST. I DID UPDATE THE HAZARDOUS WEATHER OUTLOOK TO UPDATE THE POTENTIAL CRITICAL FIRE WEATHER CONDITIONS. WITH 10K FT MSL AND ABOVE ELEVATIONS GETTING INTO THE 30S/40S EACH DAY...HIGH TERRAIN SNOW MELT SHOULD CONTINUE THROUGH MUCH OF NEXT WEEK. THURSDAY THROUGH SATURDAY...UPPER LEVEL JET STREAM IS PROJECTED TO SAG INTO THE CENTRAL MOUNTAINS THURSDAY AND FRIDAY...AND RETREAT NORTHWARD BY SATURDAY. WITH THE UPPER LEVEL JET STREAM OVERHEAD...BREEZY TO WINDY CONDITIONS WILL BE LIKELY...ESPECIALLY ACROSS THE MOUNTAINS. PACIFIC COLD FRONT FORECAST TO MOVE THROUGH THE CENTRAL ROCKIES WEDNESDAY NIGHT/THURSDAY MORNING WITH BORA TYPE MODERATE-HIGH WIND POTENTIAL THURSDAY. TEMPERATURES WILL BE SLIGHTLY COOLER ACROSS THE SOUTHEAST COLORADO PLAINS...BUT DAYTIME HUMIDITY LEVELS WILL BE BELOW 20% WITH BREEZY-WINDY CONDITIONS CONTINUING A CRITICAL FIRE WEATHER THREAT ALONG AND EAST OF I-25 CORRIDOR. THE BETTER CHANCES FOR PRECIPITATION WOULD BE AROUND THE CONTINENTAL DIVIDE WITH VERY SLIGHT CHANCE EAST OF THE CONTINENTAL DIVIDE...BUT NOT AMOUNTING TO MUCH GIVEN THE VIGOROUS WESTERLY FLOW ALOFT LATE IN THE WEEK INTO THE WEEKEND. METZE && .AVIATION... MVFR AND OCCASIONAL IFR CONDITIONS EXPECTED ACROSS THE EASTERN MTS AND IMMEDIATE ADJACENT PLAINS TONIGHT...AS SHOWERS ASSOCIATED WITH A PASSING COLD FRONT CONTINUE TO SHIFT SOUTH AND WEST ACROSS THE I-25 CORRIDOR OVERNIGHT. WEAK EAST TO SOUTHEAST FLOW BEHIND PASSING FRONT WITH KEEP MVFR AND PATCHY IFR CIGS FOR KCOS THROUGH SUNDAY MORNING...WITH MOSTLY SUNNY SKIES EXPECTED THROUGH THE AFTERNOON. -MW && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 23/17 co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MELBOURNE FL 419 AM EDT SUN MAR 23 2008 .DISCUSSION... CURRENTLY-TODAY...JET EXTENDING NORTHEASTWARD FROM THE MID ATLANTIC COAST WILL PULL WEAK UPPER TROUGH EVIDENT IN RUC ANALYSIS/SATELLITE IMAGERY ACROSS THE AREA TODAY. THIS WILL PUT AN END TO RAINFALL CURRENTLY LINGERING IN FAR SOUTHEAST SECTIONS...WHICH IS ASSOCIATED WITH WEAK WAVE ON OLD FRONTAL BOUNDARY. PASSAGE OF THE WEAK WAVE WILL INDUCE LIGHT NORTH WINDS AND START TO DRY THINGS OUT...THOUGH THE MAIN COOL/DRY AIR SHOULD REMAIN TO OUR NORTH. WILL LEAVE SMALL POP IN THE FAR SOUTH WHERE LOW LEVEL MOISTURE MAY SUPPORT SOME REDEVELOPMENT OF SHOWERS DURING DAYTIME HEATING...AS EARLY MORNING CLOUD COVER GRADUALLY BREAKS UP. TONIGHT...BROAD TROUGH ALOFT ACROSS THE EASTERN PART OF THE COUNTRY WILL AMPLIFY WHICH WILL INDUCE CYCLOGENESIS ALONG SLOW MOVING FRONTAL BOUNDARY OFF THE SOUTHEAST COAST. THIS SHOULD LEAD TO A SURGE OF NORTHWEST/NORTH FLOW AND USHER IN SOME COOLER/DRIER AIR LATE. WITH UPPER TROUGH AXIS STAYING TO OUR WEST...WOULD EXPECT SOME MID/HIGH LEVEL CLOUDINESS TO CONTINUE. MON-WED...DRY FCST IN STORE AS A STRONG W/NWRLY FLOW DEVELOPS ACROSS THE PENINSULA. THE APPROACHING COLD FRONT SHOULD PUSH INTO THE FL STRAITS BY DAYBREAK MON AS THE DLM RIDGE AXIS OVER THE HIGH PLAINS DROPS INTO THE LWR MS VALLEY. MEANWHILE...A STRONG SRN BRANCH OF THE H25 JET WILL PUSH ACROSS THE GOMEX AND WILL BE IN POSITION TO INDUCE A NEW SFC LOW ALONG THE FRONTAL BOUNDARY. AS THIS LOW FORMS...IT WILL INTERACT WITH THE APPROACHING RIDGE TO GENERATE A STEADY AND DEEP W/NW FLOW ACROSS THE REGION. MON MORNING MINS IN THE M50S/L60S WILL BE NEAR CLIMO...BUT INCREASING NWRLY FLOW THRU THE DAY WILL KEEP MAX TEMPS IN THE U60S/M70S...~5-10F DEG BLO CLIMO. CRUX OF THE COLD AIR WILL PUSH INTO THE CENTRAL PENINSULA MON NIGHT WITH MINS FALLING INTO THE L/M40S NW OF ORLANDO...AND INTO THE U40/L50S ALONG THE COAST N OF JUPITER INLET. ALL IN ALL...MINS WILL BE ~10-15F BLO CLIMO. WINDS WILL SHIFT TO THE NE ON TUE AS THE RIDGE AXIS PULLS OFF THE ERN SEABOARD. WHILE THE NRLY COMPONENT WILL KEEP MAX TEMPS BLO CLIMO ON TUE...THE ONSHORE COMPONENT WILL ADVECT MODIFIED OCEAN AIR ONSHORE...ALLOWING TEMPS TO RECOVER BACK TO NEAR CLIMO BY WED MORNING. THU-SAT...SFC RIDGE WILL BECOME ESTABLISHED OVER THE SW ATLC BY DAYBREAK THU...GENERATING A STEADY ONSHORE FLOW THAT WILL RETURN TEMPS TO NEAR CLIMO. BOTH GFS/ECMWF ARE FORECASTING THE NEXT STORM SYSTEM TO FORM OVER THE CENTRAL PLAINS ~12Z THU...TOO FAR N TO UPROOT THE RIDGE AXIS. SYSTEM MOST LIKELY WILL RIDE UP THE BACKSIDE OF THE RIDGE AND DRAG A WEAK COLD FRONT INTO THE STATE OVER THE WEEKEND. INCREASED SRLY FLOW AHEAD OF THE FRONT WOULD GENERATE ABV CLIMO TEMPS...WHILE A WEAKENING FRONT WITH LITTLE SUPPORT FROM A DEPARTING PARTING PARENT LOW WOULD GENERATE LOW END POPS AT BEST. LATEST EXTENDED MOS GUIDANCE NOW INDICATING ~20% POPS FRI THRU SUN AS THE SRLY FLOW TAPS MOISTURE OVER THE NW CARIB. HOWEVER...POTENTIAL IMPACT FROM THESE SHOWERS WILL BE LOW. PREFER NOT TO INTRODUCE THREE DAYS WORTH OF SMALL POPS WHEN THE PREVIOUS FCST WAS DRY... WILL NOT MENTION THEM FOR NOW UNTIL THE TREND BECOMES A LITTLE MORE ESTABLISHED. && .AVIATION...THERE HAVE BEEN SOME MVFR CEILINGS/FOG EARLY THIS MORNING BUT GENERALLY EXPECT VFR CONDITIONS DURING THE DAY. && .MARINE...WINDS/SEAS SHOULD NOT BE A PROBLEM TODAY AS WEAK SURFACE TROUGH MOVES ACROSS THE WATERS. BY LATE TONIGHT A NORTH WIND SURGE SHOULD BEGIN...ESPECIALLY ACROSS THE NORTH. MON-FRI...LCL PGRAD WILL TIGHTEN AFT 12Z MON AS THE SFC LOW FORMS ALONG THE FRONTAL BOUNDARY OVER THE BAHAMAS. DEPENDING ON THE STRENGTH AND ORGANIZATION OF THE LOW...COULD SEE SCA CONDITIONS DEVELOP OVER THE NRN COASTAL WATERS AS EARLY AS 18Z MON...AND AREAWIDE BY 00Z TUE. NWRLY FLOW WOULD GENERATE HIGHER THAN NORMAL SEAS DUE TO THE OPPOSING WIND/GULF STREAM DIRECTIONS. WINDS WILL DIMINISH BLO SCA BY 00Z WED AS THE STORM SYSTEM DEPARTS AND THE RIDGE BUILDS OVER THE DEEP S. HOWEVER...SEAS EXPECTED TO REMAIN ELEVATED INTO THE WEEKEND AS A NERLY SWELL GENERATED BY THE DEPARTING STORM SYSTEM BEGINS TO IMPACT THE E FL COAST. && .FIRE WEATHER...STRONG DRY AIR ADVECTION WILL OCCUR BEHIND THE COLD FRONT AS STEADY W/NWRLY FLOW PREVAILS THRU THE H100-H70 LYR. RFW CONDITIONS ANTICIPATED ALONG AND NORTH OF THE I-4 CORRIDOR DUE TO 4HR RH DURATIONS AND SFC WIND SPEEDS ~15MPH. LOW RH WILL CONTINUE TUE AFTN...BUT WITH SFC/BNDRY LYR WINDS EXPECTED TO VEER TO THE NE...RFW CONDITIONS ARE LESS LIKELY AND WOULD BE CONFINED MAINLY TO LAKE CO. && .PRELIMINARY POINT TEMPS/POPS... DAB 76 56 68 43 / 10 10 10 0 MCO 78 57 72 45 / 10 10 10 0 MLB 76 59 74 47 / 10 10 10 0 VRB 77 60 75 48 / 10 10 10 0 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING FOR COASTAL VOLUSIA-INLAND VOLUSIA-NORTHERN LAKE-ORANGE- OSCEOLA-SEMINOLE-SOUTHERN LAKE. AM...NONE. && $$ SHORT TERM/AVIATION...LASCODY LONG TERM....BRAGAW fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 345 AM EDT SUN MAR 23 2008 .SHORT TERM...CURRENT MSAS ANALYSIS SHOWS TWO DISTINCT AREAS OF LOW PRESSURE OVER THE DEEP SOUTH. THE FIRST IS OFF THE COAST OF THE CAROLINAS WITH A DRY FRONT EMANATING TO THE SOUTHWEST AND THE SECOND LOW IS PERCHED OFFSHORE THE SOUTH FLORIDA COAST. SANDWICHED BETWEEN THESE FEATURES IS A VERY WEAK HIGH PRESSURE RIDGE AXIS OVER NORTHEAST FLORIDA. LOW TO THE SOUTH CONTINUES TO SPREAD MOISTURE NORTHWARD BUT THIS HAS ONLY RESULTED IN CLOUD COVER AS OPPOSED TO PRECIP AS DOME OF HIGH PRESSURE HAS TOO LITTLE COOL AIR TO PROVIDE ENOUGH ISENTROPIC SLOPE FOR RAINFALL. TO THE WEST OF THE REGION...STRONG HIGH PRESSURE IS BUILDING SOUTHWARD THROUGH THE PLAINS AND LOWER MISSISSIPPI VALLEY BUT RIDGE INFLUENCES REMAIN NORTH OF OUR AREA. ALOFT...RUC ANALYSIS CONTINUE TO SHOW A ZONAL FLOW WITH PERIODIC IMPULSES QUICKLY TRANSLATING EASTWARD THROUGH THE REGION. FOR THE REMAINDER OF TODAY...GFS AND NAM12 IN AGREEMENT ON A MORE SIGNIFICANT MID LEVEL TROUGH SWINGING THROUGH OHIO VALLEY AND INTO THE TENNESSEE VALLEY WITH A STRONGER IMPULSE MAKING ITS WAY INTO OUR REGION AS WELL. THIS WILL ALLOW THE TWO LOW PRESSURE REGIONS TO JOIN UP INTO A SINGLE TROUGH AXIS AND BEGIN TO LIFT OUT OF THE REGION. WILL CARRY SILENT 10 POPS FOR FLORIDA ZONES TODAY...BUT THERE IS AN OPPORTUNITY FOR A CONVERGENT BAND TO SET UP IN DEVELOPING NORTHEAST COASTAL FLOW LATE THIS AFTERNOON AS EVIDENCED BY THE NAM12. STILL BELIEVE THIS WILL BE MAINLY A COASTAL WATERS PHENOMENON AND WILL KEEP POPS BELOW 20%. AS STRONG MID LEVEL TROUGH APPROACHES THE AREA MONDAY MORNING...LOW LEVELS WILL BEGIN TO DRY OUT QUICKLY WHILE A BAND OF BKN ALTO-CU SHOULD MOVE THROUGH WITHOUT MUCH FANFARE ACCORDING TO MODEL CROSS SECTIONS. DEEP LAYER DRYING WILL COMMENCE QUICKLY AFTER 18Z MONDAY WITH SUB 10% RH ABOVE 850 MB FOR MOST AREAS. HIGH TEMPS MONDAY IN DEVELOPING COLD AIR ADVECTION PATTERN WILL RUN SOME 10 DEGREES BELOW CLIMO. HIGH BRIDGES ACROSS VERY QUICKLY THROUGH TUE MORNING WITH CENTER OF HIGH OVER SOUTH CENTRAL GA...PROVIDING EXCELLENT RADIATIONAL COOLING CONDITIONS FOR OUR NORTHERN ZONES. ONLY FLY IN THE OINTMENT WILL BE THE UPPER 60S WATER TEMPS WHICH WHEN COMBINED WITH LOW TEMPS IN THE 30S OVER THE MAINLAND MAY LEAD TO MORE OF A GRADIENT THAN MODELS DEPICT. FOR THIS REASON AND THE FACT THAT GUIDANCE NUMBERS ARE NOT QUITE AS COLD AS PREVIOUS RUNS...WILL HOLD OFF ON A FREEZE WATCH FOR AN ADDITIONAL CYCLE. HIGH REMAINED OVER THE AREA FOR TUE AFTERNOON WITH MOSTLY SUNNY BUT CONTINUED UNSEASONABLY COOL CONDITIONS WITH HIGH TEMPS ONLY IN THE MID 60S. .LONG TERM...DESPITE ZONAL FLOW ALOFT...SURFACE HIGH IS STUBBORN IN SHIFTING EAST OF THE AREA BUT FINALLY DOES BY WEDNESDAY. MODERATING TEMPS EXPECTED THROUGH THE PERIOD AND SHOULD BE GOING BACK ABOVE CLIMO BY WEEKS END. RETURN FLOW ON THE WEST SIDE OF HIGH SHOULD ALLOW SOME COASTAL SHOWERS TO DEVELOP BY FRIDAY WITH MORE SUBSTANTIAL RAIN IN STORE FOR THE MAINLAND SAT NIGHT AS NEXT WEAK FRONT MOVES THROUGH. && .AVIATION...OCNL MVFR IN BR IN JAX...CRG AND GNV EARLY THIS MORNING WITH PLENTIFUL LOW LEVEL MOISTURE IN PLACE. AS COLD FRONT PUSHES THROUGH LATE THIS MORNING...ANTICIPATE CLEARING CONDITIONS AND VFR THROUGH TONIGHT. && .MARINE...WINDS WILL SHIFT TO N AND NE TODAY AS THE FRONT SLIPS S OF THE AREA. APPEARS MARGINAL SCEC CONDS ARE POSSIBLE...ESPECIALLY FOR THE OFFSHORE WATERS SO WILL INCLUDE THIS HEADLINE. REINFORCING SHOT OF COOL AIR AND WEAK LOW PRESSURE OFFSHORE AROUND 30N75W THAT TOGETHER MAY WARRANT SCA HEADLINES FOR MON INTO EARLY TUE. WINDS IN THE 20-25 KT RANGE ARE POSSIBLE. WILL HOLD FOR THIS HEADLINE FOR NOW. WINDS RELAX LATE TUE INTO WED AS HIGH PRESSURE SETTLES OVER THE AREA. S-SELY FLOW ANTICIPATED LATER IN THE WEEK AS ANOTHER COLD FRONT APPROACHES THE AREA. && .FIRE WEATHER...COLD FRONT WILL USHER IN DRIER CONDITIONS THIS AFTERNOON. HOWEVER...LOW LEVEL MOISTURE PROFILES NOT AS IMPRESSIVE AS A COUPLE OF DAYS AGO AND THUS WILL ONLY UPGRADE A PORTION OF THE FIRE WX WATCH WITH MIN RH VALUES FORECAST TO BE ABOUT 30%. FOR MONDAY...MUCH DRIER LOW LEVELS ON NWLY FLOW NEAR 10-20 MPH WITH GUSTS UP TO 25-30 MPH POSSIBLE. THUS FIRE WEATHER WATCH LOOKS GOOD...AS IT APPEARS WE WILL RATHER EASILY MEET CRITERIA IN NE FL. A LITTLE BIT TRICKER IN SE GA WHERE WE NEED TO MEET SUSTAINED WIND OF 20 MPH OR FREQ GUSTS TO 25 MPH. STILL APPEARS RED FLAG WARNINGS ARE POSSIBLE FOR TUE MAINLY INLAND AREAS OF NE FL BEFORE BETTER MOISTURE ADVECTION OCCURS. && .PRELIMINARY POINT TEMPS/POPS... AMG 71 39 62 31 / 0 0 0 0 SSI 65 46 60 41 / 0 0 0 0 JAX 71 44 65 36 / 0 0 0 0 SGJ 70 49 66 43 / 0 10 0 0 GNV 76 45 66 34 / 0 10 0 0 OCF 77 48 68 35 / 0 10 0 0 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING FOR ALACHUA-BAKER-BRADFORD-CLAY-COLUMBIA-DUVAL-FLAGLER- GILCHRIST-HAMILTON-MARION-NASSAU-PUTNAM-ST JOHNS-SUWANNEE- UNION. RED FLAG WARNING THIS AFTERNOON FOR BAKER...UNION...BRADFORD... ALACHUA...MARION. GA...FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING FOR APPLING-ATKINSON-BACON-BRANTLEY-CHARLTON-CLINCH-COASTAL CAMDEN-COASTAL GLYNN-COFFEE-ECHOLS-INLAND CAMDEN-INLAND GLYNN-JEFF DAVIS-PIERCE-WARE-WAYNE. AM...NONE. && $$ DEESE/SHASHY fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 300 AM EDT SAT MAR 22 2008 .SHORT TERM...LATEST MSAS ANALYSIS SHOWS A BROAD AREA OF LOW PRESSURE FROM THE YUCATAN PENINSULA THROUGH THE EAST CENTRAL GULF OF MEXICO. NORTH OF THIS FEATURE...A WEAK RIDGE OF HIGH PRESSURE EXISTS...GENERALLY ALONG THE INTERSTATE 10 CORRIDOR FROM LOUISIANA THROUGH THE PANHANDLE AND INTO NORTHEAST FLORIDA. ALOFT...RUC ANALYSIS SHOWS A ZONAL FLOW FROM 500 MB THROUGH 200 MB WITH CIRRUS TO THE WEST QUICKLY ADVECTING INTO THE AREA UNDER THE INFLUENCE OF STRONG WESTERLY FLOW. OTHERWISE...FLOW HAS REMAINED JUST OFFSHORE ENOUGH IN THE BOUNDARY LAYER TO KEEP A LARGE MAJORITY OF THE STRATO-CU FROM CREEPING INLAND AND RESULTING IN CONTINUED MOSTLY CLEAR CONDITIONS FOR AREAS WEST OF INTERSTATE 95. FOR THE REMAINDER OF TODAY...A CHALLENGING PRECIP FORECAST IN STORE AS MODELS AT LEAST AGREE ON A SHARP POP GRADIENT...BUT WHERE THAT GRADIENT RESIDES IS THE BIG QUESTION. BASED ON INITIALIZED FIELDS...AND LEANING HEAVILY TOWARDS THE NAM12 FOR THE SHORT TERM AS THE GFS SEEMS MUCH TOO SHARP WITH THE SURFACE AND MID LEVEL TROUGHS INITIALLY AND KEEPS THIS TREND GOING THROUGH 00Z SUN. THE NAM12 IS MUCH CLOSER TO THE INITIALIZED SURFACE PATTERN CURRENTLY OBSERVED OVER THE GULF AND PREFER ITS SOLUTION OF MORE OF AN OPEN WAVE MEANDERING SOUTH OF THE AREA ACROSS THE PENINSULA. THIS WOULDS NOT SPREAD PRECIP AS FAR NORTH AS GFS INDICATES AND POPS WOULD MAINLY BE CONFINED TO THE 3 SOUTHERN MOST COUNTIES OF THE FORECAST AREA. A MID LEVEL KICKER TROUGH ROTATES THROUGH DURING THE OVERNIGHT PERIOD ALLOWING PRECIP AXIS TO QUICKLY SHIFT SOUTH OF THE AREA. STRONG HIGH PRESSURE WILL THEN BUILD THROUGH THE CENTRAL PLAINS WITH RIDGE INFLUENCES REACHING ALL THE WAY TO THE EAST COAST. A MAJORITY OF THE COOLER AIR WILL REMAIN IN THE VICINITY OF PARENT HIGH WHILE OUR AREA CONTINUES TO SEE TEMPS SLIGHTLY BELOW NORMAL BUT STILL IN THE 70S. UPPER TROUGH SHARPENS A BIT AND SURFACE HIGH FINALLY BUILDS EASTWARD FOR MON. THIS WILL ALLOW FOR SOME COOLER AIR TO REACH THE FORECAST AREA WITH HIGHS IN THE 60S FOR MON AFTERNOON. HIGH SETTLES OVER THE AREA NICELY MON NIGHT...WITH PRIME RADIATIONAL COOLING CONDITIONS IN STORE FOR THE GA PORTION. MAY ACTUALLY SEE TEMPS APPROACH FREEZING OVER INLAND PORTIONS TUE MORNING AND EXPECT GUIDANCE NUMBERS TO COME DOWN A BIT AS WE APPROACH THE EVENT. .LONG TERM...SURFACE HIGHS INFLUENCE LOOKS TO BE LONG LASTING AS IT SHIFTS OFFSHORE NEXT WEEK BUT RIDGE AXIS MAINTAINS ITS POSITION OVER OUR AREA. MOST SYSTEMS DURING THIS TIME PERIOD WILL BE IN THE UPPER BRANCH OF THE JET AND PASS SAFELY BY TO THE NORTH. NO APPRECIABLE PRECIP ANTICIPATED IN THE EXTENDED AND TEMPS EXPECTED TO INCREASE TO ABOVE NORMAL RANGES BY THE END OF THE PERIOD. && .AVIATION...VFR CONDITIONS PREVAIL AT TAF SITES. SCT-BKN CIRRUS WILL SHIFT OVER THE AREA TODAY WITH GUIDANCE ALSO INDICATING A SCT-BKN DECK AROUND 4-6 KFT FORMING AS ISENTROPIC UPGLIDE INCREASES AHEAD OF A COLD FRONT. DRIER AIR WILL ADVECT INTO THE FORECAST AREA TONIGHT WITH VFR EXPECTED AND WIND SHIFT TO NW. && .MARINE...FAIRLY BENIGN WX CONDITIONS TODAY AS WEAK HIGH PRESSURE RIDGE DOMINATES THE AREA. SEAS OF 2-4 FT EXPECTED MOSTLY IN THE FORM OF LONG PERIOD E SWELL. THE COLD FRONT WILL SHIFT INTO THE WATERS TONIGHT WITH WINDS INCREASING FROM THE NW LATE. AT THIS TIME...SCA CONDITIONS ARE POSSIBLE FOR SUN BUT NOT CONFIDENT ENOUGH YET TO RAISE HEADLINES SO WILL WORD FOR INCREASING WINDS/SEAS IN THE FORECAST. BRISK NW FLOW CONTINUES INTO MON AS 1033 MB HIGH PRESSURE WILL REMAIN CENTERED NEAR MS WITH NW WINDS OF ABOUT 20 KT OR LESS FOR THE MARINE ZONES. WINDS AND SEAS DECREASE TUE AND WED AS HIGH PRESSURE RIDGE APPEARS TO SETTLE OVER THE REGION. SOME UPWARD TWEAKS MADE TO WAVEWATCH GUIDANCE IN THE NW-N FLOW SUN-TUE. && .FIRE WEATHER...USING A MODEL BLEND BUT WITH SOME GREATER WEIGHT PLACED ON THE NAM THERE IS A POTENTIAL FOR RED FLAG CONDS OVER NE FL OVER PORTIONS OF SUWANNEE COLUMBIA AND HAMILTON COUNTIES. HOWEVER...DURATIONS ARE MARGINAL AND GFS SOLUTION DOES NOT SUPPORT IT AT ALL. THUS WILL WORD THE FORECAST FOR LOW RH THERE TODAY AND LET DAYSHIFT MONITOR TRENDS FOR POSSIBLE SHORT FUSE WARNING. FOR SUNDAY...DRIER AIR WILL FILTER INTO THE AREA ON NLY FLOW AND LOW RH DURATIONS STILL SUPPORTIVE OF A RED FLAG WARNING. THUS WILL CONTINUE THE FIRE WEATHER WATCH WITH MIN RH POSSIBLE IN THE 25-30% RANGE IN THE WATCH AREA. ANOTHER POSSIBLE RED FLAG WARNING ON MONDAY FOR MOST OF NE FL. && .PRELIMINARY POINT TEMPS/POPS... AMG 75 45 69 42 / 10 0 0 0 SSI 69 51 68 47 / 10 0 0 0 JAX 73 50 72 45 / 10 0 0 0 SGJ 71 52 70 48 / 20 10 0 0 GNV 74 51 76 45 / 20 10 0 0 OCF 75 52 76 46 / 40 10 0 0 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING FOR ALACHUA-BAKER-BRADFORD-COLUMBIA-GILCHRIST-HAMILTON- MARION-SUWANNEE-UNION. GA...NONE. AM...NONE. && $$ DEESE/SHASHY fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 726 AM EDT SUN MAR 23 2008 .SYNOPSIS... A COLD FRONT WILL MOVE ACROSS THE REGION THIS MORNING. A STRONGER COLD FRONT WILL MOVE THROUGH THE AREA EARLY MONDAY MORNING...FOLLOWED BY HIGH PRESSURE BUILDING IN FOR MUCH OF NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... COLD FRONT HAS MOVED THROUGH CHARLESTON AND IS APPROACHING BEAUFORT. IT SHOULD CLEAR THROUGH THE CWA BY LATER THIS MORNING. AFTERNOON HIGH TEMPERATURES WILL THUS BE NOTICEABLY COOLER THAN YESTERDAY...REACHING THE UPPER 60S NORTH TO AROUND 70 DEGREES SOUTH. ONLY SKY COVER TODAY WILL BE IN THE FORM OF SOME SCATTERED CIRRUS. AN UPPER TROUGH APPROACHING FROM THE WEST THROUGHOUT THE DAY WILL BEGIN TO AMPLIFY TONIGHT AS IT NEARS THE EAST COAST. A SECONDARY SURGE OF COLD AIR WILL BEGIN TO ADVECT INTO THE FORECAST AREA TOWARD DAYBREAK MONDAY. GUIDANCE HAS TRENDED WARMER WITH OVERNIGHT LOW TEMPERATURES...WITH GFS SUGGESTING THAT THE LEADING EDGE OF THE COLD ADVECTION MAY NOT REACH THE WESTERN EDGE OF THE FORECAST AREA UNTIL AROUND DAYBREAK. HAVE INCREASED LOW TEMPERATURES A DEGREE OR TWO TONIGHT...BUT STILL KEEP VALUES BELOW GUIDANCE AT THIS POINT. HAVE REMOVED MENTION OF PATCHY FROST AS A RESULT OF THE SLIGHTLY WARMER TEMPERATURES. && .SHORT TERM /MONDAY THROUGH TUESDAY/... COLD ADVECTION WILL KICK IN ON MONDAY ON NORTHERLY WINDS BETWEEN LOW DEVELOPING IN THE WESTERN ATLANTIC AND HIGH SETTLING OVER THE SOUTHEAST. TEMPS WILL BE QUITE A BIT BELOW NORMAL MONDAY AFTERNOON DESPITE INCREASING SUNSHINE. MONDAY NIGHT WILL BE QUITE COLD FOR LATE MARCH. BASED ON CLEARING SKIES...LIGHTER WINDS...AND A MODIFIED POLAR AIR MASS...NEAR TO SLIGHTLY BELOW FREEZING TEMPS ARE EXPECTED OVER INTERIOR SECTIONS. WILL PUT UP A FREEZE WATCH FOR AREAS MAINLY NORTH AND WEST OF I-95. AFTER A CHILLY START...TUESDAY WILL BE MILDER AS COLD ADVECTION ENDS AND HIGH PRESSURE STARTS TO MOVE INTO THE WESTERN ATLANTIC. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... TEMPS WILL DROP QUICKLY AFTER SUNSET TUESDAY EVENING WITH DRY AIR...CLEAR SKIES...AND LIGHT WINDS...BUT AIR MASS SHOULD HAVE MODIFIED ENOUGH TO AVOID FREEZING TEMPS. THERE MAY BE A LITTLE FROST IN INTERIOR PROTECTED LOCATIONS...HOWEVER. THE WARM-UP THEN COMMENCES ON WEDNESDAY AS HIGH PRESSURE MAKES A DEFINITIVE MOVE INTO THE ATLANTIC AND SOUTHERLY WINDS BECOME ESTABLISHED ON THE BACK SIDE. THESE WARMER TEMPS WILL CONTINUE INTO SATURDAY. THE MODELS SHOW A COLD FRONT APPROACHING FROM THE WEST LATE SATURDAY...SO I HAVE INTRODUCED A SLIGHT CHANCE OF SHOWERS THEN...BUT THE REST OF THE PERIOD LOOKS DRY. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... WINDS HAVE SHIFTED TO THE NORTHEAST BEHIND THE FRONT AT CHS...BUT WILL TAKE A COUPLE MORE HOURS UNTIL THE FRONT MOVES THROUGH AT SAV. VWP AND START OF MORNING SOUNDING INDICATES 20+ KNOT WINDS AT 1K FEET...SO ONCE DAYTIME MIXING INITIATES...GUSTY NORTHEAST WINDS WILL DEVELOP. GRADIENT SHOULD RELAX LATER IN THE AFTERNOON. VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD...WITH MAINLY HIGH CLOUDS OVER THE TERMINALS. EXTENDED AVIATION OUTLOOK...VFR CONDITIONS EXPECTED THROUGH THE WEEK. EARLY MORNING GROUND FOG MAY BECOME AN ISSUE LATE IN THE WEEK...BUT TOO EARLY TO GET CONCERNED. && .MARINE... COLD FRONT REMAINS JUST NORTH OF THE COASTAL WATERS EARLY THIS MORNING. TIGHT PRESSURE GRADIENT BEHIND THE FRONT IN NORTH CAROLINA CONTINUES TO PRODUCE SMALL CRAFT ADVISORY CONDITIONS. ALTHOUGH WIND SURGE MAY BE A BIT DELAYED THAN ORIGINALLY DEPICTED...STILL FEEL THAT WINDS WILL INCREASE DURING AND FOLLOWING FRONTAL PASSAGE THROUGH THE MARINE ZONES. LATEST SOLUTION BY SHORT-RANGE RUC13 AGREES THAT THE GRADIENT WILL TIGHTEN AND ALLOW NORTHEAST WINDS TO SURGE INTO THE LATE MORNING HOURS. HAVE THUS MAINTAINED ONGOING ADVISORIES FOR THE NEARSHORE SC AND OFFSHORE GA WATERS. GRADIENT WILL RELAX DURING THE AFTERNOON AND WINDS SHOULD DIMINISH ACCORDINGLY. ANOTHER SURGE OF COLD AIR WILL PUSH SOUTHEAST BY EARLY MONDAY MORNING. STRONGEST WINDS AND HIGHEST SEAS WILL BE LATER MONDAY AND MONDAY NIGHT WHEN THE STRONGEST COLD ADVECTION IS OCCURRING. IT IS POSSIBLE WINDS MAY REACH SOME TYPE OF HIGHLIGHT CRITERIA FOR A FEW HOURS LATE MONDAY INTO MONDAY NIGHT...BUT IT SHOULD NOT LAST LONG AS THE GRADIENT QUICKLY RELAXES LATE MONDAY NIGHT INTO TUESDAY. TAME CONDITIONS THEN EXPECTED INTO THURSDAY UNDER HIGH PRESSURE. && .FIRE WEATHER... NEAR CRITICAL RH VALUES ARE EXPECTED THE NEXT COUPLE OF AFTERNOONS...ALTHOUGH THE COOL TEMPS MAY KEEP RH A BIT HIGHER MONDAY...WHICH IS GOOD SINCE THAT WILL BE THE DAY WITH STRONGER WINDS. RH COULD BE POTENTIALLY EVEN LOWER TUESDAY AND WEDNESDAY AFTERNOONS...BUT WINDS WILL NOT BE A PROBLEM. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...FREEZE WATCH FROM LATE MONDAY NIGHT THROUGH TUESDAY MORNING FOR GAZ087-088-099>101-114-115. SC...FREEZE WATCH FROM LATE MONDAY NIGHT THROUGH TUESDAY MORNING FOR SCZ040-042>045-047. MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR AMZ350- 352. SMALL CRAFT ADVISORY UNTIL NOON EDT TODAY FOR AMZ374. && $$ ga AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 320 AM CDT SAT MAR 22 2008 .SYNOPSIS... LATEST SFC ANALYSIS WAS INDICATING EARLY SPRING WINTER STORM CENTER OVER SOUTHEAST OH...WITH ASSOCIATED INVERTED TROF TRAILING BACK TO THE NORTHWEST INTO THE CENTRAL PORTIONS OF THE LOCAL FCST AREA. WEAK LOBE OF LLVL RIDGING WAS LOCATED FURTHER TO THE NORTHWEST FROM NEB...UP THROUGH THE THUNDER BAY REGION NORTH OF LK SUPERIOR. ALOFT...W/V IMAGERY WAS INDICATING A WAVE PUSHING OUT OF THE DAKOTAS AND ACRS WEST CENTRAL MN...AND ANOTHER ELONGATED VORT COMPLEX SHEARING OUT WITH MAIN UPPER JET AXIS FROM NORTHERN ID...PUNCHING DOWN INTO NORTHWEST MO. && .SHORT TERM...TODAY AND TONIGHT... BOTH THE NEW RUC AND NAM SUGGEST THAT LIGHT SNOW OR FLURRIES ASSOCIATED WITH LINGERING TROF AXIS EXTENDING BACK OF MAIN CYCLONE CENTER WILL CONTINUE TO SKIRT DOWN EAST-SOUTHEAST AND AFFECT THE FAR EASTERN CWA THROUGH 15Z OR SO AND WILL WALK THIS ACTIVITY OUT WITH AT LEAST SLIGHT CHC POPS. NORTHEASTERLY LLVL FLOW WILL TRY AND BRING SOME OF THE CLEARING OVER WI BEHIND LLVL STRATUS DECK SEEN ON IR LOOP INTO THE NORTHEAST AND EAST CENTRAL CWA AS THE DAY PROGRESSES...BUT ANY CLEARING MAY CU UP AGAIN WITH STEEPENING LLVL LAPSE RATES BY AFTERNOON. THE UPSTREAM VORT MENTIONED ABOVE WILL CONTINUE TO PROPAGATE DOWN ACRS THE CWA TODAY IN BROAD BUT STEEPENING UPPER CYCLONIC FLOW PATTERN. FEEL THIS FEATURE COULD GENERATE SOME PRECIP INTO AT LEAST THE NORTHWEST THIRD OF THE LOCAL FCST AREA BY THIS AFTERNOON...WITH THERMAL PROFILES SUGGESTING MAINLY SNOW NORTH OF I80...AND A MIX OF RAIN OR SNOW SHOWERS IF ANY OF THIS ACTIVITY CAN MAKE IT TO THE SOUTH OF I80. COOL FETCH NORTHEAST TRAJECTORIES SUGGEST WIDESPREAD UPPER 30S TO LOW 40S IN MOST OF THE DVN CWA AND ONGOING TEMPS LOOK GOOD. IF THE SOUTH CAN GET SOME BREAKS...STEEP MIXING WILL MAKE THE MOST OF THE COOL PROFILES AND SOME MID 40S WILL BE SEEN. TONIGHT...ANOTHER VORT ROTATING DOWN IN NORTHWEST UPPER FLOW MAY INDUCE MORE OF A ORGANIZED LIFT SCENARIO OVERNIGHT...AND WITH FCST SOUNDINGS SHOWING DEEPER SATURATION ESPECIALLY AFTER MIDNIGHT AND IN FAVORED -10 TO -20C LAYER...ITS LOOKING LIKE MORE AND MORE OF A CHANCE FOR SOME LIGHT SNOW TONIGHT. EXTENT OF FORCING AND LOW TO MID LEVEL SATURATION SUGGESTS THAT SOME AREAS MAY EVEN HAVE ACCUMULATIONS PUSHING AN INCH. MOST LOCALS WILL HAVE A DUSTING TO A FEW TENTHS BY 12Z SUNDAY. WILL GO WIDESPREAD 30 POPS FOR NOW...AND DAY CREW MAY HAVE TO BOOST THESE EVEN HIGHER. BACKING MEAN LAYER FLOW TO THE NORTH OR NORTHWEST WILL CONTINUE TO COLD ADVECT OVERNIGHT...WITH CLOUD COVER BEING THE ONLY FACTOR FROM PREVENTING LOWS FROM DIPPING INTO THE LOWER 20S OR EVEN SOME TEENS. ..12.. .LONG TERM...SUNDAY THROUGH FRIDAY... UPPER RIDGE OVER THE NORTHERN ROCKIES WILL CONTINUE TO PUMP COOL AIR INTO THE REGION FOR SUNDAY. STEEP LOW LEVEL LAPSE RATES INDICATED BY THE NAM AND GFS SUPPORT THE MENTION OF SNOW SHOWERS OR A MIX OF RAIN AND SNOW SHOWERS OVER MUCH OF THE AREA SUNDAY. KEPT MAINLY SNSH IN THE NORTH BUT CHANGED TO A MIX IN THE SRN HALF DURING THE AFTERNOON WHERE LOW LEVEL TEMPS ARE EXPECTED TO BE AROUND 40. ENERGY EJECTING OUT OF THE GULF OF ALASKA TROF WILL UNDER CUT THE RIDGE OVER THE ROCKIES MONDAY...SETTING UP A MORE ZONAL FLOW OVER THE REGION FOR THE THE MIDDLE OF THE WEEK. THE GFS/NAM/ECMWF ARE IN REASONABLE AGREEMENT EARLY ON MOVING A SURFACE LOW ALONG THE CANADIAN BORDER AND DRAGGING A COLD FRONT THROUGH THE MID MS VALLEY EARLY TUESDAY. THE COLD FRONTAL PASSAGE IS EARLIER THAN YDA SOLUTIONS...WHICH WILL HAVE AN IMPACT ON TEMPS TUESDAY. HAVE KEPT TUES TEMPS ABOUT THE SAME AS THE PREVIOUS FCST...BUT IF THE MODELS KEEP THE FROPA EARLY TUESDAY MORNING...THEN THESE TEMPS ARE TO WARM...ESPECIALLY IN THE NORTH. PCPN THREAT WITH THIS SYSTEM LOOKS NIL DUE TO THE LACK OF MOISTURE. THE GFS/ECMWF BOTH SHOW A BROAD H5 TROF DEVELOPING OVER THE WRN U.S. FOR THE END OF THE WEEK...IMPLYING TEMPS WILL HAVE A CHANCE TO RETURN TO NEAR NORMAL WITH SW FLOW DEVELOPING. PCPN CHANCES FOR THURSDAY AND FRIDAY STILL LOOK GOOD WITH BOTH THE ECMWF AND GFS DEVELOPING A SYSTEM OVER THE PLAINS BY THE END OF THE WEEK. ..DLF.. && .AVIATION... WIDESPREAD MVFR CIGS WILL CONTINUE THROUGH MID MORNING AT ALL TERMINALS...BUT THESE SHOULD RAISE TO VFR CRITERIA BY 18Z. SOME BREAKS MAY WORK IN FROM THE NORTH AND NORTHEAST OUT OF WI AND TEMPORARILY AFFECT THE DBQ AND POSSIBLY THE MLI TERMINALS DURING THE MIDDAY...BEFORE EXPECTED CU UP AGAIN BY LATE AFTERNOON DUE TO STEEP LLVL LAPSE RATES. THESE RATES MAY ALSO HELP NORTH WINDS GUST TO NEAR 20 MPH AT TIMES TODAY. SOME LIGHT MVFR SNOW COULD AFFECT THE CID TERMINAL THIS AFTERNOON...BUT A BETTER CHANCE FOR SOME MVFR OR EVEN POSSIBLE IFR CONDITIONS DUE TO LIGHT SNOW AT MOST TERMINALS BY 05Z- 06Z TONIGHT. ..12.. && .HYDROLOGY... TRIBUTARY RIVERS WILL CONTINUE TO SEE MINOR TO MODERATE FLOODING... WITH WAPSI RIVER NEAR DEWITT EXPECTED TO REACH THE MAJOR FLOOD CATEGORY BY THIS AFTERNOON. NO SIGNIFICANT PRECIPITATION IS EXPECTED THROUGH EARLY NEXT WEEK...WHICH WILL ALLOW MOST RIVER LEVELS TO FALL. THE SNOWS THAT OCCURRED OVER PARTS OF SOUTHERN WISCONSIN FRIDAY RENEWED THE SNOWPACK OVER PART OF THE PECATONICA AND ROCK RIVER BASINS. AS THIS SNOW MELTS DURING THE NEXT WEEK...THE RUNOFF WILL HELP KEEP UP THE WATER LEVELS ON THE PECATONICA AND ROCK RIVERS. ..DLF.. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ 12/DLF ia AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 255 PM MDT SUN MAR 23 2008 .DISCUSSION... 100 PM MDT SUN MAR 23 2008 NORTHWEST MID/UPPER FLOW CONTINUES ACROSS THE CENTRAL HIGH PLAINS WHILE H5 RIDGE CONTINUES TO TRANSLATE EAST/SOUTHEAST TOWARD THE CENTRAL ROCKIES. THE SHORT TERM CONCERN WILL BE THE POSSIBILITY FOR CRITICAL FIRE WEATHER CONDITIONS DEVELOPING MONDAY AFTERNOON AS DISCUSSED IN THE FIRE WEATHER SECTION BELOW. A CONTINENTAL POLAR AIRMASS WILL BUILD SOUTH ACROSS THE CENTRAL AND NORTHERN PLAINS ON TUESDAY AND THE CHALLENGE WILL BE DETERMINING IMPACT FROPA WILL HAVE ACROSS THE TRI-STATE AREA. THE COLDEST AIR WILL BE DIRECTED EAST OF THE AREA WHILE SOME CONCERN EXISTS FOR LIGHT PRECIPITATION DEVELOPING TUESDAY NIGHT INTO EARLY WEDNESDAY. 295-305K PRESSURE ADVECTION WITH CONVERGENT LOW LEVEL MOIST FLOW IN VICINITY OF WARM FRONT SUPPORTS INCREASING CLOUDS/POPS BUT CONFIDENCE IN ADDING PRECIPITATION REMAINS TO LOW. MAXIMUM TEMPERATURES MAY SURGE INTO THE 70S WEST OF SFC TROUGH AXIS WED AFTERNOON WHERE DEEPER VERTICAL MIXING IS ANTICIPATED LEADING TO THE POSSIBILITY FOR ADDITIONAL FIRE WEATHER CONCERNS. THURSDAY THROUGH SUNDAY...THERE CONTINUES TO BE CONSIDERABLE DISAGREEMENT ON THE TRACK AND TIMING OF THE MID WEEK EXTRATROPICAL CYCLONE. THE GFS IS ABOUT 18 HOURS SLOWER THAN THE ECMWF AND GEM IN THE PROGRESSION OF THE LOW FROM THE HIGH PLAINS TO THE GREAT LAKES REGION. THE GFS IS SLOWER BECAUSE IT SHOWS A VERY DEEP AND INTENSE CUTOFF LOW AT 500MB...WHICH SEAMS SUSPECT CONSIDERING THE 500MB PATTERN LATELY. THE CURRENT PROGRESSIVE PATTERN WOULD TEND TO FAVOR THE MORE PROGRESSIVE BUT LESS AMPLIFIED GEM. AS A RESULT...THE FORECAST INCLUDES SLIGHT CHANCE POPS BETWEEN 00Z AND 12Z FRIDAY...AND TEMPERATURES REBOUNDING QUICKER THAN THE GFS IS ADVERTISING. 26 44 && .FIRE WEATHER... 255 PM MDT SUN MAR 23 2008 LATEST RUNS OF THE HIGH RESOLUTION RUC13 SUGGEST RED FLAG CRITERIA COULD BE REACHED IN A LARGE PORTION OF THE FORECAST AREA MONDAY AFTERNOON. CRITICAL RH VALUES APPEAR LIKELY...WHILE WIND SPEEDS WILL BE A BIT MORE MARGINAL. HOWEVER...WITH DEEP MIXING FORECAST AT PEAK HEATING...FEEL POTENTIAL EXISTS FOR GUSTY WINDS REACHING THE 25 MPH CRITERIA FOR RED FLAG. 24 && .AVIATION... 1113 AM MDT SUN MAR 23 2008 FOR THE 18Z TAFS... VFR CONDITIONS EXPECTED THROUGH 24 HRS. SCT CU WILL DEVELOP BY EARLY AFTERNOON...WITH BASES AROUND 6KFT. CU WILL DISSIPATE WITH LOSS OF HEATING AT SUNSET. WEAKENING COLD FRONT WILL APPROACH KMCK TONIGHT...WITH WIND SHIFT TO SOUTHEAST...BUT SPEEDS WILL BE LESS THAN 10KTS SO NO AVIATION IMPACTS. 24 && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$ WFO GOODLAND ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 1113 AM MDT SUN MAR 23 2008 .DISCUSSION... 249 AM MDT SUN MAR 23 2008 NORTHWEST FLOW WILL CONTINUE THROUGH TUESDAY NIGHT WITH A RIDGE TO THE WEST. THE RIDGE FLATTENS SOME MONDAY NIGHT AS A SHORTWAVE MOVES ACROSS SOUTHERN CANADA. THE RIDGE THEN REBUILDS ITSELF TUESDAY NIGHT ACROSS THE ROCKIES. AT THE SURFACE...HIGH PRESSURE WILL BE OVER THE AREA TODAY. A TROUGH WILL SET UP OVER EASTERN COLORADO TONIGHT AND CONTINUE THROUGH MONDAY NIGHT. HIGH PRESSURE WILL BUILD IN BEHIND THEN EXITING TROUGH ON TUESDAY. LOW PRESSURE WILL MOVE INTO THE TEXAS PANHANDLE BY 06Z WED. THE MAIN FORECAST DECISIONS HAVE TO DO WITH TEMPERATURES. SUBSIDENCE DOMINATES THROUGH MONDAY. MOISTURE IS LACKING WITH THE TROUGH/FRONT MONDAY NIGHT AND INTO TUESDAY. CONSEQUENTLY THERE ARE NIL POPS FOR EACH PERIOD. THE GFS STILL SHOWS RELATIVE HUMIDITY AT 18-20 PERCENT MONDAY AFTERNOON. THE NAM IS BRINGING RH DOWN TO NEAR 15 PERCENT. GFS SURFACE WIND ARE ONLY 10=15KTS WHILE THE NAM IS SHOWING 15KTS. THE RUC IS INDICATING ONLY 10KTS SUSTAINED WITH ONLY 5KT GUSTS. THESE WINDS ARE WELL BELOW CRITICAL THRESHOLDS AND WOULD NOT BE CONFIDENT ENOUGH AT THIS POINT TO PUT OUT THE WATCH YET. 850MB TEMPERATURES START WARMING AGAIN TODAY. TEMPERATURES REACH THE MID/UPPER TEENS MONDAY AFTERNOON. TEMPERATURES FALL 5-7 DEGREES BEHIND THE FRONT ON TUESDAY. MAX TEMPERATURES SHOULD REACH INTO THE LOWER 70S MONDAY WITH MINS FALLING TO NEAR 30. FS && .AVIATION... 1113 AM MDT SUN MAR 23 2008 FOR THE 18Z TAFS... VFR CONDITIONS EXPECTED THROUGH 24 HRS. SCT CU WILL DEVELOP BY EARLY AFTERNOON...WITH BASES AROUND 6KFT. CU WILL DISSIPATE WITH LOSS OF HEATING AT SUNSET. WEAKENING COLD FRONT WILL APPROACH KMCK TONIGHT...WITH WIND SHIFT TO SOUTHEAST...BUT SPEEDS WILL BE LESS THAN 10KTS SO NO AVIATION IMPACTS. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$ WFO GOODLAND ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON KY 147 AM EDT SUN MAR 23 2008 .SHORT TERM.../THE REST OF TONIGHT/ HAVE UPDATED NDFD AND ASSOCIATED FORECAST PRODUCTS. LATEST SATELLITE TRENDS AND RUC RUNS SUPPORT IDEA OF KEEPING CLOUDS IN SOUTH FOR MUCH OF THE NIGHT...WITH BREAKS WORKING INTO THE NORTHERN PART OF FORECAST AREA. THE EXTENT OF CLOUDINESS WILL DETERMINE OVERNIGHT LOWS. HAVE KEPT LOWS AS THEY WERE IN THE NORTH...BUT RAISED LOWS A DEGREE OR TWO IN THE SOUTH WHERE CLOUDS WILL HANG ON THE LONGEST. HAVE ALSO ADJUSTED GRIDS TO HOLD ONTO SPRINKILES A LITTLE LONGER THROUGH THE EVENING IN THE NORTHERN PART OF AREA. THE PREVIOUS SHORT TERM FORECAST DISCUSSION FOLLOWS... /THE REST OF TONIGHT/ HOURLY TEMPERATURES WERE ALREADY RUNNING SEVERAL DEGREES COOLER THAN FORECAST SO HAVE UPDATED HOURLY GRIDS TO REFLECT THIS. TEMPERATURE FALL WILL BE SLOWER THE REST OF THE EVENING. COLD AIR ADVECTION WILL CONTINUE BUT WILL BE WEAK BASED ON UPSTREAM OBSERVATIONS. THERE WILL BE EXTENSIVE LOW CLOUDINESS THAT WILL LIMIT THE TEMPERATURE FALL. BASED ON LATEST SATELLITE TRENDS AND TIME HEIGHT CROSS SECTIONS FROM 18Z NAM AND GFS LOOKS LIKE OVERCAST WILL PREVAIL FOR MUCH OF THE NIGHT...WITH BREAKS TOWARDS MORNING BEFORE CLOUDS INCREASE AGAIN DURING DAY SUNDAY. LATEST RUC ALSO IN SUPPORT OF THIS. AS SUCH HAVE ALSO UPDATED SKY GRIDS. MINOR ADJUSTMENTS BASED ON CURRENT OBSERVATIONS ALSO MADE TO DEW POINTS AND WINDS. OVERALL FORECAST IN GOOD SHAPE AND NO CHANGE TO ZFP AT THIS TIME. HOWEVER AFM AND PFM HAVE BEEN UPDATED AS WELL AS NDFD AND POINT AND CLICK FORECAST. AT THE VERY LEAST AN UPDATE TO THE ZFP WILL BE NEEDED LATER TO REMOVE THE EARLY WORDING FOR TONIGHT. THE PREVIOUS SHORT TERM FORECAST DISCUSSION FOLLOWS... /TONIGHT THROUGH SUNDAY NIGHT/ THE MODELS ARE IN GOOD AGREEMENT WITH THROUGH SUNDAY NIGHT WITH A FAIRLY ZONAL FLOW BECOMING A TROUGH OVER THE AREA. THE FRONT THAT MOVED ACROSS THE AREA TODAY WAS BATTLING TO TAKE FOOT HOLD OVER THE AREA. THE SUN DID A GOOD JOB AT ERODING AWAY THE LEADING EDGE OF THE CLOUDS THAT WERE FORMING IN THE COLD AIR BEHIND THE FRONT...ESPECIALLY IN THE I 75 CORRIDOR SOUTH AND WEST OF LONDON. AS THE SUN GOES DOWN...THESE CLOUDS SHOULD BE ABLE TO CONTINUE THEIR MARCH EASTWARD AND THEN BURN OFF ON SUNDAY MORNING AS THE HIGH CLOUDS FROM THE NEXT CLIPPER LIKE SYSTEM MOVES TOWARD THE AREA. THE BIGGEST ISSUE WITH THE NEXT SYSTEM IS THE AVAILABILITY OF MOISTURE. THE NAM MODEL SOUNDING IN QUITE UNSTABLE ON SUNDAY NIGHT...HOWEVER THE MOISTURE IS QUITE LIMITED. AS SUCH...JUST WENT A MIX OF ISOLATED TO SCATTERED RAIN AND SNOW SHOWERS WHICH WILL TURN TO ALL SNOW SHOWERS IN THE EARLY MORNING HOURS. LITTLE OR NO ACCUMULATION IS EXPECTED. DUE TO THE LIMITED AVAILABILITY OF MOISTURE...LITTLE OR NOW ACCUMULATION IS EXPECTED. FOR TEMPERATURES...WENT WITH A BLEND OF THE COLDER ETA AND WARMER GFS MOS. .LONG TERM.../MONDAY THROUGH SATURDAY/ GENERAL MODEL AGREEMENT CONTINUES WITH COOLER NORTHWEST FLOW PATTERN PROGGED ACROSS THE OHIO VALLEY EARLY NEXT WEEK...TRANSITIONING TO A ZONAL FLOW PATTERN TO FOLLOW FOR THE MIDDLE AND END OF THE WEEK. UNSEASONABLY COLD AIR MASS AND A SHORT WAVE TROUGH WILL PROVIDE THE AREA WITH A FEW SNOW SHOWERS EARLY MONDAY MORNING. MODELS HAVE TRENDED STRONGER WITH THIS WAVE OVER THE PAST FEW RUNS...SO HAVE CONTINUED WITH AT LEAST ISOLATED TO SCATTERED PRECIPITATION FOR MONDAY MORNING. NAM CONTINUES TO BE A LITTLE ON THE COLD SIDE FOR HIGHS ON MONDAY...WHILE THE GFS HAS COME IN COOLER AND CLOSER TO REASONABLE VALUES...GENERALLY MID TO UPPER 40S. HIGH PRESSURE WILL THEN BUILD IN FOR MONDAY NIGHT THROUGH TUESDAY...BEFORE A COLD FRONT MOVES IN FROM THE NORTHWEST LATE TUESDAY NIGHT INTO WEDNESDAY. LATEST GUIDANCE HAS THIS FRONT COMING IN A BIT SOONER THAN BEFORE...AND GIVEN THE TRANSITION TO THE FASTER FLOW PATTERN...THIS TREND SEEMS REASONABLE. HAVE THEREFORE INCLUDED POPS IN BY LATE TUESDAY NIGHT INTO WEDNESDAY. HOW FAR SOUTH THIS FRONT MAKES IT STILL REMAINS QUESTIONABLE AT THIS TIME. MODELS HAVE TRENDED A BIT MORE LESS PROGRESSIVE WITH THE FRONT...HOLDING HIGH PRESSURE UP MORE IN THE GREAT LAKES. FORECAST THEN BECOMES ESPECIALLY LOWER CONFIDENCE FROM THURSDAY ON...AS A PLAINS SYSTEM GETS ORGANIZED OFF TO THE WEST...BRINGING THE BOUNDARY BACK NORTH OF THE AREA BY THURSDAY...AND ALLOWING US TO BE IN THE WARM SECTOR UNTIL SATURDAY...WHEN A COLD FRONT SWEEPS ACROSS THE AREA. HAVE BROAD-BRUSHED THE PRECIPITATION CHANCES THROUGH THE LATTER HALF OF THE WEEK...KEEPING AT LEAST LOW CHANCES IN EVERY PERIOD...GIVEN THE UNCERTAINTY OF THE EVOLUTION OF THE PLAINS SYSTEM. TEMPERATURES WILL START OUT BELOW NORMAL...BEFORE MODIFYING TO ABOVE NORMAL BY THE MIDDLE AND END OF NEXT WEEK. && .AVIATION.../06Z TO 06Z/...UPDATED GENERALLY MVFR CIGS CONTINUE TO HANG OVER MUCH OF EASTERN KENTUCKY... IFR IN THE HIGHER ELEVATIONS. DO NOT EXPECT STRATOCU DECK TO ERODE MUCH BETWEEN NOW AND DAWN. GRADUAL LIFTING AND SCATTERING OUT OF CLOUD BY MID MORNING SUNDAY. HOWEVER...CLOUDS WILL BE QUICK TO RETURN LATE IN THE DAY WITH APPROACH OF NEXT DISTURBANCE INTO THE REGION. && .JKL WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...JJ/SBH LONG TERM....GEOGERIAN AVIATION...RAY ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON KY 956 PM EDT SAT MAR 22 2008 .SHORT TERM.../THE REST OF TONIGHT/...UPDATED HAVE UPDATED NDFD AND ASSOCIATED FORECAST PRODUCTS. LATEST SATELLITE TRENDS AND RUC RUNS SUPPORT IDEA OF KEEPING CLOUDS IN SOUTH FOR MUCH OF THE NIGHT...WITH BREAKS WORKING INTO THE NORTHERN PART OF FORECAST AREA. THE EXTENT OF CLOUDINESS WILL DETERMINE OVERNIGHT LOWS. HAVE KEPT LOWS AS THEY WERE IN THE NORTH...BUT RAISED LOWS A DEGREE OR TWO IN THE SOUTH WHERE CLOUDS WILL HANG ON THE LONGEST. HAVE ALSO ADJUSTED GRIDS TO HOLD ONTO SPRINKILES A LITTLE LONGER THROUGH THE EVENING IN THE NORTHERN PART OF AREA. THE PREVIOUS SHORT TERM FORECAST DISCUSSION FOLLOWS... /THE REST OF TONIGHT/ HOURLY TEMPERATURES WERE ALREADY RUNNING SEVERAL DEGREES COOLER THAN FORECAST SO HAVE UPDATED HOURLY GRIDS TO REFLECT THIS. TEMPERATURE FALL WILL BE SLOWER THE REST OF THE EVENING. COLD AIR ADVECTION WILL CONTINUE BUT WILL BE WEAK BASED ON UPSTREAM OBSERVATIONS. THERE WILL BE EXTENSIVE LOW CLOUDINESS THAT WILL LIMIT THE TEMPERATURE FALL. BASED ON LATEST SATELLITE TRENDS AND TIME HEIGHT CROSS SECTIONS FROM 18Z NAM AND GFS LOOKS LIKE OVERCAST WILL PREVAIL FOR MUCH OF THE NIGHT...WITH BREAKS TOWARDS MORNING BEFORE CLOUDS INCREASE AGAIN DURING DAY SUNDAY. LATEST RUC ALSO IN SUPPORT OF THIS. AS SUCH HAVE ALSO UPDATED SKY GRIDS. MINOR ADJUSTMENTS BASED ON CURRENT OBSERVATIONS ALSO MADE TO DEW POINTS AND WINDS. OVERALL FORECAST IN GOOD SHAPE AND NO CHANGE TO ZFP AT THIS TIME. HOWEVER AFM AND PFM HAVE BEEN UPDATED AS WELL AS NDFD AND POINT AND CLICK FORECAST. AT THE VERY LEAST AN UPDATE TO THE ZFP WILL BE NEEDED LATER TO REMOVE THE EARLY WORDING FOR TONIGHT. THE PREVIOUS SHORT TERM FORECAST DISCUSSION FOLLOWS... /TONIGHT THROUGH SUNDAY NIGHT/ THE MODELS ARE IN GOOD AGREEMENT WITH THROUGH SUNDAY NIGHT WITH A FAIRLY ZONAL FLOW BECOMING A TROUGH OVER THE AREA. THE FRONT THAT MOVED ACROSS THE AREA TODAY WAS BATTLING TO TAKE FOOT HOLD OVER THE AREA. THE SUN DID A GOOD JOB AT ERODING AWAY THE LEADING EDGE OF THE CLOUDS THAT WERE FORMING IN THE COLD AIR BEHIND THE FRONT...ESPECIALLY IN THE I 75 CORRIDOR SOUTH AND WEST OF LONDON. AS THE SUN GOES DOWN...THESE CLOUDS SHOULD BE ABLE TO CONTINUE THEIR MARCH EASTWARD AND THEN BURN OFF ON SUNDAY MORNING AS THE HIGH CLOUDS FROM THE NEXT CLIPPER LIKE SYSTEM MOVES TOWARD THE AREA. THE BIGGEST ISSUE WITH THE NEXT SYSTEM IS THE AVAILABILITY OF MOISTURE. THE NAM MODEL SOUNDING IN QUITE UNSTABLE ON SUNDAY NIGHT...HOWEVER THE MOISTURE IS QUITE LIMITED. AS SUCH...JUST WENT A MIX OF ISOLATED TO SCATTERED RAIN AND SNOW SHOWERS WHICH WILL TURN TO ALL SNOW SHOWERS IN THE EARLY MORNING HOURS. LITTLE OR NO ACCUMULATION IS EXPECTED. DUE TO THE LIMITED AVAILABILITY OF MOISTURE...LITTLE OR NOW ACCUMULATION IS EXPECTED. FOR TEMPERATURES...WENT WITH A BLEND OF THE COLDER ETA AND WARMER GFS MOS. .LONG TERM.../MONDAY THROUGH SATURDAY/ GENERAL MODEL AGREEMENT CONTINUES WITH COOLER NORTHWEST FLOW PATTERN PROGGED ACROSS THE OHIO VALLEY EARLY NEXT WEEK...TRANSITIONING TO A ZONAL FLOW PATTERN TO FOLLOW FOR THE MIDDLE AND END OF THE WEEK. UNSEASONABLY COLD AIR MASS AND A SHORT WAVE TROUGH WILL PROVIDE THE AREA WITH A FEW SNOW SHOWERS EARLY MONDAY MORNING. MODELS HAVE TRENDED STRONGER WITH THIS WAVE OVER THE PAST FEW RUNS...SO HAVE CONTINUED WITH AT LEAST ISOLATED TO SCATTERED PRECIPITATION FOR MONDAY MORNING. NAM CONTINUES TO BE A LITTLE ON THE COLD SIDE FOR HIGHS ON MONDAY...WHILE THE GFS HAS COME IN COOLER AND CLOSER TO REASONABLE VALUES...GENERALLY MID TO UPPER 40S. HIGH PRESSURE WILL THEN BUILD IN FOR MONDAY NIGHT THROUGH TUESDAY...BEFORE A COLD FRONT MOVES IN FROM THE NORTHWEST LATE TUESDAY NIGHT INTO WEDNESDAY. LATEST GUIDANCE HAS THIS FRONT COMING IN A BIT SOONER THAN BEFORE...AND GIVEN THE TRANSITION TO THE FASTER FLOW PATTERN...THIS TREND SEEMS REASONABLE. HAVE THEREFORE INCLUDED POPS IN BY LATE TUESDAY NIGHT INTO WEDNESDAY. HOW FAR SOUTH THIS FRONT MAKES IT STILL REMAINS QUESTIONABLE AT THIS TIME. MODELS HAVE TRENDED A BIT MORE LESS PROGRESSIVE WITH THE FRONT...HOLDING HIGH PRESSURE UP MORE IN THE GREAT LAKES. FORECAST THEN BECOMES ESPECIALLY LOWER CONFIDENCE FROM THURSDAY ON...AS A PLAINS SYSTEM GETS ORGANIZED OFF TO THE WEST...BRINGING THE BOUNDARY BACK NORTH OF THE AREA BY THURSDAY...AND ALLOWING US TO BE IN THE WARM SECTOR UNTIL SATURDAY...WHEN A COLD FRONT SWEEPS ACROSS THE AREA. HAVE BROAD-BRUSHED THE PRECIPITATION CHANCES THROUGH THE LATTER HALF OF THE WEEK...KEEPING AT LEAST LOW CHANCES IN EVERY PERIOD...GIVEN THE UNCERTAINTY OF THE EVOLUTION OF THE PLAINS SYSTEM. TEMPERATURES WILL START OUT BELOW NORMAL...BEFORE MODIFYING TO ABOVE NORMAL BY THE MIDDLE AND END OF NEXT WEEK. && .AVIATION.../00Z TO 24Z/ MVFR CIGS HAVE BEEN TRYING TO COVER EASTERN KY FOR MOST OF THE DAY BUT THE LATE MARCH SUN KEPT ERODING THE EDGE AWAY AS FAST AS IT WAS ADVANCING. WITH THE LOSS OF THE SUNSHINE THE CLOUDS WILL FINALLY BE ABLE TO COVER THE ENTIRE AREA. EXPECT THE SHORT WAVE THAT BROUGHT THE CLOUDS TO THE AREA TO FINALLY MOVE EAST AND WITH THE RISING SUN THE CLOUDS SHOULD SCATTER OUT AND LIFT TO VFR. SOME SHRA TO MOVE INTO THE AREA BUT NOT UNTIL AFTER THE END OF THIS FCST. WILL PROBABLY HAVE SOME VCSH IN THE 06Z FCST. && .JKL WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...JJ/SBH LONG TERM....GEOGERIAN AVIATION...DUSTY ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON KY 709 PM EDT SAT MAR 22 2008 .SHORT TERM.../THE REST OF TONIGHT/...UPDATED HOURLY TEMPERATURES WERE ALREADY RUNNING SEVERAL DEGREES COOLER THAN FORECAST SO HAVE UPDATED HOURLY GRIDS TO REFLECT THIS. TEMPERATURE FALL WILL BE SLOWER THE REST OF THE EVENING. COLD AIR ADVECTION WILL CONTINUE BUT WILL BE WEAK BASED ON UPSTREAM OBSERVATIONS. THERE WILL BE EXTENSIVE LOW CLOUDINESS THAT WILL LIMIT THE TEMPERATURE FALL. BASED ON LATEST SATELLITE TRENDS AND TIME HEIGHT CROSS SECTIONS FROM 18Z NAM AND GFS LOOKS LIKE OVERCAST WILL PREVAIL FOR MUCH OF THE NIGHT...WITH BREAKS TOWARDS MORNING BEFORE CLOUDS INCREASE AGAIN DURING DAY SUNDAY. LATEST RUC ALSO IN SUPPORT OF THIS. AS SUCH HAVE ALSO UPDATED SKY GRIDS. MINOR ADJUSTMENTS BASED ON CURRENT OBSERVATIONS ALSO MADE TO DEW POINTS AND WINDS. OVERALL FORECAST IN GOOD SHAPE AND NO CHANGE TO ZFP AT THIS TIME. HOWEVER AFM AND PFM HAVE BEEN UPDATED AS WELL AS NDFD AND POINT AND CLICK FORECAST. AT THE VERY LEAST AN UPDATE TO THE ZFP WILL BE NEEDED LATER TO REMOVE THE EARLY WORDING FOR TONIGHT. THE PREVIOUS SHORT TERM FORECAST DISCUSSION FOLLOWS... /TONIGHT THROUGH SUNDAY NIGHT/ THE MODELS ARE IN GOOD AGREEMENT WITH THROUGH SUNDAY NIGHT WITH A FAIRLY ZONAL FLOW BECOMING A TROUGH OVER THE AREA. THE FRONT THAT MOVED ACROSS THE AREA TODAY WAS BATTLING TO TAKE FOOT HOLD OVER THE AREA. THE SUN DID A GOOD JOB AT ERODING AWAY THE LEADING EDGE OF THE CLOUDS THAT WERE FORMING IN THE COLD AIR BEHIND THE FRONT...ESPECIALLY IN THE I 75 CORRIDOR SOUTH AND WEST OF LONDON. AS THE SUN GOES DOWN...THESE CLOUDS SHOULD BE ABLE TO CONTINUE THEIR MARCH EASTWARD AND THEN BURN OFF ON SUNDAY MORNING AS THE HIGH CLOUDS FROM THE NEXT CLIPPER LIKE SYSTEM MOVES TOWARD THE AREA. THE BIGGEST ISSUE WITH THE NEXT SYSTEM IS THE AVAILABILITY OF MOISTURE. THE NAM MODEL SOUNDING IN QUITE UNSTABLE ON SUNDAY NIGHT...HOWEVER THE MOISTURE IS QUITE LIMITED. AS SUCH...JUST WENT A MIX OF ISOLATED TO SCATTERED RAIN AND SNOW SHOWERS WHICH WILL TURN TO ALL SNOW SHOWERS IN THE EARLY MORNING HOURS. LITTLE OR NO ACCUMULATION IS EXPECTED. DUE TO THE LIMITED AVAILABILITY OF MOISTURE...LITTLE OR NOW ACCUMULATION IS EXPECTED. FOR TEMPERATURES...WENT WITH A BLEND OF THE COLDER ETA AND WARMER GFS MOS. .LONG TERM.../MONDAY THROUGH SATURDAY/ GENERAL MODEL AGREEMENT CONTINUES WITH COOLER NORTHWEST FLOW PATTERN PROGGED ACROSS THE OHIO VALLEY EARLY NEXT WEEK...TRANSITIONING TO A ZONAL FLOW PATTERN TO FOLLOW FOR THE MIDDLE AND END OF THE WEEK. UNSEASONABLY COLD AIR MASS AND A SHORT WAVE TROUGH WILL PROVIDE THE AREA WITH A FEW SNOW SHOWERS EARLY MONDAY MORNING. MODELS HAVE TRENDED STRONGER WITH THIS WAVE OVER THE PAST FEW RUNS...SO HAVE CONTINUED WITH AT LEAST ISOLATED TO SCATTERED PRECIPITATION FOR MONDAY MORNING. NAM CONTINUES TO BE A LITTLE ON THE COLD SIDE FOR HIGHS ON MONDAY...WHILE THE GFS HAS COME IN COOLER AND CLOSER TO REASONABLE VALUES...GENERALLY MID TO UPPER 40S. HIGH PRESSURE WILL THEN BUILD IN FOR MONDAY NIGHT THROUGH TUESDAY...BEFORE A COLD FRONT MOVES IN FROM THE NORTHWEST LATE TUESDAY NIGHT INTO WEDNESDAY. LATEST GUIDANCE HAS THIS FRONT COMING IN A BIT SOONER THAN BEFORE...AND GIVEN THE TRANSITION TO THE FASTER FLOW PATTERN...THIS TREND SEEMS REASONABLE. HAVE THEREFORE INCLUDED POPS IN BY LATE TUESDAY NIGHT INTO WEDNESDAY. HOW FAR SOUTH THIS FRONT MAKES IT STILL REMAINS QUESTIONABLE AT THIS TIME. MODELS HAVE TRENDED A BIT MORE LESS PROGRESSIVE WITH THE FRONT...HOLDING HIGH PRESSURE UP MORE IN THE GREAT LAKES. FORECAST THEN BECOMES ESPECIALLY LOWER CONFIDENCE FROM THURSDAY ON...AS A PLAINS SYSTEM GETS ORGANIZED OFF TO THE WEST...BRINGING THE BOUNDARY BACK NORTH OF THE AREA BY THURSDAY...AND ALLOWING US TO BE IN THE WARM SECTOR UNTIL SATURDAY...WHEN A COLD FRONT SWEEPS ACROSS THE AREA. HAVE BROAD-BRUSHED THE PRECIPITATION CHANCES THROUGH THE LATTER HALF OF THE WEEK...KEEPING AT LEAST LOW CHANCES IN EVERY PERIOD...GIVEN THE UNCERTAINTY OF THE EVOLUTION OF THE PLAINS SYSTEM. TEMPERATURES WILL START OUT BELOW NORMAL...BEFORE MODIFYING TO ABOVE NORMAL BY THE MIDDLE AND END OF NEXT WEEK. && .AVIATION.../00Z TO 24Z/ MVFR CIGS HAVE BEEN TRYING TO COVER EASTERN KY FOR MOST OF THE DAY BUT THE LATE MARCH SUN KEPT ERODING THE EDGE AWAY AS FAST AS IT WAS ADVANCING. WITH THE LOSS OF THE SUNSHINE THE CLOUDS WILL FINALLY BE ABLE TO COVER THE ENTIRE AREA. EXPECT THE SHORT WAVE THAT BROUGHT THE CLOUDS TO THE AREA TO FINALLY MOVE EAST AND WITH THE RISING SUN THE CLOUDS SHOULD SCATTER OUT AND LIFT TO VFR. SOME SHRA TO MOVE INTO THE AREA BUT NOT UNTIL AFTER THE END OF THIS FCST. WILL PROBABLY HAVE SOME VCSH IN THE 06Z FCST. && .JKL WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...JJ/SBH LONG TERM....GEOGERIAN AVIATION...DUSTY ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 1117 PM EDT SUN MAR 23 2008 .SYNOPSIS... A WEAK TROF OF LOW PRESSURE MOVES ACROSS THE AREA LATE TONIGHT AND EARLY MONDAY. LOW PRESSURE WILL MOVE NORTHEAST AND STRENGTHEN WELL OFF THE COAST MONDAY NIGHT. HIGH PRESSURE BUILDS OVER THE TUESDAY. A WEAK COLD FRONT DROPS INTO THE REGION WEDNESDAY AFTERNOON THEN LIFTS BACK NORTH OF THE AREA AS A WARM FRONT THURSDAY AND THURSDAY NIGHT. ANOTHER COLD FRONT WILL PUSH INTO THE OHIO AND TENNEESEE VALLEYS BY LATE FRIDAY. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... 01Z SFC ANALYSIS HAS TROF OF LOW PRESSURE LCTD JUST W OF FA XTNDG FROM NR CHO ON S TO GSO WITH WEAK SFC RIDGE OVR FA. INTERESTING DROP IN TMPS THIS EVE ACROSS ERN SCTNS GIVEN CRNT DP TMPS IN THE 20-25 DEGREES. MID LCL CLD DECK (ARND 8K FT) NOW OVRSPRDG ERN PIEDMONT AREAS WITH HIGH LVL CLDNS MOBG N OF DVLPNG CSTL LOW. RADAR RETURNS HAVE BEEN INCRG ALONG TROF...HOWEVER HAVEN NOT SEEN ANY STATION RPTG ANY PCPN SINCE AIRMASS IS SO DRY. MODELS CONT TO HAVE MSTR DIFFERENCES THRU OVRNITE HRS. GFS QUITE AGGRESSIVE WITH UP TO .05 QPF WHILE NAM/RUC AND SREF SHOW LTL IF ANY MEASURABLE PCPN. FOR OVRNITE FCST...FOLLOWED A RUC/SREF BLEND OF KEEPING ANY MEASURABLE PCPN ACROSS WRN MOST CNTYS (FROM LKU-AVC) WITH A 1 CNTY BUFFER ZONE FOR SLGHT CHC MAINLY W OF I95. REWORDED PCPN AS LIGHT ALONG I95 CORRIDOR (SPRNKLS?). P-TYPE YET ANTHR CONCERN AS TMPS XPCTD TO FALL INTO L-M30S BY 12Z. GIVEN DRY AIRMASS ON LTST SNDGS...THNK MOST IF ANY PCPN WILL BE LIGHT AND IN LIQUID FORM WITH SOME WET SNOW FLAKES PSBLY MIXED IN. IT WUD HAVE TO PRECIPITATE HARD FOR ANY SGNFCNT SNOW TO OCCUR...AND THAT IS NOT XPCTD TO HAPPEN. LWRD TMPS ACROSS ERN SHORE AREAS ABOUT A CAT GIVEN TMPS INTO THE L-M 30S THIS EVE. && .SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/... MON INTO MON NGT...SFC LO PRES WILL INTENSIFY WELL OFF THE MID ATLC CST AS THE UA TROF PUSHES INTO AND ACRS THE AREA. THE COMBINATION OF THESE TWO SYSTEMS WILL RESULT IN PLENTY OF CLDS AND SLGT/SML CHC FOR RAIN. STILL DO NOT EXPECT MUCH PCPN FM THESE SYSTEMS AS QPF IS LESS THAN A TENTH OF AN INCH. MAX TEMPS WILL BE IN THE UPR 40S TO LWR 50S ON MON. SFC LO PRES WILL MOVE FARTHER OUT TO SEA TUE...AND HI PRES WILL BLD OVR THE AREA THEN OFFSHR. MSTLY SNY TUE WITH MAX TEMPS IN THE LWR 50S TO ARND 60. A WEAK COLD FRNT DROPS INTO THE REGION WED AFTN. NO PCPN EXPECTED WITH GENERALLY A PRTLY SNY SKY. MILDER TEMPS IN THE UPR 50S TO UPR 60S. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... HIGH PRESSURE MOVES OFFSHORE EARLY THURS MORNING AND WARM FRONT LIFTS NORTH THROUGH THE REGION ON THURS AFTN. NOT MUCH MOISTURE TO WORK WITH SO LEFT POPS AT SLIGHT CHANCE OR LESS. SHOULD BE PRETTY WARM ON THURS AS A RESULT...BUT LOWERED HIGH JUST A FEW DEGREES BLO GUIDANCE FOR NOW AS IT SEEMS A LITTLE OVERDONE (WENT WITH MID TO UPR 60S RATHER THAN LWR 70S THAT GUID INDICATES). EVEN WARMER ON FRI AS WARM FRONT CONTINUES TO LIFT WELL NORTH OF THE AREA AND WE SEE JUST PCLDY SKIES. EXPECTING LWR 70S MOST AREAS (MID 60S EASTERN SHORE WHICH TYPICALLY STAYS A BIT COOLER IN THIS TYPE OF REGIME)...BUT COULD EASILY SEE A FEW SPOTS CLOSER TO MID 70S WELL INLAND. SOME TIMING DIFFERENCES BETWEEN THE GFS AND ECMWF WITH THE SYSTEM MVG THROUGH THIS WEEKEND. THE ECMWF IS A TAD FASTER...BRINGING THE BULK OF THE PRECIP THROUGH FRI NIGHT THROUGH EARLY SAT MORNING WHEREAS THE GFS BRINGS IT THROUGH SAT AFTN THROUGH EARLY SUN MORNING. WILL PREFER THE SLOWER GFS SOLN FOR NOW AS THAT`S HOW THE MODELS HAVE BEEN TRENDING LATELY...CHANCE POPS FOR SAT TIMEFRAME AND KEEPING SLIGHT CHANCE THROUGH SAT NIGHT/SUN MORNING. && .AVIATION /03Z MONDAY THROUGH FRIDAY/... HAVE INCREASED CLOUD COVER NEXT 6 TO 8 HRS BUT WILL REMAIN VFR WITH NE WIND 10 KT OR LESS. WEAK UPPER LEVEL SYS WILL MOVE INTO REGION OVERNIGHT THEN DEEPER UPPER LEVEL TROF WILL KEEP CLOUDS AND COOLER TEMPS OVER THE MID ATLC FOR MON. SLIGHT CHC OF -RA/SN MIXED WEST OF RIC EARLY MON THEN CHC OF -RA OVER THE ENTIRE REGION FOR THE AFTN/EVENING PERIOD. CIGS MON LIKELY TO LOWER INTO THE 3500-5000 FT RANGE THRU THE AFTN. WINDS WILL STAY N-NE INTO MON...THEN SHIFT MORE SOUTHERLY ON TUE. TROF WILL LIFT OUT LATE MON AND HI PRES WILL BUILD INTO REGION TUE. FNTL BNDRY FCST TO STALL ACROSS AREA LATE WED INTO THU...WHICH COULD PROVE PROBLEMATIC FROM A CEILING PERSPECTIVE...ALTHO NOT A LOT OF RAIN EXPECTED ATTM. && .MARINE... SEAS IN SOUTHERN WATERS HAVE COME DOWN SO HAVE DROPPED ALL SCA. WINDS WILL PICK UP TOMORROW ESP OFFSHORE AS A LOW OFF THE SE U.S. COAST HEADS UP TO THE NNE THROUGHOUT THE DAY AND STRENGTHENS. LOOKS LIKE AT LEAST OUR SOUTHERN WATERS HAVE A GOOD CHANCE OF SCA CONDS BY EARLY EVNG...ALTHOUGH WILL NOT PUT FLAGS UP AT THIS TIME DUE TO ONGOING SCA CONDS TDY. EVNG SHIFT OR OVERNIGHT SHIFT WILL MOST LIKELY NEED TO INCLUDE HEADLINES HOWEVER. WINDS REMAIN RELATIVELY STRONG THROUGH MON NIGHT THEN DROP OFF ON TUES AS THE LOW PULLS FURTHER OFFSHORE. WINDS INCREASE BRIEFLY AGAIN ON WED AS A WEAK FRONT PUSHES OFFSHORE...BUT SCA CONDS ARE NOT EXPECTED AT THIS TIME. S WINDS OF 15 TO 20KTS ARE EXPECTED THURS NIGHT THROUGH SAT AHEAD OF THE NEXT SYSTEM EXPECTED TO MOVE THROUGH THE AREA THIS WEEKEND. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...MPR NEAR TERM...TMG SHORT TERM...TMG LONG TERM...JYM AVIATION...CY MARINE...JYM md AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 130 AM EDT SAT MAR 22 2008 .SYNOPSIS... HIGH PRESSURE WILL RESIDE OVER THE REGION INTO EARLY TONIGHT. A WEAK AREA OF LOW PRESSURE WILL APPROACH FROM THE NORTHWEST OVERNIGHT...AND MOVE THROUGH THE AREA ON SATURDAY. WEAK HIGH PRESSURE BUILDS BACK INTO THE MID ATLANTIC ON SUNDAY...AS A COASTAL LOW PRESSURE SYSTEM DEVELOPS OFF THE SOUTHEAST COAST SUNDAY NIGHT. THE LOW WILL THEN STRENGTHEN WELL OFF THE COAST ON MONDAY. HIGH PRESSURE RETURNS TUESDAY AND WEDNESDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... DEWPOINTS HAVE COME UP MORE THEN WERE FORECAST SO TWEAKED THEM UP SOME. ALSO MADE SOME SMALL CHANGES TO HOURLY TEMPS AS CURRENT DROP CORRESPONDS WITH RUC13 WHICH IS A LITTLE QUICKER THEN EARLIER FORECAST. RUC DOES SHOW THAT MINS ARE REACHED BY 09Z THEN TEMPS START RISING. WITH CURRENT PRECIP SHIELD AND SREF AND MODELS ALL DRY WILL DROP ANY CHC OF PRECIP LATE TONIGHT. && .SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/... NOT A WHOLE LOT OF MOISTURE WILL BE ASSCD WITH THIS NEXT SYSTEM AS LIFT/FORCING WEAKENS AS IT MOVES INTO OUR REGION. TRICKY MAX TEMPS AS FRONTAL BOUNDARY ASSCD WITH THIS SYSTEM SLOWLY PROGRESSES SOUTHWARD. GOOD BE A DECENT GRADIENT IN MAX TEMPS OVER NRN HALF OF THE CWA LOW-MID 50S/MID-UPR 60S WHILE LOWER 70S LOOK TO PREVAIL OVER SRN THIRD. WIND DIRECTION WILL ALSO BE TRICKY AS SSW WINDS SOUTH OF THE FRONT WHILE E/NE WINDS DVLP NORTH OF IT (MAY MAKE FOR CLOUDY SKIES ALL DAY FOR A GOOD CHUNK OF THE ERN SHORE). AS SYSTEM TRAVERSES NW/SE OVER THE CWA...SOME SHRA MAY DVLP (ESP FAR NRN ZONES). SPC HAS AREA OUTLOOKED FOR GENERAL THUNDER BUT THINK THIS IS OVERDONE AND...WITH MHX COLAB...HAVE JUST ADDED A ISO THREAT OF THUNDER OVER SE CWA NEAR THE BAY/SRN HALF OF COASTAL WATERS WHERE BEST INSTABILITY (IF ANY) WILL BE PRESENT. SHORT WINDOW OF OPPORTUNITY IN THE EVENING FOR ANY THUNDER (MAY EVEN JUST DVLP OFFSHORE) BEFORE ENERGY FROM SYSTEM MOVES INTO THE ATLANTIC AND DRYING DVLPS EARLY IN THE NIGHTTIME HOURS. SHOULD BE DECENT DRYING INTO SUNDAY WITH RH LVLS FALLING ONCE AGAIN AS HIGH PRESSURE MOVES OVRHD (ESP INLAND). IT WILL ALSO BE MUCH COOLER AS TEMPS GENERALLY WILL ONLY REACH INTO THE UPR 40S NEAR THE COASTLINE TO MID 50S FAR INLAND. NRN STREAM ENERGY PUSHES TWRDS THE REGION FROM THE NW ON SUN AS A COASTAL LOW STARTS TO DVLP OFFSHORE ON MON. MODELS STILL IN DISAGREEMENT ON OVERALL STRENGTH/LOCATION OF SYSTEM NEAR THE COASTLINE...BUT LOOKING MORE EVIDENT OF A RAIN MAKER (MAINLY SOUTHEASTERN THIRD OF THE CWA DURING THE DAY). OVERALL PRECIP WILL DEPEND HEAVILY ON TIMING OF H5 TROF AXIS AND HOW FAR OFF THE COAST THE PLACEMENT OF THE CENTER THE MAIN SYSTEM DVLPS. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... WITH THE COASTAL SYSTEM BEING KEPT EVEN FURTHER OFFSHORE BY MOST OF THE MODELS NOW...HAVE OPTED TO DECREASE POPS MON NIGHT SLIGHTLY AND TO ALSO REMOVE MENTION OF SN WITH LACK OF AVAILABLE MOISTURE. AS LONG AS THIS TREND CONTINUES...NEXT SHIFT MAY EVEN ELIMINATE POPS ALTOGETHER FOR THIS TIME PERIOD. STRONG HIGH REMAINS OVER THE SE U.S. THROUGH WEDNESDAY AND THOUGH A FRONT WILL APPROACH THE AREA ON WED...MOISTURE LOOKS TO BE LACKING SO NO POPS EXPECTED. BEST CHANCES WOULD BE LATE ON WED AS THE FRONT STALLS TO OUR SOUTH IN NC...BUT RECENT DRYING TRENDS IN THE LATEST GFS MODEL RUNS WOULD INDICATE THE CHANCE ISN`T REALLY THAT GREAT. WITH LACK OF MOISTURE/PRECIP...TEMPS ON WED HAVE THE POSSIBILITY OF GETTING QUITE WARM...MID TO UPR 60S MOST INLAND LOCATIONS. SOME DEFINITE TIMING DIFFERENCES BETWEEN THE GFS AND ECMWF ON THE NEXT SYSTEM THURS/FRI...SO DIDN`T GO OVERBOARD ON POPS FOR NOW UNTIL MODELS GET A BETTER HANDLE ON THINGS. WENT CLOSE TO CLIMO AVERAGES FOR TEMPS DUE TO UNCERTAINTY ON CLOUD CVR WITH TIMING OF NEXT SYSTEM. && .AVIATION /05Z SATURDAY THROUGH WEDNESDAY/... VFR CONDS THROUGH AT LEAST MIDDAY TODAY THEN MID CLOUDS MOVING IN. A CLIPPER LOW CROSSES THE AREA TDY BRINGING AN INCREASE IN MID CLOUDS WITH SLT CHC OF LOWERD VIS AND CIGS IN SCT RAIN. ATTM ANY PCP LOOKS TO BE WIDELY SCT AND HAVE NO WX IN THE TAFS TDY. SW WINDS 10 TO 15 KT...WITH GUSTS TO ABOUT 22 KT...AFTER 11Z LIKELY AT ORF/ECG/PHF. SOME MVFR CIGS POSSIBLE THIS AFTN...THEN CIGS RAISING AFTER FROPA. WEAK LOW PRES OFF THE CST THRU SUN NIGHT...WITH A LARGE SFC HIGH PRES SYSTEM OVER THE WATERS MON AND TUE...AND ANY SFC LOW PRES DVLPMNT WELL OFFSHORE. ECMWF STILL HAS CSTL LOW STRONGER AND FARTHER WEST FOR MON/TUE. ATTM THERE IS A CHC FOR LOWER CIGS FOR CSTL TAFS ON MON/TUE. && .MARINE... AFTER LOOKING AT LATEST NAM DATA...DECIDED TO RAISE SCA FOR CHES BAY S OF WINDMILL PT. WILL BE A MARGINAL EVENT...BUT EXPECT GUSTS TODAY IN ADVANCE OF THE FRONT TO BE AROUND 20 KT...WHICH MEETS SCA CRITERIA. THIS MORNING`S FCST IS TOUGH...A WEAK LOW MVS INTO EASTERN VA THIS MORNING REACHING THE COAST BY MIDDAY. AS THE HIGH DEPARTS AND THE LOW NEARS THE COAST...EXPECT WINDS TO INCREASE THROUGH DAYBREAK AND APPROACH SCA CRITERIA. HOWEVER COOL WATER TEMPS (BLO 50F) WILL REDUCE MIXING TO SFC...REDUCING GUST POTENTIAL. STIL EXPECT GUSTS TO 20 KT OVER THE SOUTHERN BAY WHERE SCA IS IN EFFECT TDY. THE LOW MVS OFFSHORE IN THE LATE AFTN...AND WINDS WILL DIMINISH THEREAFTER. FROM SUN THROUGH TUES WINDS LOOK TO REMAIN BLO 20 KTS...BRIEFLY INCREASING AT TIMES AS A LOW MVS NORTHEAST BUT REMAINS WELL OFFSHORE. MODELS ARE IN GOOD AGREEMENT KEEPING THIS SYSTEM WELL OFFSHORE SO HAVE LOWERED WINDS SLIGHTLY DURING THIS TIME FRAME DUE TO INCREASING CONFIDENCE. WINDS DO LOOK TO INCREASE ON WED AS THE NEXT FRONT APPROACHES...BUT TIMING MAY NEED TO BE PUSHED BACK SLIGHTLY INTO THURS BASED ON TRENDS OF THE NEXT FEW MODEL RUNS. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO 5 PM EDT THIS AFTERNOON FOR ANZ631-632. && $$ SYNOPSIS...CCW NEAR TERM...CCW/JAB SHORT TERM...CCW LONG TERM...JYM AVIATION...ALS MARINE...ALS md AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 800 PM EDT SUN MAR 23 2008 UPDATED FOR 00Z AVIATION DISCUSSION .SHORT TERM(TONIGHT AND MONDAY)... THE LATEST MSAS ANALYSIS SUGGESTS RIDGING ACROSS LAKE SUPERIOR...EXTENDING FROM THE MAIN SFC RIDGE ACROSS THE PLAINS. MEANWHILE...A WEAK SHORT WAVE ALOFT IS MOVING SE ACROSS LAKE SUPERIOR PER WATER VAPOR IMAGERY. THE SUBSIDENCE AND NVA MOVING OVER THE LAKE COMBINED WITH THE CONSIDERABLE DRY ADVECTION /SFC DWPTS IN NW ONTARIO WELL BELOW ZERO/ SHOULD SIGNIFICANTLY DIMINISH THE LAKE EFFECT SNOW THIS EVENING...ESPECIALLY AS THE WINDS BACK TO THE NORTHWEST. HOWEVER DUE TO THE UPSLOPE COMPONENT EARLY THIS EVENING COMBINED WITH LOW LAKE-AIR STABILITY /850MB TEMP -16C/...WILL CONTINUE TO CARRY LIKELY POPS IN A SMALL AREA FROM SHOT POINT EAST TO GRAND MARAIS WHERE THE RUC SUGGESTS SOME ENHANCED CONVERGENCE AS THE WINDS BACK AROUND. HOWEVER...ANY ACCUMULATIONS SHOULD HOLD LESS THAN AN INCH. AS THE WINDS BACK AROUND TONIGHT...THERE IS A POSSIBILITY THAT THE KEWEENAW PENINUSLA WILL SEE SOME ENHANCEMENT OVERNIGHT. BEST CHANCE FOR THIS TO OCCUR WOULD BE NORTH OF HOUGHTON...AND HAVE OPTED TO KEEP CHANCE POPS IN THAT AREA FOR THE ENTIRE NIGHT. HOWEVER...WITH THE COMBINATION OF DRY AIR AND STRONG SUBSIDENCE IT SEEMS UNLIKELY THAT THERE WILL BE MUCH ORGANIZATION TO THE ACTIVITY. OTHERWISE...IT SHOULD BE A FAIRLY QUIET BUT COLD NIGHT ACROSS UPPER MICHIGAN. WITH LIGHT WINDS AND A FRESH SNOW COVER IN SOME PLACES...AM THINKING THAT SOME INLAND AREAS WILL SEE TEMPS DROP TO ZERO TO 5 ABOVE TONIGHT. IF IT CAN CLEAR OUT FASTER THAN FORECAST TEMPS COULD DROP MORE THAN THAT. MONDAY SHOULD BE A QUIET DAY BEFORE THE NEXT CLIPPER SYSTEM MONDAY NIGHT/TUE MORNING. WITH THE W-SW FLOW...CANNOT RULE OUT A CHANCE OF SNOW SHOWERS NORTH OF HOUGHTON ALTHOUGH 850MB TEMPS WILL BE MARGINAL /ONLY AROUND -9C/ AND SYNOPTIC SCALE SUBSIDENCE WILL BE STRONG. NONETHELESS...WILL CARRY A SMALL POP THROUGH THE DAY IN THIS REGION. WILL SEE SOME INCREASING CLOUDS /ESPECIALLY ACROSS WESTERN UPPER MICHIGAN/ IN THE WARM ADVECTION AHEAD OF THIS SYSTEM AND SOUTHWEST WINDS WILL ALLOW FOR SOME DOWNSLOPE WARMING. MANY PLACES WILL BE PARTLY TO MOSTLY SUNNY ON MONDAY SO IT SHOULD BE PLEASANT ALTHOUGH A LITTLE CHILLY WITH HIGHS 30-35. && .LONG TERM (MON NGT THRU SUN)... FOCUS FOR MON NIGHT-TUE TURNS TO TIMING/IMPACT OF CLIPPER SHRTWV MOVING ESE FM SCNTRL CAN. PER NCEP GUIDANCE. MODELS NOW IN FAIRLY GOOD AGREEMENT WITH TIMING OF ASSOC SFC LOW WHICH IS PROGGED TO TRACK ACROSS NE MN AND NRN LAKE SUPERIOR TUE MORNING AND THEN MOVES NE OF LAKE SUPERIOR TUE AFTERNOON. MODELS STILL ADVERTISING FAIRLY IMPRESSIVE UPR DIV IN LEFT EXIT REGION OF SUPPORTING 120+ KT H3 JET MAX ALONG WITH IMPRESSIVE DPVA AND VIGOROUS 850-500 MB Q-VECT CONV. SHARP ISENTROPIC ASCENT ON 285-290K SFCS NOTED MON NIGHT IN ADVANCE OF THE SHORTWAVE...TRANSITIONING TO DESCENT BEHIND THE SHORTWAVE OVER WRN HALF COUNTIES BY 12Z TUE. IN GENERAL...THE TRACK OF THE LOW FAVORS THE NCNTRL AND ERN COUNTIES FOR THE HEAVIER/MORE SUSTAINED PCPN AND QPF FIELDS GENERALLY BARE THIS OUT. THE ONE THING THAT MAY LIMIT PCPN/SNOW AMOUNTS IS FAIRLY RAPID MOVEMENT OF SHORTWAVE/SFC LOW. STILL WITHMIXING RATIOS OF 3G/KG ADVECTING OVER THE AREA AND 6HR OF MORE WINDOW OF FAVORABLE ISENTROPIC ASCENT THE FAR ERN PORTION OF THE CWA MAY PUSH ADVISORY TOTALS WITH 3 INCHES OF MORE OF SNOW POSSIBLE MON NIGHT AND ANY ADDITIONAL SNOW ON TUE MORNING ALONG FRONTAL PASSAGE AND WRAPAROUND MOIST CYCLONIC FLOW IN WAKE OF THE LOW. WOULD EXPECT THE REST OF THE CWA THE GENERALLY FALL IN THE 2-4" RANGE FOR TOTAL SNOWFALL FROM THE SYSTEM. EXPECT PCPN TO GENERALLY DIMINISH BY TUE AFTN BEFORE ANOTHER SHORTWAVE RETURNS TUE EVENING AND BRINGS A REINFORCING COLD SHOT AND CHC OF ENHANCEMENT TO LES. LOOKS LIKE BULK OF PCPN WL FALL AS SN... BUT WITH SOME SUNSHINE POSSIBLE FOR SCNTRL AREAS IN DOWNSLOPING NW FLOW LLVLS MAY WARM ENOUGH TO MIX SNOW WITH SOME RAIN. ANOTHER CONCERN FOR TUE AFTN/EVENING WL BE WINDS ESPECIALLY FOR DOWNSLOPING AREAS OVER THE SRN TIER AND OVER THE KEWEENAW PENINSULA. GFS FCST SDNGS FOR MNM AND ESC SHOWS 35-40 KT WINDS WITHIN THE MIXED LYR AT BOTH MNM AND ESC. WINDS OVER THE KEWEENAW COULD REACH 30 KT BY TUE EVENING AS SECONDARY COLD FRONT MOVES THROUGH. IN THE WAKE OF TUE CLIPPER...EXPECT LES TO BE ONGOING TUE NGT INTO WED WITH 850 MB TEMPS OF -16 TO -18C MOVING OVER THE LAKE. HI PRES RDG AXIS WILL THEN MOVES OVHD WED NIGHT AND SHUT OFF THE LES. STILL PLENTY OF MODEL UNCERTAINTY WITH DEVELOPING STORM OVER THE PLAINS BY THU/FRI. HOWEVER...NCEP FAVORED BLEND OF 00Z GFS SOLN AND ENSEMBLE MEAN WHICH NOW TAKES LOW PRESSURE OVER LOWER GREAT LAKES AND OHIO VALLEY THU NIGHT AND FRI. ECMWF HAS BEEN EVEN FARTHER E WITH THIS SYSTEM THE LAST FEW RUNS. WHAT THIS MEANS FOR UPR MI IS THAT HEAVIER PCPN WILL LIKELY STAY SOUTH AND EAST OF THE CWA. BEST CHCS FOR PCPN THU NIGHT AND EARLY FRI WILL BE SCNTRL AND EAST WHERE I HAVE INCLUDED HIGH CHC POPS. ALSO WITH MORE SOUTHWARD TRACK...IT LOOKS LIKE PCPN TYPE WILL STAY ALL SNOW SO DECIDED TO TAKE OUT MIX WITH LIQUID/FREEZING PCPN FROM PREV FCST. BIG DIFFERENCE IN 850 MB TEMPS IN THE WAKE OF THIS SYSTEM FRI NIGHT INTO SAT. ECMWF MUCH WARMER THAN MORE AMPLIFIED SOLN OF GFS WHICH MORE COLD AIR SOUTHWARD BEHIND THE LOW. LEANED A BIT MORE TOWARD GFS TEMPS AND KEPT LOW CHC POPS FOR LES GOING INTO THE WEEKEND IN AREAS FAVORED BY WNW FLOW. && .AVIATION (FOR THE 00Z TAF ISSUANCE)... EXPECT THE WINDS TO BECOME NW THIS EVENING THEN SW BY MON MORNING. THE BACKING WINDS COMBINED WITH SUBSIDENCE FROM THE HIGH ACROSS THE AREA SHOULD LEAVE MAINLY CLEAR SKIES AT KSAW. AT KCMX MAINLY VFR CONDITIONS WILL PREVAIL. HOWEVER...THERE IS THEPOTENTIAL FOR MVFR CIGS WITH LAKE CLOUDS AND SOME FLURRIES AGAIN AFTER 06Z TONIGHT AS THE WINDS BACK TO THE WSW RESULTING IN A LONGER FETCH ACROSS WRN LAKE SUPERIOR. && .MARINE (FOR 4 PM ISSUANCE)... AS HIGH PRES BUILDS ACROSS THE LAKE THIS EVENING...WINDS AND WAVES SHOULD RELAX QUITE RAPIDLY. HOWEVER...AS THE NEXT CLIPPER SYSTEM APPROACHES ON MONDAY AND ESPECIALLY MONDAY NIGHT...SOUTHERLY WINDS WILL INCREASE TO 15-25 KT MON AFTN AND TO GALES MONDAY NIGHT INTO TUE. BEST CHANCE FOR GALES WILL BE ACROSS THE EASTERN 1/3 OF LAKE SUPERIOR AND THE NEARSHORE OF LAKE MICHIGAN. AS THE CLIPPER PASSES BY TUE INTO TUE GALES OR NEAR GALES WILL CONTINUE THROUGH TUE EVENING. W-NW WINDS NEAR 30 KT WILL CONTINUE THROUGH WED EVENING BEFORE HIGH PRES BUILDS ACROSS THE LAKE. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS/SHORT TERM...MRD LONG TERM...VOSS AVIATION...JLB MARINE...MRD mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 717 PM EDT SUN MAR 23 2008 .UPDATE... WILL UPDATE THE ZONES AND GRIDS TO LOWER POPS AND REDUCE SNOW ACCUMULATIONS FOR THE REST OF THE NIGHT. INITIAL LOW LEVEL DRY AIR AND OVERALL LACK OF ORGANIZATION TO THE PRECIPITATION ARGUES FOR LITTLE IF ANY ACCUMULATION. OVERALL LARGE SCALE ASCENT WILL WANE DURING THE EVENING. SO DO NOT EXPECT ANY FURTHOR INCREASE IN COVERAGE OF RADAR RETURNS. && .PREV DISCUSSION...ISSUED 701 PM EDT SUN MAR 23 2008 AVIATION... THE 22Z SURFACE ANALYSIS SHOWS A WEAK AREA OF LOW PRESSURE ROUGHLY AROUND LAPEER COUNTY...WITH A SURFACE COLD FRONT EXTENDING BACK INTO CENTRAL LOWER MI. CONVERGENCE ALONG THIS BOUNDARY...COUPLED WITH INCREASED MID LEVEL MOISTURE CONVERGENCE AHEAD OF THE UPPER WAVE OVER THE NORTHERN LAKES IS LEADING TO QUITE A BIT OF RETURNS ON RADAR ACROSS THE SAGINAW VALLEY AND THUMB. GIVEN LACK OF SURFACE REPORTS...SUSPECT THERE IS A LOT OF VIRGA WITH THESE RETURNS. THE LATEST TAMDAR SOUNDING OUT OF DTW DOES SHOW A LOT OF DRY AIR BELOW 5K FEET. THE LATEST NAM12 AND RUC SHOW THE SURFACE FRONT SLIDING INTO THE DETROIT AREA BY 09Z. SUSPECT LOSS OF DAYTIME HEATING WILL CAUSE AN OVERALL DECREASE IN COVERAGE OF RADAR RETURNS. LATEST RADAR HOWEVER ARGUES FOR KEEPING A TEMPO GROUP FOR SNOW SHOWERS IN THE FNT AND MBS TAF THROUGH THE NEXT FEW HOURS. AT THIS TIME...THE CHANCES FOR SNOW AT DTW/DET APPEAR TOO LOW TO INCLUDE IN THE TAFS. MODEL SOUNDINGS SHOW LOW LEVEL MOISTURE INCREASING THROUGH THE NIGHT AS SHALLOW COLD AIR FILTERS IN FROM THE NORTH. NORTHERLY FLOW OFF LAKE HURON MAY CONTRIBUTE TO SOME MVFR LAKE STRATUS OVERNIGHT INTO EARLY MON MORNING AT FNT AND DTW/DET. AT THIS TIME...WILL INCLUDE JUST A TEMPO GROUP FOR MVFR CIGS OVERNIGHT AND MONITOR SATELLITE TRENDS. NORTHERLY DOWNSLOPE FLOW SHOULD KEEP MBS PREDOMINATELY VFR OVERNIGHT. PREV DISCUSSION...ISSUED 351 PM EDT SUN MAR 23 2008 SHORT TERM...THROUGH TONIGHT A COLD FRONT WILL CONTINUE TO PUSH DOWN ACROSS LOWER MICHIGAN LATE THIS AFTERNOON AND TONIGHT AS AN UPPER LEVEL LOW DIVES INTO NORTHERN ONTARIO AND QUEBEC. WEAK SURFACE WAVE IS ALSO WORKING ITS WAY EASTWARD ACROSS THE LOWER PENINSULA RIGHT NOW...PER OBS/MSAS ANALYSIS...AND THIS FEATURE IS RIDING JUST SOUTH OF THE SURFACE FRONT. PREFER THE 12Z NAM INITIALIZATION WITH THE FRONT AND SURFACE WAVE...AND ITS DEPICTION OF HOW THESE TWO FEATURES WILL INTERACT THIS AFTERNOON/EVENING ACROSS EAST-CENTRAL MICHIGAN. MODELS ALL INDICATE BEST LOW-LEVEL CONVERGENCE AND FGEN OCCURRING THIS EVENING ACROSS THE TRI-CITIES AND THUMB AS THE CENTER OF THE SURFACE WAVE RIDES SOUTH OF THERE. UPWARD FORCING BECOMING PROGRESSIVELY WEAKER AS YOU MOVE TO THE SOUTH. CROSS SECTIONS INDICATE DEEP INSTABILITY FROM THE SURFACE UP TO 500MB...WITH MOISTURE OK BUT NOT IMPRESSIVE WITH SPECIFIC HUMIDITIES BETWEEN 1 AND 2 G/KG. FORECAST FOR AROUND AN INCH OF SNOW ACCUMULATION AROUND THE TRI-CITES AND THUMB STILL LOOKS REASONABLE...WITH AMOUNTS TAPERING TO VERY LIGHT ACCUMULATIONS (IF ANY) BY THE TIME YOU GET TOWARDS DETROIT. HAVE DECREASED POPS FOR THE SOUTH CWA AND DELAYED THEM SOMEWHAT TO MATCH CURRENT TRENDS AND EXPECTED FORCING. PRECIPITATION WILL TAPER OFF DURING THE EARLY MORNING WITH SKIES SCATTERING OUT AS MOISTURE BECOMES VERY SHALLOW BEHIND THE COLD FRONT. TEMPERATURES TONIGHT WILL FALL INTO THE UPPER TEENS TO NEAR 20. LONG TERM...MONDAY THROUGH SATURDAY... SEASONABLY COLD AIRMASS OVERHEAD TO BEGIN MONDAY...WITH 850 MB TEMPERATURES STILL EXPECTED TO BE TWO STANDARD DEVIATIONS BELOW NORMAL. ASIDE FROM SOME MIDDAY DIURNAL CU...A GOOD AMOUNT OF SOLAR INSOLATION UNDER HIGH PRESSURE WILL ATTEMPT TO MODIFY THIS AIRMASS THROUGH THE DAY. DESPITE THIS...RECOVERY STILL LOOKS LIMITED...WITH HIGHS RANGING FROM LOWER 30S NORTH TO UPPER 30S SOUTH. PROGRESSIVE SHORTWAVE AND ACCOMPANYING 120+ KT UPPER JET WILL STREAK SOUTHEAST TOWARD THE GREAT LAKES MONDAY NIGHT. THE INCREASING LARGE SCALE ACCENT AND PRE-FRONTAL ISENTROPIC LIFT/MOISTURE ADVECTION WILL BE SUFFICIENT TO OVERCOME THE INITIAL DRY LAYER AND SATURATE THE COLUMN EARLY TUESDAY. MODELS ARE TRENDING SLIGHTLY SLOWER WITH ARRIVAL OF PRECIPITATION...WITH AN ONSET BETWEEN 09-15Z...WITH THE GFS IN TYPICAL FASHION BEING SLIGHTLY FASTER THAN THE NAM. SOUNDINGS SHOW A THERMAL PROFILE COLD ENOUGH FOR ALL SNOW TO START...BUT QUICKLY WARMS THE BOUNDARY LAYER ABOVE FREEZING FROM SOUTH TO NORTH BY MID/LATE MORNING UNDER A STRENGTHENING LOW LEVEL JET /925 MB WINDS OVER 40 KNOTS/. GIVEN THE DELAYED ONSET AND POTENTIAL FOR A MIX AND THEN QUICK CHANGE OVER TO RAIN...SOUTHERN AREAS INCLUDING METRO DETROIT MAY STRUGGLE TO SEE ACCUMULATIONS OF MORE THAN AN INCH. TOWARD THE NORTH...ESPECIALLY FROM THE I-69 CORRIDOR NORTH...STILL SEE THE POTENTIAL OF 2-4 INCHES TUESDAY MORNING GIVEN SLIGHTLY BETTER FORCING/HIGHER QPF AND A LONGER DURATION OF SUB-FREEZING LOW LEVEL TEMPERATURES. LIGHT RAIN LINGERS INTO THE EVENING...POSSIBLY MIXING WITH LIGHT SNOW ON THE BACK END...BEFORE THE DEEPER MOISTURE AND BEST FORCING LIFTS EAST OVERNIGHT. HIGH PRESSURE IN CONTROL ON WEDNESDAY...AS THE UPPER LEVEL FLOW BRIEFLY BECOMES ZONAL. LOW LEVEL BOUNDARY DRAPED ACROSS THE OHIO VALLEY WILL THEN BEGIN TO LIFT BACK NORTHWARD BY WEDNESDAY NIGHT AND THURSDAY...IN RESPONSE TO A STRONG SHORTWAVE LIFTING OUT OF THE NORTHERN ROCKIES AND THE RESULTANT SFC CYCLOGENESIS THAT WILL COMMENCE ACROSS THE PLAINS. MODELS NOT SURPRISINGLY ARE STRUGGLING WITH THE DETAILS GIVEN THE OVERALL PROGRESSIVE NATURE OF THIS UPPER PATTERN. THE 00Z ECMWF/UKMET CONSENSUS MAINTAINS A MORE PROGRESSIVE/ WEAKER MID-LEVEL TROUGH...WITH THE ASSOCIATED SFC LOW OVER NEW ENGLAND FRIDAY EVENING. MEANWHILE...THE GFS AND CANADIAN BOTH SHOW A MUCH MORE AMPLIFIED TROUGH...WITH THE SFC REFLECTION STILL IN THE GREAT LAKES REGION THROUGH FRIDAY EVENING. WATER VAPOR IMAGERY OVER THE PACIFIC DOES SHOW A DEEPER SYSTEM AT THE MOMENT...LENDING SOME SUPPORT TO A STRONGER/SLOWER EVOLVING SOLUTION DESPITE THE MORE PROGRESSIVE FLOW. ONGOING FORECAST LEANS IN THIS DIRECTION ALREADY...AND SEE NO COMPELLING REASON TO PULL BACK FROM THIS THINKING JUST YET. UNDER THIS SOLUTION...INCREASING ISENTROPIC ACCENT/MOISTURE TRANSPORT ALONG THE BAROCLINIC ZONE WILL SET THE STAGE FOR A GOOD OVERRUNNING EVENT THURSDAY AND THURSDAY NIGHT. LATEST SOUNDING DATA STILL INDICATING THE POTENTIAL FOR A WINTRY MIX WITH THERMAL PROFILES/PARTIAL THICKNESSES SUPPORTING SNOW/SLEET AT ONSET THURSDAY MORNING...WITH THE LONGEST DURATION OF FROZEN PRECIP ACROSS THE NORTH. PRONOUNCED LOW LEVEL WARM LAYER WILL SURGE NORTH THROUGH THE DAY...BRINGING A TRANSITION TO FREEZING RAIN/RAIN. 12Z GFS NOW DEPICTS A LONGER PERIOD OF FREEZING RAIN...AS IT TRENDS FURTHER SOUTH WITH THE SFC LOW AND THERMAL GRADIENT AND MAINTAINS A SUB-FREEZING BOUNDARY LAYER THROUGH MUCH OF THE DAY. ONLY CHANGE AT THIS POINT WILL BE TO EXTEND THE CHANCE OF -FZRA INTO THE EVENING FOR THE M-59 CORRIDOR NORTH. CERTAINLY THE POTENTIAL EXISTS FOR A MESSY SETUP AND WILL CONTINUE TO CLOSELY WATCH THE EVOLUTION AS THE UPPER TROUGH BECOMES BETTER SAMPLED IN THE COMING DAYS. MARINE... A FRONTAL BOUNDARY WILL CONTINUE TO PUSH DOWN THROUGH LOWER MICHIGAN TONIGHT. BEHIND THE FRONT...WINDS WILL INCREASE AND TURN NORTHEAST BEFORE SLOWLY SHIFTING TO NORTHWEST BY SUNRISE. GUSTS TO 20 KNOTS...OR SLIGHTLY MORE...CAN BE EXPECTED OVER THE NEARSHORE WATERS OF LAKE HURON TONIGHT. THE PERSISTENT NORTHERLY COMPONENT TO THE WINDS WILL ALLOW WAVES TO BUILD TO NEARLY 5 FEET ALONG THE NEARSHORE WATERS OF LAKE HURON FORM PORT AUSTIN TO HARBOR BEACH BY LATE TONIGHT. THE PERIOD OF HIGHER WAVES WILL BE BRIEF HOWEVER...AS WAVES QUICKLY DROP OFF LATE TOMORROW MORNING WHEN WINDS TURN SOUTHWEST. THE NEXT LOW PRESSURE SYSTEM WILL TRACK ACROSS THE NORTHERN GREAT LAKES ON TUESDAY...BRINGING A PERIOD OF INCREASED WINDS AND WAVES MONDAY AFTERNOON THROUGH WEDNESDAY. WIND GUSTS COULD POTENTIALLY REACH GALE FORCE ACROSS THE OPEN WATERS OF LAKE HURON ON TUESDAY...AND A GALE WATCH IS NOW IN EFFECT. A SECOND LOW PRESSURE SYSTEM WILL MOVE ACROSS THE WESTERN AND NORTHERN GREAT LAKES THURSDAY NIGHT AND FRIDAY...BRINGING ANOTHER PERIOD OF UNSETTLED WEATHER. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON... GALE WATCH...LHZ361-LHZ362-LHZ363-LHZ462-LHZ463-LHZ464...FROM 4 AM TUESDAY TO 4 PM TUESDAY. LAKE ST CLAIR...NONE. MI WATERS OF LAKE ERIE...NONE. && $$ UPDATE.......SC AVIATION.....SC SHORT TERM...HLO LONG TERM....MR MARINE.......HLO YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE). mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 701 PM EDT SUN MAR 23 2008 .AVIATION... THE 22Z SURFACE ANALYSIS SHOWS A WEAK AREA OF LOW PRESSURE ROUGHLY AROUND LAPEER COUNTY...WITH A SURFACE COLD FRONT EXTENDING BACK INTO CENTRAL LOWER MI. CONVERGENCE ALONG THIS BOUNDARY...COUPLED WITH INCREASED MID LEVEL MOISTURE CONVERGENCE AHEAD OF THE UPPER WAVE OVER THE NORTHERN LAKES IS LEADING TO QUITE A BIT OF RETURNS ON RADAR ACROSS THE SAGINAW VALLEY AND THUMB. GIVEN LACK OF SURFACE REPORTS...SUSPECT THERE IS A LOT OF VIRGA WITH THESE RETURNS. THE LATEST TAMDAR SOUNDING OUT OF DTW DOES SHOW A LOT OF DRY AIR BELOW 5K FEET. THE LATEST NAM12 AND RUC SHOW THE SURFACE FRONT SLIDING INTO THE DETROIT AREA BY 09Z. SUSPECT LOSS OF DAYTIME HEATING WILL CAUSE AN OVERALL DECREASE IN COVERAGE OF RADAR RETURNS. LATEST RADAR HOWEVER ARGUES FOR KEEPING A TEMPO GROUP FOR SNOW SHOWERS IN THE FNT AND MBS TAF THROUGH THE NEXT FEW HOURS. AT THIS TIME...THE CHANCES FOR SNOW AT DTW/DET APPEAR TOO LOW TO INCLUDE IN THE TAFS. MODEL SOUNDINGS SHOW LOW LEVEL MOISTURE INCREASING THROUGH THE NIGHT AS SHALLOW COLD AIR FILTERS IN FROM THE NORTH. NORTHERLY FLOW OFF LAKE HURON MAY CONTRIBUTE TO SOME MVFR LAKE STRATUS OVERNIGHT INTO EARLY MON MORNING AT FNT AND DTW/DET. AT THIS TIME...WILL INCLUDE JUST A TEMPO GROUP FOR MVFR CIGS OVERNIGHT AND MONITOR SATELLITE TRENDS. NORTHERLY DOWNSLOPE FLOW SHOULD KEEP MBS PREDOMINATELY VFR OVERNIGHT. && .PREV DISCUSSION...ISSUED 351 PM EDT SUN MAR 23 2008 SHORT TERM...THROUGH TONIGHT A COLD FRONT WILL CONTINUE TO PUSH DOWN ACROSS LOWER MICHIGAN LATE THIS AFTERNOON AND TONIGHT AS AN UPPER LEVEL LOW DIVES INTO NORTHERN ONTARIO AND QUEBEC. WEAK SURFACE WAVE IS ALSO WORKING ITS WAY EASTWARD ACROSS THE LOWER PENINSULA RIGHT NOW...PER OBS/MSAS ANALYSIS...AND THIS FEATURE IS RIDING JUST SOUTH OF THE SURFACE FRONT. PREFER THE 12Z NAM INITIALIZATION WITH THE FRONT AND SURFACE WAVE...AND ITS DEPICTION OF HOW THESE TWO FEATURES WILL INTERACT THIS AFTERNOON/EVENING ACROSS EAST-CENTRAL MICHIGAN. MODELS ALL INDICATE BEST LOW-LEVEL CONVERGENCE AND FGEN OCCURRING THIS EVENING ACROSS THE TRI-CITIES AND THUMB AS THE CENTER OF THE SURFACE WAVE RIDES SOUTH OF THERE. UPWARD FORCING BECOMING PROGRESSIVELY WEAKER AS YOU MOVE TO THE SOUTH. CROSS SECTIONS INDICATE DEEP INSTABILITY FROM THE SURFACE UP TO 500MB...WITH MOISTURE OK BUT NOT IMPRESSIVE WITH SPECIFIC HUMIDITIES BETWEEN 1 AND 2 G/KG. FORECAST FOR AROUND AN INCH OF SNOW ACCUMULATION AROUND THE TRI-CITES AND THUMB STILL LOOKS REASONABLE...WITH AMOUNTS TAPERING TO VERY LIGHT ACCUMULATIONS (IF ANY) BY THE TIME YOU GET TOWARDS DETROIT. HAVE DECREASED POPS FOR THE SOUTH CWA AND DELAYED THEM SOMEWHAT TO MATCH CURRENT TRENDS AND EXPECTED FORCING. PRECIPITATION WILL TAPER OFF DURING THE EARLY MORNING WITH SKIES SCATTERING OUT AS MOISTURE BECOMES VERY SHALLOW BEHIND THE COLD FRONT. TEMPERATURES TONIGHT WILL FALL INTO THE UPPER TEENS TO NEAR 20. LONG TERM...MONDAY THROUGH SATURDAY... SEASONABLY COLD AIRMASS OVERHEAD TO BEGIN MONDAY...WITH 850 MB TEMPERATURES STILL EXPECTED TO BE TWO STANDARD DEVIATIONS BELOW NORMAL. ASIDE FROM SOME MIDDAY DIURNAL CU...A GOOD AMOUNT OF SOLAR INSOLATION UNDER HIGH PRESSURE WILL ATTEMPT TO MODIFY THIS AIRMASS THROUGH THE DAY. DESPITE THIS...RECOVERY STILL LOOKS LIMITED...WITH HIGHS RANGING FROM LOWER 30S NORTH TO UPPER 30S SOUTH. PROGRESSIVE SHORTWAVE AND ACCOMPANYING 120+ KT UPPER JET WILL STREAK SOUTHEAST TOWARD THE GREAT LAKES MONDAY NIGHT. THE INCREASING LARGE SCALE ACCENT AND PRE-FRONTAL ISENTROPIC LIFT/MOISTURE ADVECTION WILL BE SUFFICIENT TO OVERCOME THE INITIAL DRY LAYER AND SATURATE THE COLUMN EARLY TUESDAY. MODELS ARE TRENDING SLIGHTLY SLOWER WITH ARRIVAL OF PRECIPITATION...WITH AN ONSET BETWEEN 09-15Z...WITH THE GFS IN TYPICAL FASHION BEING SLIGHTLY FASTER THAN THE NAM. SOUNDINGS SHOW A THERMAL PROFILE COLD ENOUGH FOR ALL SNOW TO START...BUT QUICKLY WARMS THE BOUNDARY LAYER ABOVE FREEZING FROM SOUTH TO NORTH BY MID/LATE MORNING UNDER A STRENGTHENING LOW LEVEL JET /925 MB WINDS OVER 40 KNOTS/. GIVEN THE DELAYED ONSET AND POTENTIAL FOR A MIX AND THEN QUICK CHANGE OVER TO RAIN...SOUTHERN AREAS INCLUDING METRO DETROIT MAY STRUGGLE TO SEE ACCUMULATIONS OF MORE THAN AN INCH. TOWARD THE NORTH...ESPECIALLY FROM THE I-69 CORRIDOR NORTH...STILL SEE THE POTENTIAL OF 2-4 INCHES TUESDAY MORNING GIVEN SLIGHTLY BETTER FORCING/HIGHER QPF AND A LONGER DURATION OF SUB-FREEZING LOW LEVEL TEMPERATURES. LIGHT RAIN LINGERS INTO THE EVENING...POSSIBLY MIXING WITH LIGHT SNOW ON THE BACK END...BEFORE THE DEEPER MOISTURE AND BEST FORCING LIFTS EAST OVERNIGHT. HIGH PRESSURE IN CONTROL ON WEDNESDAY...AS THE UPPER LEVEL FLOW BRIEFLY BECOMES ZONAL. LOW LEVEL BOUNDARY DRAPED ACROSS THE OHIO VALLEY WILL THEN BEGIN TO LIFT BACK NORTHWARD BY WEDNESDAY NIGHT AND THURSDAY...IN RESPONSE TO A STRONG SHORTWAVE LIFTING OUT OF THE NORTHERN ROCKIES AND THE RESULTANT SFC CYCLOGENESIS THAT WILL COMMENCE ACROSS THE PLAINS. MODELS NOT SURPRISINGLY ARE STRUGGLING WITH THE DETAILS GIVEN THE OVERALL PROGRESSIVE NATURE OF THIS UPPER PATTERN. THE 00Z ECMWF/UKMET CONSENSUS MAINTAINS A MORE PROGRESSIVE/ WEAKER MID-LEVEL TROUGH...WITH THE ASSOCIATED SFC LOW OVER NEW ENGLAND FRIDAY EVENING. MEANWHILE...THE GFS AND CANADIAN BOTH SHOW A MUCH MORE AMPLIFIED TROUGH...WITH THE SFC REFLECTION STILL IN THE GREAT LAKES REGION THROUGH FRIDAY EVENING. WATER VAPOR IMAGERY OVER THE PACIFIC DOES SHOW A DEEPER SYSTEM AT THE MOMENT...LENDING SOME SUPPORT TO A STRONGER/SLOWER EVOLVING SOLUTION DESPITE THE MORE PROGRESSIVE FLOW. ONGOING FORECAST LEANS IN THIS DIRECTION ALREADY...AND SEE NO COMPELLING REASON TO PULL BACK FROM THIS THINKING JUST YET. UNDER THIS SOLUTION...INCREASING ISENTROPIC ACCENT/MOISTURE TRANSPORT ALONG THE BAROCLINIC ZONE WILL SET THE STAGE FOR A GOOD OVERRUNNING EVENT THURSDAY AND THURSDAY NIGHT. LATEST SOUNDING DATA STILL INDICATING THE POTENTIAL FOR A WINTRY MIX WITH THERMAL PROFILES/PARTIAL THICKNESSES SUPPORTING SNOW/SLEET AT ONSET THURSDAY MORNING...WITH THE LONGEST DURATION OF FROZEN PRECIP ACROSS THE NORTH. PRONOUNCED LOW LEVEL WARM LAYER WILL SURGE NORTH THROUGH THE DAY...BRINGING A TRANSITION TO FREEZING RAIN/RAIN. 12Z GFS NOW DEPICTS A LONGER PERIOD OF FREEZING RAIN...AS IT TRENDS FURTHER SOUTH WITH THE SFC LOW AND THERMAL GRADIENT AND MAINTAINS A SUB-FREEZING BOUNDARY LAYER THROUGH MUCH OF THE DAY. ONLY CHANGE AT THIS POINT WILL BE TO EXTEND THE CHANCE OF -FZRA INTO THE EVENING FOR THE M-59 CORRIDOR NORTH. CERTAINLY THE POTENTIAL EXISTS FOR A MESSY SETUP AND WILL CONTINUE TO CLOSELY WATCH THE EVOLUTION AS THE UPPER TROUGH BECOMES BETTER SAMPLED IN THE COMING DAYS. MARINE... A FRONTAL BOUNDARY WILL CONTINUE TO PUSH DOWN THROUGH LOWER MICHIGAN TONIGHT. BEHIND THE FRONT...WINDS WILL INCREASE AND TURN NORTHEAST BEFORE SLOWLY SHIFTING TO NORTHWEST BY SUNRISE. GUSTS TO 20 KNOTS...OR SLIGHTLY MORE...CAN BE EXPECTED OVER THE NEARSHORE WATERS OF LAKE HURON TONIGHT. THE PERSISTENT NORTHERLY COMPONENT TO THE WINDS WILL ALLOW WAVES TO BUILD TO NEARLY 5 FEET ALONG THE NEARSHORE WATERS OF LAKE HURON FORM PORT AUSTIN TO HARBOR BEACH BY LATE TONIGHT. THE PERIOD OF HIGHER WAVES WILL BE BRIEF HOWEVER...AS WAVES QUICKLY DROP OFF LATE TOMORROW MORNING WHEN WINDS TURN SOUTHWEST. THE NEXT LOW PRESSURE SYSTEM WILL TRACK ACROSS THE NORTHERN GREAT LAKES ON TUESDAY...BRINGING A PERIOD OF INCREASED WINDS AND WAVES MONDAY AFTERNOON THROUGH WEDNESDAY. WIND GUSTS COULD POTENTIALLY REACH GALE FORCE ACROSS THE OPEN WATERS OF LAKE HURON ON TUESDAY...AND A GALE WATCH IS NOW IN EFFECT. A SECOND LOW PRESSURE SYSTEM WILL MOVE ACROSS THE WESTERN AND NORTHERN GREAT LAKES THURSDAY NIGHT AND FRIDAY...BRINGING ANOTHER PERIOD OF UNSETTLED WEATHER. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON... GALE WATCH...LHZ361-LHZ362-LHZ363-LHZ462-LHZ463-LHZ464...FROM 4 AM TUESDAY TO 4 PM TUESDAY. LAKE ST CLAIR...NONE. MI WATERS OF LAKE ERIE...NONE. && $$ AVIATION.....SC SHORT TERM...HLO LONG TERM....MR MARINE.......HLO YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE). mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 442 PM EDT SUN MAR 23 2008 .SHORT TERM(TONIGHT AND MONDAY)... THE LATEST MSAS ANALYSIS SUGGESTS RIDGING ACROSS LAKE SUPERIOR...EXTENDING FROM THE MAIN SFC RIDGE ACROSS THE PLAINS. MEANWHILE...A WEAK SHORT WAVE ALOFT IS MOVING SE ACROSS LAKE SUPERIOR PER WATER VAPOR IMAGERY. THE SUBSIDENCE AND NVA MOVING OVER THE LAKE COMBINED WITH THE CONSIDERABLE DRY ADVECTION /SFC DWPTS IN NW ONTARIO WELL BELOW ZERO/ SHOULD SIGNIFICANTLY DIMINISH THE LAKE EFFECT SNOW THIS EVENING...ESPECIALLY AS THE WINDS BACK TO THE NORTHWEST. HOWEVER DUE TO THE UPSLOPE COMPONENT EARLY THIS EVENING COMBINED WITH LOW LAKE-AIR STABILITY /850MB TEMP -16C/...WILL CONTINUE TO CARRY LIKELY POPS IN A SMALL AREA FROM SHOT POINT EAST TO GRAND MARAIS WHERE THE RUC SUGGESTS SOME ENHANCED CONVERGENCE AS THE WINDS BACK AROUND. HOWEVER...ANY ACCUMULATIONS SHOULD HOLD LESS THAN AN INCH. AS THE WINDS BACK AROUND TONIGHT...THERE IS A POSSIBILITY THAT THE KEWEENAW PENINUSLA WILL SEE SOME ENHANCEMENT OVERNIGHT. BEST CHANCE FOR THIS TO OCCUR WOULD BE NORTH OF HOUGHTON...AND HAVE OPTED TO KEEP CHANCE POPS IN THAT AREA FOR THE ENTIRE NIGHT. HOWEVER...WITH THE COMBINATION OF DRY AIR AND STRONG SUBSIDENCE IT SEEMS UNLIKELY THAT THERE WILL BE MUCH ORGANIZATION TO THE ACTIVITY. OTHERWISE...IT SHOULD BE A FAIRLY QUIET BUT COLD NIGHT ACROSS UPPER MICHIGAN. WITH LIGHT WINDS AND A FRESH SNOW COVER IN SOME PLACES...AM THINKING THAT SOME INLAND AREAS WILL SEE TEMPS DROP TO ZERO TO 5 ABOVE TONIGHT. IF IT CAN CLEAR OUT FASTER THAN FORECAST TEMPS COULD DROP MORE THAN THAT. MONDAY SHOULD BE A QUIET DAY BEFORE THE NEXT CLIPPER SYSTEM MONDAY NIGHT/TUE MORNING. WITH THE W-SW FLOW...CANNOT RULE OUT A CHANCE OF SNOW SHOWERS NORTH OF HOUGHTON ALTHOUGH 850MB TEMPS WILL BE MARGINAL /ONLY AROUND -9C/ AND SYNOPTIC SCALE SUBSIDENCE WILL BE STRONG. NONETHELESS...WILL CARRY A SMALL POP THROUGH THE DAY IN THIS REGION. WILL SEE SOME INCREASING CLOUDS /ESPECIALLY ACROSS WESTERN UPPER MICHIGAN/ IN THE WARM ADVECTION AHEAD OF THIS SYSTEM AND SOUTHWEST WINDS WILL ALLOW FOR SOME DOWNSLOPE WARMING. MANY PLACES WILL BE PARTLY TO MOSTLY SUNNY ON MONDAY SO IT SHOULD BE PLEASANT ALTHOUGH A LITTLE CHILLY WITH HIGHS 30-35. && .LONG TERM (MON NGT THRU SUN)... FOCUS FOR MON NIGHT-TUE TURNS TO TIMING/IMPACT OF CLIPPER SHRTWV MOVING ESE FM SCNTRL CAN. PER NCEP GUIDANCE. MODELS NOW IN FAIRLY GOOD AGREEMENT WITH TIMING OF ASSOC SFC LOW WHICH IS PROGGED TO TRACK ACROSS NE MN AND NRN LAKE SUPERIOR TUE MORNING AND THEN MOVES NE OF LAKE SUPERIOR TUE AFTERNOON. MODELS STILL ADVERTISING FAIRLY IMPRESSIVE UPR DIV IN LEFT EXIT REGION OF SUPPORTING 120+ KT H3 JET MAX ALONG WITH IMPRESSIVE DPVA AND VIGOROUS 850-500 MB Q-VECT CONV. SHARP ISENTROPIC ASCENT ON 285-290K SFCS NOTED MON NIGHT IN ADVANCE OF THE SHORTWAVE...TRANSITIONING TO DESCENT BEHIND THE SHORTWAVE OVER WRN HALF COUNTIES BY 12Z TUE. IN GENERAL...THE TRACK OF THE LOW FAVORS THE NCNTRL AND ERN COUNTIES FOR THE HEAVIER/MORE SUSTAINED PCPN AND QPF FIELDS GENERALLY BARE THIS OUT. THE ONE THING THAT MAY LIMIT PCPN/SNOW AMOUNTS IS FAIRLY RAPID MOVEMENT OF SHORTWAVE/SFC LOW. STILL WITHMIXING RATIOS OF 3G/KG ADVECTING OVER THE AREA AND 6HR OF MORE WINDOW OF FAVORABLE ISENTROPIC ASCENT THE FAR ERN PORTION OF THE CWA MAY PUSH ADVISORY TOTALS WITH 3 INCHES OF MORE OF SNOW POSSIBLE MON NIGHT AND ANY ADDITIONAL SNOW ON TUE MORNING ALONG FRONTAL PASSAGE AND WRAPAROUND MOIST CYCLONIC FLOW IN WAKE OF THE LOW. WOULD EXPECT THE REST OF THE CWA THE GENERALLY FALL IN THE 2-4" RANGE FOR TOTAL SNOWFALL FROM THE SYSTEM. EXPECT PCPN TO GENERALLY DIMINISH BY TUE AFTN BEFORE ANOTHER SHORTWAVE RETURNS TUE EVENING AND BRINGS A REINFORCING COLD SHOT AND CHC OF ENHANCEMENT TO LES. LOOKS LIKE BULK OF PCPN WL FALL AS SN... BUT WITH SOME SUNSHINE POSSIBLE FOR SCNTRL AREAS IN DOWNSLOPING NW FLOW LLVLS MAY WARM ENOUGH TO MIX SNOW WITH SOME RAIN. ANOTHER CONCERN FOR TUE AFTN/EVENING WL BE WINDS ESPECIALLY FOR DOWNSLOPING AREAS OVER THE SRN TIER AND OVER THE KEWEENAW PENINSULA. GFS FCST SDNGS FOR MNM AND ESC SHOWS 35-40 KT WINDS WITHIN THE MIXED LYR AT BOTH MNM AND ESC. WINDS OVER THE KEWEENAW COULD REACH 30 KT BY TUE EVENING AS SECONDARY COLD FRONT MOVES THROUGH. IN THE WAKE OF TUE CLIPPER...EXPECT LES TO BE ONGOING TUE NGT INTO WED WITH 850 MB TEMPS OF -16 TO -18C MOVING OVER THE LAKE. HI PRES RDG AXIS WILL THEN MOVES OVHD WED NIGHT AND SHUT OFF THE LES. STILL PLENTY OF MODEL UNCERTAINTY WITH DEVELOPING STORM OVER THE PLAINS BY THU/FRI. HOWEVER...NCEP FAVORED BLEND OF 00Z GFS SOLN AND ENSEMBLE MEAN WHICH NOW TAKES LOW PRESSURE OVER LOWER GREAT LAKES AND OHIO VALLEY THU NIGHT AND FRI. ECMWF HAS BEEN EVEN FARTHER E WITH THIS SYSTEM THE LAST FEW RUNS. WHAT THIS MEANS FOR UPR MI IS THAT HEAVIER PCPN WILL LIKELY STAY SOUTH AND EAST OF THE CWA. BEST CHCS FOR PCPN THU NIGHT AND EARLY FRI WILL BE SCNTRL AND EAST WHERE I HAVE INCLUDED HIGH CHC POPS. ALSO WITH MORE SOUTHWARD TRACK...IT LOOKS LIKE PCPN TYPE WILL STAY ALL SNOW SO DECIDED TO TAKE OUT MIX WITH LIQUID/FREEZING PCPN FROM PREV FCST. BIG DIFFERENCE IN 850 MB TEMPS IN THE WAKE OF THIS SYSTEM FRI NIGHT INTO SAT. ECMWF MUCH WARMER THAN MORE AMPLIFIED SOLN OF GFS WHICH MORE COLD AIR SOUTHWARD BEHIND THE LOW. LEANED A BIT MORE TOWARD GFS TEMPS AND KEPT LOW CHC POPS FOR LES GOING INTO THE WEEKEND IN AREAS FAVORED BY WNW FLOW. && .AVIATION (FOR THE 12Z TAF ISSUANCE)... WINDS ARE STARTING TO BACK AROUND TO THE NORTH EARLY THIS AFTERNOON AS THE RIDGE AXIS BUILDS SOUTH. EXPECT THE WINDS TO RAPIDLY SHIFT TO THE NW BY EVENING THEN SW BY MON MORNING. THIS RAPID SHIFTING OF WINDS COMBINED WITH THE SUBSIDENCE FROM THE HIGH ACROSS THE AREA SHOULD ALLOW FOR THE LAKE EFFECT SNOW TO RAPIDLY DIMINISH THIS AFTERNOON AT SAW. WILL CONTINUE WITH IFR OR LIFR CONDITIONS THROUGH 20Z AT KSAW...BUT THEN RAPIDLY IMPROVE CONDITIONS TO VFR BY EVENING. AT KCMX...IT SHOULD REMAIN GENERALLY QUIET. WILL CONTINUE TO SEE SOME MVFR CIGS EARLY THIS AFTERNOON WITH A PASSING SNOW SHOWER...THEN AGAIN AFTER 06Z TONIGHT AS THE WINDS BACK AROUND TO THE SOUTHWEST. DO NOT EXPECT IFR CONDITIONS AT KCMX THROUGH THE PERIOD. && .MARINE (FOR 4 PM ISSUANCE)... AS HIGH PRES BUILDS ACROSS THE LAKE THIS EVENING...WINDS AND WAVES SHOULD RELAX QUITE RAPIDLY. HOWEVER...AS THE NEXT CLIPPER SYSTEM APPROACHES ON MONDAY AND ESPECIALLY MONDAY NIGHT...SOUTHERLY WINDS WILL INCREASE TO 15-25 KT MON AFTN AND TO GALES MONDAY NIGHT INTO TUE. BEST CHANCE FOR GALES WILL BE ACROSS THE EASTERN 1/3 OF LAKE SUPERIOR AND THE NEARSHORE OF LAKE MICHIGAN. AS THE CLIPPER PASSES BY TUE INTO TUE GALES OR NEAR GALES WILL CONTINUE THROUGH TUE EVENING. W-NW WINDS NEAR 30 KT WILL CONTINUE THROUGH WED EVENING BEFORE HIGH PRES BUILDS ACROSS THE LAKE. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS/SHORT TERM...MRD LONG TERM...VOSS AVIATION...MRD MARINE...MRD mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 127 PM EDT SUN MAR 23 2008 UPDATE AVIATION SECTION. .UPDATE... A FAIRLY STRONG UPSLOPE SNOWBAND HAS PERSISTED ACROSS NORTH CENTRAL UPPER MICHIGAN FOR THE PAST FEW HOURS. DESPITE THE RELATIVELY SHALLOW MOISTURE...THE PERSISTENT NE/UPSLOPE BOUNDARY LAYER FLOW COMBINED WITH SOME SEEDING FROM THE MID LVL CLOUDS MOVING SOUTHWARD ACROSS LAKE SUPERIOR HAS HELPED TO ENHANCE SNOWFALL FROM MARQUETTE THROUGH NEGAUNEE AND ISHPEMING. OVERALL...THE TREND FOR THE SNOW SHOULD BE TO DIMINISH LATER THIS MORNING INTO THIS AFTERNOON AFTER THE HIGHER CLOUD MOVES SOUTH OF THE AREA...SUBSIDENCE MOVES INTO THE AREA... AND UPSLOPE FLOW DECREASES AS THE BOUNDARY LAYER BACKS TO THE NORTH AND NORTHWEST THROUGH THE DAY. HOWEVER...THERE WILL BE SEVERAL MORE HOURS /THROUGH NOON/ THAT THE SNOW WILL BE ENHANCED AT TIMES ACROSS CENTRAL UPPER MI. WILL THEREFORE UPDATE THE FORECAST TO GO WITH 1 TO 3 INCHES OF SNOW IN MARQUETTE COUNTY. DESPITE THE MODERATE SNOW AT CMX...WILL NOT MAKE MANY CHANGES SINCE CMX HAS IMPROVED IN THE LAST HOUR AND NE FLOW USUALLY DOES NOT CAUSE SIGNIFICANT PROBLEMS THERE. WILL ALSO UPDATE TO GO WITH STEADY TEMPS WITH COLD ADVECTION BEHIND THE ARCTIC FRONT TODAY. GRIDS ALREADY ISSUED...ZFP OUT BY 945 AM. && .DISCUSSION... (ISSUED AT 422 AM EDT) THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS THE POTENTIAL FOR LES TODAY. WATER VAPOR IMAGERY AND RUC SHOWING A LOW EMBEDDED IN A LONGWAVE TROUGH OVER EASTERN NORTH AMERICA. A RIDGE STRETCHES OVER THE NORTHERN ROCKIES INTO THE CANADIAN ROCKIES. WEAK SHORTWAVES ARE SWEEPING THROUGH THE BASE OF THE TROUGH AND ARE OVER NORTHERN ONTARIO...IOWA...AND NORTHERN ILLINOIS. ANOTHER WEAK SHORTWAVE IS OVER SOUTHERN MANITOBA. SURFACE ANALYSIS DEPICTS A LOW OVER CENTRAL LAKE MICHIGAN...WITH FRONTS EXTENDING TO EAST THROUGH THE LOWER GREAT LAKES AND WESTWARD THROUGH IOWA INTO EASTERN MONTANA. A LARGE HIGH BLANKETS SOUTH CENTRAL CANADA. ANTI-CYCLONIC FLOW AHEAD OF THE HIGH IS DRAWING COLD AIR FROM CENTRAL CANADA INTO THE FORECAST AREA. 00Z SOUNDINGS SHOWING A THERMAL TROUGH OVER EASTERN ONTARIO IS LOWERING THE 850MB TEMPERATURES OVER LAKE SUPERIOR TO -9C. ANOTHER HIGH IS OVER THE CENTRAL HIGH PLAINS. ANOTHER LONGWAVE TROUGH IS OVER THE WEST COAST WITH AN ACCOMPANYING COLD FRONT WORKING INTO THE PACIFIC NORTHWEST. THE CLOSED LOW ROTATING THROUGH THE BASE OF THE LONGWAVE TROUGH OVER EASTERN NORTH AMERICA WILL SLIDE INTO SOUTHERN HUDSON BAY BY LATE AFTERNOON. THE RIDGE OVER THE CANADIAN ROCKIES WILL SHIFT INTO THE CANADIAN PRAIRIE. THE TROUGH OVER MANITOBA WILL SHIFT SOUTHEAST INTO WESTERN MINNESOTA...WHILE NEW SHORTWAVE DEVELOPS OVER NORTHERN MANITOBA. THE COLD FRONT OVER THE LOWER GREAT LAKES WILL SETTLE INTO THE NORTHERN OHIO RIVER VALLEY AS THE MANITOBA RIDGE SETTLE OVER THE WEST END OF THE FORECAST AREA. THE PACIFIC NORTHWEST COLD FRONT WILL RACE ACROSS THE NORTHERN ROCKIES INTO CENTRAL MONTANA. A POOL OF COLD AIR (-30C AT 850MB) WILL SETTLE OVER JAMES BAY. THE LOWEST INVERSION WILL BE AROUND 900MB. THE ASSOCIATED LAKE-900MB DELTA-T`S WILL INCREASE TO 18C. THIS SUPPORTS THE CONTINUING LES OVER THE FORECAST AREA AND MUCH COLDER SURFACE TEMPERATURES. WINDS WILL DROP OFF THIS AFTERNOON WEAKENING LES OVER THE WEST END OF THE FORECAST AREA. THUS WILL CONTINUE TO FOCUS THE HEAVIEST LES OVER THE EASTERN U.P. THIS AFTERNOON AND ONLY ISOLATED OR SCATTERED OVER THE WEST. THE MANITOBA SHORTWAVE WILL SHIFT INTO WESTERN ONTARIO...TAKING AIM AT THE U.P. TONIGHT. THE SURFACE RIDGE WILL SLIDE ACROSS UPPER MICHIGAN AND CAUSE THE WINDS TO BACK SOUTHWEST. THE DELTA-T`S WILL REMAIN AROUND 15C. TEMPERATURES WILL STILL BE FAVORABLE FOR LES...HOWEVER...THE WINDS ARE NOT. THEREFORE...PLAN TO TAPER THE LES OFF. THE THERMAL RIDGE WILL KEEP COLD AIR WELL BELOW NORMAL IN PLACE. A SURFACE LOW WILL DEVELOP OVER SOUTH CENTRAL CANADA. A NEARLY ZONAL FLOW SETS UP ACROSS THE WEST HALF CONUS ON MONDAY. A WEAK SHORTWAVE WILL SLIP INTO WESTERN U.P. THE SURFACE RIDGE WILL SHIFT INTO THE LOWER GREAT LAKES AND SOUTHERN QUEBEC...WHILE A LOW CENTRAL SWEEPS OUT OF SOUTH CENTRAL CANADA INTO THE NORTHEAST NORTH DAKOTA DRAGGING A COLD FRONT THROUGH THE NORTHERN PLAINS. A STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL PULL SOME DRIER AIR INTO THE AREA. ISENTROPIC ASCENT AHEAD OF THE FRONT WILL DEVELOP SOME SNOW SHOWERS MAINLY OVER THE EAST PART OF THE AREA. THE ZONAL FLOW WILL PERSIST THROUGH MONDAY NIGHT. THIS WILL HELP TO PUSH THE MID LEVEL LOW THROUGH THE AREA. THE SURFACE LOW WILL SWEEP INTO THE WEST END OF THE FORECAST AREA DRAGGING A COLD FRONT THROUGH THE NORTHERN PLAINS AND UPPER MISSISSIPPI RIVER VALLEY. LOW LEVEL MOISTURE WILL FEED THIS INSTABILITY ASSOCIATED WITH THE SHORTWAVE AND THE ISENTROPIC ASCENT ACCOMPANYING THE FRONT PRODUCING SOME SNOWS OVER THE AREA. ANOTHER SHORTWAVE ROTATING AROUND THE BASE OF THE EASTERN NORTH AMERICA TROUGH WILL SWEEP THROUGH THE FORECAST AREA TUESDAY. THE SURFACE LOW AND ASSOCIATE FRONTAL SYSTEM WILL MOVE THROUGH THE REST OF UPPER MICHIGAN INTO EAST CENTRAL ONTARIO. THE WINDS WILL BACK NORTHWEST BEHIND THE LOW. COOLER AIR WILL SPREAD INTO THE AREA CAUSING 850MB DELTA-T`S TO INCREASE TO AROUND 12C. THIS IS ENOUGH FOR SOME LAKE ENHANCEMENT. THUS PLANNING TO KEEP A LITTLE HIGHER POPS OVER THE NORTH HALF. THE ZONAL FLOW WILL SET UP AGAIN ACROSS THE REGION FOLLOWING THE LOW CENTER TUESDAY NIGHT. THE SURFACE LOW WILL SHIFT INTO SOUTHERN QUEBEC...A RIDGE MOVES OUT OF CENTRAL CANADA INTO MISSISSIPPI RIVER VALLEY. THIS WILL CAUSE WIND TO REMAIN OUT OF THE NORTH AND SET UP A THERMAL TROUGH OVER THE AREA CREATING A DELTA-T OF AROUND 19C. THIS APPEARS TO BE RATHER CONDUCIVE FOR LES DEVELOP AND FAVOR HEAVIEST SNOWFALL WILL BE OVER THE HIGH HILLS OVER THE NORTHERN U.P. THE RIDGE WILL PUSH OVER THE FORECAST AREA ON WEDNESDAY. THE WINDS SHOULD DIMINISH OVER THE LAKE...HOWEVER...WOULD REMAIN OUT OF THE NORTHWEST. THE ZONAL FLOW WILL PERSIST ALLOW A THERMAL POOL TO SETTLE OVER EAST CENTRAL LAKE MICHIGAN THROUGH WEDNESDAY. THE DELTA-T WILL BE AROUND 19C. THESE CONDITIONS ARE STILL FAVORABLE FOR MORE LES. DRY STABLE AIR WILL ADVECT INTO THE AREA FROM THE WEST ON WEDNESDAY. && .AVIATION (FOR THE 12Z TAF ISSUANCE)... WINDS ARE STARTING TO BACK AROUND TO THE NORTH EARLY THIS AFTERNOON AS THE RIDGE AXIS BUILDS SOUTH. EXPECT THE WINDS TO RAPIDLY SHIFT TO THE NW BY EVENING THEN SW BY MON MORNING. THIS RAPID SHIFTING OF WINDS COMBINED WITH THE SUBSIDENCE FROM THE HIGH ACROSS THE AREA SHOULD ALLOW FOR THE LAKE EFFECT SNOW TO RAPIDLY DIMINISH THIS AFTERNOON AT SAW. WILL CONTINUE WITH IFR OR LIFR CONDITIONS THROUGH 20Z AT KSAW...BUT THEN RAPIDLY IMPROVE CONDITIONS TO VFR BY EVENING. AT KCMX...IT SHOULD REMAIN GENERALLY QUIET. WILL CONTINUE TO SEE SOME MVFR CIGS EARLY THIS AFTERNOON WITH A PASSING SNOW SHOWER...THEN AGAIN AFTER 06Z TONIGHT AS THE WINDS BACK AROUND TO THE SOUTHWEST. DO NOT EXPECT IFR CONDITIONS AT KCMX THROUGH THE PERIOD. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... STRONG HIGH PRES OVER NORTHERN MANITOBA WILL WEAKEN AS IT HEADS S TODAY. SO...STRONGEST WINDS WILL OCCUR THIS MORNING. EXPECT NRLY WINDS OF 20-30KT...MAINLY OVER THE W 1/2 TO 2/3RDS OF THE LAKE. HEAVY FREEZING SPRAY IS ALSO EXPECTED DURING THE MORNING. WINDS WILL DIMINISH THIS AFTERNOON AND TONIGHT AS THE HIGH HEADS TO THE MID MISSISSIPPI VALLEY. THEN AS LOW PRES TAKES SHAPE OVER SOUTHERN CANADA MON MORNING...SW WINDS WILL RAMP UP AGAIN TO 20 TO 30 KT. AS THE LOW APPROACHES THE UPPER LAKES MON NIGHT...WINDS WILL BECOME SRLY. TYPICALLY...SRLY WINDS ARE STRONGER OVER ERN LAKE SUPERIOR... AND THIS CASE WILL BE NO DIFFERENT. WHILE WINDS WILL DIMINISH SOME OVER WRN LAKE SUPERIOR MON NIGHT...SRLY WINDS WILL INCREASE TO 30KT OVER ERN SUPERIOR. NOT OUT OF THE QUESTION GALES COULD OCCUR. ONLY MENTIONED THE POSSIBILITY OF SOME GALE GUSTS WITH THIS FCST ISSUANCE. AS THE LOW MOVES E OF THE UPPER LAKES LATE TUE...EXPECT A PERIOD OF N TO NW GALES OVER THE E 1/2 TO 2/3RDS TUE NIGHT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN...NONE. LAKE SUPERIOR...HEAVY FREEZING SPRAY WARNING UNTIL 11AM EDT THIS MORNING FOR LSZ263>267. LAKE MICHIGAN...NONE. && $$ UPDATE...MRD DISCUSSION...DLG AVIATION...MRD MARINE...ROLFSON mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 927 AM EDT SUN MAR 23 2008 .UPDATE... A FAIRLY STRONG UPSLOPE SNOWBAND HAS PERSISTED ACROSS NORTH CENTRAL UPPER MICHIGAN FOR THE PAST FEW HOURS. DESPITE THE RELATIVELY SHALLOW MOISTURE...THE PERSISTENT NE/UPSLOPE BOUNDARY LAYER FLOW COMBINED WITH SOME SEEDING FROM THE MID LVL CLOUDS MOVING SOUTHWARD ACROSS LAKE SUPERIOR HAS HELPED TO ENHANCE SNOWFALL FROM MARQUETTE THROUGH NEGAUNEE AND ISHPEMING. OVERALL...THE TREND FOR THE SNOW SHOULD BE TO DIMINISH LATER THIS MORNING INTO THIS AFTERNOON AFTER THE HIGHER CLOUD MOVES SOUTH OF THE AREA...SUBSIDENCE MOVES INTO THE AREA... AND UPSLOPE FLOW DECREASES AS THE BOUNDARY LAYER BACKS TO THE NORTH AND NORTHWEST THROUGH THE DAY. HOWEVER...THERE WILL BE SEVERAL MORE HOURS /THROUGH NOON/ THAT THE SNOW WILL BE ENHANCED AT TIMES ACROSS CENTRAL UPPER MI. WILL THEREFORE UPDATE THE FORECAST TO GO WITH 1 TO 3 INCHES OF SNOW IN MARQUETTE COUNTY. DESPITE THE MODERATE SNOW AT CMX...WILL NOT MAKE MANY CHANGES SINCE CMX HAS IMPROVED IN THE LAST HOUR AND NE FLOW USUALLY DOES NOT CAUSE SIGNIFICANT PROBLEMS THERE. WILL ALSO UPDATE TO GO WITH STEADY TEMPS WITH COLD ADVECTION BEHIND THE ARCTIC FRONT TODAY. GRIDS ALREADY ISSUED...ZFP OUT BY 945 AM. && .DISCUSSION... (ISSUED AT 422 AM EDT) THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS THE POTENTIAL FOR LES TODAY. WATER VAPOR IMAGERY AND RUC SHOWING A LOW EMBEDDED IN A LONGWAVE TROUGH OVER EASTERN NORTH AMERICA. A RIDGE STRETCHES OVER THE NORTHERN ROCKIES INTO THE CANADIAN ROCKIES. WEAK SHORTWAVES ARE SWEEPING THROUGH THE BASE OF THE TROUGH AND ARE OVER NORTHERN ONTARIO...IOWA...AND NORTHERN ILLINOIS. ANOTHER WEAK SHORTWAVE IS OVER SOUTHERN MANITOBA. SURFACE ANALYSIS DEPICTS A LOW OVER CENTRAL LAKE MICHIGAN...WITH FRONTS EXTENDING TO EAST THROUGH THE LOWER GREAT LAKES AND WESTWARD THROUGH IOWA INTO EASTERN MONTANA. A LARGE HIGH BLANKETS SOUTH CENTRAL CANADA. ANTI-CYCLONIC FLOW AHEAD OF THE HIGH IS DRAWING COLD AIR FROM CENTRAL CANADA INTO THE FORECAST AREA. 00Z SOUNDINGS SHOWING A THERMAL TROUGH OVER EASTERN ONTARIO IS LOWERING THE 850MB TEMPERATURES OVER LAKE SUPERIOR TO -9C. ANOTHER HIGH IS OVER THE CENTRAL HIGH PLAINS. ANOTHER LONGWAVE TROUGH IS OVER THE WEST COAST WITH AN ACCOMPANYING COLD FRONT WORKING INTO THE PACIFIC NORTHWEST. THE CLOSED LOW ROTATING THROUGH THE BASE OF THE LONGWAVE TROUGH OVER EASTERN NORTH AMERICA WILL SLIDE INTO SOUTHERN HUDSON BAY BY LATE AFTERNOON. THE RIDGE OVER THE CANADIAN ROCKIES WILL SHIFT INTO THE CANADIAN PRAIRIE. THE TROUGH OVER MANITOBA WILL SHIFT SOUTHEAST INTO WESTERN MINNESOTA...WHILE NEW SHORTWAVE DEVELOPS OVER NORTHERN MANITOBA. THE COLD FRONT OVER THE LOWER GREAT LAKES WILL SETTLE INTO THE NORTHERN OHIO RIVER VALLEY AS THE MANITOBA RIDGE SETTLE OVER THE WEST END OF THE FORECAST AREA. THE PACIFIC NORTHWEST COLD FRONT WILL RACE ACROSS THE NORTHERN ROCKIES INTO CENTRAL MONTANA. A POOL OF COLD AIR (-30C AT 850MB) WILL SETTLE OVER JAMES BAY. THE LOWEST INVERSION WILL BE AROUND 900MB. THE ASSOCIATED LAKE-900MB DELTA-T`S WILL INCREASE TO 18C. THIS SUPPORTS THE CONTINUING LES OVER THE FORECAST AREA AND MUCH COLDER SURFACE TEMPERATURES. WINDS WILL DROP OFF THIS AFTERNOON WEAKENING LES OVER THE WEST END OF THE FORECAST AREA. THUS WILL CONTINUE TO FOCUS THE HEAVIEST LES OVER THE EASTERN U.P. THIS AFTERNOON AND ONLY ISOLATED OR SCATTERED OVER THE WEST. THE MANITOBA SHORTWAVE WILL SHIFT INTO WESTERN ONTARIO...TAKING AIM AT THE U.P. TONIGHT. THE SURFACE RIDGE WILL SLIDE ACROSS UPPER MICHIGAN AND CAUSE THE WINDS TO BACK SOUTHWEST. THE DELTA-T`S WILL REMAIN AROUND 15C. TEMPERATURES WILL STILL BE FAVORABLE FOR LES...HOWEVER...THE WINDS ARE NOT. THEREFORE...PLAN TO TAPER THE LES OFF. THE THERMAL RIDGE WILL KEEP COLD AIR WELL BELOW NORMAL IN PLACE. A SURFACE LOW WILL DEVELOP OVER SOUTH CENTRAL CANADA. A NEARLY ZONAL FLOW SETS UP ACROSS THE WEST HALF CONUS ON MONDAY. A WEAK SHORTWAVE WILL SLIP INTO WESTERN U.P. THE SURFACE RIDGE WILL SHIFT INTO THE LOWER GREAT LAKES AND SOUTHERN QUEBEC...WHILE A LOW CENTRAL SWEEPS OUT OF SOUTH CENTRAL CANADA INTO THE NORTHEAST NORTH DAKOTA DRAGGING A COLD FRONT THROUGH THE NORTHERN PLAINS. A STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL PULL SOME DRIER AIR INTO THE AREA. ISENTROPIC ASCENT AHEAD OF THE FRONT WILL DEVELOP SOME SNOW SHOWERS MAINLY OVER THE EAST PART OF THE AREA. THE ZONAL FLOW WILL PERSIST THROUGH MONDAY NIGHT. THIS WILL HELP TO PUSH THE MID LEVEL LOW THROUGH THE AREA. THE SURFACE LOW WILL SWEEP INTO THE WEST END OF THE FORECAST AREA DRAGGING A COLD FRONT THROUGH THE NORTHERN PLAINS AND UPPER MISSISSIPPI RIVER VALLEY. LOW LEVEL MOISTURE WILL FEED THIS INSTABILITY ASSOCIATED WITH THE SHORTWAVE AND THE ISENTROPIC ASCENT ACCOMPANYING THE FRONT PRODUCING SOME SNOWS OVER THE AREA. ANOTHER SHORTWAVE ROTATING AROUND THE BASE OF THE EASTERN NORTH AMERICA TROUGH WILL SWEEP THROUGH THE FORECAST AREA TUESDAY. THE SURFACE LOW AND ASSOCIATE FRONTAL SYSTEM WILL MOVE THROUGH THE REST OF UPPER MICHIGAN INTO EAST CENTRAL ONTARIO. THE WINDS WILL BACK NORTHWEST BEHIND THE LOW. COOLER AIR WILL SPREAD INTO THE AREA CAUSING 850MB DELTA-T`S TO INCREASE TO AROUND 12C. THIS IS ENOUGH FOR SOME LAKE ENHANCEMENT. THUS PLANNING TO KEEP A LITTLE HIGHER POPS OVER THE NORTH HALF. THE ZONAL FLOW WILL SET UP AGAIN ACROSS THE REGION FOLLOWING THE LOW CENTER TUESDAY NIGHT. THE SURFACE LOW WILL SHIFT INTO SOUTHERN QUEBEC...A RIDGE MOVES OUT OF CENTRAL CANADA INTO MISSISSIPPI RIVER VALLEY. THIS WILL CAUSE WIND TO REMAIN OUT OF THE NORTH AND SET UP A THERMAL TROUGH OVER THE AREA CREATING A DELTA-T OF AROUND 19C. THIS APPEARS TO BE RATHER CONDUCIVE FOR LES DEVELOP AND FAVOR HEAVIEST SNOWFALL WILL BE OVER THE HIGH HILLS OVER THE NORTHERN U.P. THE RIDGE WILL PUSH OVER THE FORECAST AREA ON WEDNESDAY. THE WINDS SHOULD DIMINISH OVER THE LAKE...HOWEVER...WOULD REMAIN OUT OF THE NORTHWEST. THE ZONAL FLOW WILL PERSIST ALLOW A THERMAL POOL TO SETTLE OVER EAST CENTRAL LAKE MICHIGAN THROUGH WEDNESDAY. THE DELTA-T WILL BE AROUND 19C. THESE CONDITIONS ARE STILL FAVORABLE FOR MORE LES. DRY STABLE AIR WILL ADVECT INTO THE AREA FROM THE WEST ON WEDNESDAY. && .AVIATION (FOR THE 12Z TAF ISSUANCE)... IN THE WAKE OF AN ARCTIC COLD FRONT THAT HAS PASSED KCMX/KSAW OVERNIGHT...LAKE EFFECT -SHSN HAVE DEVELOPED. NARROW BAND OF MOISTURE THAT IS ENHANCING LAKE EFFECT WILL BE EXITING FROM N TO S OVER THE NEXT FEW HRS. THUS...EXPECT CONDITIONS TO IMPROVE... BEGINNING FIRST AT KCMX. AT KCMX...MAY SEE OCCASIONAL IFR VIS THRU ABOUT 14Z AND THEN OCCASIONAL MVFR VIS UNTIL 16Z. AFTER THAT...FLURRIES SHOULD NOT REDUCE VIS BLO VFR. EXPECT MVFR CIGS TO DOMINATE THRU THE FCST PERIOD...THOUGH CLOUDS MAY SCATTER OUT FOR A TIME LATE THIS AFTN. AT KSAW...NNE WINDS ARE MORE FAVORABLE FOR LAKE EFFECT -SHSN. SHOULD SEE OCCASIONAL IFR CIGS AND/OR VIS THRU 16Z. MVFR CIGS AND OCCASIONAL MVFR VIS SHOULD THEN LINGER INTO MID AFTN OR SO. AS WINDS BACK NW LATE...-SHSN WILL END AND CLOUDS WILL SCATTER OUT. VFR CONDITIONS WILL THEN PREVAIL TONIGHT. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... STRONG HIGH PRES OVER NORTHERN MANITOBA WILL WEAKEN AS IT HEADS S TODAY. SO...STRONGEST WINDS WILL OCCUR THIS MORNING. EXPECT NRLY WINDS OF 20-30KT...MAINLY OVER THE W 1/2 TO 2/3RDS OF THE LAKE. HEAVY FREEZING SPRAY IS ALSO EXPECTED DURING THE MORNING. WINDS WILL DIMINISH THIS AFTERNOON AND TONIGHT AS THE HIGH HEADS TO THE MID MISSISSIPPI VALLEY. THEN AS LOW PRES TAKES SHAPE OVER SOUTHERN CANADA MON MORNING...SW WINDS WILL RAMP UP AGAIN TO 20 TO 30 KT. AS THE LOW APPROACHES THE UPPER LAKES MON NIGHT...WINDS WILL BECOME SRLY. TYPICALLY...SRLY WINDS ARE STRONGER OVER ERN LAKE SUPERIOR... AND THIS CASE WILL BE NO DIFFERENT. WHILE WINDS WILL DIMINISH SOME OVER WRN LAKE SUPERIOR MON NIGHT...SRLY WINDS WILL INCREASE TO 30KT OVER ERN SUPERIOR. NOT OUT OF THE QUESTION GALES COULD OCCUR. ONLY MENTIONED THE POSSIBILITY OF SOME GALE GUSTS WITH THIS FCST ISSUANCE. AS THE LOW MOVES E OF THE UPPER LAKES LATE TUE...EXPECT A PERIOD OF N TO NW GALES OVER THE E 1/2 TO 2/3RDS TUE NIGHT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN...NONE. LAKE SUPERIOR...HEAVY FREEZING SPRAY WARNING UNTIL 11AM EDT THIS MORNING FOR LSZ263>267. LAKE MICHIGAN...NONE. && $$ UPDATE...MRD DISCUSSION...DLG AVIATION...ROLFSON MARINE...ROLFSON mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 745 AM EDT SUN MAR 23 2008 UPDATED AVIATION DISCUSSION FOR 12Z TAFS .DISCUSSION... (ISSUED AT 422 AM EDT) THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS THE POTENTIAL FOR LES TODAY. WATER VAPOR IMAGERY AND RUC SHOWING A LOW EMBEDDED IN A LONGWAVE TROUGH OVER EASTERN NORTH AMERICA. A RIDGE STRETCHES OVER THE NORTHERN ROCKIES INTO THE CANADIAN ROCKIES. WEAK SHORTWAVES ARE SWEEPING THROUGH THE BASE OF THE TROUGH AND ARE OVER NORTHERN ONTARIO...IOWA...AND NORTHERN ILLINOIS. ANOTHER WEAK SHORTWAVE IS OVER SOUTHERN MANITOBA. SURFACE ANALYSIS DEPICTS A LOW OVER CENTRAL LAKE MICHIGAN...WITH FRONTS EXTENDING TO EAST THROUGH THE LOWER GREAT LAKES AND WESTWARD THROUGH IOWA INTO EASTERN MONTANA. A LARGE HIGH BLANKETS SOUTH CENTRAL CANADA. ANTI-CYCLONIC FLOW AHEAD OF THE HIGH IS DRAWING COLD AIR FROM CENTRAL CANADA INTO THE FORECAST AREA. 00Z SOUNDINGS SHOWING A THERMAL TROUGH OVER EASTERN ONTARIO IS LOWERING THE 850MB TEMPERATURES OVER LAKE SUPERIOR TO -9C. ANOTHER HIGH IS OVER THE CENTRAL HIGH PLAINS. ANOTHER LONGWAVE TROUGH IS OVER THE WEST COAST WITH AN ACCOMPANYING COLD FRONT WORKING INTO THE PACIFIC NORTHWEST. THE CLOSED LOW ROTATING THROUGH THE BASE OF THE LONGWAVE TROUGH OVER EASTERN NORTH AMERICA WILL SLIDE INTO SOUTHERN HUDSON BAY BY LATE AFTERNOON. THE RIDGE OVER THE CANADIAN ROCKIES WILL SHIFT INTO THE CANADIAN PRAIRIE. THE TROUGH OVER MANITOBA WILL SHIFT SOUTHEAST INTO WESTERN MINNESOTA...WHILE NEW SHORTWAVE DEVELOPS OVER NORTHERN MANITOBA. THE COLD FRONT OVER THE LOWER GREAT LAKES WILL SETTLE INTO THE NORTHERN OHIO RIVER VALLEY AS THE MANITOBA RIDGE SETTLE OVER THE WEST END OF THE FORECAST AREA. THE PACIFIC NORTHWEST COLD FRONT WILL RACE ACROSS THE NORTHERN ROCKIES INTO CENTRAL MONTANA. A POOL OF COLD AIR (-30C AT 850MB) WILL SETTLE OVER JAMES BAY. THE LOWEST INVERSION WILL BE AROUND 900MB. THE ASSOCIATED LAKE-900MB DELTA-T`S WILL INCREASE TO 18C. THIS SUPPORTS THE CONTINUING LES OVER THE FORECAST AREA AND MUCH COLDER SURFACE TEMPERATURES. WINDS WILL DROP OFF THIS AFTERNOON WEAKENING LES OVER THE WEST END OF THE FORECAST AREA. THUS WILL CONTINUE TO FOCUS THE HEAVIEST LES OVER THE EASTERN U.P. THIS AFTERNOON AND ONLY ISOLATED OR SCATTERED OVER THE WEST. THE MANITOBA SHORTWAVE WILL SHIFT INTO WESTERN ONTARIO...TAKING AIM AT THE U.P. TONIGHT. THE SURFACE RIDGE WILL SLIDE ACROSS UPPER MICHIGAN AND CAUSE THE WINDS TO BACK SOUTHWEST. THE DELTA-T`S WILL REMAIN AROUND 15C. TEMPERATURES WILL STILL BE FAVORABLE FOR LES...HOWEVER...THE WINDS ARE NOT. THEREFORE...PLAN TO TAPER THE LES OFF. THE THERMAL RIDGE WILL KEEP COLD AIR WELL BELOW NORMAL IN PLACE. A SURFACE LOW WILL DEVELOP OVER SOUTH CENTRAL CANADA. A NEARLY ZONAL FLOW SETS UP ACROSS THE WEST HALF CONUS ON MONDAY. A WEAK SHORTWAVE WILL SLIP INTO WESTERN U.P. THE SURFACE RIDGE WILL SHIFT INTO THE LOWER GREAT LAKES AND SOUTHERN QUEBEC...WHILE A LOW CENTRAL SWEEPS OUT OF SOUTH CENTRAL CANADA INTO THE NORTHEAST NORTH DAKOTA DRAGGING A COLD FRONT THROUGH THE NORTHERN PLAINS. A STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL PULL SOME DRIER AIR INTO THE AREA. ISENTROPIC ASCENT AHEAD OF THE FRONT WILL DEVELOP SOME SNOW SHOWERS MAINLY OVER THE EAST PART OF THE AREA. THE ZONAL FLOW WILL PERSIST THROUGH MONDAY NIGHT. THIS WILL HELP TO PUSH THE MID LEVEL LOW THROUGH THE AREA. THE SURFACE LOW WILL SWEEP INTO THE WEST END OF THE FORECAST AREA DRAGGING A COLD FRONT THROUGH THE NORTHERN PLAINS AND UPPER MISSISSIPPI RIVER VALLEY. LOW LEVEL MOISTURE WILL FEED THIS INSTABILITY ASSOCIATED WITH THE SHORTWAVE AND THE ISENTROPIC ASCENT ACCOMPANYING THE FRONT PRODUCING SOME SNOWS OVER THE AREA. ANOTHER SHORTWAVE ROTATING AROUND THE BASE OF THE EASTERN NORTH AMERICA TROUGH WILL SWEEP THROUGH THE FORECAST AREA TUESDAY. THE SURFACE LOW AND ASSOCIATE FRONTAL SYSTEM WILL MOVE THROUGH THE REST OF UPPER MICHIGAN INTO EAST CENTRAL ONTARIO. THE WINDS WILL BACK NORTHWEST BEHIND THE LOW. COOLER AIR WILL SPREAD INTO THE AREA CAUSING 850MB DELTA-T`S TO INCREASE TO AROUND 12C. THIS IS ENOUGH FOR SOME LAKE ENHANCEMENT. THUS PLANNING TO KEEP A LITTLE HIGHER POPS OVER THE NORTH HALF. THE ZONAL FLOW WILL SET UP AGAIN ACROSS THE REGION FOLLOWING THE LOW CENTER TUESDAY NIGHT. THE SURFACE LOW WILL SHIFT INTO SOUTHERN QUEBEC...A RIDGE MOVES OUT OF CENTRAL CANADA INTO MISSISSIPPI RIVER VALLEY. THIS WILL CAUSE WIND TO REMAIN OUT OF THE NORTH AND SET UP A THERMAL TROUGH OVER THE AREA CREATING A DELTA-T OF AROUND 19C. THIS APPEARS TO BE RATHER CONDUCIVE FOR LES DEVELOP AND FAVOR HEAVIEST SNOWFALL WILL BE OVER THE HIGH HILLS OVER THE NORTHERN U.P. THE RIDGE WILL PUSH OVER THE FORECAST AREA ON WEDNESDAY. THE WINDS SHOULD DIMINISH OVER THE LAKE...HOWEVER...WOULD REMAIN OUT OF THE NORTHWEST. THE ZONAL FLOW WILL PERSIST ALLOW A THERMAL POOL TO SETTLE OVER EAST CENTRAL LAKE MICHIGAN THROUGH WEDNESDAY. THE DELTA-T WILL BE AROUND 19C. THESE CONDITIONS ARE STILL FAVORABLE FOR MORE LES. DRY STABLE AIR WILL ADVECT INTO THE AREA FROM THE WEST ON WEDNESDAY. && .AVIATION (FOR THE 12Z TAF ISSUANCE)... IN THE WAKE OF AN ARCTIC COLD FRONT THAT HAS PASSED KCMX/KSAW OVERNIGHT...LAKE EFFECT -SHSN HAVE DEVELOPED. NARROW BAND OF MOISTURE THAT IS ENHANCING LAKE EFFECT WILL BE EXITING FROM N TO S OVER THE NEXT FEW HRS. THUS...EXPECT CONDITIONS TO IMPROVE... BEGINNING FIRST AT KCMX. AT KCMX...MAY SEE OCCASIONAL IFR VIS THRU ABOUT 14Z AND THEN OCCASIONAL MVFR VIS UNTIL 16Z. AFTER THAT...FLURRIES SHOULD NOT REDUCE VIS BLO VFR. EXPECT MVFR CIGS TO DOMINATE THRU THE FCST PERIOD...THOUGH CLOUDS MAY SCATTER OUT FOR A TIME LATE THIS AFTN. AT KSAW...NNE WINDS ARE MORE FAVORABLE FOR LAKE EFFECT -SHSN. SHOULD SEE OCCASIONAL IFR CIGS AND/OR VIS THRU 16Z. MVFR CIGS AND OCCASIONAL MVFR VIS SHOULD THEN LINGER INTO MID AFTN OR SO. AS WINDS BACK NW LATE...-SHSN WILL END AND CLOUDS WILL SCATTER OUT. VFR CONDITIONS WILL THEN PREVAIL TONIGHT. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... STRONG HIGH PRES OVER NORTHERN MANITOBA WILL WEAKEN AS IT HEADS S TODAY. SO...STRONGEST WINDS WILL OCCUR THIS MORNING. EXPECT NRLY WINDS OF 20-30KT...MAINLY OVER THE W 1/2 TO 2/3RDS OF THE LAKE. HEAVY FREEZING SPRAY IS ALSO EXPECTED DURING THE MORNING. WINDS WILL DIMINISH THIS AFTERNOON AND TONIGHT AS THE HIGH HEADS TO THE MID MISSISSIPPI VALLEY. THEN AS LOW PRES TAKES SHAPE OVER SOUTHERN CANADA MON MORNING...SW WINDS WILL RAMP UP AGAIN TO 20 TO 30 KT. AS THE LOW APPROACHES THE UPPER LAKES MON NIGHT...WINDS WILL BECOME SRLY. TYPICALLY...SRLY WINDS ARE STRONGER OVER ERN LAKE SUPERIOR... AND THIS CASE WILL BE NO DIFFERENT. WHILE WINDS WILL DIMINISH SOME OVER WRN LAKE SUPERIOR MON NIGHT...SRLY WINDS WILL INCREASE TO 30KT OVER ERN SUPERIOR. NOT OUT OF THE QUESTION GALES COULD OCCUR. ONLY MENTIONED THE POSSIBILITY OF SOME GALE GUSTS WITH THIS FCST ISSUANCE. AS THE LOW MOVES E OF THE UPPER LAKES LATE TUE...EXPECT A PERIOD OF N TO NW GALES OVER THE E 1/2 TO 2/3RDS TUE NIGHT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN...NONE. LAKE SUPERIOR...HEAVY FREEZING SPRAY WARNING UNTIL 11AM EDT THIS MORNING FOR LSZ263>267. LAKE MICHIGAN...NONE. && $$ DISCUSSION...DLG AVIATION...ROLFSON MARINE...ROLFSON mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 422 AM EDT SUN MAR 23 2008 .DISCUSSION... THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS THE POTENTIAL FOR LES TODAY. WATER VAPOR IMAGERY AND RUC SHOWING A LOW EMBEDDED IN A LONGWAVE TROUGH OVER EASTERN NORTH AMERICA. A RIDGE STRETCHES OVER THE NORTHERN ROCKIES INTO THE CANADIAN ROCKIES. WEAK SHORTWAVES ARE SWEEPING THROUGH THE BASE OF THE TROUGH AND ARE OVER NORTHERN ONTARIO...IOWA...AND NORTHERN ILLINOIS. ANOTHER WEAK SHORTWAVE IS OVER SOUTHERN MANITOBA. SURFACE ANALYSIS DEPICTS A LOW OVER CENTRAL LAKE MICHIGAN...WITH FRONTS EXTENDING TO EAST THROUGH THE LOWER GREAT LAKES AND WESTWARD THROUGH IOWA INTO EASTERN MONTANA. A LARGE HIGH BLANKETS SOUTH CENTRAL CANADA. ANTI-CYCLONIC FLOW AHEAD OF THE HIGH IS DRAWING COLD AIR FROM CENTRAL CANADA INTO THE FORECAST AREA. 00Z SOUNDINGS SHOWING A THERMAL TROUGH OVER EASTERN ONTARIO IS LOWERING THE 850MB TEMPERATURES OVER LAKE SUPERIOR TO -9C. ANOTHER HIGH IS OVER THE CENTRAL HIGH PLAINS. ANOTHER LONGWAVE TROUGH IS OVER THE WEST COAST WITH AN ACCOMPANYING COLD FRONT WORKING INTO THE PACIFIC NORTHWEST. THE CLOSED LOW ROTATING THROUGH THE BASE OF THE LONGWAVE TROUGH OVER EASTERN NORTH AMERICA WILL SLIDE INTO SOUTHERN HUDSON BAY BY LATE AFTERNOON. THE RIDGE OVER THE CANADIAN ROCKIES WILL SHIFT INTO THE CANADIAN PRAIRIE. THE TROUGH OVER MANITOBA WILL SHIFT SOUTHEAST INTO WESTERN MINNESOTA...WHILE NEW SHORTWAVE DEVELOPS OVER NORTHERN MANITOBA. THE COLD FRONT OVER THE LOWER GREAT LAKES WILL SETTLE INTO THE NORTHERN OHIO RIVER VALLEY AS THE MANITOBA RIDGE SETTLE OVER THE WEST END OF THE FORECAST AREA. THE PACIFIC NORTHWEST COLD FRONT WILL RACE ACROSS THE NORTHERN ROCKIES INTO CENTRAL MONTANA. A POOL OF COLD AIR (-30C AT 850MB) WILL SETTLE OVER JAMES BAY. THE LOWEST INVERSION WILL BE AROUND 900MB. THE ASSOCIATED LAKE-900MB DELTA-T`S WILL INCREASE TO 18C. THIS SUPPORTS THE CONTINUING LES OVER THE FORECAST AREA AND MUCH COLDER SURFACE TEMPERATURES. WINDS WILL DROP OFF THIS AFTERNOON WEAKENING LES OVER THE WEST END OF THE FORECAST AREA. THUS WILL CONTINUE TO FOCUS THE HEAVIEST LES OVER THE EASTERN U.P. THIS AFTERNOON AND ONLY ISOLATED OR SCATTERED OVER THE WEST. THE MANITOBA SHORTWAVE WILL SHIFT INTO WESTERN ONTARIO...TAKING AIM AT THE U.P. TONIGHT. THE SURFACE RIDGE WILL SLIDE ACROSS UPPER MICHIGAN AND CAUSE THE WINDS TO BACK SOUTHWEST. THE DELTA-T`S WILL REMAIN AROUND 15C. TEMPERATURES WILL STILL BE FAVORABLE FOR LES...HOWEVER...THE WINDS ARE NOT. THEREFORE...PLAN TO TAPER THE LES OFF. THE THERMAL RIDGE WILL KEEP COLD AIR WELL BELOW NORMAL IN PLACE. A SURFACE LOW WILL DEVELOP OVER SOUTH CENTRAL CANADA. A NEARLY ZONAL FLOW SETS UP ACROSS THE WEST HALF CONUS ON MONDAY. A WEAK SHORTWAVE WILL SLIP INTO WESTERN U.P. THE SURFACE RIDGE WILL SHIFT INTO THE LOWER GREAT LAKES AND SOUTHERN QUEBEC...WHILE A LOW CENTRAL SWEEPS OUT OF SOUTH CENTRAL CANADA INTO THE NORTHEAST NORTH DAKOTA DRAGGING A COLD FRONT THROUGH THE NORTHERN PLAINS. A STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL PULL SOME DRIER AIR INTO THE AREA. ISENTROPIC ASCENT AHEAD OF THE FRONT WILL DEVELOP SOME SNOW SHOWERS MAINLY OVER THE EAST PART OF THE AREA. THE ZONAL FLOW WILL PERSIST THROUGH MONDAY NIGHT. THIS WILL HELP TO PUSH THE MID LEVEL LOW THROUGH THE AREA. THE SURFACE LOW WILL SWEEP INTO THE WEST END OF THE FORECAST AREA DRAGGING A COLD FRONT THROUGH THE NORTHERN PLAINS AND UPPER MISSISSIPPI RIVER VALLEY. LOW LEVEL MOISTURE WILL FEED THIS INSTABILITY ASSOCIATED WITH THE SHORTWAVE AND THE ISENTROPIC ASCENT ACCOMPANYING THE FRONT PRODUCING SOME SNOWS OVER THE AREA. ANOTHER SHORTWAVE ROTATING AROUND THE BASE OF THE EASTERN NORTH AMERICA TROUGH WILL SWEEP THROUGH THE FORECAST AREA TUESDAY. THE SURFACE LOW AND ASSOCIATE FRONTAL SYSTEM WILL MOVE THROUGH THE REST OF UPPER MICHIGAN INTO EAST CENTRAL ONTARIO. THE WINDS WILL BACK NORTHWEST BEHIND THE LOW. COOLER AIR WILL SPREAD INTO THE AREA CAUSING 850MB DELTA-T`S TO INCREASE TO AROUND 12C. THIS IS ENOUGH FOR SOME LAKE ENHANCEMENT. THUS PLANNING TO KEEP A LITTLE HIGHER POPS OVER THE NORTH HALF. THE ZONAL FLOW WILL SET UP AGAIN ACROSS THE REGION FOLLOWING THE LOW CENTER TUESDAY NIGHT. THE SURFACE LOW WILL SHIFT INTO SOUTHERN QUEBEC...A RIDGE MOVES OUT OF CENTRAL CANADA INTO MISSISSIPPI RIVER VALLEY. THIS WILL CAUSE WIND TO REMAIN OUT OF THE NORTH AND SET UP A THERMAL TROUGH OVER THE AREA CREATING A DELTA-T OF AROUND 19C. THIS APPEARS TO BE RATHER CONDUCIVE FOR LES DEVELOP AND FAVOR HEAVIEST SNOWFALL WILL BE OVER THE HIGH HILLS OVER THE NORTHERN U.P. THE RIDGE WILL PUSH OVER THE FORECAST AREA ON WEDNESDAY. THE WINDS SHOULD DIMINISH OVER THE LAKE...HOWEVER...WOULD REMAIN OUT OF THE NORTHWEST. THE ZONAL FLOW WILL PERSIST ALLOW A THERMAL POOL TO SETTLE OVER EAST CENTRAL LAKE MICHIGAN THROUGH WEDNESDAY. THE DELTA-T WILL BE AROUND 19C. THESE CONDITIONS ARE STILL FAVORABLE FOR MORE LES. DRY STABLE AIR WILL ADVECT INTO THE AREA FROM THE WEST ON WEDNESDAY. && .AVIATION (FOR THE 06Z TAF ISSUANCE)... A WEAK TROUGH AND ARCTIC COLD FRONT WILL MOVE SOUTH THROUGH UPPER MI OVERNIGHT. LOW LEVEL CONVERGENCE ALONG THE TROUGH WILL BRING A PERIOD OF SNOW SHOWERS FOLLOWED BY LAKE EFFECT SNOW AS COLDER AIR ARRIVES ON NORTHERLY WINDS IN THE WAKE OF THE FRONT. GENERALLY EXPECT MVFR CONDITIONS ALONG AND IMMEDIATELY BEHIND FRONT OVERNIGHT WITH THE POTENTIAL FOR IFR VISIBILITY IN MORE SUBSTANTIAL LAKE EFFECT SNOW BANDS. INFLUX OF DRIER AIR AND INCREASINGLY ANTICYCLONIC FLOW SUN MORNING SHOULD DECREASE INTENSITY OF REMAINING SNOW BANDS. LOOK FOR VBSYS TO GRADUALLY IMPROVE TO VFR IN LINGERING FLURRIES BY AFTERNOON. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... STRONG HIGH PRES OVER NORTHERN MANITOBA WILL WEAKEN AS IT HEADS S TODAY. SO...STRONGEST WINDS WILL OCCUR THIS MORNING. EXPECT NRLY WINDS OF 20-30KT...MAINLY OVER THE W 1/2 TO 2/3RDS OF THE LAKE. HEAVY FREEZING SPRAY IS ALSO EXPECTED DURING THE MORNING. WINDS WILL DIMINISH THIS AFTERNOON AND TONIGHT AS THE HIGH HEADS TO THE MID MISSISSIPPI VALLEY. THEN AS LOW PRES TAKES SHAPE OVER SOUTHERN CANADA MON MORNING...SW WINDS WILL RAMP UP AGAIN TO 20 TO 30 KT. AS THE LOW APPROACHES THE UPPER LAKES MON NIGHT...WINDS WILL BECOME SRLY. TYPICALLY...SRLY WINDS ARE STRONGER OVER ERN LAKE SUPERIOR... AND THIS CASE WILL BE NO DIFFERENT. WHILE WINDS WILL DIMINISH SOME OVER WRN LAKE SUPERIOR MON NIGHT...SRLY WINDS WILL INCREASE TO 30KT OVER ERN SUPERIOR. NOT OUT OF THE QUESTION GALES COULD OCCUR. ONLY MENTIONED THE POSSIBILITY OF SOME GALE GUSTS WITH THIS FCST ISSUANCE. AS THE LOW MOVES E OF THE UPPER LAKES LATE TUE...EXPECT A PERIOD OF N TO NW GALES OVER THE E 1/2 TO 2/3RDS TUE NIGHT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN...NONE. LAKE SUPERIOR...HEAVY FREEZING SPRAY WARNING UNTIL 11AM EDT THIS MORNING FOR LSZ263>267. LAKE MICHIGAN...NONE. && $$ DISCUSSION...DLG AVIATION...JLB MARINE...ROLFSON mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE DULUTH MN 556 AM CDT SAT MAR 22 2008 .UPDATE... INCREASED POPS IN SW CORNER OF FA THIS MORNING...FROM CASS LAKE...TO BRAINERD AND HINCKLEY WHERE -SN IS FALLING AND VSBYS OF <2SM HAVE BEEN PERSISTENT THROUGH THE NIGHT. THE MID LVL VORT AND ASSOCIATED CORRIDOR OF FORCING THAT IS PRODUCING THE SN OVER CENTRAL MN...WILL SLOWING PUSH OFF TO THE S THIS MORNING. HOWEVER...THE TIMING HAS BEEN SLOWER THAN PREV THOUGHT. THE 06Z NAM...LATEST RUC...AND SHREF RUNS ARE IN AGREEMENT THAT THE -SN REMAINS ANCHORED ACROSS THIS REGION THROUGH 15Z...BEFORE DIMINISHING AND EXITING TO THE SOUTH AFT 18Z. THE RUC AND NAM ALSO SUGGEST THAT OMEGA VALUES INCREASE ALONG THIS CORRIDOR BTW 10-15Z...RESULTING IN THE -SHSN INTENSIFYING. HOWEVER...BASED ON CURRENT RADAR TRENDS AND THE GREATER REFLECTIVITIES OFF TO THE SOUTH...NOT MUCH CONFIDENCE IN THIS SCENARIO ATTM. WILL MONITOR CLOSELY FOR ANY CHANGES. KEPT SN AMOUNTS THIS MORNING ON THE ORDER OF AN ADDITIONAL INCH...WITH LIGHT SCATTERED SNOW SHOWERS WITH LITTLE...TRACE TO HALF INCH...OF ACCUMULATION THIS AFTRN. && .PREV DISCUSSION... /ISSUED 352 AM CDT SAT MAR 22 2008/ DISCUSSION... A WV SAT IMAGE LOOP SHOWS MULTIPLE SHORT WAVES IN THE NW FLOW SLIDING ACROSS SRN CANADA AND OVER THE UPPER MIDWEST. RADAR ECHOES OF 25-30 DBZ ARE SEEN OVER NE SOUTH DAKOTA...EXTENDING INTO THE THE TWIN CITIES METRO AREA AND INTO THE ROCHESTER AREAS OF SE MN. SFC STATIONS AND WEB CAMS IN NE MN CONTINUE TO REPORTING LIGHT TO MODERATE SN SHOWERS /1-3 SM VSBY GENERALLY/ IN THE BRD LAKES...TO MILLE LACS...AND HINCKLEY REGION OF THE SWRN DLH CWA. PREV FCST ON TRACK WITH ONLY MINOR ADJUSTMENTS MADE TO POPS TODAY. THE -SN WILL PERSIST IN THE SW AREAS THROUGH THE MORNING AS THE VORT MAX SHIFT S OVER SRN MN. ANOTHER VORT MAX...CURRENTLY RESIDING IN SRN CANADA...WILL THEN TRACK OVER THE INTL BORDER...SPREADING -SN OVER THE REMAINDER OF THE WRN GREAT LAKES REGION THROUGH THE AFTRN AND EVENING HRS. DUE TO THE DRY AIR IN PLACE OVER THE ERN HALF OF THE FA...MOST AREAS WILL SEE ONLY FLURRIES OR AN ISOLD -SHSN THIS MORNING...BECOMING MORE WIDESPREAD AND INCREASING IN INTENSITY THIS AFTRN/EVENING. LIMITING FACTOR TO SN AMOUNTS OF MORE THAN AN INCH OR TWO WILL BE THE AMOUNT OF AVAILABLE MOISTURE. FOCUS TURNS TO STRONG CAA THAT SETS UP THIS AFTRN AS A CANADIAN AIR MASS BRINGS FAVORABLE CONDITIONS FOR A FEW INCHES OF LES ALONG THE SOUTH SHORE OF LAKE SUPERIOR THIS EVENING...PERSISTING INTO SUN. INCREASED POPS TO LIKELY/DEF WORDING ALONG THE SNOW BELT REGION OF THE SOUTH SHORE OVERNIGHT. THE GFS/NAM AS WELL AS BUFR SDNGS AGREE THAT LAPSE RATES BECOME FAVORABLE FOR LES SHOWERS /12-16 C BELOW ZERO AT 850 MB/...WITH A 20-25 KT 925 MB SRLY TRAJECTORY OVERNIGHT...MAINLY AFT 03Z. MODELS ALSO AGREE THAT DURING THIS TIME...A ELONGATED WEAK VORT TRACKS S OVER THE WRN GREAT LAKES REGION...BRINGING ADDITIONAL INSTABILITY AND LIFT. THIS VORT WILL KEEP THE SMALL POPS FOR SCT -SN FOR THE REMAINDER OF THE FA AS WELL. INCREASED SN AMOUNTS ALONG THE SOUTH SHORE TO THE 2-4 IN RANGE...WITH AROUND 1 INLAND. SOME UNCERTAINTY REMAINS IN TIMING TO OVERCOME THE DRY NEAR-SFC LAYER IN ORDER TO SATURATE THE COLUMN...AS WELL AS THE SPEED OF THE APPROACHING DRY AIR BEHIND THE WAVE TO SHUT THINGS OFF LATE SAT NIGHT/EARLY SUN MORNING. AVIATION... AREAS OF LIGHT SNOW WILL PERSIST ACROSS THE SOUTHWEST PORTION OF THE FORECAST AREA...INCLUDING KBRD...THROUGH ABOUT 14Z. CONDITIONS WILL IMPROVE LATER IN THE MORNING AS THE DEEPEST MOISTURE SHIFTS EAST AND SOMEWHAT DRIER LOW LEVEL AIR ADVECTS IN FROM THE NORTHEAST. ELSEWHERE...VFR CONDITIONS WILL PREVAIL THROUGH ROUGHLY 16Z-18Z. A WEAK UPPER LEVEL DISTURBANCE WILL BRING LOWERING CLOUDS...AND THE RISK FOR LIGHT SNOW SHOWERS...MAINLY SATURDAY AFTERNOON AND EVENING. EXPECTING A PERIOD OF WIDESPREAD MVFR CEILINGS...GENERALLY FROM 23Z TO 06Z...WITH IMPROVING CONDITIONS THEREAFTER. && POINT TEMPS/POPS... DLH 34 11 28 13 / 30 20 20 10 INL 35 8 25 8 / 40 20 20 10 BRD 34 19 30 15 / 70 20 20 10 HYR 35 15 27 13 / 20 30 20 10 ASX 34 15 23 11 / 20 60 40 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. $$ GRANING/GSF mn AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE JACKSON MS 1026 AM CDT SUN MAR 23 2008 .DISCUSSION...HIGH PRESSURE CENTERED OVER WESTERN KANSAS IS BRINGING GUSTY NORTHERLY WINDS TO THE CWFA THIS MORNING. CIRRUS IS SEEN ON SATELLITE IMAGERY STREAMING ACROSS THE AREA...AND THIS SHOULD CONTINUE THROUGH THE AFTERNOON BEFORE CLEARING TONIGHT. WITH CAA OVER THE AREA TODAY...TEMPERATURES HAVE BEEN COOLER TODAY THAN WE HAVE SEEN THE PAST COUPLE OF DAYS. TEMPERATURES ARE CURRENTLY ON TRACK FOR HIGHS IN THE UPPER 50S NORTH TO MIDDLE 60S SOUTH. OVERALL THE FORECAST IS IN PRETTY GOOD SHAPE AND DO NOT ANTICIPATE THE NEED FOR ANY UPDATES AT THIS TIME. && .PREVIOUS DISCUSSION...(TODAY THROUGH MONDAY)...SURFACE/RUC ANALYSIS THIS EASTER MORNING SHOWS TIGHTENING GRADIENT ACROSS THE LOWER MS VALLEY IN CAA AHEAD OF LARGE HIGH PRESSURE CORE ALONG THE FRONT RANGE OF THE CENTRAL ROCKIES. 4-5MB PRESSURE GRADIENT EXPECTED TO YIELD 13-17KTS OF NLY WINDS TODAY WITH GUSTS TOPPING 20KTS AT TIMES. MUCH DRIER AIR WILL CONTINUE INVADING AS WELL WITH DEWPOINTS DROPPING OFF INTO THE 20S THIS AFTERNOON. MEANWHILE... WLY FLOW ALOFT BRINGING ENOUGH UPGLIDE WITH WEAK SHORTWAVE TO PRODUCE CIRRUS SHIELD WHICH SHOULD REMAIN ON THE THIN SIDE BY LATER TODAY. MODELS ARE IN AGREEMENT THAT THE SURFACE HIGH CENTER(1032MB) WILL DROP INTO NRN TX TONIGHT BEFORE SLIDING EWD TO THE CENTRAL GULF COAST MONDAY AFTERNOON(1030MB). THE WINDS WILL BECOME LIGHTER THIS EVENING BUT NOT EXPECTING A COMPLETE CALMING AS RIDGE AXIS REMAINS TO OUR NW THROUGH TONIGHT. CLEARING SKIES WILL HELP IN AIDING A DECENT RADIATIONAL COOLING LATE TONIGHT IN SHELTERED AREAS WHERE PATCHY FROST WILL BE LIKELY. EVEN THOUGH PORTIONS OF NERN MS COULD BRIEFLY TOUCH FREEZING EARLY MONDAY...BELIEVE A BETTER RISK FOR FREEZING COULD DEVELOP FOR MONDAY NIGHT AS A QUICKER RADIATIONAL COOLING SETUP SHOULD BE IN PLACE. MOS GUIDANCE GENERALLY ACCEPTED WITH SMALL DOWNWARD ADJUSTMENTS FOR TONIGHT IN CENTRAL AND NRN PORTIONS. PLENTY OF SUNSHINE ON MONDAY WILL MIX IN SOME EVEN DRIER AIR WITH AFTERNOON RH LEVELS OF 20-25% OR POSSIBLY LOWER. /40/ .LONG TERM...LONG TERM...MONDAY NIGHT THROUGH SUNDAY. BIGGEST CHANGE IS THE TIMING OF THE RAIN FOR THE END OF THE WEEK. MODELS STILL NOT IN GOOD AGREEMENT. GFS LOOKS LIKE YESTERDAY`S EUROPEAN. USED A BLEND. RAISED GUIDANCE HIGHS ABOUT 3 DEGREES TOWARDS THE END OF THE WEEK. 925 TEMPS REMAIN WARM...STILL LOOKING FOR NEAR 80 TEMPS FOR MUCH OF THE EXTENDED. LOWS WERE OK. RIGHT NOW MODELS MAINTAIN HIGH PRESSURE THROUGH TUESDAY. THE BOUNDARY STALLS OVER THE MID SOUTH...MEANWHILE THE SURFACE HIGH SETTLES OVER THE SOUTHEAST US. THE NEXT LOW PRESSURE DEVELOPS JUST EAST OF THE ROCKIES AND DEEPEN AS IT TRACKS EAST AROUND THURSDAY. THE STALLED BOUNDARY GET PUSHED NORTH AND SECONDARY COLD FRONT DEVELOPS FROM THE MIDWEST DOWN INTO NORTHEAST TEXAS. THE LOW SLOWLY DRIFTS NORTHEAST...DRAGGING THE COLD FRONT ACROSS THE CWA FRIDAY INTO SATURDAY. SOUNDINGS SHOW DECENT LAPSE RATES IN THE 800-700MB RANGE. THE GFS SHOWS SOME CAPE ACROSS THE CWA...APPROACHING 1500J AS THE BOUNDARY MOVES THROUGH. LOW LEVEL JET WAS AROUND 40KTS...GENERALLY UNIDIRECTIONAL WINDS. AT THIS TIME WILL LEAVE THE HWO CLEAR AND MAINTAIN THUNDER WORDING IN THE FORECAST. HIGH PRESSURE DROPS IN FROM CANADA AROUND SUNDAY. LOOKS LIKE ANOTHER BRIEF BOUT WITH NEAR FREEZING TEMPERATURES WILL BE POSSIBLE SUNDAY NIGHT. COLD AIR WILL BE SHORT LIVED...WITH MOISTURE AND WARM AIR RETURNING AHEAD OF THE NEXT SYSTEM ON TUESDAY. WILL NOTE THAT THE EUROPEAN SOLUTION IS CONSIDERABLY DIFFERENT FOR THE WEEKEND. THE MID WEEK SOLUTIONS ARE SIMILAR WITH THE STATIONARY BOUNDARY MOVING NORTH INTO THE MIDWEST AND DEEPENING SURFACE LOW TRACKING NORTHEAST. FLOW ALOFT REMAINS RELATIVELY WEAK AND ZONAL. THE DIFFERENCE COME IN...WITH THE BOUNDARY STALLING OVER THE CWA SATURDAY. THE NEXT FEATURE DEVELOPS AND PUSHES THE BOUNDARY NORTHEAST BY MONDAY...WITH IT EXTENDING BACK TO THE SOUTHWEST. ANOTHER LOW DEVELOPS AT THE END OF THE BOUNDARY...WITH THE COLD FRONT DEVELOPING AROUND TUESDAY. HOWEVER THE CWA REMAINS WET THROUGH THE WEEKEND. WITH THE GFS FOR THE MOST PART AND KEPT THINGS DRY LATE SATURDAY AND SUNDAY. OVERALL NO BIG CHANGES TO THE FORECAST. INCREASED POPS AND ADJUSTED THE TIMING ON THE RAIN FOR FRIDAY AND EARLY SATURDAY. RAISED HIGH TEMPS A COUPLE DEGREES THROUGH THE WEEK. && .AVIATION...VFR FLIGHT CATEGORIES WILL PREVAIL THROUGH THE NEXT 24 HOURS. THE ONLY CLOUD COVER WILL BE SOME CIRRUS OVER THE AREA THAT SHOULD CONTINUE BEFORE CLEARING OVERNIGHT. GUSTY NORTHERLY WINDS WILL BEGIN TO DIE DOWN THIS EVENING. OVERALL NO PROBLEMS ARE EXPECTED FOR THE FORECAST PERIOD. && .PRELIMINARY POINT TEMPS/POPS... JACKSON 63 36 61 36 / 1 0 1 0 MERIDIAN 63 35 59 31 / 1 0 1 0 VICKSBURG 65 37 61 37 / 3 0 1 0 HATTIESBURG 66 37 63 31 / 7 0 2 0 NATCHEZ 64 39 63 37 / 3 0 1 0 GREENVILLE 60 36 60 39 / 1 0 1 0 GREENWOOD 59 35 59 37 / 1 0 1 0 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ 14 ms AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON MS 450 AM CDT SUN MAR 23 2008 .SHORT TERM...(TODAY THROUGH MONDAY)...SURFACE/RUC ANALYSIS THIS EASTER MORNING SHOWS TIGHTENING GRADIENT ACROSS THE LOWER MS VALLEY IN CAA AHEAD OF LARGE HIGH PRESSURE CORE ALONG THE FRONT RANGE OF THE CENTRAL ROCKIES. 4-5MB PRESSURE GRADIENT EXPECTED TO YIELD 13-17KTS OF NLY WINDS TODAY WITH GUSTS TOPPING 20KTS AT TIMES. MUCH DRIER AIR WILL CONTINUE INVADING AS WELL WITH DEWPOINTS DROPPING OFF INTO THE 20S THIS AFTERNOON. MEANWHILE... WLY FLOW ALOFT BRINGING ENOUGH UPGLIDE WITH WEAK SHORTWAVE TO PRODUCE CIRRUS SHIELD WHICH SHOULD REMAIN ON THE THIN SIDE BY LATER TODAY. MODELS ARE IN AGREEMENT THAT THE SURFACE HIGH CENTER(1032MB) WILL DROP INTO NRN TX TONIGHT BEFORE SLIDING EWD TO THE CENTRAL GULF COAST MONDAY AFTERNOON(1030MB). THE WINDS WILL BECOME LIGHTER THIS EVENING BUT NOT EXPECTING A COMPLETE CALMING AS RIDGE AXIS REMAINS TO OUR NW THROUGH TONIGHT. CLEARING SKIES WILL HELP IN AIDING A DECENT RADIATIONAL COOLING LATE TONIGHT IN SHELTERED AREAS WHERE PATCHY FROST WILL BE LIKELY. EVEN THOUGH PORTIONS OF NERN MS COULD BRIEFLY TOUCH FREEZING EARLY MONDAY...BELIEVE A BETTER RISK FOR FREEZING COULD DEVELOP FOR MONDAY NIGHT AS A QUICKER RADIATIONAL COOLING SETUP SHOULD BE IN PLACE. MOS GUIDANCE GENERALLY ACCEPTED WITH SMALL DOWNWARD ADJUSTMENTS FOR TONIGHT IN CENTRAL AND NRN PORTIONS. PLENTY OF SUNSHINE ON MONDAY WILL MIX IN SOME EVEN DRIER AIR WITH AFTERNOON RH LEVELS OF 20-25% OR POSSIBLY LOWER. /40/ .LONG TERM...LONG TERM...MONDAY NIGHT THROUGH SUNDAY. BIGGEST CHANGE IS THE TIMING OF THE RAIN FOR THE END OF THE WEEK. MODELS STILL NOT IN GOOD AGREEMENT. GFS LOOKS LIKE YESTERDAY`S EUROPEAN. USED A BLEND. RAISED GUIDANCE HIGHS ABOUT 3 DEGREES TOWARDS THE END OF THE WEEK. 925 TEMPS REMAIN WARM...STILL LOOKING FOR NEAR 80 TEMPS FOR MUCH OF THE EXTENDED. LOWS WERE OK. RIGHT NOW MODELS MAINTAIN HIGH PRESSURE THROUGH TUESDAY. THE BOUNDARY STALLS OVER THE MID SOUTH...MEANWHILE THE SURFACE HIGH SETTLES OVER THE SOUTHEAST US. THE NEXT LOW PRESSURE DEVELOPS JUST EAST OF THE ROCKIES AND DEEPEN AS IT TRACKS EAST AROUND THURSDAY. THE STALLED BOUNDARY GET PUSHED NORTH AND SECONDARY COLD FRONT DEVELOPS FROM THE MIDWEST DOWN INTO NORTHEAST TEXAS. THE LOW SLOWLY DRIFTS NORTHEAST...DRAGGING THE COLD FRONT ACROSS THE CWA FRIDAY INTO SATURDAY. SOUNDINGS SHOW DECENT LAPSE RATES IN THE 800-700MB RANGE. THE GFS SHOWS SOME CAPE ACROSS THE CWA...APPROACHING 1500J AS THE BOUNDARY MOVES THROUGH. LOW LEVEL JET WAS AROUND 40KTS...GENERALLY UNIDIRECTIONAL WINDS. AT THIS TIME WILL LEAVE THE HWO CLEAR AND MAINTAIN THUNDER WORDING IN THE FORECAST. HIGH PRESSURE DROPS IN FROM CANADA AROUND SUNDAY. LOOKS LIKE ANOTHER BRIEF BOUT WITH NEAR FREEZING TEMPERATURES WILL BE POSSIBLE SUNDAY NIGHT. COLD AIR WILL BE SHORT LIVED...WITH MOISTURE AND WARM AIR RETURNING AHEAD OF THE NEXT SYSTEM ON TUESDAY. WILL NOTE THAT THE EUROPEAN SOLUTION IS CONSIDERABLY DIFFERENT FOR THE WEEKEND. THE MID WEEK SOLUTIONS ARE SIMILAR WITH THE STATIONARY BOUNDARY MOVING NORTH INTO THE MIDWEST AND DEEPENING SURFACE LOW TRACKING NORTHEAST. FLOW ALOFT REMAINS RELATIVELY WEAK AND ZONAL. THE DIFFERENCE COME IN...WITH THE BOUNDARY STALLING OVER THE CWA SATURDAY. THE NEXT FEATURE DEVELOPS AND PUSHES THE BOUNDARY NORTHEAST BY MONDAY...WITH IT EXTENDING BACK TO THE SOUTHWEST. ANOTHER LOW DEVELOPS AT THE END OF THE BOUNDARY...WITH THE COLD FRONT DEVELOPING AROUND TUESDAY. HOWEVER THE CWA REMAINS WET THROUGH THE WEEKEND. WITH THE GFS FOR THE MOST PART AND KEPT THINGS DRY LATE SATURDAY AND SUNDAY. OVERALL NO BIG CHANGES TO THE FORECAST. INCREASED POPS AND ADJUSTED THE TIMING ON THE RAIN FOR FRIDAY AND EARLY SATURDAY. RAISED HIGH TEMPS A COUPLE DEGREES THROUGH THE WEEK. && .AVIATION...VFR CONDITIONS WILL PREVAIL THROUGH 12Z MONDAY WITH THE FOCUS REMAINING ON THE NLY WINDS AND GUSTS BETWEEN 14-00Z TODAY. HIGHEST WINDS WILL BE OVER THE NORTHWEST(18-22KTS AT TIMES)WITH LIGHTEST IN THE SOUTHEAST. WINDS SHOULD DIE DOWN TO 5-8KTS TONIGHT. /40/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 63 36 61 36 / 1 0 1 0 MERIDIAN 63 35 59 31 / 1 0 1 0 VICKSBURG 65 37 61 37 / 3 0 1 0 HATTIESBURG 66 37 63 31 / 7 0 2 0 NATCHEZ 64 39 63 37 / 3 0 1 0 GREENVILLE 60 36 60 39 / 1 0 1 0 GREENWOOD 59 35 59 37 / 1 0 1 0 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ 40/7 ms AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBUQUERQUE NM 1027 AM MDT SUN MAR 23 2008 .UPDATE... WILL GO AHEAD AND UPDATE ZONES TO REMOVE MORNING WORDING. VISIBLE SATELLITE IMAGERY SHOWS CLOUDS TRYING TO BREAK UP ACROSS NORTHEAST NEW MEXICO...BUT SOME ISOLATED SNOW SHOWERS LINGERING...SO WILL DECREASE POPS BUT LEAVE MENTION OF SNOW FLURRIES AND SPRINKLES THROUGH EARLY AFTERNOON. OTHERWISE MADE MINOR TWEAKS TO REFLECT CURRENT TRENDS. UPDATES OUT SHORTLY. 34 && .PREV DISCUSSION...258 AM MDT SUN MAR 23 2008... FORECAST CHALLENGES TODAY WILL BE MAINLY ACROSS THE E PLAINS WITH THE TIMING OF PRECIP DEPARTURE AND TYPE. 08Z SFC ANALYSIS SHOWS THE FRONTAL BOUNDARY DRAPED FROM NORTH TO SOUTH WITHIN THE RIO GRANDE VALLEY. CANYON WINDS HAVE CONTINUED THROUGHOUT THE NIGHT GENERALLY 15 TO 25 MPH WITH GUSTS UP TO 35 MPH. NIGHTTIME VIS SATELLITE IMAGE SHOWS LOW CLOUDS DEVELOPING OVER MUCH OF THE EAST. RUC13 GUIDANCE SHOWS MODERATE ISENTROPIC LIFT ALONG THE 300K SURFACE CORRESPONDS WELL WITH BANDED PRECIP BLOSSOMING OVER SOUTHEAST PLAINS. 00Z GFS HANDLING MID LEVEL FRONTOGENESIS VERY WELL ACROSS THE I40 CORRIDOR SOUTHWARD TO NEAR KROW THROUGH 12Z. 00Z NAM BUFKIT PROFILE AT KTCC SHOWS PRECIP BEGINNING AS RAIN WILL CHANGE TO SNOW THIS MORNING AS WET BULB ZERO LOWERS TO SURFACE. THIS MAY INTERACT WITH ISENTROPIC LIFT AND FRONTOGENESIS TO PRODUCE AN AREA OF 1 INCH SNOWFALL OVER QUAY AND CURRY COUNTIES THRU SUNRISE. RAISED POPS TO LIKELY OVER THE FAR SE TO REFLECT PRECIP DEVELOPING SE THRU NOON WITH SUPPORT FROM STRONG AGREEMENT WITHIN ENSEMBLE GUIDANCE OF MEASURABLE PRECIP IN THIS AREA. GUIDANCE SHOWS PRECIP WILL END AFTER NOON OVER THE SE SO LEFT ISOLD TO CHC POPS THRU 00Z. DRY WNW FLOW RETURNS TO THE ENTIRE CWA SUN NIGHT INTO THURSDAY. THIS WILL INCREASE THE TEMPS...WINDS AND CRITICAL FIRE WEATHER CONDITIONS BY THE MIDDLE TO END OF THE WEEK. EXPECT HIGHS TO RANGE FROM 10 TO 15 DEGREES ABOVE NORMAL. THE NEXT DISTURBANCE WILL RACE EAST ACROSS COLORADO THURSDAY NIGHT INTO FRIDAY WITH A FEW ISOLD SHOWERS POSSIBLE OVER THE FAR NORTHERN MTNS. MODELS SHOW A FRONTAL BOUNDARY ATTEMPTING TO MOVE SOUTH ACROSS THE E PLAINS BEHIND THIS EXITING WAVE WITH MOSTLY A WIND SHIFT AND INCREASE IN HUMIDITIES. GUYER .AVIATION... CENTRAL MOUNTAINS EASTWARD EXPECT WIDESPREAD MVFR CIGS THROUGH 15Z TO 18Z SUNDAY WITH IFR CIGS AND VISIBILITIES ALONG THE EAST SLOPES OF THE CENTRAL MOUNTAINS WITH SCATTERED -SHRA/-SHSN. CONDITIONS IMPROVE AFTER 18Z. VFR CONDITIONS WILL PREVAIL WEST OF THE CENTRAL MOUNTAINS. NEXT AVIATION DISCUSSION SCHEDULED FOR 21Z. 05 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 34 nm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nm AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 120 AM EDT SUN MAR 23 2008 .SYNOPSIS... A COLD FRONT WILL PUSH SOUTHEAST ACROSS THE EASTERN CAROLINAS AND OFFSHORE OVERNIGHT. COLD HIGH PRESSURE WILL BUILD ACROSS THE AREA FROM THE GULF COAST STATES SUNDAY THROUGH TUESDAY. THE CENTER OF THIS HIGH WILL MOVE ACROSS THE AREA ON WEDNESDAY...AND JUST OFFSHORE THURSDAY THROUGH FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 9 PM SATURDAY...SMALL BAND OF ALTOCUMULUS 10K-12K FT EXTENDING NE-SW ACROSS EASTERN NC AT THE MOMENT...IS HELPING TO DELINEATE THE WHEREABOUTS OF THE COLD FRONT IF 1 JUST HAD SAT IMAGERY TO WORK WITH. BETWEEN 04Z-06Z...LATEST RUC AND NAM TAKE THE COLD FRONT SOUTH AND EAST OF THE ILM CWA. COLD AIR ADVECTION TO COMMENCE IMMEDIATELY AFTER CFP AS DEPICTED BY VARIOUS THICKNESSES...850MB TEMP...AND ETC. SHULD SEE NW-N WINDS 10 TO POSSIBLY 15 KT OVER LAND WITH SOME GUSTS UP TO 20 KT ESPECIALLY AT THE PEAK OF THE CAA LATER TONIGHT INTO EARLY SUNDAY MORNING. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 3 PM SATURDAY...H5 TROUGH WILL DIG DEEP OVER EASTERN CONUS AS AIDED BY A VIGOROUS AND SHARP SHORT WAVE. MAIN EFFECT WILL BE TO DEEPEN A LOW PRESSURE SYSTEM THAT WILL FORM WELL EAST OF CAPE HATTERAS...GREATLY ENHANCING COLD AIR ADVECTION MONDAY NIGHT. THIS WILL KNOCK TEMPS TO AROUND FREEZING THROUGHOUT THE CWA AFTER MIDNIGHT MONDAY NIGHT...WELL BELOW CLIMO. A FREEZE WATCH MAY BE WARRANTED AS WE GET WITHIN THE REQUIRED 24 TO 48 HOUR WINDOW FOR THIS EVENT. MOS GUIDANCE NUMBERS ARE ALL VERY CLOSE WITH THIS SCENARIO. SHORT WAVE MAY ALSO KICK OFF SOME SHOWERS MONDAY BUT WITH VERY LIMITED MOISTURE WOULD NOT EXPECT MORE THAN A FEW HUNDREDTHS AN INCH IN ANY LOCATION. TEMPERATURES THROUGHOUT THE NEAR TERM WILL REMAIN BELOW NORMAL. && .LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 3 PM SATURDAY...MID LEVEL FLOW TRANSITIONS FROM A WESTERLY/ZONAL REGIME TO A MODEST RIDGE BY SATURDAY. AFTER A COOL START...WITH HIGH PRESSURE BASICALLY ON TOP OF THE AREA TUESDAY...A WARM AND DRY PATTERN WILL PREVAIL AS THIS SAME HIGH SLIPS OFF THE COAST AND A WARM AND RELATIVELY DRY PATTERN DEVELOPS. CONTINUED TO KEEP FORECAST DRY THIS AFTERNOON AS MEDIUM RANGE MODELS ARE VOID OF THE WEAK SYSTEM THAT WAS PRESENT DURING PREVIOUS MODEL RUNS. AS MENTIONED EARLIER...THE TRANSITION OF TEMPERATURES FROM UNSEASONABLY COOL TO UNSEASONABLY WARM READINGS WILL BE THE STORY. OVERALL...ADJUSTED TEMPERATURES UP A DEGREE OR TWO ACROSS THE BOARD TO MATCH GUIDANCE AND HPC THINKING. LOOKING FOR MID TO UPPER 70S WEDNESDAY THROUGH SATURDAY WITH THE WARMEST READINGS FRIDAY COINCIDING WITH THE WARMEST 850MB TEMPERATURES NEAR 10 DEGREES CELSIUS. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... VFR THROUGH THE PERIOD. THE COLD FRONT HAS PUSHED THROUGH KILM AND WILL MOVE THROUGH THE REMAINING TERMINALS WITHIN A COUPLE HOURS. BESIDES SOME CI SKIRTING THE COASTAL AREAS...COULD SEE SOME STRATO-CU WITH CIGS GENERALLY ABOVE 4 KFT ASSOCIATED WITH FROPA. CLOUDS WILL BE ON THE INCREASE TONIGHT AS A SHORT WAVE APPROACHES THE REGION. VFR EXPECTED TUESDAY THROUGH FRIDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 9 PM SATURDAY...MAIN CHANGE TO THE FCST IS THE RAISING OF A SHORT TERM SMALL CRAFT ADVISORY FROM MIDNIGHT SUNDAY THROUGH 3 PM SUNDAY. CURRENT SW-W WINDS AHEAD OF THE COLD FRONT ARE RUNNING 15 TO 20 KT WITH SEAS 3 TO 4 FT...UP TO 5 FT ACROSS FRYING PAN SHOALS. LATEST RUC AND NAM MODELS INDICATE BETWEEN 05Z-07Z FOR A COMPLETE COLD FRONTAL PASSAGE ACROSS THE ILM WATERS. DECENT PRESSURE RISES TO FOLLOW...CAA SURGE AND A CONTINUED TIGHTENED SFC PG...WILL ALL COMBINE AND YIELD WIND SPEEDS SURPASSING SCA THRESHOLDS OVERNIGHT THROUGH SUNDAY MORNING. WIND DRIVEN WAVES RUNNING AT 6 SECOND PERIODS OR LESS WILL COMPRISE THE SEAS. SEA HEIGHTS WILL LIKELY REACH 4 TO 5 FT...WITH 2 TO 3 FT NEAR SHORE. THERE WILL BE SOME 6 FOOTERS ACROSS THOSE PRONE WATERS...IE FRYING PAN SHOALS. HOWEVER...THE RAISING OF THE SCA IS PRIMARILY FOR WIND THRESHOLDS BEING MET. SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 3 PM SATURDAY...HIGHEST WINDS AND SEAS CAN BE EXPECTED NEAR THE END OF THE PERIOD AS A STRONG AND UNSEASONABLE COLD SURGE KICKS UP WINDS AND SEAS. MONDAY NIGHT WILL BE PRIME TIME FOR THIS WITH A STRONG NORTHERLY FLOW IN PLACE. WITH OFFSHORE FLOW AND RESULTANT LIMITED FETCH EXPECT A WIDE RANGE OF SEA HEIGHTS. SMALL CRAFT ADVISORY CRITERIA MAY BE MET MONDAY NIGHT FOR HIGH SEAS WELL AWAY FROM THE COAST. STRONG COLD SURGE WILL BE RELATIVELY SHORT LIVED HOWEVER AS HIGH PRESSURE NOSES OUT OVER THE WATERS BY DAYBREAK TUESDAY MORNING. LONG TERM /TUESDAY THROUGH WEDNESDAY/... AS OF 3 PM SATURDAY...VERY LIGHT WINDS INITIALLY AS HIGH PRESSURE IS RIGHT ON TOP OF THE COASTAL WATERS. MODEST SOUTHERLY FLOW DEVELOPS LATE TUESDAY AND REMAINS IN PLACE THROUGH THE PERIOD. WILL PROBABLY SEE A BIT OF A DIURNAL BACKING DURING THE DAY...OTHERWISE A 10-15 KNOT RANGE SHOULD SUFFICE WITH SOUTHERLY WINDS. SEAS OF 2-3 FEET SHOULD PREVAIL THROUGH THE PERIOD SANS A BRIEF UP-TICK EARLY WEDNESDAY WITH A FRONT AND INCREASED WINDS SNEAKING IN FROM THE NORTH. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 3 PM EDT SUNDAY FOR AMZ250-252-254- 256. && $$ NEAR TERM...HOEHLER SHORT TERM...KREITNER LONG TERM...KEEBLER AVIATION...SRP nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 438 PM EDT SAT MAR 22 2008 .SYNOPSIS... A COLD FRONT WITH LIMITED MOISTURE WILL DROP SOUTH THROUGH THE AREA THIS EVENING USHERING IN COOLER WEATHER AS WEAK HIGH PRES BUILDS OVER THE AREA ON SUN. AN UPPER TROUGH WILL SLOWLY SWING THROUGH THE AREA MON AND MON NIGHT LEADING TO THE DEVELOPMENT OF A SURFACE LOW OFF THE COAST MON EVENING. THE LOW WILL MOVE QUICKLY OUT TO SEA THROUGH TUE AS HIGH PRES REBUILDS OVER THE AREA. HIGH PRES MOVES S OF THE AREA ON WED AS A COLD FRONT APPROACHES FROM THE N THRU THU. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... IMPRESSIVE TEMPERATURE GRADIENT BTWN WARM ERN NC AND COOL NRN VA THIS AFTN AROUND APPOACHING COLD FRONT. QUITE A BIT OF CHANGE ON TAP THIS EVENING AND INTO EARLY SUNDAY MORNING AS FRONT MOVES THROUGH BTWN APPROX 1Z-5Z. HAVE MAINTAINED SCHC SHOWERS/TSTMS FOR NE HALF OF THE CWA...MAINLY IN THE VICINITY OF SFC LOW...FOR THIS EVENING BUT MSTR CONTINUES TO LOOK LIMITED AND WOULDNT BE SUPRISED IF NIL MEASURES. HOWEVER PREFER TO MAINTAIN CONTINUITY WITH SOME CU DVLPG UPSTREAM NEAR SFC LOW. POST FRONTAL IMPACTS MAY BE MORE NOTICEABLE WITH TEMPS DROPPING QUICKLY INTO THE 50S THEN 40S WITH BREEZY NLY WINDS. IN ADDITION...UPSTREAM SAT PICS AND MODEL TIME SECTIONS SUGGEST MODERATE AMOUNTS OF LOW LVL POST FRONTAL MSTR/CLOUDS WITH THE NLY FLOW...SO EXPECT SUNRISE EASTER SERVICES WILL BE CHILLY...BREEZY...AND SOME LINGERING LOW CLOUDS POSSIBLE. CANNOT RULE OUT SOME PATCHY DRIZZLE BEHIND THE FRONT EITHER BUT NOT EXPECTING ANYTHING MEASUREABLE AT THIS POINT SO WILL KEEP FORECAST DRY AFTER 6Z. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/... WEAK SFC HIGH BUILDS INTO THE AREA FROM THE NW ON SUN BEHIND FRONT. ANY LINGERING POST FRONTAL LOW CLOUDS SHOULD LIFT BUT COULD SEE SOME INSTABILITY CU/SCU DURING THE DAY INLAND BASED ON FORECAST SOUNDINGS AND MUCH COOLER AIR ALOFT. OVERALL DRY AND CHILLY DAY EXPECTED TOMORROW WITH HIGHS NOT EXPECTED TO GET OUT OF THE 50S WITH NLY WINDS 10-15 MPH AND STRONGER NR THE COAST. U30S FOR SUN NIGHT WITH INCRG CLOUD COVER AND POSSIBLE -RA LATE ESP NW PORTION. THE REMAINDER OF THE SHORT TERM FORECAST CONTINUES TO BE CHALLENGING WITH DIFFERENCES IN THE DETAILS BTWN NWP GUIDANCE. A MID TO UPR SHORTWAVE IS EXPECTED TO AMPLIFY JUST W OF THE AREA DURING MON AFTN AND THEN SWING THROUGH DURING THE EVENING. ASSOCIATED SFC BNDRY EXPECTED TO BE MAINLY A WEAK TROF AS IT MOVES THROUGH ERN NC BUT AS IT ENCOUNTERS STRONGER BAROCLINIC ZONE OFFSHORE AND BETTERN UPR SUPPORT WITH AMPLIFYING TROF...SFC LOW EXPECTED TO EVENTUALLY DVLP OFF THE COAST AND THEN ZIP OUT TO SEA MON NIGHT. GENERALLY WENT WITH A BLEND OF THE WETTER GFS AND THE DRIER NAM...WHICH MAINTAINS VERY LITTLE CHANGE FROM THE PREVIOUS FORECAST. SCALED BACK ON POPS ESP ERN HALF OF CWA LATE SUN NIGHT/AND MON MORNING BUT HAVE GENERALLY 40 POPS EVERYWHERE MON AFTN...THEN TAPER IT OFF QUICKLY FROM W TO E THROUGH MON EVENING. IT IS HARD TO IGNORE THE VERY LOW THICKNESSES THAT ARE EXPECTED TO ADVECT INTO THE AREA WITH THIS SYSTEM DURING MON...BUT GIVEN HIGH WET BULB ZERO HEIGHTS WHEN BULK OF THE MSTR IS EXPECTED TO BE OVER THE AREA AND PER COORDINATION WITH SURROUNDING OFFICES HAVE KEPT ALL PRECIP LIQUID AT THIS POINT. TEMPS ARE EXPECTED TO BE WELL BELOW NORMAL ON MON...STRUGGLING TO GET OUT OF THE 40S...WITH GOOD AMOUNT OF CLOUD COVER IN ADDITION TO LIGHT PRECIP. GRADUAL CLEARING FROM W TO E EXPECTED MON NIGHT WITH TEMPS DROPPING TO NEAR FREEZING EXCEPT RIGHT NEAR THE COAST. SLOWLY DIMINISHING NLY WINDS COULD KEEP FROST ISSUES LIMITED EARLY TUE MORNING...BUT WILL HAVE TO CONTINUE MONITORING THIS POTENTIAL. && .LONG TERM /TUESDAY THROUGH SATURDAY/... HIGH PRES BUILDS JUST S OF THE AREA TUE ALLOWING SLOWLY RECOVERING TEMPS. HIGH PRESSURE WILL SLIDE OFFSHORE WEDNESDAY. WEAK FRONT LOOKS TO APPROACH THE AREA THUR- FRI...BUT STALLED FRONT AND MOISTURE WILL REMAIN NORTH OF THE FORECAST AREA...SO REMOVED POPS FOR THURSDAY. NEXT PRECIP CHANCE LOOKS LIKE EARLY WEEKEND WITH ANOTHER FRONTAL SYSTEM... BUT MOISTURE LOOKS LIMITED AT THIS TIME. TEMPS GENERALLY LOW/MID 70S INLAND AND MID 60S ALONG THE OBX. && .AVIATION /21Z SATURDAY THROUGH THURSDAY/... SATELLITE PICTURES SHOWING CI HAS MOVED AWAY FROM THE AREA. HOWEVER AM SEEING SOME LOWER CLOUDS ON THE SATELLITE PICTURES...OBSERVATIONS ...AND OUT THE WINDOW. WINDS OVER TAF SITES THIS AFTERNOON A LITTLE BREEZY RUNNING ABOUT 15 TO 20 MPH AS SURFACE FRONT APPROACHES FROM THE W. FROPA EXPECTED AT TAF SITES BETWEEN SUNSET AND MIDNIGHT. NOT AN AWFUL LOT OF MOISTURE WITH THIS SYSTEM SO HAVE NOT MENTIONED ANY PRECIPITATION IN THE TAFS...HOWEVER THERE MAY BE A COUPLE OF THUNDER SHOWERS AROUND AS THE FRONT MOVES THROUGH. WIND WILL CONTINUE BREEZY THROUGH THE NIGHT AND INTO SUNDAY ASSOCIATED WITH THIS SYSTEM. OUTLOOK... HIGH PRESSURE OVER AREA SUNDAY. A STRONG UPPER LEVEL SYSTEM WILL APPROACH THE AREA SUNDAY NIGHT...HELPING A SURFACE LOW OFF THE COAST OF FLORIDA DEVELOP AND MOVE NORTH. THIS WILL BRING STRONG WINDS TO THE TAF SITES SUNDAY NIGHT THROUGH MONDAY NIGHT. MAY SEE MVFR OR IFR CONDITIONS WITH ANY PRECIPITATION WITH THIS SYSTEM. VFR EXPECTED WEDNESDAY AND THURSDAY && .MARINE... MOD SW WND OVR WTRS THIS AFTN WI SCA CONDS ON THE MID LEGS AS FRNT APPCHS FRM THE NW. LTST RUC HOLDS OFF ON FROPA OVR WTRS TIL ARND MIDNGT TNGT. GRAD BHND FRNT NOT AS TITE AS AHD OF IT. HWVR GRAD COMBINED WITH CAA SHUD BRING WNDS TO SCA CRIT OVR ALL WTRS AND SNDS AFT MIDNGT. GRAD LOOSENS SUMWHAT SUN AFTN AS SFC RDG TRIES TO BLD IN FRM THE N. HWVR AS SFC LO STRTS TO DVLP OFF THE E FL CST SUN NGT GRAD WL STRT TO TITEN AGAIN WI CONTD NLY FLO OVR THE NC WTRS INTO THE BEGINNG OF THE WORKWK. UPR LVL TROF SWINGG THRU AREA ON MON. GUD ASSCTD JET AND DYNAMICS. SFC LO DVDLPMNT OFF THE CST MON AFT. CUD SEE A BRIEF PD OF GALE CONDS BFR DVLPMNT MVS TOO FAR AWAY FRM THE CST. HV CAPPED THE FCST AT ARND 30 KTS FOR NOW. RDG OVR AREA ON TUE WL ALLW WNDS AND SEAS TO SETTLE A BIT BFR NXT SYS MVS THRU TO THE N ON TUE NGT AND WED. WI LO RMNG TO THE N...XPCT NRN WTRS TO BE MOST EFFECTED BY STRGR WND ON WED. THR FRNT WL MV BACK N THRU THE WTRS ON THU. GRAD DOESNT LUK TOO STRG RIGHT NOW SO WL KP WND BLO 20KT INTO THE WKEND. && .FIRE WEATHER... RH VALUES ARE SLOWLY RISING LATE THIS AFTN BUT GUSTY WINDS PERSIST FROM THE SOUTHWEST. ANY FIRE BURNERS/FIGHTERS THIS AFTN/EVENING SHOULD BE AWARE OF A CRITICAL WIND SHIFT EXPECTED LATER THIS EVENING WITH AN APPROACHING COLD FRONT. WINDS WILL GO NORTHWEST TO NORTH OVER THE NW PORTION OF THE AREA BY APPROX 1Z WITH THE SHIFT/FRONT MOVING SE TO OFF THE COAST BY APPROX 5Z. NLY WINDS 10-20 MPH EXPECTED ON SUN...STRONGER NEAR THE COAST ESP EARLY. RH VALUES NOT AS CRITICAL TOMORROW WITH MUCH COOLER TEMPS...BUT STILL IN THE 30-40 PERCENT RANGE INLAND. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...SMALL CRAFT ADVISORY FROM 2 AM TO 8 AM EDT SUNDAY FOR AMZ130- 135-158. SMALL CRAFT ADVISORY UNTIL 11 AM EDT SUNDAY FOR AMZ154-156. SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT SUNDAY FOR AMZ150-152. && $$ SYNOPSIS...MW NEAR TERM...MW SHORT TERM...MW LONG TERM...CLQ/MW AVIATION...CGG MARINE...CGG FIRE WEATHER...MW nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 903 PM EDT SUN MAR 23 2008 .SYNOPSIS... UPPER LEVEL DISTURBANCES MOVE THROUGH TONIGHT AND MONDAY. SOUTHERLY WINDS BRING WARMER WEATHER TUESDAY AFTERNOON WITH A COLD FRONT TUESDAY NIGHT AND WEDNESDAY. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... PIECE OF CHANNELED VORTICITY MAXIMA WORKING ACROSS SOUTHWESTERN VA AND SRN WV AT THIS TIME. LATEST RUC13 DEPICTS A REGION OF NVA WORKING INTO EASTERN KY. SAT IR IMAGERY CONFIRMING PRESENCE OF THIS FEATURE WITH AN AREA OF RAPIDLY DISSIPATING CU FIELD...AND ENHANCEMENT OF CLOUDS ALONG THE VA-WV BORDER. ANOTHER WEAK PIECE OF ENERGY WORKING ACROSS THE OH VALLEY MAY HELP KICK OF A FEW ISOLD SHOWERS FOR THE REMAINDER OF THE EVENING ACROSS NRN SECTIONS. WITH THE PROXIMITY OF THESE VARIOUS PIECES OF SHORTWAVE ENERGY...ALONG WITH THE A DEEPENING 85H THERMAL TROUGH...WILL KEEP MENTION OF ISOLD FLURRIES AND SNOW SHOWERS FOR THE REST OF TONIGHT. && .SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY/... DISTURBANCE ON MONDAY IS WEAK WITH MARGINAL CONDITIONS EVEN FOR UPSLOPE. WILL CONTINUE WILL LOW POPS AND FLURRIES. MAV MOS ONCE AGAIN LOOKS TOO WARM...SO WILL UNDER CUT. ANY REMAINING PRECIPITATION WILL TAPPER OFF MONDAY EVENING AS WARM AIR ADVECTION SETS IN. SOUTHWESTERLY WINDS PICK UP ON TUESDAY AS A SYSTEM APPROACHES FROM THE WEST. WILL INCREASE POPS IN THE AFTERNOON IN THE NORTHWEST. WILL ONCE AGAIN LEAN MORE TOWARD THE MET MOS. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... ACTIVE WEATHER PATTERN THIS PERIOD...AS MODELS HAVE A SERIES OF UPPER LEVEL SHORT WAVES TRAVERSING THE AREA IN A BASIC ZONAL FLOW PATTERN ALOFT. ONE SHORT WAVE HANDLED SIMILARLY BY MOST MODELS BRINGS A WEAKENING COLD FRONT ACROSS MOST OF OUR AREA LATER TUESDAY NIGHT AND WEDNESDAY...BEFORE BECOMING STATIONARY ACROSS OUR EXTREME SOUTHERN ZONES BY WEDNESDAY EVENING. BEST POPS WILL BE LATER TUESDAY NIGHT AND WEDNESDAY MORNING ACROSS THE NORTH...AS MOST OF THE DYNAMICS WITH THE SHORT WAVE SKIRTS ACROSS OUR NORTH. POPS DIMINISH WITH THE WEAKENING FRONT ACROSS THE CENTRAL AND SOUTH WEDNESDAY AFTERNOON. BY WEDNESDAY EVENING...MOST OF THE SHOWERS WILL HAVE DISSIPATED. NOT MUCH COLD AIR BEHIND THIS FRONT...PRETTY SIMILAR TO TUESDAY WITH NEAR NORMAL TEMPS. ANOTHER STRONGER SHORT WAVE DEVELOPS OVER THE MISSISSIPPI VALLEY ON WEDNESDAY AND WEDNESDAY NIGHT...AND AS IT ADVANCES EASTWARD...BRINGS A WARM FRONT UP ACROSS THE AREA LATER WEDNESDAY NIGHT AND THURSDAY MORNING. HERE THE GFS IS MORE AMPLIFIED WITH THIS SYSTEM THAN THE ECMWF...WITH THE CANADIAN LEANING TOWARD THE GFS AND THE UKMET TOWARD THE ECMWF. GOING WITH A COMPROMISE OF THE MODELS...WHICH STILL GOES WITH NORMAL CLIMATOLOGY WITH THESE WARM FRONTS. THAT IS...WITH THE BEST FEED OUT WEST...BEST POPS WEDNESDAY NIGHT AND THURSDAY MORNING WILL BE IN THE WEST AND NORTH BEFORE THE FRONT LIFTS NORTH OF THE AREA WITH THE SHOWERS DURING THURSDAY. THIS WILL LEAVE THURSDAY AFTERNOON AND FRIDAY IN THE WARM SECTOR...BASICALLY DRY AND QUITE WARM. COLD FRONT COMES THROUGH SATURDAY WITH SHOWERS MAINLY BEGINNING FRIDAY NIGHT...FOLLOWED BY COLDER AND DRIER AIR SUNDAY. MOST PRECIP WILL BE RAIN...EVEN BEHIND THIS FRONT...BEFORE ENDING LATER SATURDAY NIGHT. && .AVIATION /01Z MONDAY THROUGH FRIDAY/... POPCORN VARIETY OF LIGHT SNOW SHOWERS CONTINUE...MAINLY ACROSS THE SRN COALFIELDS THIS EVENING. WILL KEEP THIS ACTIVITY GOING FOR THE NEXT SEVERAL HOURS...AND SHIFT ACTIVITY TO THE NORTH FOR THE MID TO LATE EVENING HOURS AS UPPER LEVEL DISTURBANCE ENHANCES DYNAMIC LIFT. THIS WILL LEAD TO SCATTERED AREAS OF MVFR AND ISOLD IFR FLIGHT CONDITIONS FOR TONIGHT. ONCE THE UPPER LEVEL DISTURBANCE PASSES...NORTHWEST FLOW WILL BRING SOME SOME WEAK UPSLOPE CONDITIONS TO THE EASTERN MOUNTAINS. THE SNOW SHOWERS FIGURED FOR FOR EKN...BUT ELSEWHERE JUST EXPECT THAT THE CLOUDS WILL LINGER WITH CEILINGS BETWEEN 2000 FT IN THE MOUNTAINS TO AROUND 3500 IN THE WESTERN LOWLANDS. CONDITIONS IMPROVE MONDAY AS LOWER LEVEL SCOUR AND DRY. AVIATION OUTLOOK /AFTER 00Z MONDAY...NO SIGNIFICANT WEATHER AT THIS TIME. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...ESS/JMV/RPY NEAR TERM...KMC SHORT TERM...RPY LONG TERM...JMV AVIATION...KMC oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CLEVELAND OH 157 AM EDT SAT MAR 22 2008 .SYNOPSIS... LOW PRESSURE WILL MOVE FROM WEST CENTRAL ILLINOIS TO WEST VIRGINIA BY SATURDAY MORNING. HIGH PRESSURE WILL TRY AND BUILD INTO THE AREA FOR THE WEEKEND AND EARLY NEXT WEEK...BUT A WEAK TROUGH WILL MOVE THROUGH SUNDAY AND AN UPPER DISTURBANCE WILL AFFECT THE AREA ON MONDAY. UNSETTLED WEATHER CONTINUES INTO NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... UPGRADED THE SNOW ADVISORY TO A HEAVY SNOW WARNING BASED ON THE DURATION AND INTENSITY OF THE SNOW UPSTREAM AS WELL AS THE PROJECTION OF MAXIMUM PRECIPITATION ONTO THE LAKESHORE NEAR CLEVELAND BY THE RUC OVERNIGHT IN A FAIRLY NARROW SWATH. HEAVY SNOW CRITERIA OF 6 INCHES OR MORE MAY LITERALLY OCCUR WITHIN 10 MILES OF THE LAKESHORE AND THE MI BORDER. SNOW AMOUNTS WILL DIMINISH ACROSS ERIE COUNTY PA AS NORTHERN EDGE OF THE SNOW SHIELD DECREASES OVERNIGHT AS THE SURFACE LOW AND DIFFLUENT ZONE SLIDE SOUTHEAST AND DRIER AIR GETS ENTRAINED FROM THE NORTHEAST. SOME VERY WARM AIR FROM EARLIER TODAY HAS GOTTEN ELEVATED INTO THE SYSTEM ACROSS THE MIDWEST AND AREAS OF FREEZING RAIN HAVE DEVELOPED ACROSS INDIANA AS WELL AS SOME LIGHTNING AND THUNDER. HATE TO CHANGE HEADLINES MIDSTREAM BUT SOME OF THIS FREEZING RAIN WILL CROSS THE FORECAST AREA FROM FINDLAY TO MANSFIELD AND CANTON OVERNIGHT. THIS WILL CUT DOWN ON THE SNOW TOTALS IN THAT AREA AND CHANGE THE HAZARD TO A COMBINATION OF SNOW AND ICE. A HEAVY ICE ACCUMULATION IS NOT EXPECTED AS TEMPS ARE MARGINAL AND ANY HEAVIER FREEZING RAIN WILL NOT LAST LONG. A GLAZE OF ICE POSSIBLE THOUGH ESPECIALLY BEING AT NIGHT AS DEW POINTS HAVE ALREADY DROPPED AND TEMPS WILL DROP TO FREEZING OR BELOW OVERNIGHT WITH THE POSSIBLE EXCEPTION OF MARION SOUTHERN MORROW AND KNOX COUNTIES WHERE TEMPS MAY HOLD ABOVE FREEZING. && .SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/... FRIDAY NIGHT/S SYSTEM WILL BE PULLING AWAY IN THE MORNING...BUT HAVE CONTINUED LIKELY SNOW SHOWERS EAST HALF UNTIL VORT MOVES THROUGH. DEEPER MOISTURE PULLS AWAY WITH THE SFC LOW. QUIET BY SATURDAY EVENING. UPPER TROUGH AND WEAK SURFACE TROUGH FOR SUNDAY WILL BRING ANOTHER BIT OF MOISTURE WITH IT. EXPECT SCATTERED INSTABILITY TYPE SNOW SHOWERS FOR SUNDAY IN ASSOCIATION WITH AN H5 TROUGH. HAVE INCREASED POPS TO CHC CATEGORY...BUT ANY SNOW AMOUNTS WOULD BE LIGHT. BUT WITH TROUGH OVERHEAD...TEMPS WILL BE BELOW NORMAL AND GENERALLY IN THE 30S THROUGH THE WEEKEND. && .LONG TERM /MONDAY THROUGH FRIDAY/... FAST FLOW WILL PREVAIL IN THE EXTENDED PERIODS. THIS WILL LEAD TO A SERIES OF FAST MOVING SYSTEMS THROUGH THE FORECAST PERIOD. THE GFS AND ECMWF HAVE DIFFERENT TIMING ON THE WAVES. THIS WILL IMPACT THE CONFIDENCE LEVEL OF THE EXTENDED SINCE THE SYSTEMS ARE WEAK AND WILL BE TOUGH TO TIME. THE MODELS DO SHOW COLD AIR OVER THE REGION ON MONDAY. THIS WILL LEAD TO SOME SNOW SHOWERS AND POSSIBLE LAKE EFFECT OVER THE EAST. SNOW SHOWERS WILL LINGER OVER THE SNOW BELT REGIONS MONDAY NIGHT. TUESDAY THROUGH THE REMAINDER OF THE WEEK BECOME MUCH MORE TRICKY. SEVERAL WAVES ROTATE THROUGH A FAST ZONAL FLOW. TIMING OF THE SYSTEMS ARE DIFFICULT. THIS WILL LEAD TO A LOW CHC OF PCPN ON MOST DAYS IN THE EXTENDED PERIOD. TEMPERATURES WILL REMAIN SEASONAL. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... IFR CONDITIONS LIKELY FOR MUCH OF THE OVERNIGHT HOURS WITH SLOW IMPROVEMENT MVFR AFTER 12Z NORTHERN SITES FIRST AND OVER SOUTHERN AREAS BY LATE MORNING...WITH CIGS AND VSBY IMPROVING TO VFR DURING SATURDAY AFTERNOON AS THE LOW AND SNOW MOVE OFF TO THE SE. .OUTLOOK...VFR LIKELY TO CONTINUE INTO THE FIRST PART OF SUNDAY. THEN WEAK SYSTEMS MOVES THROUGH ON SUNDAY...FOLLOWED BY WARM FRONT MONDAY NIGHT AND COLD FRONT ON WEDNESDAY THESE SYSTEMS ALL LIKELY BRINING PERIOD OF NON VFR WEATHER AS THEY MOVE THROUGH. && .MARINE... LIGHT AND VARIABLE WINDS WILL SHIFT TO THE NORTHEAST AND INCREASE TO AROUND 20 KNOTS TONIGHT AS LOW PRESSURE MOVES ACROSS OHIO. WINDS WILL TURN TO THE NW AND BEGIN TO DIMINISH SATURDAY AS THE LOW MOVES EAST. RELATIVELY LIGHT WINDS THROUGH THE REMAINDER OF THE WEEKEND AS HIGH PRESSURE MOVES ACROSS THE GREAT LAKES. NEXT FRONT NOT EXPECTED UNTIL LATE WEDNESDAY. LAKE ICE IS BEGINNING TO BREAK UP A LITTLE BIT WITH SOME OPEN HOLES STARTING TO DEVELOP. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...HEAVY SNOW WARNING UNTIL 9 AM EDT THIS MORNING FOR OHZ003-007- 009>013. WINTER WEATHER ADVISORY UNTIL 9 AM EDT THIS MORNING FOR OHZ006- 008-017>019-027>032-038. SNOW ADVISORY UNTIL 9 AM EDT THIS MORNING FOR OHZ014-020>023- 033-089. PA...SNOW ADVISORY UNTIL 9 AM EDT THIS MORNING FOR PAZ001>003. MARINE...NONE. && $$ SYNOPSIS...OUDEMAN NEAR TERM...KOSARIK SHORT TERM...OUDEMAN LONG TERM...GARNET AVIATION...LOMBARDY MARINE...DJB oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 1043 AM EDT SAT MAR 22 2008 .SYNOPSIS... A 1009MB LOW OVER WV EARLY TODAY...WILL CONTINUE EASTWARD AND OFF THE VIRGINA COAST BY EVENING. COLDER AIR WITH SCATTERED FLURRIES AND SNOW SHOWERS WILL FOLLOW FOR THIS AFTERNOON THROUGH SUNDAY NIGHT. THE UPCOMING WEEK WILL START OFF ON THE DRY AND COOL SIDE...BUT TEMPERATURES WILL STEADILY MODERATE TO ABOVE NORMAL WITH A CHANCE FOR SHOWERS BY MID TO LATE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE LOW AT 12Z WAS OVER WV WITH A WARM FRONT EXTENDING JUST ABOUT DUE-EAST TO THE SOUTHERN CHES BAY. HIGH RES RUC SHOWS THE LOW LEVEL FRONTOGENETIC FORCING WANING RAPIDLY THIS MORNING...AND THAT MATCHES THE CURRENT RADAR LOOPS WHICH ARE SHOWING THE PRECIP DWINDLING AND LOSING ORGANIZATION OVER THE LAST 1-2 HOURS. MODELS SHOW WEAK MID LEVEL FGEN FORCING HANGING IN FOR A TIME THRU EARLY AFTERNOON...BUT THIS WANES AS WELL WITH THE PASSAGE OF THE MID LEVEL SHORTWAVE. IT ALL POINTS TO THE SNOW CONTINUING TO TAPER OFF TO SCATTERED SNOW SHOWERS...WITH THE SKIES BRIGHTENING AS SOME DRIER AIR WORKS IN FROM THE NORTH. PNSCTP ISSUED WITH A PRELIMINARY SUMMARY OF SNOWFALL AMOUNTS THRU MID MORNING. HEAVIEST STRIPE SEEMS TO EXTEND FROM CLEARFIELD DOWN INTO CENTRE COUNTY WIT MOST REPORTS IN THE 3-5 INCH RANGE. WILL BE CANCELING THE ADVISORY BEFORE 11 AS MOST OF THE SNOW FOR THE REST OF THE DAY SHUD REMAIN ON THE LIGHT SIDE. HIGHS WILL RANGE FROM THE MID TO UPPER 30S IN THE CENTRAL AND NORTH...TO THE LOWER 40S ACROSS THE SE ZONES. THESE TEMPS WILL EQUATE TO 8-10F BELOW NORMAL IN MANY AREAS. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/... MID AND HIGH CLOUDS (GENERALLY IN THE BKN CATEGORY) WILL GRADUALLY THIN OUT FROM THE NORTH TO SOUTH LATE TONIGHT. THE RELATIVELY LIGHT NW BREEZE...AND LATE NIGHT THINNING OUT OF THE CLOUDS...WILL ALLOW TEMPS TO DROP TO QUITE COLD LEVELS. MIN TEMPS EARLY EASTER MORNING WILL RANGE FROM THE MID TEENS ACROSS THE NRN PENN MTNS...TO THE LOWER AND MID 20S IN MOST OTHER LOCATIONS. SUNDAY WILL BE PARTLY SUNNY SE OF THE MTNS AND MAINLY CLOUDY ACROSS MUCH OF THE ALLEGHENY PLATEAU AND LAUREL HIGHLANDS. INCREASING COLD AIR ALOFT AND 850-500 HPA LAPSE RATES INCREASING TO AROUND 7.5C/KM LATE SUNDAY AND SUNDAY NIGHT ACROSS THE SOUTHERN HALF OF PENN WILL SUPPORT INCREASING SNOW SHOWERS OVER THE MTNS WITH AN OCCASIONAL FLURRY FLYING OVER THE CENTRAL AND SE PARTS OF THE STATE. LIGHT SNOW ACCUMULATION OF 0.5 TO 1.0 EXPECTED SUNDAY NIGHT ACROSS THE LAURELS AND NW MTNS. MAX TEMPS SUNDAY WILL SHOW THE GREATEST DEPARTURE BELOW NORMAL OVER THE MTNS WHERE MORE ABUNDANT CLOUDS AND THE FRESH SNOW PACK WILL BE FOUND. HIGHS IN THE LOW/MID 30S OVER THE NRN AND WRN MTNS AND 40-45F ACROSS THE SE HALF OF THE CWA WILL BE SEVERAL...TO AS MUCH AS 10-12F BELOW NORMAL. && .LONG TERM /MONDAY THROUGH FRIDAY/... UPPER TROUGH CARVES OUT ACROSS THE NORTHEAST TO START THE WEEK...KEEPING TEMPS COOL AND CLOUDS PLENTIFUL. NW FLOW WILL CONTINUE TO BE A MAJOR PLAYER THROUGH THE WEEK WITH A COUPLE OF INTRUSIONS OF WARMER AIR ALONG WITH WEAK STORM SYSTEMS. TEMPS DO WARM BACK SLIGHTLY ABOVE NORMAL FOR TUE AS CLIPPER TYPE SYSTEM SLIDES ACROSS S CANADA...DRAGGING A COOL FRONT THROUGH AND COOLING US DOWN AGAIN FOR LATE WEEK. COLDEST AIR WILL PERSIST ALONG THE NY BORDER...WITH TEMPS NEAR SEASONAL ACROSS THE SOUTHERN PORTIONS OF CWA. SOME UNCERTAINTY FOR LATE WEEK/NEXT WEEKEND...BUT IT APPEARS A WARM-UP MAY BE IN STORE AS NEXT STRONG LOW SLIDES TO OUR NW KEEPING US ON THE WARMER SIDE BUT BRINGING RAIN CHANCES FOR THE WEEKEND. && .AVIATION /14Z SATURDAY THROUGH WEDNESDAY/... REGIONAL RADAR CONTINUES TO SHOW THE SNOW DIMINISHING IN COVERAGE SO CONDITIONS AT ALL TERMINALS WILL CONTINUE TO IMPROVE. SATELLITE SHOTS SHOW PLENTY OF UPSTREAM CLOUDINESS SO CLEARING MAY BE HARD TO COME BY...BUT MOST SITES WILL SEE CEILINGS IN THE VFR/HIGH MVFR RANGE BEFORE THE AFTERNOON ENDS. VIS SHUD BE MAINLY UNLIMITED OTHER THAN FOR PASSING SNOW SHOWERS CAUSING BRIEF REDUCTIONS TO THE 2-3 MILE RANGE. MVFR/VFR STRATO CU WILL LKLY PERSIST THRU THE WEEKEND. PASSAGE OF COLD UPR TROF COULD KICK OFF SOME SCT -SHSN SUN NGT INTO MONDAY. HIGH PRES BUILDS IN FOR MON NGT/TUE AS THE TROF LIFTS OUT. A COLD FRONT WILL AFFECT THE REGION BY MID WEEK. PCPN LOOKS TO BE MAINLY RAIN WITH THIS. && .CTP WATCHES/WARNINGS/ADVISORIES... SNOW ADVISORY UNTIL NOON EDT TODAY FOR PAZ010>012-017>019-024- 025-033-045. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...FITZGERALD/LAMBERT LONG TERM...LAMBERT/RXR AVIATION...LA CORTE/STEINBUGL pa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 756 AM EDT SAT MAR 22 2008 .SYNOPSIS... AN AREA OF LOW PRESSURE NEAR COLUMBUS OHIO EARLY TODAY WILL MOVE EAST ACROSS WEST VIRGINIA AND NORTHERN VIRGINIA TODAY. THIS LOW WILL BRING SNOW TO CENTRAL AND SOUTHERN PENNSYLVANIA THROUGH THIS MORNING. COLDER AIR WITH SCATTERED FLURRIES AND SNOW SHOWERS WILL FOLLOW FOR SATURDAY AFTERNOON THROUGH SUNDAY NIGHT. THE UPCOMING WEEK WILL START OFF ON THE DRY AND COOL SIDE...BUT TEMPERATURES WILL STEADILY MODERATE TO ABOVE NORMAL MID WEEK WITH A CHANCE FOR SHOWERS BY MID TO LATE WEEK AS WELL. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... OPERATIONAL NUMERICAL MODELS...ALONG WITH THEIR KINEMATIC AND THERMODYNAMIC FIELDS...ARE NICELY HANDLING THE LOCATION AND INTENSITY OF THE NEARLY EAST TO WEST SNOW AREA STRETCHING FROM NORTHERN OHIO...ACROSS CENTRAL PENN (ROUGHLY 30-40 NM EITHER SIDE OF INTERSTATE 80). 850-700 FRONTOGENESIS MAX VIA THE 40KM NAM CAPTURES THE MORE SIGNIFICANT SNOWS...WITH THE 290K ISENTROPIC SFC (AND UVVEL ALONG IT) BEST DEPICTING THE BANDS OF EMBEDDED 1/2SM - MDT SNOW ALONG WITH THE SHARP NORTHERN GRADIENT TO THE PRECIP AREA OVER THE NRN PENN MTNS ATTM. A RELATIVELY STRONG MID/UPR SHORT WAVE CROSSING NERN OHIO AT 07Z WILL CONTINUE TO BRING SNOW AT VARYING INTENSITY (BRIEFLY 1/4-1/2SM) INTO THE LATE MORNING HOURS ACROSS MUCH OF CENTRAL AND SWRN PENN WITH ANOTHER 2-3 INCHES OF ACCUMULATION LIKELY ACROSS THE HIGHER TERRAIN BETWEEN KDUJ AND KIPT...SW TO NEAR KUNV...KJST AND KAOO. 03Z SREF MEAN QPF IS FAIRLY CONSISTENT WITH THE OPERATIONAL NAM/GFS...BUT ITS "EXTREMELY WIDE RANGE" OF QPF OVER THE NEXT 6-9 HRS SUGGESTS THE UNCERTAINTY OF NUMEROUS MEMBERS WITH RESPECT TO THE LOCATION OF THE SHARP NRN CUTOFF TO THE SNOW. COMPARISON OF NAM/RUC ISENT LIFT...FRONTOGENESIS...AND OMEGA FIELDS WITH RADAR TRENDS WILL HANDLE THE SNOWFALL LOCATION AND TIMING BEST HERE. WE EXPANDED THE CURRENT SNOW ADVISORY (WHICH RUNS UNTIL NOON EDT) SLIGHTLY TO THE NE...INCLUDING CAMERON AND CLINTON COUNTIES...WHERE THE SIGNIFICANT SNOW SHOULD BE MAINLY OVER THE SOUTHERN HALF OF BOTH COUNTIES. THE STRONG ASCENT BENEATH THE LEFT FRONT QUAD OF THE 110 KT 250 HPA JET...AND ELEVATED INSTABILITY COULD BRING SOME +TSSN TO THE LAUREL HIGHLANDS DURING THE MID TO LATE MORNING HOURS. FRONTOGENETIC FORCING/ISENT LIFT IN THE 285-295K THETA CHANNEL GRADUALLY WEAKENS LATER THIS MORNING WITH THE SNOW AREA SAGGING TO THE SE...SO I CONTINUE TO EXPECT MINIMAL ACCUMULATIONS ACROSS THE VALLEYS OF SCENT PENN AND THE CENTRAL AND LOWER SUSQ VALLEY. BEST CHC FOR AND INCH OR SO OF ACCUMULATION ACROSS THE SUSQ VALLEY WILL BE NEAR KSEG. PERIODS OF LIGHT SNOW LIKELY TO CONTINUE INTO EARLY THIS AFTERNOON MAINLY ACROSS THE WCENT MTNS AND LAURELS...WHILE SKIES STAY MAINLY CLOUDY ELSEWHERE WITH FLURRIES/SNIZZLE. SOME CLEARING EXPECTED TO DEVELOP ACROSS THE NRN MTNS LATE TODAY. MAX TEMPS TODAY WILL BE SEVERAL DEG BELOW ALL MOS GUIDANCE... PARTICULARLY WHERE THE HEAVIER SNOW IS FALLING THIS MORNING. HIGHS WILL RANGE FROM THE MID TO UPPER 30S IN THE CENTRAL AND NORTH...TO THE LOWER 40S ACROSS THE SE ZONES. THESE TEMPS WILL EQUATE TO 8-10F BELOW NORMAL IN MANY AREAS. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/... MID AND HIGH CLOUDS (GENERALLY IN THE BKN CATEGORY) WILL GRADUALLY THIN OUT FROM THE NORTH TO SOUTH LATE TONIGHT. THE RELATIVELY LIGHT NW BREEZE...AND LATE NIGHT THINNING OUT OF THE CLOUDS...WILL ALLOW TEMPS TO DROP TO QUITE COLD LEVELS. MIN TEMPS EARLY EASTER MORNING WILL RANGE FROM THE MID TEENS ACROSS THE NRN PENN MTNS...TO THE LOWER AND MID 20S IN MOST OTHER LOCATIONS. SUNDAY WILL BE PARTLY SUNNY SE OF THE MTNS AND MAINLY CLOUDY ACROSS MUCH OF THE ALLEGHENY PLATEAU AND LAUREL HIGHLANDS. INCREASING COLD AIR ALOFT AND 850-500 HPA LAPSE RATES INCREASING TO AROUND 7.5C/KM LATE SUNDAY AND SUNDAY NIGHT ACROSS THE SOUTHERN HALF OF PENN WILL SUPPORT INCREASING SNOW SHOWERS OVER THE MTNS WITH AN OCCASIONAL FLURRY FLYING OVER THE CENTRAL AND SE PARTS OF THE STATE. LIGHT SNOW ACCUMULATION OF 0.5 TO 1.0 EXPECTED SUNDAY NIGHT ACROSS THE LAURELS AND NW MTNS. MAX TEMPS SUNDAY WILL SHOW THE GREATEST DEPARTURE BELOW NORMAL OVER THE MTNS WHERE MORE ABUNDANT CLOUDS AND THE FRESH SNOW PACK WILL BE FOUND. HIGHS IN THE LOW/MID 30S OVER THE NRN AND WRN MTNS AND 40-45F ACROSS THE SE HALF OF THE CWA WILL BE SEVERAL...TO AS MUCH AS 10-12F BELOW NORMAL. && .LONG TERM /MONDAY THROUGH FRIDAY/... UPPER TROUGH CARVES OUT ACROSS THE NORTHEAST TO START THE WEEK...KEEPING TEMPS COOL AND CLOUDS PLENTIFUL. NW FLOW WILL CONTINUE TO BE A MAJOR PLAYER THROUGH THE WEEK WITH A COUPLE OF INTRUSIONS OF WARMER AIR ALONG WITH WEAK STORM SYSTEMS. TEMPS DO WARM BACK SLIGHTLY ABOVE NORMAL FOR TUE AS CLIPPER TYPE SYSTEM SLIDES ACROSS S CANADA...DRAGGING A COOL FRONT THROUGH AND COOLING US DOWN AGAIN FOR LATE WEEK. COLDEST AIR WILL PERSIST ALONG THE NY BORDER...WITH TEMPS NEAR SEASONAL ACROSS THE SOUTHERN PORTIONS OF CWA. SOME UNCERTAINTY FOR LATE WEEK/NEXT WEEKEND...BUT IT APPEARS A WARMUP MAY BE IN STORE AS NEXT STRONG LOW SLIDES TO OUR NW KEEPING US ON THE WARMER SIDE BUT BRINGING RAIN CHANCES FOR THE WEEKEND. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... REGIONAL RADAR SHOWS -SN BCMG MORE SCTD/CELLULAR THIS MORNING AS SFC LOW WEAKENS OVR NRN VA. IR SAT SHOWS BLANKET OF STRATO CU ASSOC WITH UPR LVL TROF OVR THE WRN GLKS HEADED FOR WCENT PENN...WHICH WILL KEEP MVFR/IFR CONDS AROUND FOR AWHILE AT JST/AOO/UNV. ONCL -SN MAY BRING CIGS/VIS DOWN TO MVFR AT MDT EARLY PRIOR TO 18Z. VFR TO CONT AT BFD/IPT. MVFR/VFR STRATO CU WILL LKLY PERSIST THRU THE WEEKEND. PASSAGE OF COLD UPR TROF COULD KICK OFF SOME SCT -SHSN SUN NGT INTO MONDAY. HIGH PRES BUILDS IN FOR MON NGT/TUE AS THE TROF LIFTS OUT. A CLD FNT WILL AFFECT THE REGION BY MID WEEK. PCPN LOOKS TO BE MAINLY RAIN WITH THIS SYS. && .CTP WATCHES/WARNINGS/ADVISORIES... SNOW ADVISORY UNTIL NOON EDT TODAY FOR PAZ010>012-017>019-024- 025-033-045. && $$ SYNOPSIS...LAMBERT NEAR TERM...FITZGERALD/LAMBERT SHORT TERM...FITZGERALD/LAMBERT LONG TERM...LAMBERT/RXR AVIATION...STEINBUGL pa AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 1029 AM CDT SUN MAR 23 2008 .DISCUSSION... FOCUS IS ON TEMPERATURES AND CLOUD TRENDS IN SHORT TERM UPDATE PHASE TODAY. LOOKS LIKE THE COLDEST EASTER DAY IN FOUR DECADES DESPITE A FAIR NUMBER OF MARCH EASTERS DURING THAT TIME. CAA SET TO CONTINUE THRU DAY AS SFC RIDGE AXIS BUILDS TOWARD THE I29 CORRIDOR AND SW MN LATE TODAY. ABUNDANCE OF LOW CLOUDS PRESENT ACRS AREA...WITH AN ABUNDANCE OF FLURRIES AS SHALLOW UNSTABLE LYR TOPPING OUT WITHIN DECENT ICE GENERATION TMPS. DEEPER MOISTURE CERTAINLY E...BUT DRYING PUSH NOTED SINKING THRU SW MN. MAY BE A TEMPORARY PUSH OF CLEARING AS COOLER TMPS ALFT CERTAINLY SUPPORTIVE OF SELF DESTRUCTIVE SUNSHINE. OTHER MORE PERSISTENT CLOUD BAND COULD EXIST BY MID AFTN FROM NW TO SE IN HEART OF CWA...JUST ON COLD SIDE OF BAROCLINIC BAND WHERE RETURN FLOW STARTS TO SET UP LATE IN DAY. FULL MIXING TO 900 HPA COMES UP SHORT BY MORE THAN SEVERAL DEGREES MOST LOCATIONS...AND WHERE CLOUDS CONTINUE LONGER THRU DAY IS LKLY TO END UP EVEN COOLER THAN MIXING SUGGESTS. A DROP OF ABOUT 3-4F ACROSS THE BOARD SEEMS REASONABLE...AND MAY NEED MORE WHERE CLOUDS END UP THE MOST PERSISTENT. && .AVIATION... MORE MVFR CIGS WITH PERIODS OF MVFR VSBYS IN FLURRIES LKLY TO PERSIST THRU MOST OF AFTN. WHOLE SCALE CLEARING EXPECTED TO COMMENCE LATE AFTN INTO EARLY EVNG...LOSING CIGS IN 22Z-01Z WINDOW. && .PREV DISCUSSION... QUIET CONDITIONS EXPECTED ACROSS OUR FA THROUGH THE FIRST HALF OF THE WORK WEEK...BEFORE MORE ACTIVE PATTERN TAKES SHAPE AGAIN LATE IN THE WEEK. FOR TODAY STILL SOME LOW LEVEL MOISTURE/FLURRIES ROTATING SOUTH ACROSS THE AREA THIS MORNING...BUT NOT CLOSE TO YESTERDAY IN REGARDS TO COVERAGE/INTENSITY OF SNOW SHOWERS...AND ISOLATED TO SCATTERED FLURRIES SHOULD COVER WELL IN AREAS WHERE RUC SHOWS BEST MOISTURE AVAILABLE IN FAVORED SNOW GROWTH TEMPERATURE RANGE. INFLUX OF DRIER AIR SHOULD ALLOW WESTERN CWA TO SEE FAIR AMOUNT OF SUNSHINE BY THIS AFTERNOON...WHILE SOME STRATUS LINGERS OVER MN/IA COUNTIES. 925MB TEMPS EVEN COOLER ACROSS THE NORTHEAST CWA BY LATE AFTERNOON THAN THEY WERE YESTERDAY...BUT SHOULD SEE A LITTLE SUN TO HELP OFFSET SO WILL GO WITH HIGHS SIMILAR TO YESTERDAY IN THE NORTHEAST FA...AND WARM UP WESTERN AREAS WHERE GREATER SUNSHINE IS EXPECTED. CLEARING SKIES AND LIGHT WINDS ACCOMPANY WEAK HIGH PRESSURE THROUGH THE AREA TONIGHT...WITH SOUTHERLY WIND PICKING UP QUICKLY ON MONDAY IN ADVANCE OF COOL FRONT. MONDAY WILL BE FIRST ABOVE NORMAL DAY IN A WHILE...AND ALAS WILL BE THE ONLY ONE FOR A GOOD PORTION OF THE UPCOMING WEEK. NORTHERN STREAM SHORTWAVE STILL ON TRACK TO PASS BY NORTH OF OUR FA MONDAY NIGHT...DRAGGING AFOREMENTIONED COOL FRONT THROUGH THE AREA. BOTH NAM/GFS STRUGGLE TO SATURATE LOWER ATMOSPHERE BELOW 800MB...SO WILL LEAVE THE FRONTAL PASSAGE DRY WITH JUST AN INCREASE IN MID CLOUDS. DEEP WEST-NORTHWEST FLOW BEHIND THE FRONT THROUGH THE DAY TUESDAY WILL ALLOW FOR STRONG MIXING...WITH BOTH GFS/NAM MIXING TO ABOVE 800MB. GFS/ECMWF HAVE BACKED OFF A LITTLE ON WINDS FOR TUESDAY...BUT STILL SHOWING POTENTIAL FOR GUSTS OVER 30MPH DURING PEAK MIXING... THOUGH EVEN WITH DEEPER MIXING TEMPS WILL BE COOLER THAN MONDAY. STRONGER SHORTWAVE MOVES ACROSS THE NORTHERN ROCKIES WEDNESDAY AND INTO THE NORTHERN PLAINS WEDNESDAY NIGHT. DIFFERENCES IN MODELS ON TIMING/PLACEMENT OF BEST PRECIP CHANCES...THOUGH MOST SHOW SOME LIGHT WARM ADVECTION PRECIP MOVING INTO WESTERN FA EARLIER THAN PREVIOUSLY FORECAST...AND HAVE ADDED SOME LOWER CHANCE POPS TO WESTERN CWA FOR THE EVENING. BIGGEST QUESTION AT THIS TIME WITH THIS SYSTEM IS HOW MUCH COLDER AIR WILL BE PULLED INTO THE FA LATER IN THE DAY THURSDAY AND THURSDAY NIGHT. GOING FORECAST HAS PRIMARILY RAIN THROUGH THE DAYLIGHT HOURS...ASIDE FROM POTENTIAL FOR SOME FREEZING RAIN IN THE NORTHEAST DURING THE EARLY MORNING. LOW LEVEL TEMPS CONTINUE TO SUPPORT THIS EVEN WITH 700MB TEMPS COOLING TO BELOW -10C IN THE WESTERN CWA BY LATE IN THE DAY...SO HAVE NOT MADE ANY CHANGES TO PRECIP TYPE FOR THE LATE WEEK SYSTEM AT THIS POINT. JH && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ CHAPMAN sd AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 355 AM CDT SUN MAR 23 2008 .DISCUSSION... QUIET CONDITIONS EXPECTED ACROSS OUR FA THROUGH THE FIRST HALF OF THE WORK WEEK...BEFORE MORE ACTIVE PATTERN TAKES SHAPE AGAIN LATE IN THE WEEK. FOR TODAY STILL SOME LOW LEVEL MOISTURE/FLURRIES ROTATING SOUTH ACROSS THE AREA THIS MORNING...BUT NOT CLOSE TO YESTERDAY IN REGARDS TO COVERAGE/INTENSITY OF SNOW SHOWERS...AND ISOLATED TO SCATTERED FLURRIES SHOULD COVER WELL IN AREAS WHERE RUC SHOWS BEST MOISTURE AVAILABLE IN FAVORED SNOW GROWTH TEMPERATURE RANGE. INFLUX OF DRIER AIR SHOULD ALLOW WESTERN CWA TO SEE FAIR AMOUNT OF SUNSHINE BY THIS AFTERNOON...WHILE SOME STRATUS LINGERS OVER MN/IA COUNTIES. 925MB TEMPS EVEN COOLER ACROSS THE NORTHEAST CWA BY LATE AFTERNOON THAN THEY WERE YESTERDAY...BUT SHOULD SEE A LITTLE SUN TO HELP OFFSET SO WILL GO WITH HIGHS SIMILAR TO YESTERDAY IN THE NORTHEAST FA...AND WARM UP WESTERN AREAS WHERE GREATER SUNSHINE IS EXPECTED. CLEARING SKIES AND LIGHT WINDS ACCOMPANY WEAK HIGH PRESSURE THROUGH THE AREA TONIGHT...WITH SOUTHERLY WIND PICKING UP QUICKLY ON MONDAY IN ADVANCE OF COOL FRONT. MONDAY WILL BE FIRST ABOVE NORMAL DAY IN A WHILE...AND ALAS WILL BE THE ONLY ONE FOR A GOOD PORTION OF THE UPCOMING WEEK. NORTHERN STREAM SHORTWAVE STILL ON TRACK TO PASS BY NORTH OF OUR FA MONDAY NIGHT...DRAGGING AFOREMENTIONED COOL FRONT THROUGH THE AREA. BOTH NAM/GFS STRUGGLE TO SATURATE LOWER ATMOSPHERE BELOW 800MB...SO WILL LEAVE THE FRONTAL PASSAGE DRY WITH JUST AN INCREASE IN MID CLOUDS. DEEP WEST-NORTHWEST FLOW BEHIND THE FRONT THROUGH THE DAY TUESDAY WILL ALLOW FOR STRONG MIXING...WITH BOTH GFS/NAM MIXING TO ABOVE 800MB. GFS/ECMWF HAVE BACKED OFF A LITTLE ON WINDS FOR TUESDAY...BUT STILL SHOWING POTENTIAL FOR GUSTS OVER 30MPH DURING PEAK MIXING... THOUGH EVEN WITH DEEPER MIXING TEMPS WILL BE COOLER THAN MONDAY. STRONGER SHORTWAVE MOVES ACROSS THE NORTHERN ROCKIES WEDNESDAY AND INTO THE NORTHERN PLAINS WEDNESDAY NIGHT. DIFFERENCES IN MODELS ON TIMING/PLACEMENT OF BEST PRECIP CHANCES...THOUGH MOST SHOW SOME LIGHT WARM ADVECTION PRECIP MOVING INTO WESTERN FA EARLIER THAN PREVIOUSLY FORECAST...AND HAVE ADDED SOME LOWER CHANCE POPS TO WESTERN CWA FOR THE EVENING. BIGGEST QUESTION AT THIS TIME WITH THIS SYSTEM IS HOW MUCH COLDER AIR WILL BE PULLED INTO THE FA LATER IN THE DAY THURSDAY AND THURSDAY NIGHT. GOING FORECAST HAS PRIMARILY RAIN THROUGH THE DAYLIGHT HOURS...ASIDE FROM POTENTIAL FOR SOME FREEZING RAIN IN THE NORTHEAST DURING THE EARLY MORNING. LOW LEVEL TEMPS CONTINUE TO SUPPORT THIS EVEN WITH 700MB TEMPS COOLING TO BELOW -10C IN THE WESTERN CWA BY LATE IN THE DAY...SO HAVE NOT MADE ANY CHANGES TO PRECIP TYPE FOR THE LATE WEEK SYSTEM AT THIS POINT. && .AVIATION... MOSTLY MVFR TO IFR CEILINGS THIS MORNING...THEN VFR BY THIS EVENING. SCATTERED LIGHT SNOW SHOWERS WILL BE POSSIBLE AT LOCAL TAF SITES THIS MORNING ALONG WITH A SMALL POSSIBILITY OF LIGHT FREEZING DRIZZLE. CHANCES FOR LIGHT PRECIPITATION WILL SHIFT EAST THIS AFTERNOON AS HIGH PRESSURE BUILDS INTO THE AREA AND SKIES BEGIN TO CLEAR. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ JH/LIEBL sd AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX 110 PM CDT SUN MAR 23 2008 .UPDATE... THE SURFACE PRESSURE GRADIENT WILL CONTINUE TO GRADUALLY WEAKEN ACROSS THE REGION TODAY. AS THIS OCCURS...GAP WINDS THROUGH THE GUADALUPE MOUNTAINS WILL DECREASE. THE HIGH WIND WARNING HAS BEEN ALLOWED TO EXPIRE AT 18Z. .AVIATION... WIDESPREAD STRATUS WITH MVFR CIGS WILL PERSIST ACROSS MOST AREA TAF SITES THROUGH THIS AFTERNOON AND INTO THE EARLY EVENING. WE MAY ALSO SEE SOME LIGHT RAIN SHOWERS AT THE KHOB AND KMAF TERMINALS THROUGH 20Z. WE EXPECT THE MVFR CIGS TO GRADUALLY LIFT THIS EVENING...BUT WE CAN STILL EXPECT STRATUS CLOUDS THROUGH THE EVENING HOURS. IF STRATUS CONTINUES TO BREAK UP/LIFT...WE MAY SEE SOME PATCHY FOG ACROSS THE AREA...ESPECIALLY FOR THOSE AREAS THAT HAD DECENT RAINFALL. FOR NOW...WILL KEEP THE LOWEST VISIBILITIES CONFINED TO KMAF GIVEN OBSERVED RAINFALL. SOME PATCHY FOG WILL ALSO BE POSSIBLE AT KINK AND KPEQ AFTER 10Z. && .PREV DISCUSSION... /ISSUED 1157 AM CDT SUN MAR 23 2008/ UPDATE... WE HAVE UPDATED THE FORECAST TO LOWER RAIN CHANCES ACROSS ALL AREAS FOR THE REMAINDER OF THIS AFTERNOON. RADAR DATA AND THE LATEST RUC13 AND NAM12 SUGGEST SOME LIGHT PRECIPITATION WILL REMAIN POSSIBLE FOR AREAS GENERALLY ALONG AND EAST OF THE GUADALUPE AND DAVIS MOUNTAINS. MOST AREAS WILL REMAIN CLOUDY...ALTHOUGH THERE COULD BE SOME INTERMITTENT BREAKS IN THE CLOUDS ACROSS THE BIG BEND REGION THIS AFTERNOON. PREV DISCUSSION... /ISSUED 625 AM CDT SUN MAR 23 2008/ AVIATION... SCATTERED SOWERS AND THUNDERSTORMS WILL AFFECT ALL THE TAF SITES EXCEPT KCNM AND KHOB THIS MORNING. IFR CEILINGS AND VISIBILITIES COULD OCCUR AS THESE STORMS PASS OVER THE TAF SITES. OTHERWISE... IFR CEILINGS WILL DEVELOP AREAWIDE DURING THE MORNING AND PERSIST THROUGH MOST OF THE AFTERNOON BEFORE CLOUD COVER CLEARS THE ARA THIS EVENING. NORTHEAST WINDS WILL BE AROUND 20KT AT MOST TAF SITES THROUGH THE MORNING WITH GUSTS TO AROUND 30KT POSSIBLE. WIND SHOULD DIMINISH A LITTLE THIS AFTERNOON...THEN BECOME LIGHT AND VARIABLE THIS EVENING. 67 PREV DISCUSSION... /ISSUED 448 AM CDT SUN MAR 23 2008/ DISCUSSION... SHOWER ACTIVITY HAS BEEN INCREASING IN COVERAGE THIS EASTER SUNDAY NORTH OF THE PECOS RIVER. STEEP LAPSE RATES AND MUCAPE NEAR 300 J/KG HAVE BEEN SUFFICIENT FOR ISOLATED SEVERE THUNDERSTORMS ACROSS THIS AREA SINCE MIDNIGHT. STORM INTENSITY SHOULD BEGIN DROP OFF AFTER SUNRISE AS INSTABILITY AXIS BEGINS TO DIMINISH. SHOWERS WILL CONTINUE DURING THE DAY ACROSS THE PERMIAN BASIN AND SOUTHEASTERN NEW MEXICO AS WARM AIR ADVECTION WILL ENHANCE THIS ACTIVITY. RAIN SHOULD BEGIN TO TAPER OFF THIS EVENING FROM NORTHWEST TO SOUTHEAST. HIGHS TODAY WILL BE WELL BELOW AVERAGE AS COLD AIR CONTINUES TO PUSH IN FROM THE NORTHWEST AND OVERCAST CONDITIONS CONTINUE THROUGH THE AFTERNOON. IN ADDITION... NORTHEAST WINDS WILL BE AROUND 20 MPH AREAWIDE AND HIGH WINDS ARE EXPECTED ACROSS THE GUADALUPE MOUNTAINS. TUESDAY THROUGH FRIDAY WILL BE BRING WARMER TEMPERATURES BACK TO THE AREA. EXPECTING HIGHS BE INTO THE LOW TO MID 80S BY MIDWEEK AS WESTERLY FLOW RETURNS. BY THE END OF THE DAY...RAINFALL SHOULD HELP TO RELIEVE DRY CONDITIONS THAT HAVE PLAGUED THE AREA OVER THE LAST FEW MONTHS. FIRE CONCERNS WILL AGAIN BE ELEVATED THIS WEEK AS WEST WINDS INCREASE AND DRY AIR RETURNS TO THE WESTERN PORTIONS OF THE CWA. DEPENDING ON HOW MUCH RAIN FALLS TODAY AND WHAT AREAS RECEIVE APPRECIABLE AMOUNTS...THE FIRE DANGER MAY BE A LITTLE LESS THAN OF LATE. BY THE END OF THIS WEEK...UPPER LEVEL FLOW WILL BEGIN TO AMPLIFY AS THE NEXT TROUGH TRAVERSES ACROSS THE U.S. MODELS ARE SUGGESTING ANOTHER STRONG COLD FRONT TO MOVE THROUGH THE AREA LATE IN THE WEEK BUT THE TIMING OF THIS FRONT IS STILL A LITTLE UP IN THE AIR. ATTM NOT EXPECTING ANY PRECIP THROUGH NEXT WEEKEND AS GULF MOISTURE WILL BE CUT OFF BY STRONG WESTERLY WINDS FOR MOST OF THE AREA. && .MAF WATCHES/WARNINGS/ADVISORIES... NM...NONE. TX...HIGH WIND WARNING FROM 11 AM THIS MORNING TO NOON MDT TODAY FOR THE FOLLOWING ZONES...GUADALUPE MOUNTAINS. && $$ 06 tx AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 1228 PM CDT SUN MAR 23 2008 .AVIATION...VFR CONDITIONS ARE EXPECTED TO PERSIST ACROSS SOUTH TEXAS FOR THE NEXT 24 HOURS. GUSTY NORTHEASTERLY WINDS SHOULD GRADUALLY SUBSIDE AROUND SUNSET AS HIGH PRESSURE SETTLES ACROSS WEST- CENTRAL TEXAS. && .PREV DISCUSSION... /ISSUED 1040 AM CDT SUN MAR 23 2008/ UPDATE...RUC ANALYZED/WV IMAGERY DEPICTS A 400MB VORT MAX ACROSS CENTRAL TX GENERATING HIGH CLOUDS ACROSS SOUTH TEXAS. STILL THINK THE ATMOSPHERE IS TOO DRY (PER 12Z CRP SOUNDING) AND THE FORCING IS TOO WEAK TO GENERATE ANY PRECIP ACROSS THE REGION TODAY. WILL MAINTAIN THE SILENT 10 POPS IN THE GRIDS AS A RESULT. AT THE SURFACE...PRESSURE GRADIENT IS STARTING TO TIGHTEN AS HIGH PRESSURE BUILDS INTO THE PANHANDLES. SOME REGIONAL TCOON OBS IN THE BAYS ARE REPORTING 20KT WINDS WITH HIGHER GUSTS. DECIDED TO UPDATE THE CWF TO HOIST SCA FLAGS FOR THE BAYS UNTIL THIS AFTERNOON WHEN THE HIGH PRESSURE CENTER SHOULD BE IN WEST TEXAS AND THE GRADIENT RELAXES SOMEWHAT ACROSS THE COASTAL WATERS. ALSO UPDATED THE ZFP TO INCREASE WIND SPEEDS ACROSS THE NORTHERN CWA PER CURRENT OBS/TRENDS. OTHERWISE...THE REMAINING WEATHER ELEMENTS ARE IN GOOD SHAPE. UPDATED PRODUCTS HAVE BEEN SENT. PREV DISCUSSION... /ISSUED 407 AM CDT SUN MAR 23 2008/ SHORT TERM (TODAY THROUGH MONDAY)...MODELS ALL SIMILAR WITH BRINGING A WEAK AND RELATIVELY PRECIP-FREE FRONT THROUGH THE REGION THIS MORNING. NAM IS A LITTLE SLOWER WITH THE FRONT THAN THE GFS. HAVE COMPRISED TO A MIDDLE OF THE ROAD SOLUTION...SIMILAR TO THE SREF. THUS...THINK THE WINDS WILL BEGIN TO INCREASE FROM N TO S AROUND 15Z TODAY...WITH THE FRONT SOUTH OF THE REGION AFT 18Z. EXPECT BREEZY NE WINDS OF 15-25 MPH TODAY. MOISTURE AND LARGE SCALE LIFT TOO LIMITED TO ALLOW FOR ANY SIGNIFICANT PRECIP CHANCES. THUS HAVE LEFT 10% POPS. ALL MODELS SHOWING MOSTLY CLOUDY CONDITIONS TODAY...WITH MOISTURE TRAPPED AROUND 5K FT (~850 MB). ALREADY SEEING LOW LEVEL MOISTURE MOVING INTO THE SOUTHERN CWA. EXPECT MOSTLY CLOUDY CONDITIONS TO PERSIST TONIGHT...THEN CLOUDS DECREASE BY MONDAY AFTERNOON. ALTHOUGH TIMING IS ONLY SLIGHTLY DIFFERENT BETWEEN THE NAM AND GFS...MOS GUIDANCE IS QUITE DIFFERENT FOR MAXES TODAY. MAINTAINED A COMPROMISE BETWEEN THE MUCH WARMER NAM AND COOLER GFS. COOLER TONIGHT WITH LOWS IN THE 40S...EXCEPT 50S NEAR THE COAST. THESE TEMPS WILL BE 10-12 DEGS BELOW NORMAL. BY MONDAY...GIVEN THAT THE DAY WILL AT LEAST START MOSTLY CLOUDY AND THERE WILL BE STILL SOME WEAK COLD ADVECTION...HAVE KEPT COOLER TEMPS IN THE UPPER 60S TO LOWER 70S. LOW LEVEL FLOW IS EXPECTED TO VEER TO MORE EASTERLY BY LATE DAY. MARINE...WINDS ARE EXPECTED TO INCREASE TO LOW END SCA LEVELS BETWEEN 15 AND 18Z TODAY OVER THE GULF (SCEC BAYS)...WITH SCA CONDITIONS PERSISTING INTO MONDAY AFTERNOON. WINDS AND SEAS WILL GRADUALLY DECREASE BY LATE MONDAY BELOW SCA LEVELS. HAVE LEFT SCA UP THROUGH 21Z MONDAY MAINLY DUE TO SEAS REMAINING NEAR 7FT OVER THE GULF. AVIATION...A LITTLE SURPRISINGLY THIS MORNING LRD CIGS HAVE DROPPED TO MVFR LEVELS. EXPECT THIS TO PERSIST THROUGH MID MORNING...THEN RAISE BACK TO VFR. ALL AREAS GENERALLY EXPECTED TO HAVE VFR CONDITIONS TODAY AND TONIGHT...WITH CIGS AOB 35K FT. NOT EXPECTING ANY PROBLEMS WITH SIGNIFICANT FOG THIS MORNING. COULD BE A BRIEF PERIOD THROUGH 13Z TODAY WITH VSBYS 3-5SM IN BR. FIRE WEATHER...BECOMING DRIER AND BREEZY TODAY...BUT RH AND WINDS ARE EXPECTED TO REMAIN BELOW RED FLAG LEVELS. CONTINUED DRY ON MONDAY...BUT WINDS ARE EXPECTED TO BE LIGHTER. LONG TERM (MONDAY NIGHT THROUGH SATURDAY)...THE GFS/NOGAPS/ECMWF CONVERGE WITH RESPECT TO THE UPPER PATTERN INCLUDING AN UPPER SYSTEM PROGD TO MOVE ACRS THE PLAINS LATE FRI/SAT. YET...THE GFS PROGS SIGNIFICANTLY GREATER AMPLITUDE WITH RESPECT TO THIS SYSTEM...RESULTING IN A FROPA SAT. HWR...GIVEN THE SPREAD IN THE 500MB ENSEMBLES NOT CONFIDENT THAT FROPA WL OCCUR THIS FAR SOUTH. THUS...WL MAINTAIN ONSHORE FLOW DRG THE PERIOD. ALTHOUGH THE GFS PROGS A REGION OF MSTR TO ENTER THE SWRN GULF TDA THEN EVENTUALLY INTO THE CWFA BY TUE...GOES SOUNDER DATA INDICATES THAT THE REGION OF ENHANCED PW VALUES DID NOT ADVANCE DRG THE PAST 24 HRS. NOT SURE IF THE MSTR RETURN WL OCCUR BY TUE. THUS...REMOVE THE POPS FOR TUE. ALTHOUGH MSTR WL LIKELY ENTER THE REGION AFTERWARD...THE GFS MAINTAINS A SIGNIFICANT THERMODYNAMIC CAP DRG THE THU-SAT PERIOD. THUS...WL MAINTAIN DRY CONDITIONS. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 71 50 71 58 74 / 10 10 0 10 10 VICTORIA 70 45 69 51 72 / 10 10 0 10 10 LAREDO 74 52 74 60 82 / 10 10 10 10 10 ALICE 71 48 71 53 76 / 10 10 0 10 10 ROCKPORT 70 52 68 59 71 / 10 10 0 10 10 COTULLA 71 46 72 52 78 / 10 10 0 10 10 KINGSVILLE 71 49 71 57 75 / 10 10 10 10 10 NAVY CORPUS 71 55 67 60 72 / 10 10 0 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY UNTIL 4 PM CDT MONDAY FOR THE FOLLOWING ZONES: COASTAL WATERS BAFFIN BAY TO PORT ARANSAS OUT 20 NM...COASTAL WATERS PORT ARANSAS TO MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS BAFFIN BAY TO PORT ARANSAS 20 TO 60 NM... WATERS PORT ARANSAS TO MATAGORDA SHIP CHANNEL 20 TO 60 NM. SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR THE FOLLOWING ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT ARANSAS...BAYS AND WATERWAYS FROM PORT ARANSAS TO PORT O`CONNOR. && $$ TM/95...AVIATION/UPDATE tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX 1157 AM CDT SUN MAR 23 2008 .UPDATE... WE HAVE UPDATED THE FORECAST TO LOWER RAIN CHANCES ACROSS ALL AREAS FOR THE REMAINDER OF THIS AFTERNOON. RADAR DATA AND THE LATEST RUC13 AND NAM12 SUGGEST SOME LIGHT PRECIPITATION WILL REMAIN POSSIBLE FOR AREAS GENERALLY ALONG AND EAST OF THE GUADALUPE AND DAVIS MOUNTAINS. MOST AREAS WILL REMAIN CLOUDY...ALTHOUGH THERE COULD BE SOME INTERMITTENT BREAKS IN THE CLOUDS ACROSS THE BIG BEND REGION THIS AFTERNOON. && .PREV DISCUSSION... /ISSUED 625 AM CDT SUN MAR 23 2008/ AVIATION... SCATTERED SOWERS AND THUNDERSTORMS WILL AFFECT ALL THE TAF SITES EXCEPT KCNM AND KHOB THIS MORNING. IFR CEILINGS AND VISIBILITIES COULD OCCUR AS THESE STORMS PASS OVER THE TAF SITES. OTHERWISE... IFR CEILINGS WILL DEVELOP AREAWIDE DURING THE MORNING AND PERSIST THROUGH MOST OF THE AFTERNOON BEFORE CLOUD COVER CLEARS THE ARA THIS EVENING. NORTHEAST WINDS WILL BE AROUND 20KT AT MOST TAF SITES THROUGH THE MORNING WITH GUSTS TO AROUND 30KT POSSIBLE. WIND SHOULD DIMINISH A LITTLE THIS AFTERNOON...THEN BECOME LIGHT AND VARIABLE THIS EVENING. 67 PREV DISCUSSION... /ISSUED 448 AM CDT SUN MAR 23 2008/ DISCUSSION... SHOWER ACTIVITY HAS BEEN INCREASING IN COVERAGE THIS EASTER SUNDAY NORTH OF THE PECOS RIVER. STEEP LAPSE RATES AND MUCAPE NEAR 300 J/KG HAVE BEEN SUFFICIENT FOR ISOLATED SEVERE THUNDERSTORMS ACROSS THIS AREA SINCE MIDNIGHT. STORM INTENSITY SHOULD BEGIN DROP OFF AFTER SUNRISE AS INSTABILITY AXIS BEGINS TO DIMINISH. SHOWERS WILL CONTINUE DURING THE DAY ACROSS THE PERMIAN BASIN AND SOUTHEASTERN NEW MEXICO AS WARM AIR ADVECTION WILL ENHANCE THIS ACTIVITY. RAIN SHOULD BEGIN TO TAPER OFF THIS EVENING FROM NORTHWEST TO SOUTHEAST. HIGHS TODAY WILL BE WELL BELOW AVERAGE AS COLD AIR CONTINUES TO PUSH IN FROM THE NORTHWEST AND OVERCAST CONDITIONS CONTINUE THROUGH THE AFTERNOON. IN ADDITION... NORTHEAST WINDS WILL BE AROUND 20 MPH AREAWIDE AND HIGH WINDS ARE EXPECTED ACROSS THE GUADALUPE MOUNTAINS. TUESDAY THROUGH FRIDAY WILL BE BRING WARMER TEMPERATURES BACK TO THE AREA. EXPECTING HIGHS BE INTO THE LOW TO MID 80S BY MIDWEEK AS WESTERLY FLOW RETURNS. BY THE END OF THE DAY...RAINFALL SHOULD HELP TO RELIEVE DRY CONDITIONS THAT HAVE PLAGUED THE AREA OVER THE LAST FEW MONTHS. FIRE CONCERNS WILL AGAIN BE ELEVATED THIS WEEK AS WEST WINDS INCREASE AND DRY AIR RETURNS TO THE WESTERN PORTIONS OF THE CWA. DEPENDING ON HOW MUCH RAIN FALLS TODAY AND WHAT AREAS RECEIVE APPRECIABLE AMOUNTS...THE FIRE DANGER MAY BE A LITTLE LESS THAN OF LATE. BY THE END OF THIS WEEK...UPPER LEVEL FLOW WILL BEGIN TO AMPLIFY AS THE NEXT TROUGH TRAVERSES ACROSS THE U.S. MODELS ARE SUGGESTING ANOTHER STRONG COLD FRONT TO MOVE THROUGH THE AREA LATE IN THE WEEK BUT THE TIMING OF THIS FRONT IS STILL A LITTLE UP IN THE AIR. ATTM NOT EXPECTING ANY PRECIP THROUGH NEXT WEEKEND AS GULF MOISTURE WILL BE CUT OFF BY STRONG WESTERLY WINDS FOR MOST OF THE AREA. && .MAF WATCHES/WARNINGS/ADVISORIES... NM...NONE. TX...HIGH WIND WARNING FROM 10 AM THIS MORNING TO NOON MDT TODAY FOR THE FOLLOWING ZONES...GUADALUPE MOUNTAINS. && $$ 06/21 tx AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 1040 AM CDT SUN MAR 23 2008 .UPDATE...RUC ANALYZED/WV IMAGERY DEPICTS A 400MB VORT MAX ACROSS CENTRAL TX GENERATING HIGH CLOUDS ACROSS SOUTH TEXAS. STILL THINK THE ATMOSPHERE IS TOO DRY (PER 12Z CRP SOUNDING) AND THE FORCING IS TOO WEAK TO GENERATE ANY PRECIP ACROSS THE REGION TODAY. WILL MAINTAIN THE SILENT 10 POPS IN THE GRIDS AS A RESULT. AT THE SURFACE...PRESSURE GRADIENT IS STARTING TO TIGHTEN AS HIGH PRESSURE BUILDS INTO THE PANHANDLES. SOME REGIONAL TCOON OBS IN THE BAYS ARE REPORTING 20KT WINDS WITH HIGHER GUSTS. DECIDED TO UPDATE THE CWF TO HOIST SCA FLAGS FOR THE BAYS UNTIL THIS AFTERNOON WHEN THE HIGH PRESSURE CENTER SHOULD BE IN WEST TEXAS AND THE GRADIENT RELAXES SOMEWHAT ACROSS THE COASTAL WATERS. ALSO UPDATED THE ZFP TO INCREASE WIND SPEEDS ACROSS THE NORTHERN CWA PER CURRENT OBS/TRENDS. OTHERWISE...THE REMAINING WEATHER ELEMENTS ARE IN GOOD SHAPE. UPDATED PRODUCTS HAVE BEEN SENT. && .PREV DISCUSSION... /ISSUED 407 AM CDT SUN MAR 23 2008/ SHORT TERM (TODAY THROUGH MONDAY)...MODELS ALL SIMILAR WITH BRINGING A WEAK AND RELATIVELY PRECIP-FREE FRONT THROUGH THE REGION THIS MORNING. NAM IS A LITTLE SLOWER WITH THE FRONT THAN THE GFS. HAVE COMPRISED TO A MIDDLE OF THE ROAD SOLUTION...SIMILAR TO THE SREF. THUS...THINK THE WINDS WILL BEGIN TO INCREASE FROM N TO S AROUND 15Z TODAY...WITH THE FRONT SOUTH OF THE REGION AFT 18Z. EXPECT BREEZY NE WINDS OF 15-25 MPH TODAY. MOISTURE AND LARGE SCALE LIFT TOO LIMITED TO ALLOW FOR ANY SIGNIFICANT PRECIP CHANCES. THUS HAVE LEFT 10% POPS. ALL MODELS SHOWING MOSTLY CLOUDY CONDITIONS TODAY...WITH MOISTURE TRAPPED AROUND 5K FT (~850 MB). ALREADY SEEING LOW LEVEL MOISTURE MOVING INTO THE SOUTHERN CWA. EXPECT MOSTLY CLOUDY CONDITIONS TO PERSIST TONIGHT...THEN CLOUDS DECREASE BY MONDAY AFTERNOON. ALTHOUGH TIMING IS ONLY SLIGHTLY DIFFERENT BETWEEN THE NAM AND GFS...MOS GUIDANCE IS QUITE DIFFERENT FOR MAXES TODAY. MAINTAINED A COMPROMISE BETWEEN THE MUCH WARMER NAM AND COOLER GFS. COOLER TONIGHT WITH LOWS IN THE 40S...EXCEPT 50S NEAR THE COAST. THESE TEMPS WILL BE 10-12 DEGS BELOW NORMAL. BY MONDAY...GIVEN THAT THE DAY WILL AT LEAST START MOSTLY CLOUDY AND THERE WILL BE STILL SOME WEAK COLD ADVECTION...HAVE KEPT COOLER TEMPS IN THE UPPER 60S TO LOWER 70S. LOW LEVEL FLOW IS EXPECTED TO VEER TO MORE EASTERLY BY LATE DAY. MARINE...WINDS ARE EXPECTED TO INCREASE TO LOW END SCA LEVELS BETWEEN 15 AND 18Z TODAY OVER THE GULF (SCEC BAYS)...WITH SCA CONDITIONS PERSISTING INTO MONDAY AFTERNOON. WINDS AND SEAS WILL GRADUALLY DECREASE BY LATE MONDAY BELOW SCA LEVELS. HAVE LEFT SCA UP THROUGH 21Z MONDAY MAINLY DUE TO SEAS REMAINING NEAR 7FT OVER THE GULF. AVIATION...A LITTLE SURPRISINGLY THIS MORNING LRD CIGS HAVE DROPPED TO MVFR LEVELS. EXPECT THIS TO PERSIST THROUGH MID MORNING...THEN RAISE BACK TO VFR. ALL AREAS GENERALLY EXPECTED TO HAVE VFR CONDITIONS TODAY AND TONIGHT...WITH CIGS AOB 35K FT. NOT EXPECTING ANY PROBLEMS WITH SIGNIFICANT FOG THIS MORNING. COULD BE A BRIEF PERIOD THROUGH 13Z TODAY WITH VSBYS 3-5SM IN BR. FIRE WEATHER...BECOMING DRIER AND BREEZY TODAY...BUT RH AND WINDS ARE EXPECTED TO REMAIN BELOW RED FLAG LEVELS. CONTINUED DRY ON MONDAY...BUT WINDS ARE EXPECTED TO BE LIGHTER. LONG TERM (MONDAY NIGHT THROUGH SATURDAY)...THE GFS/NOGAPS/ECMWF CONVERGE WITH RESPECT TO THE UPPER PATTERN INCLUDING AN UPPER SYSTEM PROGD TO MOVE ACRS THE PLAINS LATE FRI/SAT. YET...THE GFS PROGS SIGNIFICANTLY GREATER AMPLITUDE WITH RESPECT TO THIS SYSTEM...RESULTING IN A FROPA SAT. HWR...GIVEN THE SPREAD IN THE 500MB ENSEMBLES NOT CONFIDENT THAT FROPA WL OCCUR THIS FAR SOUTH. THUS...WL MAINTAIN ONSHORE FLOW DRG THE PERIOD. ALTHOUGH THE GFS PROGS A REGION OF MSTR TO ENTER THE SWRN GULF TDA THEN EVENTUALLY INTO THE CWFA BY TUE...GOES SOUNDER DATA INDICATES THAT THE REGION OF ENHANCED PW VALUES DID NOT ADVANCE DRG THE PAST 24 HRS. NOT SURE IF THE MSTR RETURN WL OCCUR BY TUE. THUS...REMOVE THE POPS FOR TUE. ALTHOUGH MSTR WL LIKELY ENTER THE REGION AFTERWARD...THE GFS MAINTAINS A SIGNIFICANT THERMODYNAMIC CAP DRG THE THU-SAT PERIOD. THUS...WL MAINTAIN DRY CONDITIONS. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 71 50 71 58 74 / 10 10 0 10 10 VICTORIA 70 45 69 51 72 / 10 10 0 10 10 LAREDO 74 52 74 60 82 / 10 10 10 10 10 ALICE 71 48 71 53 76 / 10 10 0 10 10 ROCKPORT 70 52 68 59 71 / 10 10 0 10 10 COTULLA 71 46 72 52 78 / 10 10 0 10 10 KINGSVILLE 71 49 71 57 75 / 10 10 10 10 10 NAVY CORPUS 71 55 67 60 72 / 10 10 0 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY UNTIL 4 PM CDT MONDAY FOR THE FOLLOWING ZONES: COASTAL WATERS BAFFIN BAY TO PORT ARANSAS OUT 20 NM...COASTAL WATERS PORT ARANSAS TO MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS BAFFIN BAY TO PORT ARANSAS 20 TO 60 NM... WATERS PORT ARANSAS TO MATAGORDA SHIP CHANNEL 20 TO 60 NM. SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR THE FOLLOWING ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT ARANSAS...BAYS AND WATERWAYS FROM PORT ARANSAS TO PORT O`CONNOR. && $$ TM/95...UPDATE tx AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX 101 PM CDT SAT MAR 22 2008 .UPDATE... MINOR CHANGES HAVE BEEN MADE TO THE CURRENT FORECAST. WINDS AND DEW POINTS HAVE BEEN ADJUSTED BASED ON CURRENT OBSERVATIONAL TRENDS AND THE LATEST RUC13 DATA. WE HAVE ALSO ADDED A MENTION OF ISOLATED THUNDERSTORMS AFTER 21Z ACROSS THE WESTERN LOW ROLLING PLAINS AND EASTERN PERMIAN BASIN...MAINLY EAST OF A LAMESA TO GARDEN CITY LINE. LAPSE RATES REMAIN RATHER STEEP IN THIS REGION AS DAYTIME HEATING AND MOISTURE RETURN COMMENCE THROUGH THE AFTERNOON. FOR NOW...HAVE KEPT POPS LOW AND WILL ONLY MENTION ISOLATED THUNDERSTORMS IN THE FORECAST. && .AVIATION... OVERALL...THE CURRENT TAF FORECASTS ARE IN GOOD SHAPE AND GENERALLY MINOR CHANGE HAVE BEEN MADE. VFR CONDITIONS WILL PREVAIL THROUGH THIS EVENING WITH A GRADUAL INCREASE IN MID AND UPPER LEVEL CLOUDS. EAST WINDS WILL ALSO GRADUALLY INCREASE THROUGH THIS AFTERNOON AND INTO THE EARLY EVENING...WITH SUSTAINED WIND SPEEDS AT OR ABOVE 12KTS FOR MOST SITES AROUND 00Z. A STRONG COLD FRONT WILL BACK WINDS TO THE NORTHEAST LATE THIS EVENING AND OVERNIGHT WITH SPEEDS INCREASING TO 15 TO 20KT AND GUSTS TO NEAR 30 KT...PARTICULARLY AT KHOB...KINK AND KMAF. THESE STRONGER WINDS WILL PERSIST THROUGH MUCH OF SUNDAY MORNING...WITH MVFR CEILINGS EXPECTED AT ALL TAF SITES BY 23/12Z. THE CHANCE OF THUNDERSTORMS WILL INCREASE AFTER 23/06Z...AT KHOB AND KMAF...THEN INTO THE KINK AND KPEQ TERMINALS AFTER 09Z. FOR NOW...WE HAVE KEPT THUNDER OUT OF THE KFST AND KCNM TERMINALS AS THESE SITES WILL BE REMOVED FROM THE GREATEST INSTABILITY. SOME OF THE STORMS COULD PRODUCE HAIL...WITH THE BETTER CHANCES OF HAIL PRODUCING STORMS CONFINED TO TERMINALS EAST OF THE PECOS RIVER. MVFR CIGS WILL LIKELY CONTINUE AT ALL TERMINALS THROUGH 18Z TOMORROW. && .PREV DISCUSSION... /ISSUED 638 AM CDT SAT MAR 22 2008/ AVIATION... VFR CONDITIONS WILL PREVAIL THROUGH THIS EVENING. EASTERLY WINDS WILL INCREASE TO AROUND 10KT MOST TAF SITES THIS AFTERNOON...THEN TO AROUND 15KT THIS EVENING. A STRONG COLD FRONT WILL BACK WINDS TO THE NORTHEAST LATE TONIGHT WITH SPEEDS INCREASING TO 15 TO 20KT AND GUSTS TO NEAR 30 KT...PARTICULARLY AT KHOB...KINK AND KMAF. THESE STRONGER WINDS WILL LAST THROUGH MUCH OF SUNDAY MORNING. MVFR CEILINGS ARE EXPECTED TO DEVELOP OVER...OR MOVE INTO...ALL TAF SITES BY 23/12Z. THE CHANCE OF THUNDERSTORMS WILL INCREASE AFTER 23/06Z AT KHOB AND KMAF...THEN AT THE REST OF THE TAF SITES THROUGH 23/12Z. SOME OF THE STORMS COULD PRODUCE HAIL. PREV DISCUSSION... /ISSUED 418 AM CDT SAT MAR 22 2008/ DISCUSSION... THE FRONT THAT MOVED THROUGH THE AREA AND STALLED ALONG THE DAVIS AND GUADALUPE MOUNTAINS HAS BECOME DIFFUSED. TEMPERATURES TODAY WILL BE SIMILAR TO YESTERDAY IF NOT A FEW DEGREES COOLER. MID/HIGH LEVEL CLOUDS WILL BEGIN INFILTRATING THE NORTHERN HALF OF THE CWA THIS AFTERNOON WHICH MIGHT KEEP TEMPS DOWN SOMEWHAT. OTHERWISE... LITTLE ACTIVITY IS EXPECTED DURING THE DAY. SOUTHEASTERLY SURFACE AND 850MB WINDS TODAY WILL BEGIN INCREASING MOISTURE ACROSS WEST TEXAS. CONVECTION THEN IS EXPECTED TO DEVELOP ACROSS SOUTHEASTERN NEW MEXICO AND MOVE SOUTHEASTWARD ACROSS THE PERMIAN BASIN AND WESTERN LOW ROLLING PLAINS. GFS AND NAM ARE SUGGESTING LAPSE RATES TO BE 7-8 C/KM AND LI/S AROUND -4. 0-6 KM SHEAR NEAR 40 KTS WOULD BE CONDUCIVE FOR A FEW SEVERE THUNDERSTORMS TO DEVELOP WITH THE MAIN THREAT BEING HAIL. A STRONG COLD FRONT WILL THEN PUSH THROUGH ON SUNDAY MORNING. BY THAT TIME PRECIP SHOULD BE IN THE FORM OF SHOWERS INSTEAD OF THUNDERSTORMS IN RESPONSE TO LESS INSTABILITY AVAILABLE. TEMPERATURES DURING THE DAY SUNDAY WILL BE SIGNIFICANTLY COOLER BEHIND THIS FRONT AS OVERCAST CONDITIONS WILL ACCOMPANY THIS FRONT. EXPECT THE QPF TO BE HIGHER OVER EASTERN PORTIONS OF THE CWA. SHOWERS WILL BEGIN TAPERING OFF SUNDAY NIGHT AS THE SYSTEM MOVES SOUTHEASTWARD. TEMPERATURES WILL REBOUND QUICKLY DURING THE WEEK WITH THE RETURN OF WEST TO SOUTHWEST WINDS. EXPECT HIGHS TO BE IN THE 80S FOR MUCH OF THE AREA BY MIDWEEK AND RELATIVE HUMIDITY DROPPING BACK INTO THE LOW 20S OVER THE EAST AND SINGLE DIGITS OVER THE WESTERN HALF OF THE AREA. THEREFORE...FIRE WEATHER CONCERNS WILL AGAIN BE THE MAIN FOCUS. FIRE WEATHER... ALTHOUGH RECOVERY THIS MORNING WAS FAIR TO GOOD AREAWIDE...RH/S WILL DROP TO THE 5 TO 10 PERCENT RANGE AGAIN FROM THE GUADALUPE MOUNTAINS AND ADJACENT SOUTHEAST NEW MEXICO PLAINS...SOUTH THROUGH THE UPPER TRANS PECOS...VAN HORN AREA...MARFA PLATEAU...DAVIS MOUNTAINS... PRESIDIO VALLEY AND BIG BEND REGION. HOWEVER...20 FOOT WIND SPEEDS ARE EXPECTED TO REMAIN BELOW 20 MPH THROUGH THE DAY. WINDS WILL PICK UP OUT OF THE EAST THIS EVENING...THEN NORTHEAST OVERNIGHT AS COLDER AIR MOVES INTO THE AREA. FIRE WEATHER CONCERNS WILL BE MUCH LESS THROUGH SUNDAY NIGHT AND EVEN MONDAY AS MINIMUM RH/S WILL BE WELL ABOVE 15 PERCENT SUNDAY AFTERNOON...AND 20 PERCENT AT THE LEAST MONDAY AFTERNOON. DRIER AIR WILL MOVE INTO THE AREA TUESDAY AS WINDS INCREASE FROM THE SOUTHWEST. SPEEDS DO NOT LOOK STRONG ENOUGH AT THIS TIME FOR ANY CRITICAL FIRE WEATHER CONDITIONS THOUGH. WEDNESDAY MAY BE A CRITICAL FIRE WEATHER DAY THOUGH AS WINDS COULD INCREASE FURTHER AND THE DRY AIR REMAINS OVER THE AREA. && .MAF WATCHES/WARNINGS/ADVISORIES... NM...NONE. TX...NONE. && $$ 06 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SEATTLE WA 300 PM PDT SAT MAR 22 2008 .SYNOPSIS...A VIGOROUS COLD FRONT WILL BRING RAIN AND BREEZY CONDITIONS LATE TONIGHT AND SUNDAY AS IT MOVES THROUGH WESTERN WASHINGTON. A RATHER COLD UPPER LEVEL TROUGH IN THE NORTHEAST PACIFIC AND MOIST ONSHORE FLOW WILL GIVE COOL AND UNSETTLED CONDITIONS THROUGH NEXT WEEK. && .SHORT TERM...A NICE LOOKING COLD FRONT OFFSHORE THIS AFTERNOON. IT ISN`T TAPPED IN TO A GREAT DEAL OF MOISTURE LIKE YOU SEE IN EARLY WINTER OR ANYTHING IN FACT THERE ISN`T MUCH OF A FRONT EXTENDING SOUTH OF 40N BUT RATHER JUST A SKINNY ROPE CLOUD VISIBLE. WHILE IT IS A FAR CRY FROM A NOV/DEC SYSTEM BUOY5 IS UP TO 30KT SO FAR AND THERE ARE GALE FORCE SOUTHERLIES IN THE MM5 OVER THE COASTAL WATERS AND PERHAPS THE NORTHERN WATERS AS WELL BY 12Z SUNDAY. THE MM5GFS ALSO SHOWS A GOOD SHOT OF WESTERLY GALES DEVELOPING LATER IN THE AFTERNOON COASTAL WATERS AND STRAIT...ON THE 4KM MM5GFS THERE IS QUITE A LULL BETWEEN FROPA AROUND PUGET SOUND AT 15Z AND THE DEVELOPMENT OF THE WESTERLY GALES OVER THE COASTAL WATERS LATER IN THE AFTERNOON...WHICH ARE ASSOCIATED WITH A VIGOROUS SURFACE TROUGH. I HAVE ISSUED A SNOW ADVISORY FOR SUNDAY THRU SUNDAY NIGHT FOR THE MOUNTAINS...IT WILL BE MORE WINTERLIKE AT WHITE PASS AND PARADISE AND HURRICANE RIDGE. NOT SO BAD ON THE LOWER PASSES STEVENS AND SNOQUALMIE WHERE THE SNOW MAY NOT STICK TO THE ROADS DURING THE DAY. BUT COLD AIR DOES FOLLOW THE TROUGH SUNDAY NIGHT WITH A SNOW LEVEL FALLING TO 1500 FEET OR SO WITH A BETTER CHANCE OF HEAVIER SNOW SHOWERS IN THE MOUNTAINS AS THE WESTERLIES DEVELOP. SHOWERS AND ONSHORE FLOW THRU MONDAY NIGHT. 19 .LONG TERM...THE GFS IS WET EVERY DAY. MAY NOT BE AS BAD AS THAT BUT RATHER SHOWERY. UNSTABLE AIR MASS SO CLOUDS WILL BREAK UP AT TIMES. CERTAINLY NOT IN FOR A STRETCH OF WARM ADVECTION THAT WOULD PUT STABLE DRIZZLY CONDITIONS IN HERE. STILL...IT WILL BE CHILLY WITH A SNOW LEVEL OF 1500 FEET...OR LOWER IN THE NIGHT AND MORNING HOURS IN HEAVIER SHOWERS. SPRINGTIME INSOLATION SHOULD PREVENT ANY LASTING ACCUMULATION BELOW 1500 FEET. GFS 500MB TEMP IN THE -32C TO -36C RANGE ALL NEXT WEEK. SOME GRAUPEL OR ICE PELLETS EVEN IN THE LOWLANDS. GFS HAS -40C 500MB POSSIBLY WORKING IN OVER BRITISH COLUMBIA LATER IN THE WEEK...YOU DON`T SEE THAT TOO OFTEN IN LATE MARCH. MM5 EXTENSION HAD SOME SNOW ACCUMULATION FROM TIME TO TIME IN THE LOWLANDS...MOSTLY WITH A FEATURE THAT AFFECTED THE SOUTHWEST INTERIOR ON ONE DAY. HOWEVER EVERYTHING WILL HAVE TO SET UP JUST RIGHT. MORE LIKELY ONLY SNOWFLAKES IN HEAVY SHOWERS...MAYBE IN THE PSCZ ONE DAY...AND BEST CHANCE ON THE FOOTHILLS. OTHERWISE TOO EARLY TO SAY. DID DROP THE MAX TEMPS A COUPLE DEGREES AS 50F HIGHS WILL BE A STRUGGLE. MAY HAVE TO LOWER THE MIN TEMPS AS WELL TUE-FRI DEPENDING ON AMOUNT OF ONSHORE FLOW. 19 && .AVIATION...UPPER LEVEL RIDGE MOVED INTO EASTERN WA THIS AFTERNOON WITH CLOUDS INCREASING ACROSS W WA...AHEAD OF ADVANCING COLD FRONT. IR AND RUC ANALYSIS SHOW THE FRONT RIGHT ABOUT 130W AT 22Z. THIS FRONT WILL HEAD DUE EAST THIS EVENING WITH PRECIP REACHING THE COAST BY 06-09Z. FROPA FOR THE COAST WILL AROUND 12Z...AND 15Z FOR THE INTERIOR. ONSHORE FLOW AND UNSTABLE AIRMASS WILL LEAD TO NUMEROUS SHOWERS ACROSS WESTERN WA SUNDAY AFTERNOON/EVENING. KSEA...CLOUDS WILL INCREASE THIS EVENING AS COLD FRONT OFFSHORE APPROACHES WA. LIGHT AND VARIABLE WINDS WILL SWITCH TO SELY AS WELL. PRECIP TIMING LOOKS TO BE ABOUT 09-12Z WITH FROPA AROUND 15Z. RAIN AT TIMES WILL LEAD TO LOWER CIGS FROM OVC020-030 DURING THE MORNING. NUMEROUS SHOWERS EXPECTED DURING THE AFTERNOON AND EVENING. 33 && .MARINE...A 997 MB SFC LOW LOCATED OFF THE BC COAST WILL HEAD NE TOWARD THE QUEEN CHARLOTTES THIS EVENING...WITH SELY FLOW INCREASING ACROSS WA. EXPECTING GALES ACROSS THE COASTAL WATERS AND WEST ENTRANCE OF JDF WITH SMALL CRAFT ADVISORIES FOR THE INTERIOR WATERS THIS EVENING. COLD FRONT WITH THIS SYSTEM WILL PASS THROUGH THE COASTAL WATERS OVERNIGHT WITH FROPA ABOUT 12Z...AND 15Z FOR THE INTERIOR. WESTERLY ONSHORE FLOW WILL INCREASE SUN AFTERNOON AND EVENING AS ANOTHER SHORTWAVE TROUGH PASSES THROUGH. THIS SYSTEM WILL PROVIDE A PRETTY GOOD WLY PUSH THROUGH THE STRAIT AND HOISTED ANOTHER SMALL CRAFT ADVISORY FOR NOW...WILL TO TO WATCH FOR POTENTIAL GALES WITH ANY GUSTS. ONSHORE FLOW AND UNSETTLED WEATHER REMAINS THROUGH EARLY NEXT WEEK. 33 && .SEW WATCHES/WARNINGS/ADVISORIES... .SNOW ADVISORY FOR THE OLYMPICS AND CASCADES SUNDAY AND SUNDAY NIGHT. .GALE WARNING COAST AND WEST ENTRANCE THIS EVENING. .SMALL CRAFT ADVISORY EAST ENTRANCE...ADMIRALTY INLET...NORTHERN INLAND WATERS AND PUGET SOUND/HOOD CANAL THIS EVENING. .SMALL CRAFT ADVISORY CENTRAL STRAIT SUN AFTERNOON. .SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR CONDITIONS. $$ WEATHER.GOV/SEATTLE wa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREEN BAY WI 322 AM CDT SUN MAR 23 2008 .SYNOPSIS...FLOW AT HIGH LATITUDES WL REMAIN QUITE BLOCKY THROUGHOUT THE FCST PERIOD. FARTHER S ACRS THE CONUS...UPR TROF OVER THE E WL FINISH AMPLIFYING DURING THE NEXT DAY OR SO...THEN EXPECT THE FLOW TO FLATTEN BACK INTO A SEASONABLY STG BAND OF WESTERLIES BY MID- WK. THE FLOW FCST REAMPLIFY DURING THE LATTER PART OF THE WK...AT THE SAME TIME THAT TROF NEW PROGRESSES EWD ACRS THE PLAINS. NWLY UPR FLOW INTO THE ERN CONUS TROF WL KEEP TEMPS SUBSTANTIALLY BLO NORMAL EARLY IN THE FCST PERIOD. TEMPS LATER IN THE FCST WL DEPEND ON THE LCN OF FRONTAL BOUNDARY THAT SETS UP ALONG THE SRN EDGE OF THE WESTERLIES. RIGHT NOW IT APPEARS THAT WL BE S OF THE AREA...SO READINGS LIKELY TO REMAIN AT LEAST SOMEWHAT BLO NORMAL. WIDESPREAD LGT PCPN EVENT EXPECTED MON NGT AS THE FLOW FLATTENS AND WARMER AIR ALOFT STARTS TO RETURNS TO THE AREA. THE LIKELIHOOD OF A SIG PCPN EVENT LATER IN THE WEEK WAS INCREASING. LOOKS LIKE A STG BUT SLOW MOVG FRONTAL ZONE WL SET UP FM THE PLAINS INTO THE LOWER GREAT LAKES RGN AS THE UPR FLOW STARTS TO BACK SW AHEAD OF DEVELOPING TROF OVER THE ROCKIES/PLAINS. MED RANGE MODELS STILL NOT IN GOOD AGREEMENT ON TIMING...BUT IN BETTER AGREEMENT ON OVERALL EVOLUTION OF THE PATTERN. LOOKS LIKE ONE SHOT OF PCPN WITH INITIAL SFC WV RIDING ALONG THE FRONT...WITH THE POSSIBILITY OF A SECOND SHOT AS MAIN SFC SYSTEM LIFTS NEWD TOWARD THE LOWER GREAT LAKES. SWLY UPR FLOW WL BRING GULF MOISTURE INTO PLAY...SO PCPN AMNTS COULD BE SUBSTANTIAL. THE BULK OF THE GUID SUGGESTS PCPN WOULD BE SNOW... BUT THAT CAN GET TRICKY THIS LATE IN THE YEAR. && .SHORT TERM...TDA/TNG/MON. WK DISTURBANCE WL SLIDE SE ACRS THE AREA TDA. MODELS...ESP RUC...SEEM TO HAVE PICKED UP ON LINGERING DRY AIR AT LOW-LEVELS ACRS THE AREA. THAT FIT WELL WITH AREA AIRCRAFT SOUNDINGS FM YDA EVENING. GIVEN WK FORCING AND LTD MOISTURE TO START WITH...TOUGH TO GO FOR MORE THAN JUST A CHC S-/S--. SOME FZDZ REPORTED OUT TO THE WEST OVERNIGHT...BUT GIVEN WE HAVE THE DRY AIR AT LOW-LEVELS THAT SHOULDN/T BE A CONCERN HERE. STLT LOOP INDICATED VIRTUALLY CLOUD-FREE AIR MASS N OF LAKE SUPERIOR. SO...GOT MORE AGGRESSIVE IN DECR CLDS LATER TDA/TNGT. MAY NEED TO DECR SKYCON FURTHER...ESP IF WE DON/T GET ANY CLDS OFF LAKE SUPERIOR. HIGH CLDS SHOULD INCR FM THE W AGAIN MON AFTN. TEMPS DID NOT FALL OFF VERY MUCH SO FAR EARLY THIS MORNING. WK FRONTAL BOUNDARY SHOULD START TO WORK S ACRS THE AREA DURING THE NEXT COUPLE HRS...AND THAT MAY ALLOW FOR A BIGGER DROP ACRS THE N. IN ANY CASE...TEMPS RUNNING ABV 3 HOURLY GUID...SO WENT A LITTLE ABV GUID FOR HIGHS FOR MUCH OF THE AREA FOR TDA. .LONG TERM...MONDAY NITE THRU SATURDAY. FORECAST FOCUS ON SYSTEM AFFECTING THE REGION EARLY AND LATE PART OF THE WORK WEEK. MODELS ARE FAIRLY CONSISTENT WITH THE CLIPPER SYSTEM MOVING THRU LAKE SUPERIOR MONDAY NITE AND TUESDAY. THE BRUNT OF THE PRECIP WITH THIS SYSTEM WILL BE AHEAD OF IT MONDAY NITE WITH WARM AIR ADVECTION SNOWFALL. A QUICK 1 TO 3 INCHES OF SNOW IS EXPECTED MONDAY NITE AS THE LOW QUICKLY INTO THE WESTERN GREAT LAKES. SNOWFALL AMOUNTS WILL DEPEND ON THE SPEED OF THE LOW AND HOW MUCH MOISTURE THE SYSTEM PICKS UP...HOWEVER 1 TO 3 INCHES SEEMS TO ENCOMPASS THE HIGHER AND LOWER ENDS OF THE MODEL SOLUTIONS. MUCH OF THE MOISTURE WILL BE EAST OF THE CWA ON TUESDAY...SO NOT MUCH ADDITIONAL ACCUMULATION IS EXPECTED. THE BEST CHANCE FOR ADDITIONAL SNOW WILL BE ACROSS THE NORTH WHERE A SECONDARY VORT MAX SWINGS THRU...HOWEVER SURFACE TEMPERATURES WILL LIMIT ADDITIONAL SNOW ACCUMULATIONS AS A RAIN/SNOW MIX IS EXPECTED. A STRONGER LOW PRESSURE SYSTEM TAKES AIM FOR THE WESTERN GREAT LAKES IN LATE IN THE WEEK. DESPITE DIFFERENCES IN THE TIMING OF THE LOW...THE MODELS SEEM TO AGREE ON A LOW PRESSURE SYSTEM MOVING THRU NORTHERN ILLINOIS EITHER THURSDAY OR THURSDAY NITE. THE CANADIAN IS THE QUICKEST TO MOVE THE SYSTEM THRU...WHILE THE GFS MOVES THE SYSTEM THRU THE SLOWEST. THE TRACK OF THE LOW SUGGESTS NORTHERN WISCONSIN COULD SEE SEVERAL INCHES OF MEASURABLE SNOW AS GFS BUFKIT SOUNDINGS ARE MOSTLY BELOW FREEZING WHEN THE BRUNT OF THE PRECIP COMES THRU. HOWEVER THE MODELS THEMSELVES HAVE BEEN HOPPING AROUND A BIT...ESPECIALLY THE ECMWF...SO WILL ONLY MAKE MINOR CHANGES TO THE PREVIOUS FORECAST AT THIS TIME. && .AVIATION...SOME MVFR CONDITIONS ARE POSSIBLE ACRS THE N FOR A TIME THIS MORNING. OTHERWISE...MVFR CONDITIONS SHOULD BE MAINLY W OF THE AREA...WTIH PRIMARILY VFR CONDTIONS ACRS THE AREA TDA AND TNGT. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SKOWRONSKI/KURIMSKI wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 253 AM MDT MON MAR 24 2008 .DISCUSSION... 252 AM MDT MON MAR 24 2008 UPPER FLOW IS NORTHWEST INITIALLY AND THEN TRANSITIONS TO ZONAL FLOW BY TUESDAY NIGHT AND CONTINUES THROUGH WED NIGHT. A SURFACE TROUGH WILL BE OVER EASTERN COLORADO THIS MORNING AND SHIFT INTO WESTERN KANSAS THIS AFTERNOON/EVENING. A FRONT WILL PUSH SOUTH INTO NORTHWEST KANSAS EARLY TUESDAY MORNING FOLLOWED BY HIGH PRESSURE. ANOTHER TROUGH WILL MOVE INTO EASTERN COLORADO WEDNESDAY NIGHT. SUBSIDENCE AND LACK OF MOISTURE WILL KEEP POPS NIL THROUGH THIS ENTIRE FORECAST. FIRE WEATHER CONCERNS DEAL WITH WHAT TO DO WITH THE CURRENT FIRE WEATHER WATCH. RELATIVE HUMIDITY VALUES BY BOTH THE NAM/RUC ARE LOW ENOUGH IN THE AFTERNOON TO JUSTIFY A WARNING. THE GFS HAS HIGHER RH VALUES SLIGHTLY ABOVE CRITERIA. THE MAIN ISSUE IS WHETHER THE WIND WILL BE STRONG ENOUGH. WITH A SURFACE TROUGH COMING OVERHEAD DURING MAX HEATING DO NOT EXPECT WINDS TO BE AS STRONG. ACCORDING THE BUFKIT DATA THE MAX WIND THAT CAN BE MIXED DOWN WOULD BE 15KTS OR ABOUT 17 MPH. THIS IS NOT QUITE UP TO THE 25 MPH REQUIRED. ALTHOUGH THE WATCH COULD BE CANCELED...PLAN TO KEEP IT GOING AND THE DAY SHIFT CAN ISSUE THE WARNING IN THE MORNING IF IT LOOKS MORE LIKELY THAT WINDS WILL BE PICKING UP. COORDINATION WITH SURROUNDING OFFICES INDICATES CONSENSUS ON NOT ISSUING THE RED FLAG WARNING DUE TO MARGINAL WIND. STRATUS MAY BE POSSIBLE TUESDAY MORNING ACROSS NORTHERN ZONES BEHIND THE FRONT. 850MB TEMPERATURES RISE INTO THE MID TEENS TODAY. ON TUESDAY A COLD FRONT COMES INTO THE FORECAST AREA TUESDAY WITH SOME COOLER TEMPERATURES IN THE EASTERN ZONES. MAX TEMPERATURES TODAY SHOULD BE IN THE LOWER 70S COOLING TO THE UPPER 60S BY WEDNESDAY. MIN TEMPERATURES SHOULD BE IN THE LOWER 30S. FS && .AVIATION...FOR THE 06Z TAFS... VFR CONDITIONS WILL CONTINUE THE NEXT 24 HOURS. EXPECT SOUTHWEST WINDS 15-25 KNOTS TO DEVELOP AFTER 15Z. ML && .GLD WATCHES/WARNINGS/ADVISORIES... KS...FIRE WEATHER WATCH FROM 10 AM MDT /11 AM CDT/ THIS MORNING THROUGH THIS AFTERNOON FOR KSZ001>004-013>016-027>029-041- 042. NE...FIRE WEATHER WATCH FROM 10 AM MDT /11 AM CDT/ THIS MORNING THROUGH THIS AFTERNOON FOR NEZ079>081. CO...FIRE WEATHER WATCH FROM 10 AM MDT THIS MORNING THROUGH THIS AFTERNOON FOR COZ252>254. && $$ WFO GOODLAND ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 1210 AM MDT MON MAR 24 2008 .DISCUSSION...NORTHWEST MID/UPPER FLOW CONTINUES ACROSS THE CENTRAL HIGH PLAINS WHILE H5 RIDGE CONTINUES TO TRANSLATE EAST/SOUTHEAST TOWARD THE CENTRAL ROCKIES. THE SHORT TERM CONCERN WILL BE THE POSSIBILITY FOR CRITICAL FIRE WEATHER CONDITIONS DEVELOPING MONDAY AFTERNOON AS DISCUSSED IN THE FIRE WEATHER SECTION BELOW. A CONTINENTAL POLAR AIRMASS WILL BUILD SOUTH ACROSS THE CENTRAL AND NORTHERN PLAINS ON TUESDAY AND THE CHALLENGE WILL BE DETERMINING IMPACT FROPA WILL HAVE ACROSS THE TRI-STATE AREA. THE COLDEST AIR WILL BE DIRECTED EAST OF THE AREA WHILE SOME CONCERN EXISTS FOR LIGHT PRECIPITATION DEVELOPING TUESDAY NIGHT INTO EARLY WEDNESDAY. 295-305K PRESSURE ADVECTION WITH CONVERGENT LOW LEVEL MOIST FLOW IN VICINITY OF WARM FRONT SUPPORTS INCREASING CLOUDS/POPS BUT CONFIDENCE IN ADDING PRECIPITATION REMAINS TO LOW. MAXIMUM TEMPERATURES MAY SURGE INTO THE 70S WEST OF SFC TROUGH AXIS WED AFTERNOON WHERE DEEPER VERTICAL MIXING IS ANTICIPATED LEADING TO THE POSSIBILITY FOR ADDITIONAL FIRE WEATHER CONCERNS. THURSDAY THROUGH SUNDAY...THERE CONTINUES TO BE CONSIDERABLE DISAGREEMENT ON THE TRACK AND TIMING OF THE MID WEEK EXTRATROPICAL CYCLONE. THE GFS IS ABOUT 18 HOURS SLOWER THAN THE ECMWF AND GEM IN THE PROGRESSION OF THE LOW FROM THE HIGH PLAINS TO THE GREAT LAKES REGION. THE GFS IS SLOWER BECAUSE IT SHOWS A VERY DEEP AND INTENSE CUTOFF LOW AT 500MB...WHICH SEAMS SUSPECT CONSIDERING THE 500MB PATTERN LATELY. THE CURRENT PROGRESSIVE PATTERN WOULD TEND TO FAVOR THE MORE PROGRESSIVE BUT LESS AMPLIFIED GEM. AS A RESULT...THE FORECAST INCLUDES SLIGHT CHANCE POPS BETWEEN 00Z AND 12Z FRIDAY...AND TEMPERATURES REBOUNDING QUICKER THAN THE GFS IS ADVERTISING. && .FIRE WEATHER...LATEST RUNS OF THE HIGH RESOLUTION RUC13 SUGGEST RED FLAG CRITERIA COULD BE REACHED IN A LARGE PORTION OF THE FORECAST AREA MONDAY AFTERNOON. CRITICAL RH VALUES APPEAR LIKELY...WHILE WIND SPEEDS WILL BE A BIT MORE MARGINAL. HOWEVER...WITH DEEP MIXING FORECAST AT PEAK HEATING...FEEL POTENTIAL EXISTS FOR GUSTY WINDS REACHING THE 25 MPH CRITERIA FOR RED FLAG. && .AVIATION...FOR THE 06Z TAFS... VFR CONDITIONS WILL CONTINUE THE NEXT 24 HOURS. EXPECT SOUTHWEST WINDS 15-25 KNOTS TO DEVELOP AFTER 15Z. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...FIRE WEATHER WATCH FROM 10 AM MDT /11 AM CDT/ THIS MORNING THROUGH THIS AFTERNOON FOR KSZ001>004-013>016-027>029-041- 042. NE...FIRE WEATHER WATCH FROM 10 AM MDT /11 AM CDT/ THIS MORNING THROUGH THIS AFTERNOON FOR NEZ079>081. CO...FIRE WEATHER WATCH FROM 10 AM MDT THIS MORNING THROUGH THIS AFTERNOON FOR COZ252>254. && $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CARIBOU ME 335 AM EDT MON MAR 24 2008 .SYNOPSIS... AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE REGION TODAY AND EXIT INTO NEW BRUNSWICK THIS EVENING. HIGH PRESSURE WILL RESET ITSELF OVER THE AREA TONIGHT AND SLIDE EAST OF THE REGION ON TUESDAY. LOW PRESSURE WILL APPROACH FROM THE WEST TUESDAY NIGHT AND TRACK WELL NORTH OF THE STATE ON WEDNESDAY. HIGH PRESSURE WILL RETURN FOR THURSDAY AND FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... MAIN FOCUS WILL BE S/WV AFFECTING THE CWA TODAY AND TEMPERATURES TONIGHT. UA ANALYSIS SHOWS 55-60KT JET FROM 700-500MBS DIVING DOWN ACROSS THE NORTHERN GREAT LAKES INTO THE TROF THIS MORNING. THIS FEATURE IS PICKED UP WELL ON THE LATEST IR/WV SATL IMAGERY. SOME SNOW SHOWERS SETTING OFF ACROSS LAKES ERIE AND ONTARIO IN RESPONSE TO THE S/WV. LATEST GFS AND SREF MATCHING UP W/THIS FEATURE AS WELL AS THE RUC13. THEREFORE...STARTED OUT THE GRIDS W/THE RUC13 AS THE BACKGROUND AND THEN LOADED IN THE GFS/SREF FOR POPS THIS AFTERNOON. A COLD START TO THE MORNING W/MANY SITES ACROSS NORTHERN MAINE BLO ZERO. CARIBOU SET A RECORD LOW ON THE 23RD W/-6F WHICH WAS SET BEFORE MIDNIGHT. AIRMASS PRETTY DRY GIVEN DEWPOINTS ACROSS THE NORTH AND WEST BLO ZERO THIS MORNING. HOWEVER...LOOKING AT THE 850MB ANAL INDICATING MOISTURE W/DEWPOINT DEPRESSIONS 3 DEGS OR LESS OVER ONTARIO. THIS AIRMASS WILL BE ADVECTED EASTWARD TODAY W/CLOUDS INCREASING BY 18Z. INCREASED THE POPS FROM THE PREVIOUS SET W/AREAL COVERAGE IN THE SCATTERED CATEGORY (40-50%). SNOW WILL BE OF A FINE NATURE WILL ACCUMS NO MORE THAN AN INCH AT BEST AND THIS COULD BE PUSHING IT. USED A 12:1 RATIO AND BLENDED HPC W/THE GFS FOR QPF WHICH LEADS TO AROUND .03-.05" LIQUID EQUIVALENT. THIS WILL NEED TO BE MONITORED TODAY. HPC QPF LOOKED A BIT OVERDONE AND THAT IS THE REASON FOR THE BLEND W/THE GFS AS IT IS RUNNING LIGHTER W/ITS QPF. S/WV EXITS INTO NEW BRUNSWICK THIS EVENING W/SKIES CLEARING PRETTY QUICKLY. CLR SKIES TONIGHT AND LIGHT WINDS WILL LEAD TO ANOTHER VERY COLD NIGHT FOR LATE MARCH. DAYCREW/S TEMPERATURES FOR TONIGHT LOOKED GOOD AND DECIDED TO RUN W/THEM GIVING FAR NORTHERN AND NORTHWESTERN AREAS -15F OR COLDER. CAR...PQI...HUL WILL MOST LIKELY COME IN NEAR RECORD LOWS. WILL ADD THIS WORDING TO THE FCST TONIGHT. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... TUESDAY WILL BEGIN COLD AGAIN ACROSS MUCH OF THE AREA. HOWEVER... WITH PARTIAL SUNSHINE OVER MUCH OF THE REGION AND TEMPS MODERATING IN THE BOUNDARY LAYER...TEMPS BY AFTERNOON WILL RISE TO NEAR FREEZING OVER THE NORTH AND MID 30S DOWNEAST. WE`LL THEN BE WATCHING A CLIPPER TYPE LOW PRESSURE SYSTEM TRACKING THROUGH SOUTHERN CANADA AND REACHING QUEBEC LATE TUESDAY NIGHT. WARM ADVECTION SNOW SHOULD SPREAD INTO THE STATE LATE TUESDAY NIGHT AND CONTINUE INTO EARLY WEDNESDAY MORNING AS THE LOW TRACKS NORTH OF THE AREA. THE SNOW IS EXPECTED TO BE LIGHT AND WITH TEMPS RISING INTO THE 30S ROAD SURFACES WILL LIKELY JUST BE WET BY AFTERNOON. A COLD FRONT FOLLOWS THE LOW WEDNESDAY NIGHT USHERING IN A RETURN OF COLDER AIR. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... A CHILLY AIRMASS IS EXPECTED TO KEEP TEMPS BELOW NORMAL LATE IN THE WEEK...BUT NOT TO THE EXTREME THAT WE`VE EXPERIENCED THE LAST FEW DAYS. WEAK RIDGING IN EASTERN CANADA SHOULD THEN BRING MODERATION TO NEAR NORMAL OVER THE WEEKEND. AT THE PRESENT TIME NO LARGE STORM SYSTEMS ARE ADVERTISED THROUGH THE COMING WEEKEND. HOWEVER...THERE IS A WEAK TROUGH AND ASSOCIATED LOW WHICH MAY BRING A CHANCE FOR SNOW SATURDAY NIGHT INTO SUNDAY. ANOTHER LOW MAY BRING SNOW OR MIXED PRECIPITATION ON TUESDAY. AT PRESENT TIME NEITHER OF THESE STORM SYSTEMS LOOK WELL ORGANIZED...BUT THIS IS THE TIME OF YEAR WHEN LONG RANGE FORECASTING CAN BE ESPECIALLY CHALLENGING WITH THE CHANGE OF SEASONS MODULATING THE WEATHER PATTERN SO THIS COULD ALWAYS CHANGE. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... VFR CONDITIONS ARE EXPECTED THROUGH TUESDAY. THE ONLY EXCEPTION WILL BE A BRIEF PERIOD OF MVFR CONDITIONS ESP FOR THE VSBYS THIS AFTERNOON W/THE SCATTERED SNOW SHOWER ACTIVITY. CONDITIONS ARE THEN EXPECTED TO LOWER TO IFR AFTER MIDNIGHT TUESDAY NIGHT IN SNOW AND REMAIN IFR IN SNOW AND RAIN SHOWERS WEDNESDAY MORNING. CONDITIONS SHOULD IMPROVE TO VFR DOWNEAST AND MVFR OVER THE NORTH LATER WEDNESDAY AND THEN BE VFR THROUGHOUT THE AREA THURSDAY INTO EARLY SATURDAY. && .MARINE... NEAR TERM: NO HEADLINES ATTM. SWELL BE GENERATED OUT THERE W/SEAS AROUND 3 FT WHICH ABOUT A FOOT ABOVE WNAWAVE. STARTED THE WAVE HEIGHTS OUT A FOOT ABOVE WNAWAVE AND THEN DROP THEM BACK BY THE AFTERNOON W/A LIGHT OFFSHORE BREEZE. SHORT TERM: AN SCA WILL LIKELY BE NEEDED VERY LATE TUESDAY NIGHT THROUGH WEDNESDAY IN RESPONSE TO LOW PRESSURE TRACKING ACROSS THE NORTH. WINDS AND SEAS SHOULD THEN BE BELOW SCA THURSDAY THROUGH SATURDAY. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...HEWITT SHORT TERM...BLOOMER LONG TERM...BLOOMER AVIATION...HEWITT MARINE...HEWITT/BLOOMER me AREA FORECAST DISCUSSION...CORRECTED NATIONAL WEATHER SERVICE MARQUETTE MI 450 AM EDT MON MAR 24 2008 .DISCUSSION... THE MAIN CONCERN IS THE SNOW AMOUNT FOR TONIGHT AND TUESDAY. WATER VAPOR IMAGERY AND RUC SHOW A LONGWAVE TROUGH OVER THE EASTERN CONUS AND A RIDGE OVER THE WESTERN CONUS. THE SHORTWAVE THAT RECENTLY CAME ONSHORE OVER NORTHERN WASHINGTON WILL IMPACT THE UPPER GREAT LAKES REGION LATE TONIGHT INTO TUESDAY. CLEAR SKIES ARE DOMINATING MOST OF THE UPPER GREAT LAKES REGION THIS MORNING...EXCEPT HIGH CLOUDS ARE INCREASING OVER LAKE SUPERIOR AND LOW CLOUDS HAVE STUCK AROUND PARTS OF SOUTHERN WI AND SOUTHERN LOWER MI. TODAY...CUT BACK ON POPS OVER LAKE SUPERIOR...KEWEENAW AND EAST OF MUNISING. THERE ARE ONLY HIGH CLOUDS OVER THE KEWEENAW PENINSULA...AND SKIES REMAIN CLEAR OVER THE EASTERN CWA. KEPT ISOLATED SNOW SHOWERS OVER THE LAKE FOR TODAY TO ACCOUNT FOR ANY LINGERING SNOW SHOWERS. TONIGHT AND TUESDAY...MODELS ARE IN FAIR AGREEMENT OF A LOW PRESSURE SYSTEM TRACKING ALONG THE U.S./CANADIAN BORDER TODAY AND TONIGHT...AND ACROSS NORTHERN LAKE SUPERIOR TUE. PCPN AMOUNTS ARE ALSO IN GOOD AGREEMENT. A WIDESPREAD SNOW UP TO 2 INCHES IS LIKELY ACROSS THE CWA TONIGHT. ANOTHER INCH IN LAKE EFFECT OVER THE WEST AND UP TO 2 INCHES OVER THE EAST WITH THE LINGERING SYSTEM ARE POSSIBLE ON TUE. THEREFORE...INCREASED POPS FOR EARLY TONIGHT. THE SYSTEM SHOULD MAKE IT INTO THE WEST HALF BY 06Z AND CONCENTRATE ON THE EAST HALF AFTER 06Z. MODELS AGREE THAT A "DRY SLOT" WILL INTERFERE WITH PCPN FROM 12Z TO 18Z...SO BACKED OFF POPS OVER INTERIOR WEST HALF ALONG THE WI BORDER. KEPT CHC RAIN OR SNOW IN SOUTHERN PART OF CWA TUE AFTERNOON FOR NOW DUE TO THE EXPECTED HIGH TEMPS AROUND 40F. HOWEVER...WITH THE PASSAGE OF COLD FRONT...ANY RAIN WILL CHANGE BACK OVER TO SNOW PRETTY QUICKLY. 850MB TEMPS IMMEDIATELY BEHIND THE FRONT ARE AROUND -7C AND RAPIDLY DROP OFF TO -13C. WITH TEMPS THAT COLD...LES SHOULD LINGER BEHIND THE SYSTEM THROUGH TUESDAY NIGHT. WEDNESDAY...GFS IS HINTING AT A SHORTWAVE PRODUCING SNOW ACROSS THE ENTIRE CWA WED AFTERNOON. WILL NOT JUMP ON THE LATEST RUN...BUT NEXT SHIFTS WILL NEED TO KEEP AN EYE ON THIS. FOR NOW...KEPT CHC LES MAINLY ACROSS NORTH HALF OF CWA. THURSDAY...ECMWF AND GFS BOTH TRACK A MOISTURE-PACKED LOW PRESSURE SYSTEM WELL TO THE SOUTH OF OUR CWA. IN COORDINATION WITH GRB AND DLH...DECREASED POPS TO AROUND 30 FOR THU AFTERNOON. && .AVIATION (FOR THE 06Z TAF ISSUANCE)... DRY AIR AND SUBSIDENCE WILL KEEP MAINLY CLEAR SKIES AND VFR CONDITIONS OVERNIGHT WITH ONLY A FEW HIGH CLOUDS MOVING THROUGH THE REGION. MID CLOUDS WILL INCREASE LATE IN THE DAY AHEAD OF A LOW PRESSURE SYSTEM MOVING TOWARD THE REGION. IN ADDITION...STRONG S TO SW FLOW MAY ALSO RESULT IN LOW LEVEL WIND SHEAR BY LATE EVENING. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... MAIN CONCERN IS ON SRLY GALES DEVELOPING TONIGHT AS LOW PRESSURE TRACKS TOWARD THE UPPER LAKES REGION. WELL AHEAD OF THE SYSTEM...SW WINDS WILL INCREASE TODAY INTO THE 20-30KT RANGE OVER MUCH OF LAKE SUPERIOR. PRES GRADIENT TIGHTENS FURTHER TONIGHT AS LOW MOVES CLOSER. WITH ASSISTANCE OF MAX PRESSURE FALLS PASSING ACROSS THE AREA...SRLY WINDS WILL LIKELY INCREASE TO GALES BY LATE EVENING OVER ROUGHLY THE E HALF OF LAKE SUPERIOR. GALES WILL ALSO OCCUR IN THE NEARSHORE WATERS E OF MUNISING...ESPECIALLY AROUND GRAND MARAIS WHICH TYPICALLY EXPERIENCES STRONG WINDS WITH SRLY FLOW. GRADIENT WILL SLACKEN SUFFICIENTLY FOR GALES TO END BY LATE TUE MORNING. AS THE LOW HEADS E TUE NIGHT...A PERIOD OF NW GALES WILL LIKELY OCCUR DURING THE EVENING...AGAIN MAINLY OVER THE E HALF OF LAKE SUPERIOR. WINDS SHOULD REMAIN UNDER 25KT FROM WED AFTN THRU FRI. OVER THE NRN LAKE MICHIGAN NEARSHORE WATERS (EXCLUDING THE BAY OF GREEN BAY)...SETUP LOOKS ESPECIALLY FAVORABLE FOR GALES TONIGHT INTO TUE MORNING AS TRACK OF MAX PRES FALLS JUST N OF LAKE MICHIGAN PROVIDES AN ADDED BOOST TO WINDS. NOT OUT OF THE QUESTION THAT HIGH END GALE FORCE GUSTS COULD OCCUR AT SOME POINT BTWN ABOUT 06Z AND 12Z TUE. IN THE WAKE OF THE LOW...NW WINDS TUE NIGHT SHOULD GENERALLY BE IN THE 15-25KT RANGE. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN...NONE LAKE SUPERIOR...GALE WARNING 11 PM THIS EVENING TO 10 AM EDT TUE LSZ250-251-266-267. LAKE MICHIGAN...GALE WARNING MIDNIGHT TONIGHT TO NOON EDT TUE LMZ248-250. && $$ DISCUSSION...MRC AVIATION...JLB MARINE...ROLFSON mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 125 AM EDT MON MAR 24 2008 UPDATED FOR 06Z AVIATION DISCUSSION .SHORT TERM(TONIGHT AND MONDAY)... THE LATEST MSAS ANALYSIS SUGGESTS RIDGING ACROSS LAKE SUPERIOR...EXTENDING FROM THE MAIN SFC RIDGE ACROSS THE PLAINS. MEANWHILE...A WEAK SHORT WAVE ALOFT IS MOVING SE ACROSS LAKE SUPERIOR PER WATER VAPOR IMAGERY. THE SUBSIDENCE AND NVA MOVING OVER THE LAKE COMBINED WITH THE CONSIDERABLE DRY ADVECTION /SFC DWPTS IN NW ONTARIO WELL BELOW ZERO/ SHOULD SIGNIFICANTLY DIMINISH THE LAKE EFFECT SNOW THIS EVENING...ESPECIALLY AS THE WINDS BACK TO THE NORTHWEST. HOWEVER DUE TO THE UPSLOPE COMPONENT EARLY THIS EVENING COMBINED WITH LOW LAKE-AIR STABILITY /850MB TEMP -16C/...WILL CONTINUE TO CARRY LIKELY POPS IN A SMALL AREA FROM SHOT POINT EAST TO GRAND MARAIS WHERE THE RUC SUGGESTS SOME ENHANCED CONVERGENCE AS THE WINDS BACK AROUND. HOWEVER...ANY ACCUMULATIONS SHOULD HOLD LESS THAN AN INCH. AS THE WINDS BACK AROUND TONIGHT...THERE IS A POSSIBILITY THAT THE KEWEENAW PENINUSLA WILL SEE SOME ENHANCEMENT OVERNIGHT. BEST CHANCE FOR THIS TO OCCUR WOULD BE NORTH OF HOUGHTON...AND HAVE OPTED TO KEEP CHANCE POPS IN THAT AREA FOR THE ENTIRE NIGHT. HOWEVER...WITH THE COMBINATION OF DRY AIR AND STRONG SUBSIDENCE IT SEEMS UNLIKELY THAT THERE WILL BE MUCH ORGANIZATION TO THE ACTIVITY. OTHERWISE...IT SHOULD BE A FAIRLY QUIET BUT COLD NIGHT ACROSS UPPER MICHIGAN. WITH LIGHT WINDS AND A FRESH SNOW COVER IN SOME PLACES...AM THINKING THAT SOME INLAND AREAS WILL SEE TEMPS DROP TO ZERO TO 5 ABOVE TONIGHT. IF IT CAN CLEAR OUT FASTER THAN FORECAST TEMPS COULD DROP MORE THAN THAT. MONDAY SHOULD BE A QUIET DAY BEFORE THE NEXT CLIPPER SYSTEM MONDAY NIGHT/TUE MORNING. WITH THE W-SW FLOW...CANNOT RULE OUT A CHANCE OF SNOW SHOWERS NORTH OF HOUGHTON ALTHOUGH 850MB TEMPS WILL BE MARGINAL /ONLY AROUND -9C/ AND SYNOPTIC SCALE SUBSIDENCE WILL BE STRONG. NONETHELESS...WILL CARRY A SMALL POP THROUGH THE DAY IN THIS REGION. WILL SEE SOME INCREASING CLOUDS /ESPECIALLY ACROSS WESTERN UPPER MICHIGAN/ IN THE WARM ADVECTION AHEAD OF THIS SYSTEM AND SOUTHWEST WINDS WILL ALLOW FOR SOME DOWNSLOPE WARMING. MANY PLACES WILL BE PARTLY TO MOSTLY SUNNY ON MONDAY SO IT SHOULD BE PLEASANT ALTHOUGH A LITTLE CHILLY WITH HIGHS 30-35. .LONG TERM (MON NGT THRU SUN)... FOCUS FOR MON NIGHT-TUE TURNS TO TIMING/IMPACT OF CLIPPER SHRTWV MOVING ESE FM SCNTRL CAN. PER NCEP GUIDANCE. MODELS NOW IN FAIRLY GOOD AGREEMENT WITH TIMING OF ASSOC SFC LOW WHICH IS PROGGED TO TRACK ACROSS NE MN AND NRN LAKE SUPERIOR TUE MORNING AND THEN MOVES NE OF LAKE SUPERIOR TUE AFTERNOON. MODELS STILL ADVERTISING FAIRLY IMPRESSIVE UPR DIV IN LEFT EXIT REGION OF SUPPORTING 120+ KT H3 JET MAX ALONG WITH IMPRESSIVE DPVA AND VIGOROUS 850-500 MB Q-VECT CONV. SHARP ISENTROPIC ASCENT ON 285-290K SFCS NOTED MON NIGHT IN ADVANCE OF THE SHORTWAVE...TRANSITIONING TO DESCENT BEHIND THE SHORTWAVE OVER WRN HALF COUNTIES BY 12Z TUE. IN GENERAL...THE TRACK OF THE LOW FAVORS THE NCNTRL AND ERN COUNTIES FOR THE HEAVIER/MORE SUSTAINED PCPN AND QPF FIELDS GENERALLY BARE THIS OUT. THE ONE THING THAT MAY LIMIT PCPN/SNOW AMOUNTS IS FAIRLY RAPID MOVEMENT OF SHORTWAVE/SFC LOW. STILL WITHMIXING RATIOS OF 3G/KG ADVECTING OVER THE AREA AND 6HR OF MORE WINDOW OF FAVORABLE ISENTROPIC ASCENT THE FAR ERN PORTION OF THE CWA MAY PUSH ADVISORY TOTALS WITH 3 INCHES OF MORE OF SNOW POSSIBLE MON NIGHT AND ANY ADDITIONAL SNOW ON TUE MORNING ALONG FRONTAL PASSAGE AND WRAPAROUND MOIST CYCLONIC FLOW IN WAKE OF THE LOW. WOULD EXPECT THE REST OF THE CWA THE GENERALLY FALL IN THE 2-4" RANGE FOR TOTAL SNOWFALL FROM THE SYSTEM. EXPECT PCPN TO GENERALLY DIMINISH BY TUE AFTN BEFORE ANOTHER SHORTWAVE RETURNS TUE EVENING AND BRINGS A REINFORCING COLD SHOT AND CHC OF ENHANCEMENT TO LES. LOOKS LIKE BULK OF PCPN WL FALL AS SN... BUT WITH SOME SUNSHINE POSSIBLE FOR SCNTRL AREAS IN DOWNSLOPING NW FLOW LLVLS MAY WARM ENOUGH TO MIX SNOW WITH SOME RAIN. ANOTHER CONCERN FOR TUE AFTN/EVENING WL BE WINDS ESPECIALLY FOR DOWNSLOPING AREAS OVER THE SRN TIER AND OVER THE KEWEENAW PENINSULA. GFS FCST SDNGS FOR MNM AND ESC SHOWS 35-40 KT WINDS WITHIN THE MIXED LYR AT BOTH MNM AND ESC. WINDS OVER THE KEWEENAW COULD REACH 30 KT BY TUE EVENING AS SECONDARY COLD FRONT MOVES THROUGH. IN THE WAKE OF TUE CLIPPER...EXPECT LES TO BE ONGOING TUE NGT INTO WED WITH 850 MB TEMPS OF -16 TO -18C MOVING OVER THE LAKE. HI PRES RDG AXIS WILL THEN MOVES OVHD WED NIGHT AND SHUT OFF THE LES. STILL PLENTY OF MODEL UNCERTAINTY WITH DEVELOPING STORM OVER THE PLAINS BY THU/FRI. HOWEVER...NCEP FAVORED BLEND OF 00Z GFS SOLN AND ENSEMBLE MEAN WHICH NOW TAKES LOW PRESSURE OVER LOWER GREAT LAKES AND OHIO VALLEY THU NIGHT AND FRI. ECMWF HAS BEEN EVEN FARTHER E WITH THIS SYSTEM THE LAST FEW RUNS. WHAT THIS MEANS FOR UPR MI IS THAT HEAVIER PCPN WILL LIKELY STAY SOUTH AND EAST OF THE CWA. BEST CHCS FOR PCPN THU NIGHT AND EARLY FRI WILL BE SCNTRL AND EAST WHERE I HAVE INCLUDED HIGH CHC POPS. ALSO WITH MORE SOUTHWARD TRACK...IT LOOKS LIKE PCPN TYPE WILL STAY ALL SNOW SO DECIDED TO TAKE OUT MIX WITH LIQUID/FREEZING PCPN FROM PREV FCST. BIG DIFFERENCE IN 850 MB TEMPS IN THE WAKE OF THIS SYSTEM FRI NIGHT INTO SAT. ECMWF MUCH WARMER THAN MORE AMPLIFIED SOLN OF GFS WHICH MORE COLD AIR SOUTHWARD BEHIND THE LOW. LEANED A BIT MORE TOWARD GFS TEMPS AND KEPT LOW CHC POPS FOR LES GOING INTO THE WEEKEND IN AREAS FAVORED BY WNW FLOW. && .AVIATION (FOR THE 06Z TAF ISSUANCE)... DRY AIR AND SUBSIDENCE WILL KEEP MAINLY CLEAR SKIES AND VFR CONDITIONS OVERNIGHT WITH ONLY A FEW HIGH CLOUDS MOVING THROUGH THE REGION. MID CLOUDS WILL INCREASE LATE IN THE DAY AHEAD OF A LOW PRESSURE SYSTEM MOVING TOWARD THE REGION. IN ADDITION...STRONG S TO SW FLOW MAY ALSO RESULT IN LOW LEVEL WIND SHEAR BY LATE EVENING. && .MARINE (FOR 4 PM LAKE FCST ISSUANCE)... AS HIGH PRES BUILDS ACROSS THE LAKE THIS EVENING...WINDS AND WAVES SHOULD RELAX QUITE RAPIDLY. HOWEVER...AS THE NEXT CLIPPER SYSTEM APPROACHES ON MONDAY AND ESPECIALLY MONDAY NIGHT...SOUTHERLY WINDS WILL INCREASE TO 15-25 KT MON AFTN AND TO GALES MONDAY NIGHT INTO TUE. BEST CHANCE FOR GALES WILL BE ACROSS THE EASTERN 1/3 OF LAKE SUPERIOR AND THE NEARSHORE OF LAKE MICHIGAN. AS THE CLIPPER PASSES BY TUE INTO TUE GALES OR NEAR GALES WILL CONTINUE THROUGH TUE EVENING. W-NW WINDS NEAR 30 KT WILL CONTINUE THROUGH WED EVENING BEFORE HIGH PRES BUILDS ACROSS THE LAKE. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS/SHORT TERM...MRD LONG TERM...VOSS AVIATION...JLB MARINE...MRD mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 1000 AM EDT MON MAR 24 2008 .SYNOPSIS... 13Z WATER VAPOR AND H4 RUC ANALYSIS SHOWING AN AMPLIFIED BUT PROGRESSIVE UPPER PATTERN ACROSS THE CONUS THIS MORNING. THE PATTERN IS SIMPLIFIED TO GENERAL TROUGHING IN THE EAST AND RIDGING UPSTREAM OVER THE WEST. TROUGHING IN THE EAST IS ANCHORED BY THE POLAR VORTEX OVER NORTHERN QUEBEC WITH AN AXIS RUNNING SOUTHWARD THROUGH THE EASTERN GREAT LAKES...THEN DOWN THE SPINE OF THE APPALACHIANS TO THE NORTHEAST GULF OF MEXICO. POTENT PIECE OF MID LEVEL SHORTWAVE ENERGY IS EMBEDDED WITHIN THE TROUGH DIVING SOUTHEAST OUT OF THE MIDDLE MISSISSIPPI VALLEY. THIS PIECE OF ENERGY WILL MAKE AN UNEVENTFUL PASS THROUGH OUR FORECAST AREA THIS AFTERNOON AND EARLY EVENING. THE RIDGING FURTHER UPSTREAM ACROSS THE WEST RUNS ALONG AN AXIS FROM THE NORTHERN PLAINS STATES TO THE FOUR CORNERS REGION. AT THE SURFACE...ARCTIC FRONT IS NOW WELL TO OUR SOUTH INTO THE CENTRAL AND SOUTHERN PORTIONS OF THE FLORIDA PENINSULA. NORTHERLY FLOW BEHIND THIS BOUNDARY IS DELIVERING QUITE A COOL AND DRY AIRMASS TO THE REGION. STRONG 1032MB SURFACE HIGH PRESSURE HAS DROPPED DOWN INTO THE LOWER MISSISSIPPI VALLEY AND WILL BE MOVING EAST TOWARD OUR AREA INTO THE EVENING HOURS. TEMPERATURES ACROSS THE AREA CURRENTLY RUNNING IN THE 40S TO NEAR 50 WITH DEWPOINTS IN THE 20S. && .DISCUSSION... POTENT MID LEVEL SHORTWAVE WILL CROSS THE FORECAST AREA THIS AFTERNOON BEFORE EXITING OFF THE SOUTHEAST COAST THIS EVENING. LARGE SWATH OF MID/HIGH LEVEL CLOUDS ASSOCIATED WITH THIS TROUGH AND A 120KT UPPER LEVEL JET WILL EXIT TO THE EAST OF THE FORECAST AREA THROUGH THE EARLY AFTERNOON AS JET ENERGY LIFTS TO THE NORTH AND THE EAST. THIS WILL RESULT IN A MOSTLY SUNNY AFTERNOON FORECAST AREA WIDE...OTHER THAN A FEW CU DEVELOPING ACROSS OUR NORTHERN AREAS FROM KDHN TO KABY UNDER THE COOLEST MID LEVEL AIR AND BEST SHORTWAVE ENERGY. 850MB TEMPS BEHIND LAST NIGHTS FRONT DROPPING TO AROUND -2C OVER OUR SOUTHERN ZONES AND AS LOW AS -4C TO THE NORTH. VERY UNUSUAL AIRMASS FOR LATE MARCH ACROSS OUR AREA. THESE TEMPS ARE AROUND 3.0 STANDARD DEVIATIONS FROM NORMAL FOR THE END OF MARCH. IN CLEARER TERMS...THIS MEAN THAT THERE IS ONLY AROUND A 4% PROBABILITY OF OCCURRENCE FOR THIS COLD AN AIRMASS BASED ON CLIMATOLOGY. THE RESULT WILL BE AFTERNOON HIGH TEMPS FROM 10 TO 15 DEGREES BELOW NORMAL. IT WILL FEEL EVEN COOLER AS GUSTY NORTHERLY WINDS DEVELOP OVER THE NEXT FEW HOURS. SURFACE RIDGE BUILDS EAST THIS EVENING BEFORE SETTLING OVERHEAD DURING THE SECOND HALF OF THE NIGHT. WITH THE HIGH IN CLOSE PROXIMITY WIND WILL BECOME VERY LIGHT AND COMBINE WITH THE COOL AND DRY AIRMASS TO PRODUCE A GOOD RADIATIONAL COOLING SETUP. THIS IS GOING TO RESULT IN A VERY COLD NIGHT FOR LATE MARCH. FREEZE WATCHES ARE IN EFFECT FOR THE ENTIRE AREA AWAY FROM THE IMMEDIATE COAST AT THIS TIME AND MAY BE UPGRADED TO FREEZE WARNINGS WITH THE AFTERNOON FORECAST PACKAGE. NOT EXPECTING A BLANKET FREEZING SCENARIO BUT CERTAINLY NORMALLY COOLER LOCATIONS UNDER RADIATIONAL SETUPS WILL HAVE A CHANCE TO DROP A FEW DEGREES BELOW 32 FOR A COUPLE HOURS LATE TONIGHT INTO EARLY TUESDAY MORNING. URBAN CENTERS WILL LIKELY BOTTOM OUT CLOSER TO THE MIDDLE 30S...HOWEVER THE SUBTLETIES OF RADIATIONAL COOLING SAY THAT NO AREA SHOULD COMPLETELY LET THEIR GUARD DOWN IN DEALING WITH SENSITIVE VEGETATION. OF NOTE THE RECORD LOW FOR MARCH 25TH AT THE TALLAHASSEE REGIONAL AIRPORT IS 28F SET IN 1968. HIGH PRESSURE REMAINS PARKED OVERHEAD FOR THE DAY ON WEDNESDAY. MID-LEVEL COOL POOL EXITS EAST EARLY IN THE DAY WITH 850MB TEMPS REBOUNDING TO BETWEEN 4C AND 7C BY EARLY EVENING. WHILE STILL EXPECTING BELOW NORMAL HIGHS...TEMPS SHOULD BE ABLE TO REACH THE MIDDLE AND UPPER 60S. THE BIG DIFFERENCE WILL BE THE LACK OF WIND ALLOWING IT TO FEEL SIGNIFICANTLY WARMER ON TUESDAY AFTERNOON THAN IT WILL THIS AFTERNOON. && .AVIATION... VFR CONDITIONS TO PREVAIL ACROSS AREA THROUGH THE NEXT FEW DAYS AS STRONG HIGH PRESSURE SETTLES OVER AREA. DRY LOW LEVEL AIR WILL PREVENT ANY FOG FORMATION OVERNIGHT. SURFACE WINDS ALL TERMINALS WILL CONTINUE NORTHERLY TODAY WITH SOME GUSTS NEAR 20KTS. WINDS WILL CLOCK AROUND TO NORTHEASTERLY AND NOT AS STRONG TUESDAY. && .MARINE... SMALL CRAFT ADVISORY CONDITIONS CONTINUE ACROSS THE MARINE AREA WITH NORTHERLY WINDS BETWEEN 20 AND 25 KNOTS THIS MORNING. SEAS AS THE BUOY SOUTH OF PANAMA CITY HAVE BEEN AVERAGING AROUND 8FT. GUIDANCE IN AGREEMENT OF A SLIGHT DECREASE IN WINDS DURING THE AFTERNOON HOURS (POSSIBLY JUST BELOW ADVISORY LEVELS FOR A SHORT TIME) BEFORE COMING BACK UP TO BETWEEN 20 AND 25 KNOTS THIS EVENING. WILL KEEP THE CURRENT ADVISORY THROUGH TONIGHT GOING DESPITE THE BRIEF LETUP TO AVOID CONFUSION. WINDS AND SEAS SHOULD COME DOWN SIGNIFICANTLY TUESDAY MORNING/EARLY AFTERNOON AS HIGH PRESSURE SETTLES JUST TO THE NORTH. MAY SEE AN INCREASE IN WINDS TUESDAY NIGHT WHICH IS A NORMAL OCCURRENCE UNDER EASTERLY FLOW...HOWEVER THIS INCREASE LOOKS TO REMAIN BELOW HEADLINE CRITERIA. && .FIRE WEATHER... THERE IS EXCELLENT AGREEMENT AMONG THE VARIOUS GUIDANCE AND UPSTREAM OBSERVATIONS TO SUPPORT A WIDESPREAD RED FLAG EVENT TODAY...DUE TO THE COMBINATION OF GUSTY NORTH WINDS AND LOW RELATIVE HUMIDITY. ALTHOUGH THE WINDS WILL BE MUCH LIGHTER TUESDAY...THE RELATIVE HUMIDITY WILL BE JUST AS LOW SO RED FLAG CONDITIONS ARE LIKELY AGAIN. && .TAE WATCHES/WARNINGS/ADVISORIES... AL...FREEZE WATCH FROM LATE TONIGHT THROUGH TUESDAY MORNING FOR THE FOLLOWING ZONES: COFFEE...DALE...GENEVA...HENRY...HOUSTON. LAKE WIND ADVISORY FROM 7 AM THIS MORNING TO 7 PM CDT THIS EVENING FOR THE FOLLOWING ZONES: COFFEE...DALE...GENEVA... HENRY...HOUSTON. FIRE WEATHER WATCH TUESDAY AFTERNOON FOR THE FOLLOWING ZONES: COFFEE...DALE...GENEVA...HENRY...HOUSTON. RED FLAG WARNING FROM NOON TODAY TO 6 PM CDT THIS AFTERNOON FOR THE FOLLOWING ZONES: COFFEE...DALE...GENEVA...HENRY... HOUSTON. GA...FREEZE WATCH FROM LATE TONIGHT THROUGH TUESDAY MORNING FOR THE FOLLOWING ZONES: BAKER...BEN HILL...BERRIEN...BROOKS... CALHOUN...CLAY...COLQUITT...COOK...DECATUR...DOUGHERTY... EARLY...GRADY...IRWIN...LANIER...LEE...LOWNDES...MILLER... MITCHELL...QUITMAN...RANDOLPH...SEMINOLE...TERRELL... THOMAS...TIFT...TURNER...WORTH. LAKE WIND ADVISORY FROM 8 AM THIS MORNING TO 8 PM EDT THIS EVENING FOR THE FOLLOWING ZONES: BAKER...BEN HILL... BERRIEN...BROOKS...CALHOUN...CLAY...COLQUITT...COOK... DECATUR...DOUGHERTY...EARLY...GRADY...IRWIN...LANIER... LEE...LOWNDES...MILLER...MITCHELL...QUITMAN...RANDOLPH... SEMINOLE...TERRELL...THOMAS...TIFT...TURNER...WORTH. FIRE WEATHER WATCH TUESDAY AFTERNOON FOR THE FOLLOWING ZONES: BAKER...BEN HILL...BERRIEN...BROOKS...CALHOUN...CLAY... COLQUITT...COOK...DECATUR...DOUGHERTY...EARLY...GRADY... IRWIN...LANIER...LEE...LOWNDES...MILLER...MITCHELL... QUITMAN...RANDOLPH...SEMINOLE...TERRELL...THOMAS...TIFT... TURNER...WORTH. RED FLAG WARNING FROM 1 PM THIS AFTERNOON TO 7 PM EDT THIS EVENING FOR THE FOLLOWING ZONES: BAKER...BEN HILL... BERRIEN...BROOKS...CALHOUN...CLAY...COLQUITT...COOK... DECATUR...DOUGHERTY...EARLY...GRADY...IRWIN...LANIER... LEE...LOWNDES...MILLER...MITCHELL...QUITMAN...RANDOLPH... SEMINOLE...TERRELL...THOMAS...TIFT...TURNER...WORTH. FL...FREEZE WATCH FROM LATE TONIGHT THROUGH TUESDAY MORNING FOR THE FOLLOWING ZONES: BAY...CALHOUN...COASTAL WALTON...DIXIE... FRANKLIN...GADSDEN...GULF...HOLMES...INLAND WALTON... JACKSON...JEFFERSON...LAFAYETTE...LEON...LIBERTY... MADISON...TAYLOR...WAKULLA...WASHINGTON. LAKE WIND ADVISORY FROM 8 AM EDT /7 AM CDT/ THIS MORNING TO 8 PM EDT /7 PM CDT/ THIS EVENING FOR THE FOLLOWING ZONES: BAY... CALHOUN...COASTAL WALTON...DIXIE...FRANKLIN...GADSDEN... GULF...HOLMES...INLAND WALTON...JACKSON...JEFFERSON... LAFAYETTE...LEON...LIBERTY...MADISON...TAYLOR...WAKULLA... WASHINGTON. FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY EVENING FOR THE FOLLOWING ZONES: BAY...CALHOUN...DIXIE... FRANKLIN...GADSDEN...GULF...HOLMES...INLAND WALTON... JACKSON...JEFFERSON...LAFAYETTE...LEON...LIBERTY... MADISON...TAYLOR...WAKULLA...WASHINGTON. RED FLAG WARNING FROM 9 AM EDT /8 AM CDT/ THIS MORNING TO 10 PM EDT /9 PM CDT/ THIS EVENING FOR THE FOLLOWING ZONES: BAY... CALHOUN...DIXIE...FRANKLIN...GADSDEN...GULF...HOLMES... INLAND WALTON...JACKSON...JEFFERSON...LAFAYETTE...LEON... LIBERTY...MADISON...TAYLOR...WAKULLA...WASHINGTON. GM...SMALL CRAFT ADVISORY UNTIL 8 AM EDT TUESDAY FOR THE FOLLOWING ZONES: APALACHEE BAY OR COASTAL WATERS FROM KEATON BEACH TO OCHLOCKONEE RIVER FL OUT TO 20 NM...COASTAL WATERS FROM OCHLOCKONEE RIVER TO APALACHICOLA FL OUT TO 20 NM...COASTAL WATERS FROM SUWANNEE RIVER TO KEATON BEACH OUT 20 NM... COASTAL WATERS FROM APALACHICOLA TO DESTIN FL OUT 20 NM... WATERS FROM SUWANNEE RIVER TO APALACHICOLA FL FROM 20 TO 60 NM...WATERS FROM APALACHICOLA TO DESTIN FL FROM 20 TO 60 NM. && $$ PUBLIC/MARINE...MROCZKA AVIATION...GOREE FIRE WX...FOURNIER fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 526 AM MDT MON MAR 24 2008 .DISCUSSION...UPPER FLOW IS NORTHWEST INITIALLY AND THEN TRANSITIONS TO ZONAL FLOW BY TUESDAY NIGHT AND CONTINUES THROUGH WED NIGHT. A SURFACE TROUGH WILL BE OVER EASTERN COLORADO THIS MORNING AND SHIFT INTO WESTERN KANSAS THIS AFTERNOON/EVENING. A FRONT WILL PUSH SOUTH INTO NORTHWEST KANSAS EARLY TUESDAY MORNING FOLLOWED BY HIGH PRESSURE. ANOTHER TROUGH WILL MOVE INTO EASTERN COLORADO WEDNESDAY NIGHT. SUBSIDENCE AND LACK OF MOISTURE WILL KEEP POPS NIL THROUGH THIS ENTIRE FORECAST. FIRE WEATHER CONCERNS DEAL WITH WHAT TO DO WITH THE CURRENT FIRE WEATHER WATCH. RELATIVE HUMIDITY VALUES BY BOTH THE NAM/RUC ARE LOW ENOUGH IN THE AFTERNOON TO JUSTIFY A WARNING. THE GFS HAS HIGHER RH VALUES SLIGHTLY ABOVE CRITERIA. THE MAIN ISSUE IS WHETHER THE WIND WILL BE STRONG ENOUGH. WITH A SURFACE TROUGH COMING OVERHEAD DURING MAX HEATING DO NOT EXPECT WINDS TO BE AS STRONG. ACCORDING THE BUFKIT DATA THE MAX WIND THAT CAN BE MIXED DOWN WOULD BE 15KTS OR ABOUT 17 MPH. THIS IS NOT QUITE UP TO THE 25 MPH REQUIRED. ALTHOUGH THE WATCH COULD BE CANCELED...PLAN TO KEEP IT GOING AND THE DAY SHIFT CAN ISSUE THE WARNING IN THE MORNING IF IT LOOKS MORE LIKELY THAT WINDS WILL BE PICKING UP. COORDINATION WITH SURROUNDING OFFICES INDICATES CONSENSUS ON NOT ISSUING THE RED FLAG WARNING DUE TO MARGINAL WIND. STRATUS MAY BE POSSIBLE TUESDAY MORNING ACROSS NORTHERN ZONES BEHIND THE FRONT. 850MB TEMPERATURES RISE INTO THE MID TEENS TODAY. ON TUESDAY A COLD FRONT COMES INTO THE FORECAST AREA TUESDAY WITH SOME COOLER TEMPERATURES IN THE EASTERN ZONES. MAX TEMPERATURES TODAY SHOULD BE IN THE LOWER 70S COOLING TO THE UPPER 60S BY WEDNESDAY. MIN TEMPERATURES SHOULD BE IN THE LOWER 30S. FS && .AVIATION...FOR THE 12Z TAFS...ONLY CIRRUS CLOUDS ARE EXPECTED THE NEXT 24 HOURS...SO VFR CONDITIONS WILL CONTINUE. EXPECT SOUTHWEST WINDS 15-25 KNOTS TO DEVELOP AFTER 16Z. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...FIRE WEATHER WATCH FROM 10 AM MDT /11 AM CDT/ THIS MORNING THROUGH THIS AFTERNOON FOR KSZ001>004-013>016-027>029-041- 042. NE...FIRE WEATHER WATCH FROM 10 AM MDT /11 AM CDT/ THIS MORNING THROUGH THIS AFTERNOON FOR NEZ079>081. CO...FIRE WEATHER WATCH FROM 10 AM MDT THIS MORNING THROUGH THIS AFTERNOON FOR COZ252>254. && $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAKE CHARLES LA 1015 AM CDT MON MAR 24 2008 .UPDATE... AFTER A CHILLY START THIS MORNING...TEMPERATURES ARE WARMING NICELY ACROSS THE FORECAST AREA WITH CONSIDERABLE CAA USHERING IN A FAIRLY DRY AIRMASS WITH DEWPOINTS IN THE 20S AND 30S. 12Z KLCH SOUNDING SHOWS THIS WELL WITH A PWAT OF ONLY 0.29 INCHES AND A NICE NORTHERLY BACKING WIND PROFILE. DESPITE ALL OF THIS...WITH FULL SUNSHINE AND TEMPS WARMING UP QUICKLY WILL NUDGE HIGH TEMPS FOR TODAY UP A TAD...MAINLY ACROSS SOUTHEAST TEXAS ZONES. REST OF FORECAST IS ON TRACK AND NO FURTHER UPDATES ARE PLANNED. && .MARINE... MSAS ANALYSIS CONTINUES TO INDICATE SCEC CONDITIONS OVER THE NEARSHORE WATERS AND SCA CONDITIONS ACROSS THE OUTER COASTAL WATERS THIS MORNING...AND WILL EXTEND SCA THROUGH 1 PM FOR THE OUTER WATERS. 12Z RUC INDICATES WINDS WILL RAPIDLY DIMINISH THIS AFTERNOON AS HIGH PRESSURE RIDGES INTO THE AREA...AND DO NOT EXPECT TO EXTEND FLAGS PAST THE EARLY AFTERNOON HOURS. && SHAMBURGER && .PREV DISCUSSION... /ISSUED 313 AM CDT MON MAR 24 2008/ SHORT TERM... QUIET WEATHER ON TAP FOR THE NEXT 48 HOURS. SURFACE HIGH PRESSURE CENTERED OVER THE SOUTH CENTRAL PLAINS TODAY REACHES THE SOUTHEAST US COAST BY TUESDAY EVENING. WHAT STARTS OUT AS COOLER THAN NORMAL TEMPS WITH OFFSHORE FLOW SHIFTS TO NEAR NORMAL TEMPS AS WINDS SHIFT MORE TO THE SOUTH OR SOUTHEAST BY TUESDAY. NO PRECIPITATION IS EXPECTED. LONG TERM... SEASONAL TEMPERATURES MID-WEEK WARM TO ABOVE NORMAL BY THE END OF THE WORKWEEK. THE NEXT THREAT FOR RAIN STILL APPEARS TO BE LOW...ONLY AROUND 20 PERCENT...BY NEXT WEEKEND AS A COLD FRONT TRIES TO SAG SOUTHWARD ACROSS EAST TEXAS AND CENTRAL LOUISIANA...BUT LOSES STEAM AND STALLS OUT OR WEAKENS. WILL BE WATCHING MODEL TRENDS ON THIS SYSTEM THROUGH THE WEEK TO SEE IF THIS RAIN THREAT CAN BE TAKEN ANY MORE SERIOUSLY. AVIATION... VFR CONDITIONS PREVAIL TODAY. MARINE... WILL ALLOW SCA TO RUN THROUGH 15Z AND EXPIRE TODAY. STARTING TO SEE NOCTURNAL TREND OF HIGHER WINDS LATE AT NIGHT. && .PRELIMINARY POINT TEMPS/POPS... KLCH 67 45 72 58 / 0 0 0 10 KBPT 67 47 72 59 / 0 0 0 10 KAEX 63 39 74 54 / 0 0 0 10 KLFT 65 41 72 54 / 0 0 0 10 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...SMALL CRAFT EXERCISE CAUTION UNTIL 1 PM MONDAY FOR THE FOLLOWING ZONES: WATERS FROM CAMERON, LA TO HIGH ISLAND, TX EXTENDING TO 20 NM...WATERS FROM INTRACOASTAL CITY, LA TO CAMERON, LA EXTENDING TO 20 NM...AND WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL CITY, LA EXTENDING TO 20 NM. SMALL CRAFT ADVISORY UNTIL 1 PM MONDAY FOR THE FOLLOWING ZONES: WATERS FROM CAMERON, LA TO HIGH ISLAND, TX EXTENDING FROM 20 NM TO 60 NM...WATERS FROM INTRACOASTAL CITY, LA TO CAMERON, LA EXTENDING FROM 20 NM TO 60 NM...AND WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL CITY, LA EXTENDING FROM 20 NM TO 60 NM. && $$ la AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 735 AM EDT MON MAR 24 2008 UPDATED AVIATION DISCUSSION FOR 12Z TAFS .DISCUSSION... (ISSUED AT 450 AM EDT) THE MAIN CONCERN IS THE SNOW AMOUNT FOR TONIGHT AND TUESDAY. WATER VAPOR IMAGERY AND RUC SHOW A LONGWAVE TROUGH OVER THE EASTERN CONUS AND A RIDGE OVER THE WESTERN CONUS. THE SHORTWAVE THAT RECENTLY CAME ONSHORE OVER NORTHERN WASHINGTON WILL IMPACT THE UPPER GREAT LAKES REGION LATE TONIGHT INTO TUESDAY. CLEAR SKIES ARE DOMINATING MOST OF THE UPPER GREAT LAKES REGION THIS MORNING...EXCEPT HIGH CLOUDS ARE INCREASING OVER LAKE SUPERIOR AND LOW CLOUDS HAVE STUCK AROUND PARTS OF SOUTHERN WI AND SOUTHERN LOWER MI. TODAY...CUT BACK ON POPS OVER LAKE SUPERIOR...KEWEENAW AND EAST OF MUNISING. THERE ARE ONLY HIGH CLOUDS OVER THE KEWEENAW PENINSULA...AND SKIES REMAIN CLEAR OVER THE EASTERN CWA. KEPT ISOLATED SNOW SHOWERS OVER THE LAKE FOR TODAY TO ACCOUNT FOR ANY LINGERING SNOW SHOWERS. TONIGHT AND TUESDAY...MODELS ARE IN FAIR AGREEMENT OF A LOW PRESSURE SYSTEM TRACKING ALONG THE U.S./CANADIAN BORDER TODAY AND TONIGHT...AND ACROSS NORTHERN LAKE SUPERIOR TUE. PCPN AMOUNTS ARE ALSO IN GOOD AGREEMENT. A WIDESPREAD SNOW UP TO 2 INCHES IS LIKELY ACROSS THE CWA TONIGHT. ANOTHER INCH IN LAKE EFFECT OVER THE WEST AND UP TO 2 INCHES OVER THE EAST WITH THE LINGERING SYSTEM ARE POSSIBLE ON TUE. THEREFORE...INCREASED POPS FOR EARLY TONIGHT. THE SYSTEM SHOULD MAKE IT INTO THE WEST HALF BY 06Z AND CONCENTRATE ON THE EAST HALF AFTER 06Z. MODELS AGREE THAT A "DRY SLOT" WILL INTERFERE WITH PCPN FROM 12Z TO 18Z...SO BACKED OFF POPS OVER INTERIOR WEST HALF ALONG THE WI BORDER. KEPT CHC RAIN OR SNOW IN SOUTHERN PART OF CWA TUE AFTERNOON FOR NOW DUE TO THE EXPECTED HIGH TEMPS AROUND 40F. HOWEVER...WITH THE PASSAGE OF COLD FRONT...ANY RAIN WILL CHANGE BACK OVER TO SNOW PRETTY QUICKLY. 850MB TEMPS IMMEDIATELY BEHIND THE FRONT ARE AROUND -7C AND RAPIDLY DROP OFF TO -13C. WITH TEMPS THAT COLD...LES SHOULD LINGER BEHIND THE SYSTEM THROUGH TUESDAY NIGHT. WEDNESDAY...GFS IS HINTING AT A SHORTWAVE PRODUCING SNOW ACROSS THE ENTIRE CWA WED AFTERNOON. WILL NOT JUMP ON THE LATEST RUN...BUT NEXT SHIFTS WILL NEED TO KEEP AN EYE ON THIS. FOR NOW...KEPT CHC LES MAINLY ACROSS NORTH HALF OF CWA. THURSDAY...ECMWF AND GFS BOTH TRACK A MOISTURE-PACKED LOW PRESSURE SYSTEM WELL TO THE SOUTH OF OUR CWA. IN COORDINATION WITH GRB AND DLH...DECREASED POPS TO AROUND 30 FOR THU AFTERNOON. && .AVIATION (FOR THE 12Z TAF ISSUANCE)... VFR CONDITIONS WILL PREVAIL AT KCMX AND KSAW THRU THE AFTN. AHEAD OF APPROACHING LOW PRES SYSTEM TONIGHT...STRONG SRLY FLOW WILL DEVELOP. ALTHOUGH LOW-LEVEL WIND SHEAR HAS BEEN INCLUDED IN THE FCST...IT`S QUITE POSSIBLE THE LOW-LEVELS WILL REMAIN JUST MIXED ENOUGH DOWN TO THE SFC TO PREVENT DEVELOPMENT OF A WIND SHEAR LAYER. EXPECT A ROUGHLY 3-5HR PERIOD OF SN AT BOTH SITES OVERNIGHT WITH MVFR CIGS AND IFR VIS. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... MAIN CONCERN IS ON SRLY GALES DEVELOPING TONIGHT AS LOW PRESSURE TRACKS TOWARD THE UPPER LAKES REGION. WELL AHEAD OF THE SYSTEM...SW WINDS WILL INCREASE TODAY INTO THE 20-30KT RANGE OVER MUCH OF LAKE SUPERIOR. PRES GRADIENT TIGHTENS FURTHER TONIGHT AS LOW MOVES CLOSER. WITH ASSISTANCE OF MAX PRESSURE FALLS PASSING ACROSS THE AREA...SRLY WINDS WILL LIKELY INCREASE TO GALES BY LATE EVENING OVER ROUGHLY THE E HALF OF LAKE SUPERIOR. GALES WILL ALSO OCCUR IN THE NEARSHORE WATERS E OF MUNISING...ESPECIALLY AROUND GRAND MARAIS WHICH TYPICALLY EXPERIENCES STRONG WINDS WITH SRLY FLOW. GRADIENT WILL SLACKEN SUFFICIENTLY FOR GALES TO END BY LATE TUE MORNING. AS THE LOW HEADS E TUE NIGHT...A PERIOD OF NW GALES WILL LIKELY OCCUR DURING THE EVENING...AGAIN MAINLY OVER THE E HALF OF LAKE SUPERIOR. WINDS SHOULD REMAIN UNDER 25KT FROM WED AFTN THRU FRI. OVER THE NRN LAKE MICHIGAN NEARSHORE WATERS (EXCLUDING THE BAY OF GREEN BAY)...SETUP LOOKS ESPECIALLY FAVORABLE FOR GALES TONIGHT INTO TUE MORNING AS TRACK OF MAX PRES FALLS JUST N OF LAKE MICHIGAN PROVIDES AN ADDED BOOST TO WINDS. NOT OUT OF THE QUESTION THAT HIGH END GALE FORCE GUSTS COULD OCCUR AT SOME POINT BTWN ABOUT 06Z AND 12Z TUE. IN THE WAKE OF THE LOW...NW WINDS TUE NIGHT SHOULD GENERALLY BE IN THE 15-25KT RANGE. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN...NONE LAKE SUPERIOR...GALE WARNING 11 PM THIS EVENING TO 10 AM EDT TUE LSZ250-251-266-267. LAKE MICHIGAN...GALE WARNING MIDNIGHT TONIGHT TO NOON EDT TUE LMZ248-250. && $$ DISCUSSION...MRC AVIATION...ROLFSON MARINE...ROLFSON mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 1124 AM EDT MON MAR 24 2008 .SYNOPSIS... A STRONG UPPER LEVEL DISTURBANCE WILL MOVE ACROSS NORTH CAROLINA TODAY... THEN MOVE OFFSHORE THIS EVENING. HIGH PRESSURE WILL BUILD BACK OVER THE STATE TONIGHT AND TUESDAY... CONTINUING THE CHILLY TEMPERATURES. THIS HIGH WILL QUICKLY SHIFT EAST ON WEDNESDAY... BRINGING A WARMING TREND TO THE AREA MID TO LATE WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1015 AM MONDAY... KRAX RADAR IMAGERY CURRENTLY SHOWS AREA OF PRECIPITATION LIFTING SLOWLY NE ACROSS THE FORECAST AREA. LIGHT SNOW WAS REPORTED ACROSS THE TRIAD AND AROUND ROXBORO EARLIER THIS MORNING...WITH ONLY RAIN SPRINKLES AROUND THE TRIANGLE. THIS AREA OF PRECIPITATION WAS IN ASSOCIATION WITH SHARPENING MID-LEVEL S/W...COINCIDENT WITH THE RIGHT ENTRANCE REGION OF A 130 KNOT UPPER LEVEL JET EXTENDING FROM THE CENTRAL APPALACHIANS NORTHEASTWARD OFF THE MID ATLANTIC COAST. THE RUC DID A GOOD JOB EARLIER THIS MORNING WITH INDICATING GOOD 925-850MB FRONTOGENESIS ALONG THE MID-LEVEL SHEAR AXIS AND ALONG THE LEADING EDGE OF DRIER AIR...THEN SHOWS WEAKENING AS THE ASSOCIATED TROUGH AXIS SHIFTS EASTWARD INTO THE COASTAL PLAIN THIS MORNING WITH FURTHER MID-LEVEL DRY AIR ENTRAINMENT. THUS EXPECT A LULL FOR THE REMAINDER OF THE MORNING AND INTO THE AFTERNOON...UNTIL LATER THIS AFTERNOON WITH INCREASING MID-LEVEL DYNAMICS/INSTABILITY COLD POOL ASSOCIATED WITH MID LEVEL WAVE. -CBL THE PARTIAL CLEARING AND ASSOCIATED INSOLATION WILL SET THE STAGE FOR ANOTHER ROUND OF SHOWERS THIS AFTERNOON AND EVENING...AS A POSITIVELY TILTED BUT AMPLIFYING UPPER LEVEL TROUGH EXTENDING FROM THE OHIO VALLEY SOUTHWESTWARD INTO THE LOWER MS VALLEY APPROACHES. STRONG MID LEVEL HEIGHT FALLS ON THE ORDER OF 50 TO 100 METERS/12 HRS AND THE APPROACH OF THE ASSOCIATED MID LEVEL COLD POOL (H5 TEMPS B/W -30 AND -35 C) AND STEEP MID LEVEL LAPSE RATES WILL OVERSPREAD THE CWA BETWEEN 18Z AND 06Z. THOUGH DEEP LAYER MOISTURE IS RATHER LIMITED (PWATS RANGING FROM .25 TO .50" W/E ACROSS THE CWA)... BELIEVE THE COMBINATION OF SFC HEATING BENEATH THE COLD POOL ALOFT AND STRONG DPVA AHEAD OF THE AMPLIFYING TROUGH WILL OVERCOME THE OVERALL RELATIVE DRYNESS OF THE COLUMN. IN FACT... THE SHOWERS OVER THE OHIO VALLEY AND UPPER MIDWEST WITH SIMILAR PWATS SUNDAY ARE A GOOD INDICATION OF WHAT WE CAN EXPECT OVER OUR AREA TODAY. THE HEAVIER SHOWERS WILL HAVE THE POTENTIAL TO PRODUCE WIND GUSTS TO NEAR 40 MPH... AS MID LEVEL DRY ENTRAINMENT AND SUB CLOUD DIABATIC COOLING WITH INVERTED-V MODEL FORECAST SOUNDINGS WILL ENHANCE DOWNDRAFT POTENTIAL. SUCH WIND GUSTS WILL BE MOST LIKELY FROM RDU WESTWARD... WHERE NEARLY DRY ADIABATIC LOW LEVEL LAPSE RATES WILL DEVELOP WITH THE EXPECTED PARTIAL CLEARING... WHILE THE LINGERING CLOUDS IN THE EAST WILL STUNT THE DEVELOPMENT OF SUCH LOW LEVEL LAPSE RATES IN THE EAST. LASTLY... A FEW WET FLAKES COULD MIX IN WITH THE RAIN SHOWERS IF THEY PERSIST LONG ENOUGH INTO THE EVENING HOURS... WHEN THE BOUNDARY LAYER COOLS SUFFICIENTLY TO SUPPORT SOMETHING OTHER THAN ALL LIQUID. ANY FLAKES WOULD HAVE NO IMPACT GIVEN THEIR FLEETING NATURE.-MWS CONCERNING TEMPERATURES...THE OBSERVED LOW LEVEL THICKNESS AT GSO THIS MORNING WAS 1294M. WITH WEAK LOW LEVEL COLD AIR ADVECTION WILL CONTINUE THIS MORNING...AND WITH THE LINGERING CLOUD COVER OVER THE OVER EASTERN NC AND THE RE-DEVELOPMENT OF CLOUDS WITH SHARPENINIG MID-LEVEL VORT...HAVE ELECTED TO LOWER TEMPERATURES TO THE 48-52 RANGE FROM NORTH TO SOUTH. IT IS POSSIBLE THAT THESE TEMPERATURES COULD STILL BE TOO WARM IF THE CLOUD COVER DOES NOT SCATTER OUT BY EARLY AFTERNOON. -BLS/CBL AFTER LINGERING AND DISSIPATING SHOWERS THROUGH MIDNIGHT... EXPECT CLEARING AND COLDER CONDITIONS IN THE WAKE OF THE UPPER TROUGH OVERNIGHT...AS HEIGHT RISES ALOFT AND SURFACE HIGH PRESSURE BUILD ACROSS OUR AREA. EXPECT LOW TO DIP INTO THE UPPER 20S TO AROUND 30 NW TO MID 30S SE. && .SHORT TERM /TUESDAY THROUGH THURSDAY/... AS OF 245 AM MONDAY... TUESDAY THROUGH WEDNESDAY NIGHT: THE UPPER FLOW PATTERN WILL BECOME ZONAL OVER OUR AREA THIS PERIOD. THE SURFACE RIDGE AXIS SLIDES EAST TUESDAY AFTERNOON... AND ALLOWS A WEAK SOUTH SOUTHWESTERLY FLOW TO DEVELOP LATE. H85 TEMPERATURES WARM FROM ABOUT -6 TO 0 C FROM 12Z TUES TO 00Z WED WITH THE PASSAGE OF AN H85 WARM FRONT. THOUGH WE PROBABLY WILL NOT REALIZE THE FULL DEGREE OF WARM ADVECTION... HIGHS SHOULD STILL TOP OUT IN THE UPPER 50S NE TO LOWER 60S SW... UNDER MOSTLY SUNNY SKIES. THE SURFACE HIGH WILL CONTINUE OFFSHORE TUESDAY NIGHT AND WEDNESDAY... BUT CONTINUE TO EXTEND INTO THE SOUTHEASTERN US AND RESULT IN WARMING SOUTHWESTERLY LOW LEVEL FLOW THROUGH THE SHORT TERM AND BEYOND. A COLD FRONT PUSHES INTO VIRGINIA WEDNESDAY AFTERNOON... BUT STALLS AS IT ENCOUNTERS THE MID LEVEL AND SURFACE RIDGING OVER THE SOUTHEAST. HIGHS WEDNESDAY IN THE UPPER 60S TO LOW 70S. LOWS A DEGREE OR TWO BELOW THE 30 YR AVERAGE (AROUND 40 DEGREES) WEDNESDAY MORNING... THEN ABOUT 5 ABOVE THURSDAY MORNING. -MWS AT THE SURFACE... A WARM FRONT SHOULD BE WELL NORTH OF NC BEGINNING THURSDAY... WITH BERMUDA HIGH PRESSURE ESTABLISHED. THIS WILL BRING A WARM WSW FLOW ACROSS THE STATE WITH WELL ABOVE NORMAL TEMPS. WE WILL BUMP UP HIGHS INTO THE LOWER TO MID 70S THURSDAY. -BADGETT && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... S OF 1115 AM MONDAY... THE PERIOD STARTS WITH A MODERATE LONG WAVE TROUGH ALOFT ACROSS THE WESTERN CONUS AND FLAT RIDGE OFF THE EAST COAST. A SURFACE RIDGE EXTENDS FROM THE GULF STREAM ATLANTIC INTO THE GULF OF MEXICO RESULTING IN WEST SOUTHWESTERLY FLOW ACROSS CENTRAL NC. FORECAST SOUNDINGS SHOW SUBSIDENCE WARMING AND DRYING IN THE MID LEVELS WITH PREDOMINANT WESTERLY FLOW THROUGH FRIDAY. THIS SHOULD YIELD ABOVE NORMAL TEMPERATURES WITH LOWS IN THE 50S AND HIGHS WELL INTO THE 70S TO AROUND 80. FRI NIGHT-SAT...MODELS ARE REASONABLY TOGETHER IN SHOWING A COLD FRONT APPROACHING FROM THE WEST FRI NIGHT. BUT THERE EXISTS A 6-12 HOUR UNCERTAINTY IN THE MOVEMENT OF THE FRONT ACROSS CENTRAL NC GIVEN RUN-TO-RUN VARIATIONS IN THE GFS AND AMONG OTHER MEMBERS OF THE MODEL SUITE. A PREVAILING WESTERLY COMPONENT IN THE LOWER LEVEL FLOW SUGGESTS MINIMAL MOISTURE CONVERGENCE POTENTIAL EAST OF THE MOUNTAINS AND ONLY A SCATTERING OF SHOWERS ACROSS THE RAH CWA WITH THE FRONT. POPS WILL BE KEPT IN THE SLIGHT OR SMALL CHANCE RANGE OF 20-30 PERCENT...MAINLY FOR SAT. THE AIRMASS SHOULD REMAIN MILD IN THE PREFRONTAL SECTOR FRI NIGHT WITH LOWS IN THE 50S. TEMPERATURES WILL BE IN TRANSITION FOR SAT AND WITH CLOUD COVER GREATEST TO THE NW... HIGHS SHOULD RANGE FROM NEAR 70 NW TO NEAR 80 SE. SAT NIGHT-MON...MODELS SHOW CONFLUENCE IN THE UPPER FLOW PATTERN OVER THE OHIO VALLEY BY SAT NIGHT. THIS SHOULD HELP PUSH COOLER DRIER AIR QUICKLY INTO THE REGION BEHIND THE FRONT OVERNIGHT. THE REPLACING AIRMASS IS MAINLY SOUTHERN STREAM CONTINENTAL TRAVERSING FROM THE CENTRAL PLAINS UP THE OHIO VALLEY AND THEN INTO NC. THIS SHOULD MEAN COOLING TEMPERATURES TO NEAR NORMAL FOR SUN. BY MONDAY...MODELS SHOW A LARGE MERIDIONAL RIDGE DOWN THE EAST COAST FROM A 1035-1040 MB CENTER OVER NEW ENGLAND AND THE MARITIMES. THIS SHOULD MAINTAIN A DRY AIRMASS EAST OF THE APPALACHIANS...BUT POSSIBLY CIRRUS OR MID CLOUD ADVANCEMENT FROM A PROGRESSIVE TROUGH IN THE CENTRAL CONUS LATE IN THE DAY. TEMPERATURES SHOULD REMAIN NEAR NORMAL WITH LOWS IN THE LOWER TO MID 40S AND HIGHS 65-70. -RFG && .AVIATION /16Z MONDAY THROUGH FRIDAY/... AS OF 200 AM MONDAY... PATCHY LIGHT SHOWERS OF RAIN AND RAIN MIXED WITH WET SNOW CONTINUE TO REACH THE GROUND IN THE KINT/KGSO AREAS OF THE NW PIEDMONT. RADAR RETURNS WERE MOVING NORTHWARD WITH THE MOST CONCENTRATED SHOWERS SHIFTING NORTH OF THE PIEDMONT TRIAD REGION AS OF 145 AM. THERE CONTINUED TO BE MORE PATCHY LIGHT SHOWERS DEVELOPING TO THE SOUTH AND SOUTHWEST OF KINT/KGSO... WHICH WILL AFFECT THOSE AREAS THROUGH AT LEAST 09Z. COOLING ALOFT HAS LED TO A CHANCE OVER TO WET SNOW IN THE NORTHERN FOOTHILLS... AND A MIX WITH SNOW INTO THE NW PIEDMONT (KINT/KGSO) IN THE HEAVIER BURSTS OF SHOWERS. THIS PROCESS WILL CONTINUE FOR THE NEXT FEW HOURS. HOWEVER... THE PRECIPITATION RATES ARE EXPECTED TO REMAIN LIGHT ENOUGH... AND THE SURFACE TEMPS WILL REMAIN ABOVE 32 PRECLUDING ANY SNOWFALL ACCUMULATION. IT APPEARS THE 00Z/24 MARCH GFS WAS VERIFYING A BIT BETTER IN THE LOCATION OF THE CURRENT LIGHT QPF. THIS LIGHT PRECIP SHOULD SLOWLY SPREAD NORTHEAST TOWARD KBUY AND KDAN THROUGH DAYBREAK... AS IT DIMINISHES IN COVERAGE AND INTENSITY. WE WILL HAVE TO CARRY SOME IFR CIGS AT LEAST TEMPORARILY OVER THE TRIAD REGION THROUGH AROUND DAYBREAK... LIFTING TO MVFR CIGS THIS MORNING AND AFTERNOON. MVFR CIGS LIKELY FOR A TIME AT KRDU/KRWI TODAY AS WELL. THE LIGHT SHOWERS SHOULD REDUCE VSBY AT TIME OVER THE KINT/KGSO AREAS INTO THE MVFR CATEGORY THROUGH 12Z. OTHERWISE NO VSBY RESTRICTIONS ARE EXPECTED. SCATTERED SHOWERS ARE POSSIBLE AGAIN THIS AFTERNOON... MAINLY IN THE KINT/KGSO/KRDU AREAS... BUT VSBYS SHOULD REMAIN 6+. VFR CONDITIONS WILL RETURN TONIGHT AND CONTINUE THROUGH AT LEAST THURSDAY. && .CLIMATE... WFO RALEIGH WILL START THE 2008 SPRING FROST/FREEZE PROGRAM WITH 4AM FORECAST PACKAGE ON MARCH 30TH. THIS DATE IS APPROXIMATELY A WEEK EARLIER ACROSS THE PIEDMONT THAN THE AVERAGE DATE FOR THE LAST SPRING FREEZE (APR 9TH)...DUE TO THE ABOVE NORMAL TEMPERATURES EXPERIENCED IN FEBRUARY (4 TO 5 DEGREES F) AND WITH MARCH CURRENTLY RUNNING 2 TO 3 DEGREES ABOVE NORMAL. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...BADGETT NEAR TERM...BLS/CBL/MWS SHORT TERM...MWS LONG TERM...RFG AVIATION...BADGETT CLIMATE...CBL nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND FORKS ND 1055 AM CDT MON MAR 24 2008 .DISCUSSION... FORECAST CHALLENGE CONCERNS TEMPERATURES...WIND POTENTIAL AND PCPN CHANCES. SURFACE LOW POSITION ON TRACK WITH GFS INITIALIZING BEST BUT MODELS CLOSE. FEATURE STILL EXPECTED TO SLIDE SE AND TRACK JUST NORTH OF INTERNATIONAL BORDER AREA. REGIONAL 88D`S SHOWING WEAK RETURNS HOWEVER MODEL SOUNDINGS CONSISTENT IN DEPICTING PRETTY DRY COLUMN SO RETURNS LIKELY ONLY MID LEVEL CLOUDS. ALSO SEEING A PRETTY GOOD DRY SLOT WHICH WILL SPREAD ACROSS NORTHERN OF FA LATER THIS AM INTO AFTERNOON. AT THIS POINT NOT VERY EXCITED ABOUT SEEING MUCH IN THE WAY OF PCPN UNTIL LATER THIS AFTERNOON/EVENING AS LOW APPROACHES. WILL BACK OFF ON POPS UNTIL MID/LATE AFTERNOON. TEMPERATURES WILL ALSO BE A BIG CHALLENGE. PRETTY STRONG WARM ADVECTION AND MIXING HOWEVER STEEP INVERSION WILL LIMIT MIXING WARMER AIR DOWN. ALWAYS A CONCERN ABOUT BRIEF WARMING AS PREFRONTAL TROUGH PASSES AND QUICK WARM UP WITH WSHFT. FOR THIS WILL LEAVE TEMPERATURES AS IS. WIND WILL ALSO NEED WATCHING. RUC SHOWING POTENTIAL WITH MIXED LAYER DEVELOPING HOWEVER GFS AND NAM KEEP SHARP INVERSION IN PLACE. STILL LOOKS WINDY HOWEVER WILL NEED TO BREAK DOWN INVERSION TO GET BIG WINDS WHICH AT THIS POINT DOES NOT SEEM LIKELY BUT WILL MONITOR. && .AVIATION... MVFR CEILINGS/VSBYS IN -SN LIKELY NOT TO AFFECT FA UNTIL LATE AFTERNOON EVENING AND PRIMARILY ACROSS NW MN. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ VOELKER nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 340 PM MDT MON MAR 24 2008 .SHORT TERM... (TONIGHT AND TUESDAY) ...WARM/MILD AND BREEZY/WINDY WEATHER CONTINUES NEXT 24 HOURS... ...MARGINAL CRITICAL FIRE WEATHER CONCERNS STILL DEVELOPING... CURRENTLY...WATER VAPOR IMAGERY AND RUC MODEL UPPER AIR ANALYSES SHOWED THE WESTERLY FLOW WELL UNDERWAY ACROSS THE CENTRAL ROCKIES AND WESTERN UNITED STATES. LAPS SOUNDING ANALYSIS HAD +10C TO +15C 24 HOUR TEMPERATURE CHANGES VERTICALLY FROM 850MB THROUGH 500MB EARLY THIS AFTERNOON...SO THE WELL ADVERTISED WARMER AIR IS HERE. PERIODIC THIN SCT-BKN HIGH MOUNTAIN WAVE CLOUDS HAVE BEEN OCCURRING. THE WIND HAS BEEN A BIG CHALLENGE WITH A POSSIBLE ROTOR ON EAST SIDE OF PIKES PEAK AS COLORADO SPRINGS WIND DIRECTION HAS BEEN ALL OVER THE PLACE. BREEZY CONDITIONS HAVE BEEN OCCURRING...PERIODICALLY...IN GAP FLOW AREAS LIKE THE MIDDLE TO LOWER AR RIVER VALLEY FROM CANON CITY TO PUEBLO TO LA JUNTA. AND LA VETA PASS TO WALSENBURG. THE OTHER BIG CHALLENGE HAS BEEN SURFACE DEW POINTS WITH BELOW OF VALUES ACROSS MUCH OF THE MOUNTAINS AND PLACES WHERE THE WIND PICKS UP ALONG THE I-25 CORRIDOR AND SOUTHEAST CO PLAINS. SOME AREAS HAVE BEEN FLIRTING WITH RED FLAG WEATHER CRITERIA ALONG THE I-25 CORRIDOR...BUT THIS AREA EXPERIENCED NEARLY WIDESPREAD WETTING PRECIPITATION 48 HOURS AGO. THE DEAD FINER FUELS...1 HOUR GRASSES/WEEDS/BRUSH...ARE STILL CURING. LATE THIS AFTERNOON AND TONIGHT...THE WARM WESTERLY FLOW SHOULD CONTINUE THROUGH TONIGHT. LOOKING FOR MOST LOWER ELEVATION LOCATIONS TO HAVE WINDS DECOUPLE AFTER SUNSET. WINDS MAY KEEP BLOWING ACROSS THE HIGHER TERRAIN...PORTIONS OF THE EAST FACING SLOPES...AND GAP FLOW AREAS THROUGH THE NIGHT. TEMPERATURES WILL SLOWLY FALL THIS EVENING AND MAY BECOME STEADY OR SLOWLY RISE ALONG THE "BANANA-BELT" AROUND 6K-9K FT MSL GENERALLY ALONG AND WEST OF I-25 CORRIDOR TOWARDS THE MOUNTAINS AND ALONG VALLEY EDGES TONIGHT. MINIMUM TEMPERATURES ARE A BIGGER CHALLENGE IN THE LOWER AR RIVER VALLEY WITH A LARGE POTENTIAL DROP CONSIDERING DEW POINTS IN THE SINGLE DIGITS/TEENS IN THE EVENING. THERE SHOULD BE SOME SURFACE DEW POINT RECOVERY...THOUGH. TUESDAY...WESTERLY WARM FLOW TO CONTINUE ACROSS THE CENTRAL ROCKIES. STILL HINTS OF A VERY SHALLOW AND WEAK COLD FRONT TO MOVE INTO EAST CENTRAL/SOUTHEAST CO/WESTERN KS DURING TUESDAY MORNING...BUT MIXING OUT AS THE WESTERLY SURFACE/PBL FLOW DEVELOPS. MARGINAL CRITICAL FIRE WEATHER CONCERNS WILL CONTINUE. FINER FUELS WILL CONTINUE TO CURE/DRY OUT...ESPECIALLY ALONG I-25 CORRIDOR. SURFACE DEW POINTS AND WINDS WILL BE THE BIG CHALLENGE AGAIN. PLAYED THE DEW POINTS SIMILAR TO TODAY. THE ABOVE AVERAGE TEMPERATURES...DAYTIME HUMIDITY VALUES LESS THAN 20%...AND HAINES 4-5 WILL BE IN PLACE. THE WIND WILL BE CRUCIAL IF RED FLAG CONDITIONS DEVELOP. THERE COULD BE SOME LOCAL SPOTS THAT BRIEFLY REACH RED FLAG CRITERIA FOR THE MINIMUM 3 HOUR TEMPORAL RULE...BUT TOUGH TO SAY EXACTLY WHERE. AREA FORECAST DISCUSSIONS AND HAZARDOUS WEATHER OUTLOOKS ALREADY HIGHLIGHT THE POTENTIAL HAZARD...SO WILL HOLD OFF ISSUING FIRE HEADLINES FOR THE NEAR MARGINAL EVENT. ACTUALLY...LOOKING FOR THE WEATHER CONDITIONS TO BE FAIRLY SIMILAR TO TODAY. MET MOS MIGHT BE A LITTLE TOO WINDY AND WARM...STAYED CLOSER TO THE CURRENT DIGITAL FORECAST DATABASE WHICH IS CLOSE TO THE MAV MOS GUIDANCE. METZE .LONG TERM... (TUESDAY NIGHT-MONDAY) TUESDAY NIGHT-WEDNESDAY...MODERATE TO STRONG WESTERLY FLOW CONTINUES ACROSS THE STATE WITH A STRONG JET STREAM PERSISTING ACROSS THE PAC NW THROUGH THE NORTHERN TIER. NAM AND GFS TO A LESSER EXTENT INDICATING WEAK BOUNDARY MOVING ACROSS THE FAR EASTERN PLAINS TUESDAY NIGHT BRINGING IN SLIGHTLY COOLER AND MORE MOIST AIRMASS OVERNIGHT WITH LEE TROUGHING ACROSS THE I-25 CORRIDOR KEEPING BREEZY CONDITIONS AND MILD OVERNIGHT TEMPERATURES ACROSS THE EASTERN MTS AND IMMEDIATE PLAINS. LEE TROUGH KICKS EAST ACROSS THE EASTERN PLAINS THROUGH THE DAY WEDNESDAY AHEAD OF AN EMBEDDED SHORT WAVE MOVING ACROSS THE NORTHERN GREAT BASIN. MODELS INDICATING H7 TEMPS BETWEEN 0C AND 4C AND WITH GOOD MIXING UP TO H6...SHOULD SEE BREEZY TO WINDY CONDITIONS ON WEDNESDAY SUPPORTING ANOTHER DAY WELL ABOVE SEASONAL AVERAGES...ESPECIALLY ACROSS THE PLAINS. WITH THE DEEP MIXING...SHOULD SEE DEW PTS TANK ACROSS THE AREA ONCE AGAIN AND ALONG WITH THE GUSTY WINDS...WILL NEED TO CONTINUE TO MONITOR FOR THE POTENTIAL OF CRITICAL FIRE WEATHER BEHAVIOR ACROSS PORTIONS OF THE PLAINS ON WEDNESDAY. WEDNESDAY NIGHT-FRIDAY NIGHT...SOME DIFFERENCES IN MODELS THROUGH THIS PERIOD AS NORTHERN GREAT BASIN SYSTEM AND ASSOCIATED COLD FRONT CONTINUES ACROSS THE NORTHERN ROCKIES AND INTO THE NORTHERN HIGH PLAINS THROUGH THURSDAY NIGHT. WITH THE STRONG WESTERLY FLOW AND LEE TROUGHING AHEAD OF SYSTEM...SHOULD SEE MILD OVERNIGHT LOWS ACROSS THE PLAINS AGAIN. FRONT MOVES ACROSS THE NORTHEAST PLAINS THURSDAY MORNING AND WILL LIKELY OOZE ACROSS THE PALMER DVD THROUGH THE LATE MORNING AND EARLY AFTERNOON OWNING TO A HIGH SPREAD IN TEMPERATURES ACROSS THE SOUTHEAST PLAINS. HAVE BUMPED UP POPS ACROSS THE CENTRAL MTS WITH GOOD OROGRAPHICS AND UVV ASSOCIATED WITH BOUNDARY AND HAVE KEPT ISOLATED POPS ACROSS THE PALMER DVD FOR THURSDAY AFTERNOON. FRONT LOOKS TO CONTINUE ACROSS THE REST OF THE PLAINS THURSDAY NIGHT AND HAVE CONTINUED TO KEEP CHANCE AND SLIGHT CHANCE POPS ACROSS THE EASTERN MTS AND PLAINS WITH LIFT ALONG BOUNDARY. LOW LEVEL UPSLOPE CONTINUES ACROSS THE PLAINS ON FRIDAY KEEPING COOL TEMPERATURES IN PLACE ALONG WITH SLIGHT CHANCES POPS ACROSS THE HIGHER TERRAIN. SATURDAY-MONDAY...WESTERLY FLOW ALOFT SATURDAY BECOMES INCREASINGLY SOUTHWEST AHEAD OF ANOTHER STRONG SYSTEM MOVING ACROSS THE GREAT BASIN ON SUNDAY...OWNING TO ANOTHER WARM AND WINDY DAY ACROSS THE AREA SUNDAY. SOME MODEL DIFFERENCES ON SATURDAY WITH GFS INDICATING SOME WAA PRECIP ACROSS THE PLAINS AHEAD OF THE NEXT SYSTEM...THOUGH HAVE KEPT POPS SILENT ATTM. GREAT BASIN SYSTEM AND ASSOCIATED FRONT PROGGED TO MOVE ACROSS THE STATE ON MONDAY...BRINGING IN COOLER TEMPERATURES AND PRECIP CHANCES TO THE AREA ONCE AGAIN. -MW && .AVIATION...PER SHORT TERM DISCUSSION....VFR HIGH CLOUDINESS WILL CONTINUE FOR KCOS...KPUB...AND KALS SITES. METZE && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 17/23 co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 410 PM EDT MON MAR 24 2008 .SYNOPSIS... 19Z WATER VAPOR AND H4 RUC ANALYSIS CONTINUE TO SHOW AN AMPLIFIED BUT PROGRESSIVE UPPER PATTERN ACROSS THE CONUS THIS AFTERNOON. THE PATTERN IS SIMPLIFIED TO GENERAL TROUGHING IN THE EAST AND RIDGING UPSTREAM OVER THE WEST. TROUGHING IN THE EAST IS ANCHORED BY THE POLAR VORTEX OVER NORTHERN QUEBEC WITH AN AXIS RUNNING SOUTHWARD THROUGH THE EASTERN GREAT LAKES...THEN DOWN THE SPINE OF THE APPALACHIANS TO THE NORTHEAST GULF OF MEXICO. POTENT PIECE OF MID LEVEL ENERGY IS MAKING AN UNEVENTFUL PASS THROUGH OUR FORECAST AREA LATE THIS AFTERNOON AND EARLY EVENING. THE RIDGING FURTHER UPSTREAM ACROSS THE WEST RUNS ALONG AN AXIS FROM THE NORTHERN PLAINS STATES TO THE FOUR CORNERS REGION. AT THE SURFACE...NORTHERLY FLOW CONTINUES TO DELIVER A COOL AND DRY AIRMASS TO THE REGION. STRONG 1030MB SURFACE HIGH PRESSURE HAS DROPPED DOWN INTO THE LOWER MISSISSIPPI VALLEY AND WILL BE MOVING EAST TOWARD OUR AREA THROUGH THE EVENING HOURS. TEMPERATURES ACROSS THE AREA CURRENTLY RUNNING IN THE UPPER 50S TO LOWER 60S WITH DEWPOINTS IN THE 20S AND TEENS. && .SHORT TERM...THIS EVENING THROUGH TUESDAY NIGHT. POTENT MID LEVEL SHORTWAVE WILL EXIT OFF THE SOUTHEAST COAST LATER THIS EVENING. A FEW CU ACROSS OUR NORTHERN AREAS FROM KDHN TO KABY ASSOCIATED WITH THE COOLEST MID LEVEL AIR (500MB TEMPS AS LOW AS -30C) AND BEST SHORTWAVE ENERGY WILL BE DISSIPATING TOWARD SUNSET WITH MOSTLY CLEAR SKIES FOR THE REST OF THE NIGHT. 850MB TEMPS BEHIND LAST NIGHTS FRONT HAVE DROPPED TO AROUND -2C OVER OUR SOUTHERN ZONES AND AS LOW AS -4C TO THE NORTH. VERY UNUSUAL AIRMASS FOR LATE MARCH ACROSS OUR AREA. THESE TEMPS ARE AROUND 3.0 STANDARD DEVIATIONS FROM NORMAL. IN CLEARER TERMS...THIS MEAN THAT THERE IS ONLY AROUND A 4% PROBABILITY OF OCCURRENCE FOR THIS COLD AN AIRMASS BASED ON CLIMATOLOGY. SURFACE RIDGE BUILDS EAST THIS EVENING BEFORE SETTLING OVERHEAD DURING THE SECOND HALF OF THE NIGHT. WITH THE HIGH IN CLOSE PROXIMITY...WINDS WILL BECOME VERY LIGHT AND COMBINE WITH THE COOL AND DRY AIRMASS TO PRODUCE A GOOD RADIATIONAL COOLING SETUP. THIS IS GOING TO RESULT IN A VERY COLD NIGHT FOR LATE MARCH. FREEZE WARNINGS ARE NOW IN EFFECT FOR THE ENTIRE AREA AWAY FROM THE IMMEDIATE COAST FOR LATE TONIGHT INTO EARLY TUESDAY MORNING. NOT EXPECTING A BLANKET FREEZE SCENARIO BUT CERTAINLY NORMALLY COOLER LOCATIONS UNDER RADIATIONAL SETUPS WILL HAVE A CHANCE TO DROP A FEW DEGREES BELOW 32F FOR A COUPLE HOURS LATE TONIGHT INTO EARLY TUESDAY MORNING. URBAN CENTERS WILL LIKELY BOTTOM OUT CLOSER TO THE MIDDLE 30S...HOWEVER THE SUBTLETIES OF RADIATIONAL COOLING SAY THAT NO AREA SHOULD COMPLETELY LET THEIR GUARD DOWN IN DEALING WITH SENSITIVE VEGETATION. OF NOTE THE RECORD LOW FOR MARCH 25TH AT THE TALLAHASSEE REGIONAL AIRPORT IS 28F SET IN 1968. HIGH PRESSURE REMAINS PARKED OVERHEAD FOR THE DAY ON TUESDAY. MID-LEVEL COOL POOL EXITS EAST EARLY IN THE DAY WITH MID LEVEL FLOW BECOMING MUCH MORE ZONAL AND WITH 850MB TEMPS REBOUNDING TO BETWEEN 4C AND 7C BY EARLY EVENING. WHILE STILL EXPECTING BELOW NORMAL HIGHS...TEMPS SHOULD BE ABLE TO REACH THE MIDDLE AND UPPER 60S. THE BIG DIFFERENCE WILL BE THE LACK OF WIND ALLOWING IT TO FEEL SIGNIFICANTLY WARMER ON TUESDAY THAN IT HAS THIS PAST AFTERNOON. HIGH PRESSURE REMAIN IN CLOSE PROXIMITY TUESDAY NIGHT ALLOWING FOR ANOTHER RADIATIONAL COOLING SETUP. HOWEVER THE COOLEST PART OF THE AIRMASS WILL HAVE EXITED BY THIS TIME SO NOT EXPECTING TEMPS TO BE DROP QUITE AS LOW AS TONIGHT. GENERALLY LOOKING FOR MIDDLE AND UPPER 30S INLAND AND UPPER 30S TO MIDDLE 40S ALONG THE COAST. WITH A BIT HIGHER LEVELS OF MOISTURE A FEW NORMALLY COLDER LOCATIONS MIGHT STILL EXPERIENCE SOME PATCHY FROST TOWARD SUNRISE WEDNESDAY MORNING. FAIR WEATHER AND MODERATING TEMPS CONTINUE INTO WEDNESDAY AS RIDGING CONTINUES OVER THE AREA FROM HIGH PRESSURE CENTERED OFF THE SOUTHEAST COAST. HIGHS WILL BE BACK UP INTO THE 70S. EXCEPTIONS WILL BE ALONG THE IMMEDIATE COAST WHERE AFTERNOON SEA BREEZES WILL HELP KEEP TEMPS DOWN IN THE UPPER 60S. && .LONG TERM... THURSDAY THROUGH MONDAY) ONLY SENSIBLE WEATHER IN THE LONG TERM PORTION WILL BE CONFINED TO THE LATTER HALF OF THE FORECAST PERIOD. SURFACE RIDGING AND WEAK MID LEVEL RIDGING IN PLACE AT THE BEGINNING OF THE PERIOD WILL GRADUALLY BREAK DOWN AND SHIFT EASTWARD INTO FRIDAY AND ALLOW FOR A SLIGHT CHANCE OF SHOWERS IN OUR WESTERN ZONES UNDER MOIST SOUTHERLY FLOW WITH TEMPERATURES WARMING INTO THE LOWER 80S. THIS IS A MORE TYPICAL MID APRIL PATTERN...BUT IT WON`T PERSIST AS AN APPROACHING MID LEVEL DISTURBANCE WILL BRING SLIGHTLY BETTER RAIN CHANCES TO THE REGION. CONFIDENCE WITH THIS SYSTEM IS LOW...OWING TO THE DIFFERENCES THAT EXIST BETWEEN THE OPERATIONAL GFS...EURO...AND GFS ENSEMBLE MEAN. THE 24/00Z GFS ENSEMBLE MEAN CONTINUES TO SUPPORT A COLD FRONTAL PASSAGE OVER THE WEEKEND TIME FRAME...WHEREAS THE OPERATIONAL GFS AND 23/12Z EURO STALL THE BOUNDARY JUST TO OUR NORTH OR BARELY BRING IT INTO OUR FORECAST AREA. AT THIS POINT...WILL WEIGHT FORECAST TOWARD PERSISTENCE FROM THE PREVIOUS FORECAST...WHICH IS SIMILAR TO THE GFS ENSEMBLE MEAN. THIS MAKES MORE SENSE THAN INDICATING A STALLING BOUNDARY GIVEN ALL THE DISAGREEMENT BETWEEN THE MODELS. THIS NETS 20 POPS THROUGHOUT THE WEEKEND...WITH RAIN CHANCES DIMINISHING BY THE FIRST OF THE WEEK. HOPEFULLY...FUTURE MODEL RUNS WILL YIELD BETTER CLARITY ON THE STRENGTH AND PROGRESS OF THIS SYSTEM. TEMPERATURES WILL GENERALLY BE A COUPLE OF DEGREES ABOVE CLIMO FOR THE PERIOD WITH HIGHS NEARING 80 DEGREES WITH SOME AREAS EXCEEDING THE 80 DEGREE MARK ON FRIDAY AND SATURDAY. && .AVIATION... VFR CONDITIONS TO PREVAIL ACROSS AREA THROUGH THE NEXT FEW DAYS AS STRONG HIGH PRESSURE SETTLES OVER AREA. DRY LOW LEVEL AIR WILL PRECLUDE ANY FOG FORMATION OVERNIGHT. SURFACE WINDS ALL TERMINALS WILL CONTINUE NORTHERLY OVER 10KTS DURING LATE AFTERNOON WITH SOME GUSTS. WINDS WILL CLOCK AROUND TO NORTHEASTERLY AND NOT AS STRONG TUESDAY. && .MARINE... STRONG NORTHERLY WINDS WILL CONTINUE OVER THE FORECAST WATERS INTO TONIGHT. ADVISORY CONDITIONS ARE EXPECTED TO CONTINUE THROUGH A GOOD PORTION OF THE NIGHT BEFORE BEGINNING TO SUBSIDE LATE. WINDS AND SEAS WILL DIMINISH QUICKLY TUESDAY MORNING AS HIGH PRESSURE BECOMES CENTERED OVER OR NEAR THE COASTAL WATERS. THIS HIGH WILL MOVE EAST OFF THE SOUTHEAST U.S. COAST BY MID WEEK WITH FLOW COMING AROUND TO THE SOUTHEAST && .FIRE WEATHER... RED FLAG CONDITIONS WILL CONTINUE INTO THE MIDDLE EVENING HOURS ACROSS A LARGE PORTION OF THE AREA. HIGH PRESSURE RESIDES OVER THE FORECAST AREA ON TUESDAY. ALTHOUGH WINDS WILL BE LIGHT...DRY AIR IN PLACE AND SLOWLY MODERATING TEMPERATURES WILL RESULT IN ANOTHER DAY OF WIDESPREAD LONG DURATIONS OF CRITICAL RELATIVE HUMIDITY VALUES. RED FLAG WARNINGS ARE ONCE AGAIN IN EFFECT FOR ALL ZONES. THE HIGH SLIPS OFF THE SOUTHEAST COAST ON WEDNESDAY ALLOWING FOR SOME ADDITIONAL MOISTURE TO BEGIN TO OVERSPREAD. HOWEVER...CONTINUED WARMING TEMPS STILL MAY ALLOW FOR INLAND PORTIONS OF THE EASTERN FL PANHANDLE AND FLORIDA BIG BEND TO REACH DURATIONS OF CRITICAL RH DURING THE AFTERNOON. CLOSER TO THE COAST DEVELOPING SEA BREEZES WILL KEEP RH VALUES HIGHER. && .PRELIMINARY POINT TEMPS/POPS... TALLAHASSEE 31 66 35 74 45 / 0 0 0 0 0 PANAMA CITY 37 64 45 71 52 / 0 0 0 0 0 DOTHAN 32 66 37 74 47 / 0 0 0 0 0 ALBANY 31 66 36 73 45 / 0 0 0 0 0 VALDOSTA 32 66 38 75 46 / 0 0 0 0 0 CROSS CITY 32 67 37 77 47 / 0 0 0 0 0 && .TAE WATCHES/WARNINGS/ADVISORIES... AL...RED FLAG WARNING UNTIL 6 PM CDT THIS AFTERNOON AND FROM 12 PM TO 6 PM CDT TUESDAY AFTERNOON. FOR THE FOLLOWING ZONES: COFFEE...DALE...GENEVA...HENRY...HOUSTON. FREEZE WARNING FROM 3 AM TO 8 AM CDT TUESDAY FOR THE FOLLOWING ZONES: COFFEE...DALE...GENEVA...HENRY...HOUSTON. FIRE WEATHER WATCH WEDNESDAY AFTERNOON FOR THE FOLLOWING ZONES: COFFEE...DALE...GENEVA...HENRY...HOUSTON. LAKE WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR THE FOLLOWING ZONES: COFFEE...DALE...GENEVA...HENRY...HOUSTON. GA...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING AND FROM 1 PM TO 7 PM EDT TUESDAY FOR THE FOLLOWING ZONES: BAKER...BEN HILL... BERRIEN...BROOKS...CALHOUN...CLAY...COLQUITT...COOK...DECATUR... DOUGHERTY...EARLY...GRADY...IRWIN...LANIER...LEE...LOWNDES... MILLER...MITCHELL...QUITMAN...RANDOLPH...SEMINOLE...TERRELL... THOMAS...TIFT...TURNER...WORTH. FREEZE WARNING FROM 4 AM TO 9 AM EDT TUESDAY FOR THE FOLLOWING ZONES: BAKER...BEN HILL...BERRIEN...BROOKS...CALHOUN... CLAY...COLQUITT...COOK...DECATUR...DOUGHERTY...EARLY... GRADY...IRWIN...LANIER...LEE...LOWNDES...MILLER... MITCHELL...QUITMAN...RANDOLPH...SEMINOLE...TERRELL... THOMAS...TIFT...TURNER...WORTH. FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY EVENING FOR THE FOLLOWING ZONES: BAKER...BEN HILL... BERRIEN...BROOKS...CALHOUN...CLAY...COLQUITT...COOK... DECATUR...DOUGHERTY...EARLY...GRADY...IRWIN...LANIER... LEE...LOWNDES...MILLER...MITCHELL...QUITMAN...RANDOLPH... SEMINOLE...TERRELL...THOMAS...TIFT...TURNER...WORTH. LAKE WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR THE FOLLOWING ZONES: BAKER...BEN HILL...BERRIEN...BROOKS...CALHOUN... CLAY...COLQUITT...COOK...DECATUR...DOUGHERTY...EARLY... GRADY...IRWIN...LANIER...LEE...LOWNDES...MILLER... MITCHELL...QUITMAN...RANDOLPH...SEMINOLE...TERRELL... THOMAS...TIFT...TURNER...WORTH. FL...FREEZE WARNING FROM 4 AM EDT /3 AM CDT/ TO 9 AM EDT /8 AM CDT/ TUESDAY FOR THE FOLLOWING ZONES: BAY...CALHOUN...COASTAL WALTON...DIXIE...FRANKLIN...GADSDEN...GULF...HOLMES... INLAND WALTON...JACKSON...JEFFERSON...LAFAYETTE...LEON... LIBERTY...MADISON...TAYLOR...WAKULLA...WASHINGTON. LAKE WIND ADVISORY UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR THE FOLLOWING ZONES: BAY...CALHOUN...COASTAL WALTON... DIXIE...FRANKLIN...GADSDEN...GULF...HOLMES...INLAND WALTON...JACKSON...JEFFERSON...LAFAYETTE...LEON...LIBERTY... MADISON...TAYLOR...WAKULLA...WASHINGTON. RED FLAG WARNING UNTIL 10 PM EDT /9 PM CDT/ THIS EVENING AND FROM /11 AM EDT /10 AM CDT/ TO 8 PM EDT /7 PM CDT TUESDAY FOR THE FOLLOWING ZONES: BAY...CALHOUN...DIXIE...FRANKLIN... GADSDEN...GULF...HOLMES...INLAND WALTON...JACKSON... JEFFERSON...LAFAYETTE...LEON...LIBERTY...MADISON...TAYLOR... WAKULLA...WASHINGTON. FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY EVENING FOR THE FOLLOWING ZONES: CALHOUN...DIXIE... GADSDEN...HOLMES...INLAND WALTON...JACKSON...JEFFERSON... LAFAYETTE...LEON...LIBERTY...MADISON...TAYLOR...WAKULLA... WASHINGTON. GM...SMALL CRAFT ADVISORY UNTIL 2 AM EDT TUESDAY FOR THE FOLLOWING ZONES: APALACHEE BAY OR COASTAL WATERS FROM KEATON BEACH TO OCHLOCKONEE RIVER FL OUT TO 20 NM...COASTAL WATERS FROM OCHLOCKONEE RIVER TO APALACHICOLA FL OUT TO 20 NM...COASTAL WATERS FROM SUWANNEE RIVER TO KEATON BEACH OUT 20 NM... COASTAL WATERS FROM APALACHICOLA TO DESTIN FL OUT 20 NM. SMALL CRAFT ADVISORY UNTIL 8 AM EDT TUESDAY FOR THE FOLLOWING ZONES: WATERS FROM SUWANNEE RIVER TO APALACHICOLA FL FROM 20 TO 60 NM...WATERS FROM APALACHICOLA TO DESTIN FL FROM 20 TO 60 NM. && $$ PUBLIC/MARINE...MROCZKA AVIATION/FIRE WEATHER...GOREE LONG TERM...GODSEY fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TOPEKA KS ISSUED BY NATIONAL WEATHER SERVICE WICHITA KS 232 PM CDT MON MAR 24 2008 .UPDATE... WINDS HAVE BEEN INCREASING UPSTREAM ACROSS SOUTH CENTRAL KANSAS. A LOOK AT THE MOMENTUM TRANSPORT WINDS FROM THE 24/18Z RUC BUFKIT SOUNDINGS SUGGESTS AN INCREASE IN WINDS INTO THE WIND ADVISORY RANGE IS QUITE PROBABLE ACROSS THE FLATTER TERRAIN AREAS. MIXED LAYER WINDS REMAIN 35-40 KNOTS THROUGH ABOUT 00Z. THEREFORE...WILL BE ISSUING A WIND ADVISORY SHORTLY. KRC && .PREV DISCUSSION... /ISSUED ISSUED BY NATIONAL WEATHER SERVICE WICHITA KS/ SYNOPSIS... DATA ANALYSIS AT 18Z SHOWS TWO STRONG UPPER LEVEL LOWS INFLUENCING NORTH AMERICA. THE FIRST IS A POLAR VORTEX EAST OF HUDSON BAY AND THE SECOND IS IN THE GULF OF ALASKA. THE MEAN FLOW PATTERN HAS BEEN TO ALLOW WEAK DISTURBANCES TO MOVE ACROSS THE NORTHERN UNITED STATES IN THE FAST FLOW BENEATH THESE LOWS. AS A RESULT...MUCH OF THE SENSIBLE WEATHER IMPACTS HAVE REMAINED NORTH OF THE FORECAST AREA. THE FORECAST OF 5 DAY AVERAGED 500 MB HEIGHTS SHOWS THIS PATTERN BREAKING DOWN SO THAT BY DAY 5 AN UPPER LEVEL POLAR VORTEX EXISTS OVER NORTHERN CANADA WITH PROGRESSIVE FLOW OVER THE LOWER 48 STATES. THIS SHOULD CAUSE AN INCREASE IN ACTIVITY BY THE END OF THE PERIOD. KRC DISCUSSION... MAIN FORECAST FOCUS WILL BE CONVECTIVE CHANCES. THE 24/12Z NAM/GFS AND 00Z/GFS SOLUTIONS ARE IN SOME GENERAL AGREEMENT. A COLD FRONT WILL MOVE THROUGH THE FORECAST AREA TUESDAY. THIS FRONT SHOULD STALL LATER IN THE DAY TUESDAY. THAT SAID...GFS/NAM STALL THE FRONT OVER KANSAS WHILE THE ECMWF PUSHES IT AS FAR SOUTH AS OKLAHOMA. DPROG/DT HAS SHOWN A TREND OF THE FRONT STALLING FURTHER NORTH WITH EACH MODEL RUN. AS A RESULT...THE GFS/NAM SOLUTION SEEMS MOST APPROPRIATE. BUFKIT SOUNDINGS FROM BOTH THE GFS/NAM SHOW ELEVATED INSTABILITY UP TO 500 J/KG TUESDAY NIGHT AND NEAR 1000 J/KG WEDNESDAY AND THURSDAY NIGHT. THIS IS IN CONJUNCTION WITH SOME LOW LEVEL MOISTURE TRANSPORT OVER THE SAME AREA. THINK THIS IS ENOUGH TO WARRANT A 20-30 PERCENT CHANCE OF CONVECTION OVER THE FORECAST AREA TUESDAY NIGHT...AND SOMEWHAT HIGHER WEDNESDAY AND THURSDAY NIGHT. PROBABILITIES SHOULD INCREASE FROM NORTH TO SOUTH. AT THIS TIME...SHEAR/CAPE PARAMETERS INDICATE A LOW PROBABILITY CHANCE OF SEVERE WEATHER ACROSS EXTREME SOUTHEAST KANSAS WEDNESDAY AND THURSDAY NIGHTS. SHOULD THE TREND OF THE FRONT STALLING FURTHER NORTH AS PREVIOUSLY MENTIONED...THIS COULD AFFECT THE SOUTHERN MOST PORTION OF THE FORECAST AREA. HIGH PRESSURE MOVES INTO THE FORECAST AREA SATURDAY...THEN EXITS QUICKLY. SOUTHERLY FLOW THEN IS REESTABLISHED OVER THE FORECAST AREA. A MODERATE TO SIGNIFICANT AMOUNT OF ISENTROPIC LIFT AND MOISTURE TRANSPORT SUGGESTS ANOTHER CHANCE OF PRECIPITATION /ELEVATED CONVECTION/ SUNDAY NIGHT AND EARLY MONDAY. FORECAST CONFIDENCE IN THIS SCENARIO THIS FAR IN ADVANCE IS RATHER LOW. KRC AVIATION...18Z TAFS. IN CONCERN WILL BE WINDS OVER THE NEXT 24 HOURS WITH OTHERWISE VFR CONDITIONS. STEEPENING LEE TROF OVER HIGH PLAINS WILL YIELD SOUTHERLY WINDS GUSTING TO 28-35KT THIS PM. LOW- LEVEL JET TONIGHT WILL KEEP SOME GUSTS GOING FOR MUCH OF THE NIGHT. MODELS PROG COLD FRONT ARRIVING INTO CENTRAL/SOUTH CENTRAL KS TUES AM...WHICH WILL SWITCH WINDS TO A N-NERLY COMPONENT BUT LIGHTER SPEEDS. JMC && .TOP WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY UNTIL 7 PM MONDAY FOR KSZ034-KS && $$ KRC ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 435 PM EDT MON MAR 24 2008 .SYNOPSIS... 20Z WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS SHOWED AN UPPER TROUGH OVER THE NE PACIFIC...ZONAL FLOW ACROSS THE PACIFIC NW (WITH A 120-130KT JET NEAR 200MB FROM NRN OREGON INTO WRN MONTANA)...AND TROUGHING FROM ERN ONTARIO SOUTHWARD INTO GEORGIA. UPPER LEVEL MOISTURE IN THE FORM OF HIGH CLOUDS ARE STREAMING THROUGH THE ZONAL FLOW AREA...EXTENDING W OF OREGON INTO THE UPPER MISSISSIPPI VALLEY. THIS WESTERLY FLOW DOWNSLOPING OFF THE ROCKIES...IN COMBINATION WITH DPVA FROM A SHRTWV ALONG THE MONTANA/SASKATCHEWAN BORDER...HAS RESULTED IN 996MB LOW PRESSURE NEAR REGINA SASKATCHEWAN. WARM AIR ADVECTION AHEAD OF THIS SHRTWV...NOTED BY 850MB TEMPS OF 3C AT BIS AND 6C AT GGW AT 12Z ALONG WITH SW TO W WINDS OF 25-40 KT...COMPARED TO TEMPS OF -9C AT INL. DESPITE THE WARM ADVECTION...MOISTURE WAS FAIRLY SPARSE AT 12Z WITH DEWPOINT DEPRESSIONS OF 10C OR MORE BTWN 725 AND 900MB...MAINLY DUE TO THE FACT THAT THE GULF OF MEXICO IS CUT-OFF FROM THIS SYSTEM. HOWEVER...SOUTHERLY WINDS ARE BRINGING SOME LOW TO MID 20S DEWPOINTS UP THROUGH THE PLAINS AND ERN DAKOTAS...AND THIS MOISTURE BEING LIFTED UP THROUGH THE WARM ADVECTION PROCESS HAS RESULTED IN A FRONTOGENETIC BAND OF SNOW. RADAR IMAGERY DEPICTS THIS BAND FROM SOUTHERN MANITOBA INTO NW MN. CLOSER TO HOME...OUTSIDE OF INCREASING HIGH CLOUDS OVER THE WESTERN CWA...SUNNY SKIES HAVE GENERALLY BEEN THE RULE. THE SUN COMBINED WITH GRADUALLY WARMING 850MB TEMPS FROM THE WEST AND INCREASING SOUTHERLY WINDS HAVE ALLOWED READINGS TO CLIMB INTO THE 30S. A FEW DOWNSLOPING SPOTS EVEN MANAGED TO REACH THE LOW 40S. && .SHORT TERM (TONIGHT AND TUESDAY)... OUT OF ALL THE MODELS...OUR LOCAL WRF-ARW RUN APPEARS TO BE HANDLING THE BEST SO FAR WITH THE SYSTEM...AND HAVE WEIGHTED MORE OF THE FORECAST TO THIS MODEL. SHRTWV OVER NORTHERN MONTANA IS PROGGED TO DIG A LITTLE SOUTHWARD OVER THE NEXT 24 HOURS...REACHING WESTERN UPPER MI AROUND 12Z TUE AND NW LAKE HURON AROUND 18Z. DPVA AND WARM ADVECTION/MID-LEVEL FRONTOGENESIS AHEAD OF THE SHRTWV SHOULD CONTINUE TO SUPPORT THE DEVELOPING BAND OF PCPN OVER NORTHERN MN AS IT TRACKS EASTWARD WITH THE SHRTWV. MOISTURE CONTINUES TO INCREASE THROUGH THE NIGHT...THANKS TO INCREASING SOUTHERLY FLOW...WITH MIXING RATIOS ON THE 285K SURFACE JUMPING FROM 2 G/KG RIGHT NOW TO 3 OR 4 G/KG BY THE TIME THE FRONTOGENESIS BAND MOVES IN. GIVEN THE INCREASING MOISTURE...IN ADDITION TO THE LOW LEVEL JET INCREASING IN SPEED...THE BAND SHOULD INTENSIFY AS IT MOVES INTO THE CWA. THEREFORE...GREATEST PCPN AMOUNTS ARE EXPECTED OVER THE EASTERN PORTION OF THE CWA. GENERAL QPF CONSENSUS IS BTWN 0.10-0.30...THOUGH THE GFS PAINTS UP TO 0.40 NEAR MANISTIQUE. AMOUNTS SEEM REASONABLE BASED ON MOISTURE AVAILABILITY AND QUICK MOVING NATURE OF THE SYSTEM. SNOW TO WATER RATIOS SHOULD BE NEAR 10 TO 1 DUE TO 7000 FT OR SO OF AGGREGATION...BUT WENT A BIT HIGHER (12 TO 1) AS THE DENDRITIC GROWTH ZONE IS A BIT LOWER IN THE ATMOSPHERE (700MB INSTEAD OF 600MB). THIS RESULTS IN A GENERAL 1 TO 4 INCHES OF SNOW...GREATEST IN THE EASTERN CWA. HAVE WENT AHEAD AND ISSUED A SNOW ADVISORY FOR SCHOOLCRAFT AND LUCE SINCE THEY ARE ON THE HIGH END OF AMOUNTS AND WITH THE GFS SUGGESTING A LITTLE MORE PCPN. IN ADDITION...THIS AREA MAY SEEM SOME BREEZY WIND GUSTS OVERNIGHT...PERHAPS UP TO 40 MPH NEAR THE LAKE MI SHORELINE PER MOMENTUM TRANSFER ON MODEL SOUNDINGS. IN THE WAKE OF THE SNOWBAND...THE AREA APPEARS TO BE DRY-SLOTTED AS THE SHRTWV CROSSES. THEREFORE HAVE WENT AHEAD AND DRIED THE CWA OUT IN THE MORNING BEHIND THE BAND. SOME CONCERN EXISTS FOR UPSLOPE DRIZZLE/FREEZING DRIZZLE OVER THE WESTERN CWA...BUT WITH CLOUD BASES EXPECTED UP AROUND 2000 FT ALONG WITH A BREEZY WEST WIND...DO NOT THINK DRIZZLE WILL BE TOO MUCH OF A PROBLEM. DURING THE AFTERNOON...MODELS STARTING GENERATING PCPN AGAIN...ESPECIALLY AS THE COLD FRONT WITH THE SYSTEM SWINGS THROUGH. MUCH OF THIS PCPN APPEARS TO BE DIURNALLY DRIVEN...THANKS TO STEEP LAPSE RATES WITH THE SHRTWV AND STRONG SURFACE HEATING. 500MB TEMPS ARE PROGGED AT 18Z NEAR -30C. THEREFORE HAVE MAINTAINED CHANCE POPS AFTER 18Z...WITH EVEN SOME 20 POPS OVER THE WESTERN U.P. AFTER 15Z WHEN SOME LIGHT SHOWERS COULD START DEVELOPING. MAINTAINED A MENTION OF RAIN WITH THE SHOWERS AHEAD OF THE COLD FRONT AS WET-BULB ZERO HEIGHTS ARE PROGGED AT OR ABOVE 1500 FT. BROUGHT TEMPS UP A FEW DEGREES TONIGHT DUE TO WARMER THAN EXPECTED CONDITIONS TODAY AND A BREEZY SOUTH WIND. ALSO RAISED TEMPERATURES ON TUESDAY CLOSER TO A BLEND OF THE GUIDANCE AND MAY HAVE TO BE RAISED MORE...IF MORE SUNSHINE OCCURS THAN CURRENTLY FORECAST. .LONG TERM... THE CLOSED LOW EMBEDED IN THE LONGWAVE TROUGH OVER HUDSON BAY WILL SHIFT INTO JAMES BAY ON ON WEDNESDAY. ONE SHORTWAVE WILL SLIDE TO THE SOUTH OF THE FORECAST AREA AS ANOTHER RACES ACROSS NORTHERN LAKE SUPERIOR. THE SURFACE LOW WILL MOVE FROM NORTHEAST ONTARIO INTO CENTRAL QUEBEC. THE FRONTAL SYSTEM OVER THE FORECAST AREA WILL SWEEP INTO THE LOWER GREAT LAKES. 850MB THERMAL TROUGH WILL SWEEP THROUGH THE FORECAST AREA ON WEDNESDAY. THE LAKE-850MB DELTA-T`S WILL REACH 18C. LOW LEVEL MOISTURE WILL BE MARGINAL ACROSS THE AREA. THUS LOOKING FOR LES OVER THE NORTHERN U.P. AND JUST A SLIGHT CHANCE OVER THE SOUTHERN U.P. WEAK SHORTWAVE ENERGY WILL SLIDE OUT OF THE FORECAST AREA THURSDAY NIGHT AS DRY AIR INVADES THE U.P. THUS LOOKING FOR LAKE EFFECT SNOWS TO END THURSDAY NIGHT. DRY AIR OVER THE AREA SHOULD KEEP SNOW SHOWERS OUT OF THE AREA. MODELS VERY INCONSISTENT AND DIFFICULT TO DETERMINE WHICH TO FOLLOW FOR THURSDAY AFTERNOON. ECMWF INDICATES VERY DRY AIR OVER THE AREA...AND NAM EXPECTS ALOT OF MOISTURE. GFS IS AND GLOBEL ARE IN BETWEEN. THE RIDGE WILL START TO INVADE THE AREA FROM THE NORTHWEST. PLAN TO TAKE MOST OF THE MOISTURE CHANCES OUT OF THE FORECAST BUT NOT ALL BECAUSE OF THE UNCERTAINTY. AS POINTED OUT BY HPC CONFIDENCE IS LOW IN ANY SOLUTION. THE GFS/ECMWF HAVE THE CLOSEST SOLUTIONS OF ANY OF THE OPTIONS AND PLAN TO GO WITH A BLEND OF THE TWO FOR NOW. THE LONGWAVE TROUGH WILL SWEEP INTO THE UPPER MISSISSIPPI RIVER VALLEY ON FRIDAY WHILE A SURFACE LOW PASSES THROUGH ONTARIO. LOW LEVEL MOISTURE WILL CONTINUE TO BE MARGINAL. HOWEVER...THIS SHOULD BE ENOUGH TO PRODUCE A CHANCE OF SNOW SHOWERS. DRIER AIR WILL ADVECT INTO THE AREA LATE FRIDAY AS THE RIDGE MOVES INTO THE AREA. WINDS WILL REMAIN LIGHT AND OUT OF THE NORTH. AN 850MB THERMAL TROUGH OVER THE AREA WILL KEEP DELTA-T TEMPERATURES AROUND 15C. STILL ENOUGH LOW LEVEL MOISTURE TO KEEP AT LEAST A MENTION OF SHOWERS IN THE FORECAST THROUGH SATURDAY. THE UPPER LEVEL AND SURACE RIDGE WILL SWEEP THROUGH THE FORECAST AREA SATURDAY MORNING. WINDS WILL BACK SOUTHWEST FOLLOWING THE RIDGE DRAWING MORE LOW LEVEL MOISTURE INTO THE AREA. THE NEXT SHORTWAVE WILL SWEEP THROUGH THE AREA ON SUNDAY AND MONDAY. A SURFACE LOW WILL LIFT OUT OF THE CENTRAL PLAINS INTO THE UPPER MISSISSIPPI RIVER VALLEY ON MONDAY. THIS WILL PRODUCE ISENTROPIC ASCENT OVER THE AREA AND TOGETHER IS INCREASE MOISTURE SHOULD GENERATE MORE SNOW. && .AVIATION (FOR THE 18Z TAF ISSUANCE)... VFR CONDITIONS WILL PREVAIL AT KCMX AND KSAW THRU THE AFTN. AHEAD OF AN APPROACHING LOW PRES SYSTEM TONIGHT...STRONG SRLY FLOW WILL DEVELOP. ALTHOUGH LOW-LEVEL WIND SHEAR HAS BEEN INCLUDED IN THE FCST...IT`S QUITE POSSIBLE THE LOW-LEVELS WILL REMAIN JUST MIXED ENOUGH DOWN TO THE SFC TO PREVENT DEVELOPMENT OF A WIND SHEAR LAYER. SNOW BAND CURRENTLY DEVELOPING OVER THE ERN DAKOTAS WILL MOVE EASTWARD ACROSS THE TAF SITES AFTER MIDNIGHT...WITH A 3-5 HR PERIOD OF IFR VIS AND MVFR CIGS...POSSIBLY DROPPING DOWN INTO THE LIFR VIS AND IFR CIG RANGE. WESTERLY WINDS IN THE WAKE OF THE SNOW BAND MAY GUST UP TO 30 KT BY LATE MORNING AT KCMX...DUE TO THE FUNNELING WIND DIRECTION. OTHERWISE...MVFR CIGS ARE EXPECTED TO PERSIST AT BOTH TAF SITES WITH LOW LEVEL MOISTURE REMAINING IN THE WAKE OF THE SNOW. SOME OF THESE CLOUDS MAY MIX OUT...BUT ANY SCATTERING OUT OF THE CLOUDS SHOULD NOT OCCUR UNTIL TUE EVENING...AS DAYTIME HEATING AND COLD AIR ALOFT HELPS FORM MORE CLOUDS. && .MARINE (FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)... WINDS HAVE APPROACHED 30 KT ACROSS WESTERN LAKE SUPERIOR MON AFTN AHEAD OF THE LOW MOVING ACROSS SOUTHERN SASKATCHEWAN. THIS WIND CORE SHOULD SHIFT INTO EASTERN LAKE SUPERIOR THIS EVENING AND INCREASE AS THE LOW PRESSURE AREA NEARS. GOING SOUTHERLY GALES OF 35-40 KT SEEM REASONABLE. AFTER THE SYSTEMS WARM FRONT CROSSES TUE MORNING...A BRIEF OF PERIOD OF WEST TO 30 KT WINDS SEEMS LIKELY ALONG THE KEWEENAW...AIDED BY PRESSURE RISES. LATER TUE AFTERNOON AND TUE EVENING...A COLD FRONT WILL DROP SOUTH ACROSS THE LAKE. BEHIND THIS FRONT...A BRIEF PERIOD OF NW GALES APPEARS LIKELY...MAINLY OVER THE EASTERN HALF. BEYOND TUE NIGHT...WINDS FALL BELOW 30 KT AS HIGH PRESSURE OVER CENTRAL CANADA BUILDS SOUTHWEST AND REMAINS FAIRLY CLOSE TO LAKE SUPERIOR. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN...SNOW ADVISORY FROM 2 AM TO 11 AM EDT TUESDAY FOR MIZ007-014-085. LAKE SUPERIOR...GALE WARNING 11 PM THIS EVENING TO 10 AM EDT TUE LSZ250-251-266-267. LAKE MICHIGAN...GALE WARNING MIDNIGHT TONIGHT TO NOON EDT TUE LMZ248-250. && $$ SHORT TERM...AJ LONG TERM...DLG AVIATION...AJ MARINE...AJ mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 135 PM EDT MON MAR 24 2008 UPDATED AVIATION DISCUSSION FOR 18Z TAFS .DISCUSSION... (ISSUED AT 450 AM EDT) THE MAIN CONCERN IS THE SNOW AMOUNT FOR TONIGHT AND TUESDAY. WATER VAPOR IMAGERY AND RUC SHOW A LONGWAVE TROUGH OVER THE EASTERN CONUS AND A RIDGE OVER THE WESTERN CONUS. THE SHORTWAVE THAT RECENTLY CAME ONSHORE OVER NORTHERN WASHINGTON WILL IMPACT THE UPPER GREAT LAKES REGION LATE TONIGHT INTO TUESDAY. CLEAR SKIES ARE DOMINATING MOST OF THE UPPER GREAT LAKES REGION THIS MORNING...EXCEPT HIGH CLOUDS ARE INCREASING OVER LAKE SUPERIOR AND LOW CLOUDS HAVE STUCK AROUND PARTS OF SOUTHERN WI AND SOUTHERN LOWER MI. TODAY...CUT BACK ON POPS OVER LAKE SUPERIOR...KEWEENAW AND EAST OF MUNISING. THERE ARE ONLY HIGH CLOUDS OVER THE KEWEENAW PENINSULA...AND SKIES REMAIN CLEAR OVER THE EASTERN CWA. KEPT ISOLATED SNOW SHOWERS OVER THE LAKE FOR TODAY TO ACCOUNT FOR ANY LINGERING SNOW SHOWERS. TONIGHT AND TUESDAY...MODELS ARE IN FAIR AGREEMENT OF A LOW PRESSURE SYSTEM TRACKING ALONG THE U.S./CANADIAN BORDER TODAY AND TONIGHT...AND ACROSS NORTHERN LAKE SUPERIOR TUE. PCPN AMOUNTS ARE ALSO IN GOOD AGREEMENT. A WIDESPREAD SNOW UP TO 2 INCHES IS LIKELY ACROSS THE CWA TONIGHT. ANOTHER INCH IN LAKE EFFECT OVER THE WEST AND UP TO 2 INCHES OVER THE EAST WITH THE LINGERING SYSTEM ARE POSSIBLE ON TUE. THEREFORE...INCREASED POPS FOR EARLY TONIGHT. THE SYSTEM SHOULD MAKE IT INTO THE WEST HALF BY 06Z AND CONCENTRATE ON THE EAST HALF AFTER 06Z. MODELS AGREE THAT A "DRY SLOT" WILL INTERFERE WITH PCPN FROM 12Z TO 18Z...SO BACKED OFF POPS OVER INTERIOR WEST HALF ALONG THE WI BORDER. KEPT CHC RAIN OR SNOW IN SOUTHERN PART OF CWA TUE AFTERNOON FOR NOW DUE TO THE EXPECTED HIGH TEMPS AROUND 40F. HOWEVER...WITH THE PASSAGE OF COLD FRONT...ANY RAIN WILL CHANGE BACK OVER TO SNOW PRETTY QUICKLY. 850MB TEMPS IMMEDIATELY BEHIND THE FRONT ARE AROUND -7C AND RAPIDLY DROP OFF TO -13C. WITH TEMPS THAT COLD...LES SHOULD LINGER BEHIND THE SYSTEM THROUGH TUESDAY NIGHT. WEDNESDAY...GFS IS HINTING AT A SHORTWAVE PRODUCING SNOW ACROSS THE ENTIRE CWA WED AFTERNOON. WILL NOT JUMP ON THE LATEST RUN...BUT NEXT SHIFTS WILL NEED TO KEEP AN EYE ON THIS. FOR NOW...KEPT CHC LES MAINLY ACROSS NORTH HALF OF CWA. THURSDAY...ECMWF AND GFS BOTH TRACK A MOISTURE-PACKED LOW PRESSURE SYSTEM WELL TO THE SOUTH OF OUR CWA. IN COORDINATION WITH GRB AND DLH...DECREASED POPS TO AROUND 30 FOR THU AFTERNOON. && .AVIATION (FOR THE 18Z TAF ISSUANCE)... VFR CONDITIONS WILL PREVAIL AT KCMX AND KSAW THRU THE AFTN. AHEAD OF AN APPROACHING LOW PRES SYSTEM TONIGHT...STRONG SRLY FLOW WILL DEVELOP. ALTHOUGH LOW-LEVEL WIND SHEAR HAS BEEN INCLUDED IN THE FCST...IT`S QUITE POSSIBLE THE LOW-LEVELS WILL REMAIN JUST MIXED ENOUGH DOWN TO THE SFC TO PREVENT DEVELOPMENT OF A WIND SHEAR LAYER. SNOW BAND CURRENTLY DEVELOPING OVER THE ERN DAKOTAS WILL MOVE EASTWARD ACROSS THE TAF SITES AFTER MIDNIGHT...WITH A 3-5 HR PERIOD OF IFR VIS AND MVFR CIGS...POSSIBLY DROPPING DOWN INTO THE LIFR VIS AND IFR CIG RANGE. WESTERLY WINDS IN THE WAKE OF THE SNOW BAND MAY GUST UP TO 30 KT BY LATE MORNING AT KCMX...DUE TO THE FUNNELING WIND DIRECTION. OTHERWISE...MVFR CIGS ARE EXPECTED TO PERSIST AT BOTH TAF SITES WITH LOW LEVEL MOISTURE REMAINING IN THE WAKE OF THE SNOW. SOME OF THESE CLOUDS MAY MIX OUT...BUT ANY SCATTERING OUT OF THE CLOUDS SHOULD NOT OCCUR UNTIL AFTER THE TAF FORECAST PERIOD. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... MAIN CONCERN IS ON SRLY GALES DEVELOPING TONIGHT AS LOW PRESSURE TRACKS TOWARD THE UPPER LAKES REGION. WELL AHEAD OF THE SYSTEM...SW WINDS WILL INCREASE TODAY INTO THE 20-30KT RANGE OVER MUCH OF LAKE SUPERIOR. PRES GRADIENT TIGHTENS FURTHER TONIGHT AS LOW MOVES CLOSER. WITH ASSISTANCE OF MAX PRESSURE FALLS PASSING ACROSS THE AREA...SRLY WINDS WILL LIKELY INCREASE TO GALES BY LATE EVENING OVER ROUGHLY THE E HALF OF LAKE SUPERIOR. GALES WILL ALSO OCCUR IN THE NEARSHORE WATERS E OF MUNISING...ESPECIALLY AROUND GRAND MARAIS WHICH TYPICALLY EXPERIENCES STRONG WINDS WITH SRLY FLOW. GRADIENT WILL SLACKEN SUFFICIENTLY FOR GALES TO END BY LATE TUE MORNING. AS THE LOW HEADS E TUE NIGHT...A PERIOD OF NW GALES WILL LIKELY OCCUR DURING THE EVENING...AGAIN MAINLY OVER THE E HALF OF LAKE SUPERIOR. WINDS SHOULD REMAIN UNDER 25KT FROM WED AFTN THRU FRI. OVER THE NRN LAKE MICHIGAN NEARSHORE WATERS (EXCLUDING THE BAY OF GREEN BAY)...SETUP LOOKS ESPECIALLY FAVORABLE FOR GALES TONIGHT INTO TUE MORNING AS TRACK OF MAX PRES FALLS JUST N OF LAKE MICHIGAN PROVIDES AN ADDED BOOST TO WINDS. NOT OUT OF THE QUESTION THAT HIGH END GALE FORCE GUSTS COULD OCCUR AT SOME POINT BTWN ABOUT 06Z AND 12Z TUE. IN THE WAKE OF THE LOW...NW WINDS TUE NIGHT SHOULD GENERALLY BE IN THE 15-25KT RANGE. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN...NONE LAKE SUPERIOR...GALE WARNING 11 PM THIS EVENING TO 10 AM EDT TUE LSZ250-251-266-267. LAKE MICHIGAN...GALE WARNING MIDNIGHT TONIGHT TO NOON EDT TUE LMZ248-250. && $$ DISCUSSION...MRC AVIATION...AJ MARINE...ROLFSON mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 155 PM EDT MON MAR 24 2008 .SYNOPSIS... AN UPPER LEVEL DISTURBANCE WITH COOL NORTHERLY FLOW NEAR THE SURFACE WILL DRIFT OFFSHORE TONIGHT. HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE GULF STATES ON TUESDAY. THIS HIGH PRESSURE SYSTEM WILL EXTEND FROM THE GULF STATES TO BERMUDA WED THROUGH FRI WITH A WARMING TREND AND DRY WEATHER OVER CENTRAL NC. && .NEAR TERM /THROUGH TUESDAY/... AS OF 1015 AM MONDAY... KRAX RADAR IMAGERY CURRENTLY SHOWS AREA OF PRECIPITATION LIFTING SLOWLY NE ACROSS THE FORECAST AREA. LIGHT SNOW WAS REPORTED ACROSS THE TRIAD AND AROUND ROXBORO EARLIER THIS MORNING...WITH ONLY RAIN SPRINKLES AROUND THE TRIANGLE. THIS AREA OF PRECIPITATION WAS IN ASSOCIATION WITH SHARPENING MID-LEVEL S/W...COINCIDENT WITH THE RIGHT ENTRANCE REGION OF A 130 KNOT UPPER LEVEL JET EXTENDING FROM THE CENTRAL APPALACHIANS NORTHEASTWARD OFF THE MID ATLANTIC COAST. THE RUC DID A GOOD JOB EARLIER THIS MORNING WITH INDICATING GOOD 925-850MB FRONTOGENESIS ALONG THE MID-LEVEL SHEAR AXIS AND ALONG THE LEADING EDGE OF DRIER AIR...THEN SHOWS WEAKENING AS THE ASSOCIATED TROUGH AXIS SHIFTS EASTWARD INTO THE COASTAL PLAIN THIS MORNING WITH FURTHER MID-LEVEL DRY AIR ENTRAINMENT. THUS EXPECT A LULL FOR THE REMAINDER OF THE MORNING AND INTO THE AFTERNOON...UNTIL LATER THIS AFTERNOON WITH INCREASING MID-LEVEL DYNAMICS/INSTABILITY COLD POOL ASSOCIATED WITH MID LEVEL WAVE. -CBL THE PARTIAL CLEARING AND ASSOCIATED INSOLATION WILL SET THE STAGE FOR ANOTHER ROUND OF SHOWERS THIS AFTERNOON AND EVENING...AS A POSITIVELY TILTED BUT AMPLIFYING UPPER LEVEL TROUGH EXTENDING FROM THE OHIO VALLEY SOUTHWESTWARD INTO THE LOWER MS VALLEY APPROACHES. STRONG MID LEVEL HEIGHT FALLS ON THE ORDER OF 50 TO 100 METERS/12 HRS AND THE APPROACH OF THE ASSOCIATED MID LEVEL COLD POOL (H5 TEMPS B/W -30 AND -35 C) AND STEEP MID LEVEL LAPSE RATES WILL OVERSPREAD THE CWA BETWEEN 18Z AND 06Z. THOUGH DEEP LAYER MOISTURE IS RATHER LIMITED (PWATS RANGING FROM .25 TO .50" W/E ACROSS THE CWA)... BELIEVE THE COMBINATION OF SFC HEATING BENEATH THE COLD POOL ALOFT AND STRONG DPVA AHEAD OF THE AMPLIFYING TROUGH WILL OVERCOME THE OVERALL RELATIVE DRYNESS OF THE COLUMN. IN FACT... THE SHOWERS OVER THE OHIO VALLEY AND UPPER MIDWEST WITH SIMILAR PWATS SUNDAY ARE A GOOD INDICATION OF WHAT WE CAN EXPECT OVER OUR AREA TODAY. THE HEAVIER SHOWERS WILL HAVE THE POTENTIAL TO PRODUCE WIND GUSTS TO NEAR 40 MPH... AS MID LEVEL DRY ENTRAINMENT AND SUB CLOUD DIABATIC COOLING WITH INVERTED-V MODEL FORECAST SOUNDINGS WILL ENHANCE DOWNDRAFT POTENTIAL. SUCH WIND GUSTS WILL BE MOST LIKELY FROM RDU WESTWARD... WHERE NEARLY DRY ADIABATIC LOW LEVEL LAPSE RATES WILL DEVELOP WITH THE EXPECTED PARTIAL CLEARING... WHILE THE LINGERING CLOUDS IN THE EAST WILL STUNT THE DEVELOPMENT OF SUCH LOW LEVEL LAPSE RATES IN THE EAST. LASTLY... A FEW WET FLAKES COULD MIX IN WITH THE RAIN SHOWERS IF THEY PERSIST LONG ENOUGH INTO THE EVENING HOURS... WHEN THE BOUNDARY LAYER COOLS SUFFICIENTLY TO SUPPORT SOMETHING OTHER THAN ALL LIQUID. ANY FLAKES WOULD HAVE NO IMPACT GIVEN THEIR FLEETING NATURE.-MWS CONCERNING TEMPERATURES...THE OBSERVED LOW LEVEL THICKNESS AT GSO THIS MORNING WAS 1294M. WITH WEAK LOW LEVEL COLD AIR ADVECTION WILL CONTINUE THIS MORNING...AND WITH THE LINGERING CLOUD COVER OVER THE OVER EASTERN NC AND THE RE-DEVELOPMENT OF CLOUDS WITH SHARPENINIG MID-LEVEL VORT...HAVE ELECTED TO LOWER TEMPERATURES TO THE 48-52 RANGE FROM NORTH TO SOUTH. IT IS POSSIBLE THAT THESE TEMPERATURES COULD STILL BE TOO WARM IF THE CLOUD COVER DOES NOT SCATTER OUT BY EARLY AFTERNOON. -BLS/CBL AFTER LINGERING AND DISSIPATING SHOWERS THROUGH MIDNIGHT... EXPECT CLEARING AND COLDER CONDITIONS IN THE WAKE OF THE UPPER TROUGH OVERNIGHT...AS HEIGHT RISES ALOFT AND SURFACE HIGH PRESSURE BUILD ACROSS OUR AREA. EXPECT LOW TO DIP INTO THE UPPER 20S TO AROUND 30 NW TO MID 30S SE. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... AS OF 145 PM MONDAY... MODELS FEATURE ZONAL FLOW ALOFT THIS PERIOD WITH MODEST HEIGHT RISES IN THE SERN U.S. ON THU. AT THE SURFACE...A 1030 MB HIGH CENTER NEAR SAVANNAH GA DRIFTS OFF THE COAST AND ELONGATES WITH AN AXIS WEST TO EAST FROM THE GULF STATES TO BEYOND BERMUDA. THIS RESULTS IN A RELATIVELY DRY AIRMASS OVER CENTRAL NC...WITH SUBSIDENCE WARMING AND DRYING IN LOWER TO MID LEVELS AND A MODERATE WARMING TREND AT THE SURFACE. THE MORE ACTIVE WEATHER TRACK REMAINS WELL NORTH OF THE AREA ACROSS THE OHIO VALLEY TO THE MID ATLANTIC STATES. OVERNIGHT LOWS CLOSE TO 40 ACROSS THE RAH CWA TUE NIGHT SHOULD GAIN 5-8 DEG FOR LOWS WED NIGHT. HIGHS UPPER 60S TO AROUND 70 WED SHOULD RISE TO 70-75 FOR THU UNDER FLEETING CIRRUS OTHERWISE MOSTLY SUNNY SKIES. -RFG && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... S OF 1115 AM MONDAY... THE PERIOD STARTS WITH A MODERATE LONG WAVE TROUGH ALOFT ACROSS THE WESTERN CONUS AND FLAT RIDGE OFF THE EAST COAST. A SURFACE RIDGE EXTENDS FROM THE GULF STREAM ATLANTIC INTO THE GULF OF MEXICO RESULTING IN WEST SOUTHWESTERLY FLOW ACROSS CENTRAL NC. FORECAST SOUNDINGS SHOW SUBSIDENCE WARMING AND DRYING IN THE MID LEVELS WITH PREDOMINANT WESTERLY FLOW THROUGH FRIDAY. THIS SHOULD YIELD ABOVE NORMAL TEMPERATURES WITH LOWS IN THE 50S AND HIGHS WELL INTO THE 70S TO AROUND 80. FRI NIGHT-SAT...MODELS ARE REASONABLY TOGETHER IN SHOWING A COLD FRONT APPROACHING FROM THE WEST FRI NIGHT. BUT THERE EXISTS A 6-12 HOUR UNCERTAINTY IN THE MOVEMENT OF THE FRONT ACROSS CENTRAL NC GIVEN RUN-TO-RUN VARIATIONS IN THE GFS AND AMONG OTHER MEMBERS OF THE MODEL SUITE. A PREVAILING WESTERLY COMPONENT IN THE LOWER LEVEL FLOW SUGGESTS MINIMAL MOISTURE CONVERGENCE POTENTIAL EAST OF THE MOUNTAINS AND ONLY A SCATTERING OF SHOWERS ACROSS THE RAH CWA WITH THE FRONT. POPS WILL BE KEPT IN THE SLIGHT OR SMALL CHANCE RANGE OF 20-30 PERCENT...MAINLY FOR SAT. THE AIRMASS SHOULD REMAIN MILD IN THE PREFRONTAL SECTOR FRI NIGHT WITH LOWS IN THE 50S. TEMPERATURES WILL BE IN TRANSITION FOR SAT AND WITH CLOUD COVER GREATEST TO THE NW... HIGHS SHOULD RANGE FROM NEAR 70 NW TO NEAR 80 SE. SAT NIGHT-MON...MODELS SHOW CONFLUENCE IN THE UPPER FLOW PATTERN OVER THE OHIO VALLEY BY SAT NIGHT. THIS SHOULD HELP PUSH COOLER DRIER AIR QUICKLY INTO THE REGION BEHIND THE FRONT OVERNIGHT. THE REPLACING AIRMASS IS MAINLY SOUTHERN STREAM CONTINENTAL TRAVERSING FROM THE CENTRAL PLAINS UP THE OHIO VALLEY AND THEN INTO NC. THIS SHOULD MEAN COOLING TEMPERATURES TO NEAR NORMAL FOR SUN. BY MONDAY...MODELS SHOW A LARGE MERIDIONAL RIDGE DOWN THE EAST COAST FROM A 1035-1040 MB CENTER OVER NEW ENGLAND AND THE MARITIMES. THIS SHOULD MAINTAIN A DRY AIRMASS EAST OF THE APPALACHIANS...BUT POSSIBLY CIRRUS OR MID CLOUD ADVANCEMENT FROM A PROGRESSIVE TROUGH IN THE CENTRAL CONUS LATE IN THE DAY. TEMPERATURES SHOULD REMAIN NEAR NORMAL WITH LOWS IN THE LOWER TO MID 40S AND HIGHS 65-70. -RFG && .AVIATION /18Z MONDAY THROUGH SATURDAY/... AS OF 1 PM MONDAY...AN EXTENSIVE CAA STRATOCU FIELD HAS MANIFESTED ITSELF ACROSS THE NC MTNS AND FOOTHILLS...BARELY CLIPPING THE WESTERN PIEDMONT...AS SHORT-TERM MODELS INDICATE INCREASING INSTABILITY ALOFT AS LOW-LEVEL LAPSE RATES (0 TO 3 KM) TO 8.0 TO 8.5C. MEANWHILE...ACROSS THE CENTRAL PIEDMONT...LOW STRATUS HAS BEEN SLOW TO THIN AND DISSIPATE...AS EASTWARD PUSH OF 850 CONVERGENT TROUGH AXIS HAS SLOWED DOWN DUE TO THE INTENSIFYING UPSTREAM MID-LEVEL S/W TROUGH. VISIBLE SATELLITE IMAGERY DEPICTS THE STRATUS SLOWLY ERODING ALONG THE EASTER EDGES...AS TEMPERATURES CLIMB INTO THE UPPER 40S...WITH FURTHER EROSION EXPECTED ON THE WESTERN FRINGES FROM CAA. AS THE SHARPENING MID-LEVEL TROUGH DIGS THROUGH THE SOUTHEAST LATE THIS AFTERNOON AND INTO THE EVENING...MID-LEVEL COLD CORE INSTABILITY SHOWERS WILL PASS NORTH TO SOUTH ACROSS THE FORECAST AREA. CEILINGS SHOULD REMAIN AT VFR...HOWEVER SOME OF THE STRONGER SHOWERS COULD TRANSFER A STIFF NORTHERLY WIND GUSTS OF 30 TO 35 KTS DOWN TO THE SURFACE. DUE TO THE EXPECTED SCATTERED NATURE OF THE SHOWER COVERAGE...WILL INCLUDE VCSH ONLY. CLOUDS WILL SCOUR OUT LATE THIS EVENING AS MID-LEVEL TROUGH PASSES EAST OF THE AREA...RESULTING IN CLEAR SKIES BY DAYBREAK. MAINLY VFR CONDITIONS EXPECTED THROUGH THE PERIOD. A COLD FRONT WILL APPROACH THE AREA ON SATURDAY. THERE IS THE POTENTIAL FOR MORNING FOG/STRATUS BY LATE WEEK (FRIDAY AND SATURDAY)...AS LOW-LEVEL MOISTURE INCREASES AHEAD OF THE APPROACHING FRONT. && .CLIMATE... WFO RALEIGH WILL START THE 2008 SPRING FROST/FREEZE PROGRAM WITH 4AM FORECAST PACKAGE ON MARCH 30TH. THIS DATE IS APPROXIMATELY A WEEK EARLIER ACROSS THE PIEDMONT THAN THE AVERAGE DATE FOR THE LAST SPRING FREEZE (APR 9TH)...DUE TO THE ABOVE NORMAL TEMPERATURES EXPERIENCED IN FEBRUARY (4 TO 5 DEGREES F) AND WITH MARCH CURRENTLY RUNNING 2 TO 3 DEGREES ABOVE NORMAL. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...RFG NEAR TERM...CBL SHORT TERM...RFG LONG TERM...RFG AVIATION...CBL CLIMATE...CBL nc