Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 11/15/12


AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
934 AM MST TUE NOV 13 2012 .UPDATE...WEAK SHORTWAVE CURRENTLY MOVING ACROSS AREA. WEB CAMS SUGGEST SOME VERY LIGHT SNOW FALLING OVER THE HIGHEST PEAKS OF SUMMIT AND GRAND COUNTIES...BUT HARD TO VERIFY. RADAR SHOWING SOME RETURNS ACROSS NORTHERN WELD COUNTY...BUT SURFACE OBS AND WEB CAMS THERE NOT INDICATING ANY PRECIPITATION REACHING GROUND. WAVE TO EXIT AREA BY THE AFTERNOON WITH CLEARING AND SUBSIDENCE IN ITS WAKE. LATEST RUC AND NAM HOLD ONTO MEASURABLE PRECIP OVER THE HIGHER MOUNTAINS AND NORTHEAST PLAINS THROUGH THE MORNING...THOUGH LOOKING OVERDONE ACROSS PLAINS. CURRENT FORECAST TRENDS STILL SEEM ON TRACK. TEMPERATURES TO BE A BIT TRICKY ACROSS WELD AND MORGAN COUNTIES...ESPECIALLY THE LOW LYING AREAS. MAY END UP TWEAKING THE VALUES AT THE LAST MINUTE...DEPENDING ON HOW LONG SURFACE INVERSION PERSISTS. WINDS LOOKING RESONABLE...PERHAPS A BIT MORE WIND NEEDED ACROSS MOUNTAINS AND FOOTHILLS TONIGHT WITH DEVELOPMENT OF MOUNTAIN WAVE. && .AVIATION...WINDS TRENDING TOWARD NORTHWEST ACROSS AREA AIRPORTS...WITH SPEEDS LESS THAN 8 KTS. LATEST RUC INDICATING A NORTHERLY COMPONENT BY 17Z CONTINUING THROUGH AROUND 00Z. OVERALL CURRENT TAF TRENDS SEEM ON TRACK. ONLY CHANGE WOULD BE TO INCLUDE A NORTHEAST COMPONENT AT DIA IN THE 20Z-22Z TIME FRAME WITH SPEEDS BELOW 8 KTS. && .PREV DISCUSSION... /ISSUED 400 AM MST TUE NOV 13 2012/ SHORT TERM...SHORTWAVE TROUGH PASSING THIS MORNING LOOKS TO BE A FEW HOURS FASTER THAN THE MODELS...SO WE MAY SEE THE HIGH CLOUD DECK CLEARING DENVER LATE THIS MORNING. THERE ARE SOME CLOUDS JUST ABOVE MOUNTAINTOP BEHIND THE TROUGH AXIS...SO SOME CLOUDS WILL LINGER WEST OF THE DIVIDE THIS MORNING AND POSSIBLY MUCH OF THE DAY. WILL HANG ON TO THE ISOLATED LIGHT SNOW SHOWERS IN ZONE 31 AS THESE CLOUDS SKIM OVER THE RIDGES. WEAK PRESSURE RISES BEHIND THE TROUGH SHOULD PRODUCE A TENDENCY TOWARD WIND ROTATING THROUGH NORTHWEST AND NORTH THIS MORNING...THOUGH SPEEDS WILL LIKELY STILL BE PRETTY LIGHT UNDER THE INVERSION. PROBABLY JUST LIGHT THIS AFTERNOON AS THE PRESSURE WAVE WASHES OUT. I DID WARM TEMPERATURES IN AND NEAR THE MOUNTAINS A LITTLE IN LIGHT OF YESTERDAYS HIGHS AND EXPECTED WARMING. PRETTY WELL LEFT THE PLAINS ALONE...HARD TO TELL HOW MUCH IMPACT ANY NORTH WINDS WILL HAVE IN THE DENVER AREA BUT LEFT A PATTERN OF COOLER TEMPERATURES OUT AROUND DIA AND WARMER NEAR THE MOUNTAINS. EXPECTING SOME HIGH CLOUDS TO RETURN TONIGHT AS ANOTHER JET STREAK PASSES NORTH OF US. WARM ADVECTION ALOFT AND A LITTLE MORE FLOW WILL LIKELY ALSO PRODUCE A MOUNTAIN WAVE WITH ASSOCIATED CLOUDS AND STRONGER WINDS OVER THE FRONT RANGE. AT THIS TIME NOT EXPECTING STRONG WINDS TO PENETRATE THE INVERSION HOWEVER...MAYBE SOME GUSTS TO 40 MPH IN THE FOOTHILLS AT TIMES ON THE INTERFACE. LONG TERM...MODELS KEEP THE WEST-NORTHWESTERLY FLOW ALOFT OVER THE FORECAST AREA WEDNESDAY THROUGH THURSDAY NIGHT. THERE IS A VERY WEAK UPPER TROUGH TO GRAZE THE NORTHEASTERN CWA AROUND 12Z THURSDAY MORNING. THERE IS AN UPPER RIDGE AXIS OVER THE FORECAST AREA BY 06Z THURSDAY NIGHT AND THE FLOW ALOFT BECOMES DUE WESTERLY. FOR THE MOST PART...THE SYNOPTIC SCALE ENERGY FOR THE CWA IS NEUTRAL THROUGH THE FOUR PERIODS. LOW LEVEL PRESSURE AND WIND FIELDS SHOW SOUTHWESTERLY DOWNSLOPING BOUNDARY LAYER WINDS WEDNESDAY. A WEAK COLD FRONT MOVES ACROSS THE FORECAST AREA EARLY THURSDAY MORNING WITH SOME WEAK UPSLOPE THURSDAY. BY LATE DAY...SOUTHEASTERLIES COVER THE PLAINS. FAIRLY STRONG SOUTHERLY FLOW IS PROGGED THURSDAY NIGHT...ESPECAILLY OVER THE EASTERN HALF OF THE PLAINS. FOR MOISTURE...MODELS HAVE VARIOUS AMOUNTS IN THE MID AND UPPER LEVELS MUCH OF THE FOUR PERIODS...WITH THE GFS SHOWING MORE THAN THE NAM. THERE IS NO MEASURABLE PRECIPITATION OVER THE CWA ON THE QPF FIELDS MUCH OF THE TIME. THE EXCEPTION IS BETWEEN 06Z AND 12Z WEDNESDAY NIGHT...THERE A TINY BIT IS PROGGED OVER THE FAR NORTHWESTERN CORNER. WILL GO WITH NO POPS THIS TIME AROUND. FOR TEMPERATURES...WEDNESDAY`S HIGHS ARE PROGGED TO BE 1.5-3.0 C WARNER THAN TODAY`S. THURSDAY HIGHS COOL OFF A TAD...1-3 C FROM WEDNESDAY`S HIGHS. FOR THE LATER DAYS...FRIDAY THROUGH MONDAY...MODELS MAINLY KEEP FAIRLY WEAK ZONAL FLOW ALOFT FOR THE CWA. THERE MAY BE A PIDDLY UPPER TROUGH SATURDAY NIGHT INTO SUNDAY...OR NOT. WILL LEAVE SOME MINOR ALPINE POPS GOING SATURDAY NIGHT INTO EARLY SUNDAY. TEMPERATURES STAY WARMER THAN NORMAL. AVIATION...VFR CONDITIONS AND LIGHT WINDS TODAY. SOME UNCERTAINTY ABOUT DIRECTION BUT EXPECT SEVERAL HOURS WITH A NORTHERLY COMPONENT AROUND MIDDAY. BACK TO SOUTH/WEST DRAINAGE WINDS THIS EVENING. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...D-L LONG TERM....RJK AVIATION...D-L
AREA FORECAST DISCUSSION
NWS TOPEKA KS
551 PM CST WED NOV 14 2012 ...UPDATE TO AVIATION... .DISCUSSION... SHORT TERM FORECAST - TONIGHT AND THURSDAY... 21Z RAP SURFACE ANALYSIS INDICATES A WEAK AREA OF BROAD LOW PRESSURE OVER THE HIGH PLAINS WITH ANOTHER BROAD AREA OF HIGH PRESSURE OVER THE SE CONUS. BETWEEN THESE TWO FEATURES A WEAK SURFACE PRESSURE GRADIENT HAS CAUSED SOUTHERLY WINDS AROUND 5 TO 10 MPH TO PERSIST THROUGHOUT THE DAY. EXPECT THESE SOUTHERLY WINDS TO PERSIST OVERNIGHT AROUND 5 MPH...WHICH MAY HELP TO KEEP TEMPS SLIGHTLY WARMER THAN TUESDAY NIGHT AS LOWS ARE EXPECTED TO STAY IN THE LOWER TO MID 30S. THURSDAY WILL LIKELY BE A REPEAT OF WEDNESDAY WITH SUNNY SKIES...HOWEVER WINDS MAY BE SLIGHTLY MORE OUT OF THE WEST THAN WEDNESDAY AND THIS MAY ALLOW FOR TEMPS TO RISE SLIGHTLY HIGHER THAN WEDNESDAY...WITH HIGHS EXPECTED TO BE IN THE LOWER 60S. JL LONG TERM - THURSDAY NIGHT THROUGH WEDNESDAY... THE LONG TERM PERIOD WILL BE ON THE QUIET SIDE WITH A RATHER DRY AIRMASS REMAINING ENTRENCHED ACROSS THE PLAINS. THE FLOW PATTERN ALOFT WILL SEE A FEW DISTURBANCES MOVE THROUGH THE REGION. THE FIRST MOVES THROUGH ON THURSDAY NIGHT BUT IS A FAST MOVING SYSTEM THROUGH A MOISTURE STARVED REGION...WHICH WILL RESULT IN A DRY FRONTAL PASSAGE AND A SLIGHTLY COOLER AIRMASS FOR FRIDAY AND SATURDAY. THE UPPER FLOW WILL BECOME MORE SOUTHWESTERLY FOR THE WEEKEND WITH WARM ADVECTION ALOFT AND A WEAK DISTURBANCE SCHEDULED TO AFFECT THE AREA BY SUNDAY EVENING. TEMPERATURES WILL BE ABOVE NORMAL INTO SUNDAY NIGHT...AND CURRENT INDICATIONS SUGGEST THAT SUFFICIENT MOISTENING WILL OCCUR IN ADVANCE OF THIS DISTURBANCE TO PROVIDE A CHANCE FOR SCATTERED SHOWERS ON SUNDAY NIGHT AND EARLY MONDAY IN A ZONE OF DEEP ASCENT IMMEDIATELY IN ADVANCE OF THE SHORT WAVE. A SLIGHTLY DEEPER TROUGH WILL QUICKLY FOLLOW AND MERGE WITH THE INITIAL SHORT WAVE TROUGH BY MONDAY NIGHT. WHILE THIS WILL BE A DEEPER SYSTEM...ANY PRECIPITATION WILL LIKELY HOLD OFF UNTIL THE TWO WAVES MERGE AND STRENGTHEN...EAST OF THE FORECAST AREA. SO HAVE A DRY FORECAST BEYOND MONDAY WITH CONTINUED ABOVE NORMAL TEMPERATURES AS UPPER RIDGING AND WARM ADVECTION BUILD INTO THE REGION THROUGH MID WEEK. BARJENBRUCH && .AVIATION... VFR CONDITIONS WITH LIGHT WINDS EXPECTED THROUGH THE PERIOD. WIND SHIFT TOT HE WEST AND NORTHWEST AFTER 19Z AS A SURFACE BOUNDARY MOVES THROUGH THE TERMINALS. 53 && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
316 PM EST TUE NOV 13 2012 .SYNOPSIS... IN THE WAKE OF A COLD FRONT...A COOLER ARCTIC AIR MASS WILL CONTINUE TO BUILD INTO THE AREA THIS EVENING WITH A FEW FLURRIES POSSIBLE ACROSS THE NORTH. HIGH PRESSURE BUILDING IN FROM THE SOUTHWEST WILL ALLOW FOR DRY WEATHER AND INCREASED SUNSHINE FOR THE REMAINDER OF THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A MID-LEVEL TROUGH ACROSS EASTERN CANADA WITH THE UPPER OHIO VALLEY AT THE BASE OF THIS FEATURE. IN THE WAKE OF A COLD FRONT...COLD AIR ADVECTION IS ONGOING WITH 850MB TEMPS COOLING TO -7C TO -10C ACROSS THE AREA. A NORTHWESTERLY 850MB FLOW OFF OF LAKE ERIE ALONG WITH THE TROUGH AXIS ALOFT HAVE PROVIDED MOSTLY CLOUDY SKIES ACROSS MUCH OF THE AREA WITH A FEW FLURRIES NORTH OF PITTSBURGH. TONIGHT...SURFACE RIDGING WILL BUILD INTO THE AREA...WITH A HIGH CENTERED ACROSS LAKE ERIE BY 06Z WED. THIS BRING AN END TO CAA...AS WAA AT 850MB RETURNS WITH THE RIDGE. RIDGING WILL ALLOW FOR CLOUD COVERAGE TO BEGIN TO DECREASE FROM THE SOUTHWEST OVERNIGHT. THERE IS STILL SOME UNCERTAINTY IN LOW TEMP FORECAST TONIGHT AS IT WILL BE DEPENDENT ON CLEARING/RETREATING OF STRATOCUMULUS. LOCATIONS WHERE CLEARING OCCURS WILL HAVE OVERNIGHT TEMPS DROP OFF QUITE A BIT WITH RADIATIONAL COOLING. WITH THIS IN MIND...LOWS RANGE FROM THE LOWER 20S IN EASTERN OHIO AND THE RIDGES OF WV/MD TO THE MID 20S IN WESTERN PA. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY/... THE ORIGINAL SURFACE HIGH ACROSS THE AREA WILL SHIFT NORTHEAST OF THE REGION ON WEDNESDAY NIGHT WITH ANOTHER HIGH FROM THE NORTHERN PLAINS MOVING OVER THE REGION BY FRIDAY. THIS WILL ALLOW FOR A DRY PATTERN TO CONTINUE ACROSS THE FORECAST AREA. EARLY STRATOCUMULUS WILL DIMINISH ON WEDNESDAY WITH SKIES CLEARING AS DRIER AND WARMER LOW-LEVEL AIR ADVECTS IN FROM THE SOUTHWEST. THERE IS OPERATIONAL MODEL AGREEMENT THAT A SHORT WAVE TROUGH WILL MOVE FROM THE CENTRAL PLAINS INTO THE TENNESSEE VALLEY...BRINGING CIRRUS TO THE THE AREA FOR THURSDAY AND FRIDAY. TEMPERATURES WILL SLOWLY MODERATE EACH DAY...WITH 850MB TEMPS WARMING TO AROUND 2-3C ON WEDNESDAY AND LITTLE THERMAL ADVECTION FOR THURSDAY AND FRIDAY. THERE IS LITTLE VARIATION BETWEEN DETERMINISTIC MODELS IN TEMPS WITH HIGHS FORECAST TO BE AROUND 5 DEGREES BELOW NORMAL THROUGH THIS PERIOD. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... A QUIET EXTENDED PERIOD AS A BROAD AREA OF HIGH PRESSURE WILL DOMINATE THE REGION. DO EXPECT AN INCREASE IN CLOUDS LATE SUNDAY INTO TUESDAY AS AN AREA OF LOW PRESSURE ALOFT MOVES SOUTH OF THE UPPER OHIO VALLEY...AND THE ASSOCIATED COASTAL LOW MOVES NORTH ALONG THE EASTERN SEABOARD. NO PRECIPITATION IS EXPECTED FROM THIS SYSTEM BASED ON CURRENT EXPECTED MOVEMENT. TEMPERATURES CLOSE TO HPC PROGS. && .AVIATION /20Z TUESDAY THROUGH SUNDAY/... MODEL SOUNDINGS INDICATE STRATUS WILL BE TRAPPED UNDER INVERSION INTO THE EVENING ESPECIALLY FROM PITTSBURGH NORTH. FOR PORTIONS OF EASTERN OHIO AND AREAS SOUTH OF PITTSBURGH STRATOCU APPEARS MORE DIURNAL ON VIS SAT PIX AND SHOULD BE EASIER TO MIX OUT THIS EVENING. HAVE KEPT VFR BKN CIGS IN TERMINALS FROM 00Z AT ZZV TO 04Z AT KDUJ. SKIES SHOULD THEN BEGIN TO CLEAR AS SURFACE RIDGE CONTINUES TO BUILD EAST. MAINLY CLEAR WEDNESDAY. WINDS WILL BE LIGHT OVERNIGHT AND THEN NORTHEAST UNDER 10 KTS WEDNESDAY. .OUTLOOK.../WEDNESDAY NIGHT THROUGH SUNDAY/... VFR WILL REMAIN PREVALENT THIS PERIOD DUE TO HIGH PRESSURE SUBSIDENCE. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ SYNOPSIS...WOODRUM NEAR TERM...WOODRUM SHORT TERM...WOODRUM LONG TERM...RSMITH AVIATION...RSMITH
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1144 AM EST TUE NOV 13 2012 .SYNOPSIS... IN THE WAKE OF A COLD FRONT...A COOLER ARCTIC AIR MASS WILL CONTINUE TO BUILD INTO THE AREA TODAY WITH A FEW LAKE EFFECT SNOW SHOWERS POSSIBLE ACROSS THE NORTH. HIGH PRESSURE BUILDING IN FROM THE SOUTHWEST WILL ALLOW FOR DRY WEATHER AND INCREASED SUNSHINE FOR THE REMAINDER OF THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... A QUICK UPDATE HAS BEEN ISSUED TO INCREASE CLOUD COVERAGE TODAY FOR LOCATIONS SOUTH OF PITTSBURGH. OTHERWISE...NO CHANGE TO THE ONGOING FORECAST. THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A MID-LEVEL TROUGH ACROSS EASTERN CANADA WITH THE UPPER OHIO VALLEY AT THE BASE OF THIS FEATURE. IN THE WAKE OF A COLD FRONT...COLD AIR ADVECTION IS ONGOING WITH 850MB TEMPS COOLING TO -4C TO -8C ACROSS THE AREA. 850MB FLOW AT 280-290 DEGREES OFF OF LAKE ERIE ALONG WITH THE TROUGH AXIS ALOFT HAVE PROVIDED MOSTLY CLOUDY SKIES NORTH OF THE PITTSBURGH METRO. SOUTHWARD...LOW-LEVEL MOISTURE HAS BEEN SUFFICIENT FOR DIURNAL CUMULUS TO DEVELOP. TODAY...THE FORECAST AREA WILL REMAIN IN A COOL...WESTERLY 850MB FLOW WITH A SLIGHT NORTHERLY COMPONENT ALLOWING FOR CLOUDY SKIES NORTH OF PITTSBURGH AND MOSTLY CLOUDY SKIES SOUTHWARD. HRRR SUPPORTS A FEW LAKE EFFECT SNOW SHOWERS ALONG THE I-80 CORRIDOR...ALTHOUGH INVERSION HEIGHTS BELOW 5000FT WILL LIMIT SNOW SHOWERS FOR THE MOST PART. SUBSIDENCE WITH HIGH PRESSURE BUILDING IN FROM THE MISSOURI VALLEY WILL PREVENT SHOWERS ELSEWHERE. WITH CAA ONGOING AND CLOUD COVERAGE...TEMPS WILL STRUGGLE TO REACH 40 ACROSS MOST OF THE AREA TODAY. HIGHS WILL RANGE FROM LOWER 30S ACROSS THE EASTERN RIDGES TO THE LOWER 40S IN PORTIONS OF EASTERN OHIO AND NORTH-CENTRAL WV. TONIGHT...SURFACE RIDGING WILL BUILD INTO THE AREA...WITH A HIGH CENTERED ACROSS LAKE ERIE BY 06Z WED. THIS BRING AN END TO CAA...AS WAA AT 850MB RETURNS WITH RIDGING. RIDGING WILL ALLOW FOR SKIES GRADUALLY CLEARING. RADIATIONAL COOLING TONIGHT WILL BRING LOWS WELL INTO THE 20S WITH LIGHT WINDS. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY/... SURFACE HIGH PRESSURE WILL REMAIN ACROSS THE OHIO VALLEY THROUGH THE TIME PERIOD. ALTHOUGH AN UPPER LEVEL SHORTWAVE WILL MOVE ACROSS THE EASTERN UNITED STATES THURSDAY INTO THURSDAY NIGHT...A GENERAL LACK OF ASSOCIATED MOISTURE SHOULD DO LITTLE MORE THAN INCREASE CLOUD COVER. TEMPERATURES WILL SLOWLY RETURN TO NEAR NORMAL LEVELS BY THE END OF THE WORK WEEK. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... DRY AND SEASONABLY COOL WEATHER IS EXPECTED THROUGH THE WEEKEND INTO EARLY NEXT WEEK. ALTHOUGH A STORM MAY DEVELOP OFF THE EAST COAST OVER THE WEEKEND...IT APPEARS AT THIS TIME THAT THERE IS ONLY A SLIGHT CHANCE OF THE PRECIPITATION SHIELD BRUSHING THE RIDGES. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... AREA OF STRATOCU ACROSS THE I-80 CORRIDOR WILL REMAIN IN PLACE THROUGH THE AFTERNOON. ELSEWHERE STRATOCU WAS BEING DEPLETED BY DRIER AIR WORKING IN ON WESTERLY FLOW, BUT COLDER 850MB TEMPS HELPING CU TO FILL BACK IN. OVERALL VFR CIGS WITH OCNL MVFR ACROSS THE NORTH. INCOMING HIGH PRESSURE SHOULD PROMOTE VFR CONDITIONS AREA WIDE BY TONIGHT. SURFACE WINDS WILL BE MAINLY FROM THE WEST AT NO MORE THAN 10 KTS TODAY...THEN BECOME LIGHT TONIGHT. .OUTLOOK.../WEDNESDAY THROUGH SATURDAY/... VFR WILL REMAIN PREVALENT THIS PERIOD DUE TO HIGH PRESSURE SUBSIDENCE. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1052 AM EST TUE NOV 13 2012 .SYNOPSIS... IN THE WAKE OF A COLD FRONT...A COOLER ARCTIC AIR MASS WILL CONTINUE TO BUILD INTO THE AREA TODAY WITH A FEW LAKE EFFECT SNOW SHOWERS POSSIBLE ACROSS THE NORTH. HIGH PRESSURE BUILDING IN FROM THE SOUTHWEST WILL ALLOW FOR DRY WEATHER AND INCREASED SUNSHINE FOR THE REMAINDER OF THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... 15Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO INCREASE CLOUD COVERAGE ACROSS THE FORECAST AREA. THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A MID-LEVEL TROUGH ACROSS EASTERN CANADA WITH THE UPPER OHIO VALLEY AT THE BASE OF THIS FEATURE. IN THE WAKE OF A COLD FRONT...COLD AIR ADVECTION IS ONGOING WITH 850MB TEMPS COOLING TO -4C TO -8C ACROSS THE AREA. 850MB FLOW AT 280-290 DEGREES OFF OF LAKE ERIE ALONG WITH THE TROUGH AXIS ALOFT HAVE PROVIDED MOSTLY CLOUDY SKIES NORTH OF THE PITTSBURGH METRO. SOUTHWARD...LOW-LEVEL MOISTURE HAS BEEN SUFFICIENT FOR DIURNAL CUMULUS TO DEVELOP. TODAY...THE FORECAST AREA WILL REMAIN IN A COOL...WESTERLY 850MB FLOW WITH A SLIGHT NORTHERLY COMPONENT ALLOWING FOR MOSTLY CLOUDY SKIES NORTH OF PITTSBURGH AND PARTLY SUNNY SKIES SOUTHWARD. HRRR SUPPORTS A FEW LAKE EFFECT SNOW SHOWERS ALONG THE I-80 CORRIDOR...ALTHOUGH INVERSION HEIGHTS BELOW 5000FT WILL LIMIT SNOW SHOWERS FOR THE MOST PART. SUBSIDENCE WITH HIGH PRESSURE BUILDING IN FROM THE MISSOURI VALLEY WILL PREVENT SHOWERS ELSEWHERE. WITH CAA ONGOING AND CLOUD COVERAGE...TEMPS WILL STRUGGLE TO REACH 40 ACROSS MOST OF THE AREA TODAY. HIGHS WILL RANGE FROM LOWER 30S ACROSS THE EASTERN RIDGES TO THE LOWER 40S IN PORTIONS OF EASTERN OHIO AND NORTH-CENTRAL WV. TONIGHT...SURFACE RIDGING WILL BUILD INTO THE AREA...WITH A HIGH CENTERED ACROSS LAKE ERIE BY 06Z WED. THIS BRING AN END TO CAA...AS WAA AT 850MB RETURNS WITH RIDGING. RIDGING WILL ALLOW FOR SKIES GRADUALLY CLEARING. RADIATIONAL COOLING TONIGHT WILL BRING LOWS WELL INTO THE 20S WITH LIGHT WINDS. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY/... SURFACE HIGH PRESSURE WILL REMAIN ACROSS THE OHIO VALLEY THROUGH THE TIME PERIOD. ALTHOUGH AN UPPER LEVEL SHORTWAVE WILL MOVE ACROSS THE EASTERN UNITED STATES THURSDAY INTO THURSDAY NIGHT...A GENERAL LACK OF ASSOCIATED MOISTURE SHOULD DO LITTLE MORE THAN INCREASE CLOUD COVER. TEMPERATURES WILL SLOWLY RETURN TO NEAR NORMAL LEVELS BY THE END OF THE WORK WEEK. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... DRY AND SEASONABLY COOL WEATHER IS EXPECTED THROUGH THE WEEKEND INTO EARLY NEXT WEEK. ALTHOUGH A STORM MAY DEVELOP OFF THE EAST COAST OVER THE WEEKEND...IT APPEARS AT THIS TIME THAT THERE IS ONLY A SLIGHT CHANCE OF THE PRECIPITATION SHIELD BRUSHING THE RIDGES. && .AVIATION /15Z TUESDAY THROUGH SATURDAY/... AREA OF STRATOCU ACROSS THE I-80 CORRIDOR WILL REMAIN IN PLACE THROUGH THE AFTERNOON. ELSEWHERE STRATOCU WAS BEING DEPLETED BY DRIER AIR WORKING IN ON WESTERLY FLOW, BUT COLDER 850MB TEMPS HELPING CU TO FILL BACK IN. OVERALL VFR CIGS WITH OCNL MVFR ACROSS THE NORTH. INCOMING HIGH PRESSURE SHOULD PROMOTE VFR CONDITIONS AREA WIDE BY TONIGHT. SURFACE WINDS WILL BE MAINLY FROM THE WEST AT NO MORE THAN 10 KTS TODAY...THEN BECOME LIGHT TONIGHT. .OUTLOOK.../WEDNESDAY THROUGH SATURDAY/... VFR WILL REMAIN PREVALENT THIS PERIOD DUE TO HIGH PRESSURE SUBSIDENCE. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
721 AM EST TUE NOV 13 2012 .SYNOPSIS... TEMPERATURES HAVE DROPPED SHARPLY BEHIND A COLD FRONT...BUT DRY CONDITIONS ARE EXPECTED FOR THE REST OF THE WEEK AS TEMPERATURES SLOWLY MODERATE. && .NEAR TERM /THROUGH TONIGHT/... EARLY MORNING UPDATE TO ADJUST SKY GRIDS FOR MORE CLOUDS THIS MORNING PITTSBURGH AND NORTH WITH CLEAR SKIES ACROSS THE SOUTH EXCEPT FOR THE RIDGES. NO CHANGE TO FORECAST HIGHS. PREVIOUS DISCUSSION FOLLOWS. WINDS WILL GET A BIT OF A NORTHERLY COMPONENT TODAY...ENOUGH THAT SOME ADDITIONAL MOISTURE SHOULD BE TAPPED FROM LAKE ERIE. HOWEVER...WITH LOW INVERSION HEIGHTS...THINK THAT ONLY THE VERY NORTHERN COUNTIES COULD POSSIBLY SEE AN ISOLATED SHOWER. EVEN WITHOUT PRECIPITATION...CLOUDS ARE EXPECTED TO STICK AROUND MUCH OF THE DAY NORTH AND EAST OF PITTSBURGH. WITH MODELS APPEARING TO BE A BIT LOW WITH CLOUD COVER...WENT A COUPLE DEGREES BELOW TEMPERATURE GUIDANCE FOR HIGHS...WHICH IS ALREADY 10-15 DEGREES BELOW NORMAL. BY TONIGHT SURFACE RIDGE WILL WORK ACROSS REGION CUTTING OFF FLOW FROM LAKE. SKIES WILL GRADUALLY CLEAR BRINGING A COLD NIGHT WITH LOWS WELL INTO THE 20S WITH LIGHT WINDS. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY/... SURFACE HIGH PRESSURE WILL REMAIN ACROSS THE OHIO VALLEY THROUGH THE TIME PERIOD. ALTHOUGH AN UPPER LEVEL SHORTWAVE WILL MOVE ACROSS THE EASTERN UNITED STATES THURSDAY INTO THURSDAY NIGHT...A GENERAL LACK OF ASSOCIATED MOISTURE SHOULD DO LITTLE MORE THAN INCREASE CLOUD COVER. TEMPERATURES WILL SLOWLY RETURN TO NEAR NORMAL LEVELS BY THE END OF THE WORK WEEK. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... DRY AND SEASONABLY COOL WEATHER IS EXPECTED THROUGH THE WEEKEND INTO EARLY NEXT WEEK. ALTHOUGH A STORM MAY DEVELOP OFF THE EAST COAST OVER THE WEEKEND...IT APPEARS AT THIS TIME THAT THERE IS ONLY A SLIGHT CHANCE OF THE PRECIPITATION SHIELD BRUSHING THE RIDGES. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... BLEND OF RECENT SURFACE AND SATELLITE DATA COUPLED WITH RAP AND NAM MODEL OUTPUT SHOW POST FRONTAL STRATOCUMULUS CAN LINGER ACROSS THE UPPER OHIO VALLEY TODAY. COVERAGE WILL VARY BETWEEN SCATTERED AND BROKEN WITH CEILINGS MAINLY IN VFR RANGE. THE LONE EXCEPTION MAY BE ACROSS NORTHWEST PENNSYLVANIA WHERE POST SYSTEM COLD POOL LAKE-ENHANCED INSTABILITY CAN RENEW MVFR STRATOCUMULUS AND ISOLATED SHOWERS IN VICINITY OF KFKL AND KDUJ THROUGH AFTERNOON. INCOMING HIGH PRESSURE SHOULD PROMOTE VFR CONDITIONS AREA WIDE BY TONIGHT. SURFACE WINDS WILL BE MAINLY FROM THE WEST AT NO MORE THAN 10 KTS TODAY...THEN BECOME LIGHT TONIGHT. .OUTLOOK.../WEDNESDAY THROUGH SATURDAY/... VFR WILL REMAIN PREVALENT THIS PERIOD DUE TO HIGH PRESSURE SUBSIDENCE. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
615 AM EST TUE NOV 13 2012 .SYNOPSIS... TEMPERATURES HAVE DROPPED SHARPLY BEHIND A COLD FRONT...BUT DRY CONDITIONS ARE EXPECTED FOR THE REST OF THE WEEK AS TEMPERATURES SLOWLY MODERATE. && .NEAR TERM /THROUGH TONIGHT/... A FEW ISOLATED SHOWERS REMAIN ACROSS THE SOUTHEASTERN RIDGES...BUT ALL PRECIPITATION SHOULD SHIFT EAST BY SUNRISE. PLENTY OF CLOUDS REMAIN IN THE WAKE OF THE COLD FRONT...ALTHOUGH THERE IS SOME PARTIAL CLEARING SOUTH AND WEST OF WHEELING. WINDS WILL GET A BIT OF A NORTHERLY COMPONENT TODAY...ENOUGH THAT SOME ADDITIONAL MOISTURE SHOULD BE TAPPED FROM LAKE ERIE. HOWEVER...WITH LOW INVERSION HEIGHTS...THINK THAT ONLY THE VERY NORTHERN COUNTIES COULD POSSIBLY SEE AN ISOLATED SHOWER. EVEN WITHOUT PRECIPITATION...CLOUDS ARE EXPECTED TO STICK AROUND MUCH OF THE DAY NORTH AND EAST OF PITTSBURGH. WITH MODELS APPEARING TO BE A BIT LOW WITH CLOUD COVER...WENT A COUPLE DEGREES BELOW TEMPERATURE GUIDANCE FOR HIGHS...WHICH IS ALREADY 10-15 DEGREES BELOW NORMAL. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY/... SURFACE HIGH PRESSURE WILL REMAIN ACROSS THE OHIO VALLEY THROUGH THE TIME PERIOD. ALTHOUGH AN UPPER LEVEL SHORTWAVE WILL MOVE ACROSS THE EASTERN UNITED STATES THURSDAY INTO THURSDAY NIGHT...A GENERAL LACK OF ASSOCIATED MOISTURE SHOULD DO LITTLE MORE THAN INCREASE CLOUD COVER. TEMPERATURES WILL SLOWLY RETURN TO NEAR NORMAL LEVELS BY THE END OF THE WORK WEEK. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... DRY AND SEASONABLY COOL WEATHER IS EXPECTED THROUGH THE WEEKEND INTO EARLY NEXT WEEK. ALTHOUGH A STORM MAY DEVELOP OFF THE EAST COAST OVER THE WEEKEND...IT APPEARS AT THIS TIME THAT THERE IS ONLY A SLIGHT CHANCE OF THE PRECIPITATION SHIELD BRUSHING THE RIDGES. && .AVIATION /11Z TUESDAY THROUGH SATURDAY/... BLEND OF RECENT SURFACE AND SATELLITE DATA COUPLED WITH RAP AND NAM MODEL OUTPUT SHOW POSTFRONTAL STRATOCUMULUS CAN LINGER ACROSS THE UPPER OHIO VALLEY TODAY. COVERAGE WILL VARY BETWEEN SCATTERED AND BROKEN WITH CEILINGS MAINLY IN VFR RANGE. THE LONE EXCEPTION MAY BE ACROSS NORTHWEST PENNSYLVANIA WHERE POST SYSTEM COLD POOL LAKE-ENHANCED INSTABILITY CAN RENEW MVFR STRATOCUMULUS AND ISOLATED SHOWERS IN VICINITY OF KFKL AND KDUJ THROUGH AFTERNOON. INCOMING HIGH PRESSURE SHOULD PROMOTE VFR CONDITIONS AREA WIDE BY TONIGHT. SURFACE WINDS WILL BE MAINLY FROM THE WEST AT NO MORE THAN 10 KTS TODAY...THEN BECOME LIGHT TONIGHT. .OUTLOOK.../WEDNESDAY THROUGH SATURDAY/... VFR WILL REMAIN PREVALENT THIS PERIOD DUE TO HIGH PRESSURE SUBSIDENCE. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1229 PM EST TUE NOV 13 2012 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 440 AM EST TUE NOV 13 2012 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR TROF OVER THE GREAT LAKES BTWN RDG OFF THE E COAST AND A MORE ZONAL FLOW OVER WRN NAMERICA. SINCE THE FASTEST WINDS ALF ARE ON THE E SIDE OF THE UPR TROF...THIS IS A STRONG SIGNAL THIS TROF IS WEAKENING AND LIFTING TO THE NE. IN FACT...12Z-24Z H5 HGT RISES IN EXCESS OF 100M AND EVEN 150M OCCURRED OVER MUCH OF THE NCENTRAL CONUS BEHIND THE UPR TROF. FAIRLY SHARP LLVL CYC WNW FLOW OVER THE GREAT LKS UNDER THE UPR TROF TRANSITIONS QUICKLY TO A SHARP SFC RDG AXIS OVER MN UNDER THESE HGT RISES/SUBSIDENCE. BUT QUITE A BIT OF LLVL MSTR LINGERS PER THE 00Z INL RAOB...SO A LO CLD OVC LINGERS ALL THE WAY W TO THE RDG AXIS. CLOSER TO HOME...LES RESPSONSIBLE FOR UP TO 6 INCHES OF SN LINGERS OVER THE W AS OF 06Z...WITH THE MORE PRONOUNCED REFLECTIVITIES FROM ONTAONGAON TOWARD THE HURON MTNS WHERE SHARP LLVL CNVGC BTWN LARGER SCALE WNW FLOW OVER THE KEWEENAW AND A MORE WSW LAND BREEZE FLOW OFF NW WI THAT IS INFLUENCING THE AREA CLOSER TO THE WI BORDER. LATEST TRENDS SHOW REFLECTIVITIES TENDING TO WEAKEN TO THE W...A SIGN THE STRONG SUBIDENCE MOVING IN FM THE W MIGHT BE HAVING AN IMPACT. AS FCST ISSUANCE APRCHS...THE RADAR REFLECTIVIES ARE DIMINISHING RAPIDLY TO THE W. THE DOMINANT LES BAND THAT WAS OVER ERN LK SUP HAS MOVED ONSHORE AS OF 09Z BUT HAS WEAKENED QUITE A BIT. WITH DOWNSLOPING FLOW OF UNMODIFIED AIR...SKIES OVER THE SCENTRAL ARE MOCLR. MAIN FCST CONCERNS IN THE SHORT TERM ARE LES TRENDS/GOING HEADLINES AND POSSIBLE NEED FOR AN ADVY OVER THE ERN CWA NEAR LK SUP THIS MRNG. TODAY...AREA OF SHARP HGT RISES/DEEP LYR QVECTOR DVGC/SUBSIDENCE TO THE W ARE FCST TO OVERSPREAD THE UPR GRT LKS AS TROF WEAKENS AND LIFTS OUT TO THE NE...LEAVING A ZONAL FLOW ALF OVER THE AREA BY LATE IN THE DAY. WITH ARRIVAL OF SHARP ACYC FLOW/LOWERING SUBSIDENCE INVRN/DRYING IN THE DGZ...THINK LES WL QUICKLY DIMINISH W-E. GIVEN THE RADAR TRENDS OVER THE W...OPTED TO CANX ADVY THAT WAS GOING TO EXPIRE AT 12Z ANYWAY. REMOVED ANY MENTION OF -FZDZ GIVEN SFC DEWPT DEPRESSIONS OF 5-10F EVEN THOUGH LINGERING LLVL MSTR WL BE CONFINED BLO THE DGZ. ALTHOUGH THE BANDS COMING ASHORE OVER THE E MIGHT DROP A COUPLE INCHES OF SN IN A FEW HRS EARLY THIS MRNG... LATEST FCST PROFILE FM THE LOCAL WRF-ARW FOR GRAND MARAIS IN ALGER COUNTY SHOWS INVRN BASE SINKING TO NEAR 5K FT BY 12Z WITH DRYING IN THE DGZ. SINCE THE DOMINANT BAND HAS WEAKENED ALREADY AND THE LES MODE WL TREND TOWARD A MULTIPLE BAND REGIME IN THE LLVL NW FLOW IN ADVANCE OF INCOMING SFC RDG AXIS...WL ISSUE SPS TO COVER SOME LOCALLY HEAVIER SN THIS MRNG AND NOT GO WITH AN ADVY. BY EARLY-MID AFTN... THE PROFILE OVER THE E IS FCST TO DRY OUT COMPLETELY WITH THE ARRIVAL OF THE SFC RDG AXIS. OTRW...LINGERING MRNG SC WL GIVE WAY TO MOSUNNY CONDITIONS WITH THE ARRIVAL OF THE SFC RDG. IN FACT... THE LLVL FLOW WL SHIFT TO THE SW LATER THIS AFT ONCE THE RDG AXIS SHIFTS TO THE E. TNGT...ALTHOUGH THE NGT WL START MOCLR...EXPECT INCRSG MID CLDS IN THE PREVAILING SW FLOW BTWM DEPARTING SFC RDG AXIS TO THE E AND A LO PRES TROF ASSOCIATED WITH A SHRTWV MOVING E THRU THE NRN PLAINS IN THE ZONAL FLOW ALF. THE ISENTROPIC ASCENT IS MOST PRONOUNCED ON THE 285-290K SFCS /H8-7/. WITH LINGERING DRY AIR BLO THE MID LVL MOISTENING AND ABSENCE OF ANY OTHER FORCING...EXPECT NO PCPN. EXPECT LO TEMPS TO OCCUR RELATIVELY EARLY BEFORE THE ARRIVAL OF THE MID CLD. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 440 AM EST TUE NOV 13 2012 UPPER LEVEL PATTERN BECOMING MORE ZONAL AND SPLIT ON WEDNESDAY AS LONG TERM BEGINS. NORTHERN STREAM TROUGH OVER WESTERN CANADA MOVES TO THE UPPER GREAT LAKES BY 12Z THURSDAY. GOOD AGREEMENT FROM NWP ON THE POSITION/DEPTH OF THIS RELATIVELY MINOR TROUGH. WEAK 1.5PVU ANAMOLY AHEAD OF TROUGH ALONG WITH STEADY H85-H7 WARM AIR ADVECTION AND A BIT OF MOISTURE ADVECTION AT H85-H7 MAY BE ENOUGH TO KICK OFF LGT PRECIP ON WEDNESDAY. AMOUNTS WILL BE LIGHT SO WILL ONLY HAVE A MENTION OF ISOLD RAIN/SNOW SHOWERS AND/OR FLURRIES/SPRINKLES. NO BIG DEAL AT ALL. MAIN ISSUE WILL BE A CLOUDY SKY LIMITING MAX TEMPS. PRIMARY LEAD PV ANAMOLY AND 300MB JET STREAK COME ACROSS UPR LAKES ON WEDNESDAY NIGHT. IF ENOUGH MOISTURE IS PRESENT...MAY BE ABLE TO SQUEEZE OUT ISOLD SNOW SHOWERS. WORTH A MENTION...ESPECIALLY WITH ELEVATED H7-H5 LAPSE RATES TOWARD 7 C/KM. SIMILAR FCST ON THURSDAY WITH TROUGH AXIS OVERHEAD AND BETTER AGREEMENT ON STEEPER MID-LEVEL LAPSE RATES. DAYTIME HEATING WILL NOT HURT CAUSE EITHER FOR POP-UP ISOLD RAIN/SNOW SHOWERS AHEAD OF ASSOCIATED SFC TROUGH THAT MOVES THROUGH THURSDAY EVENING. MOISTURE AVAILABLE TO THE TROUGH MAKES IT AN OVERALL LOW CHANCE OCCURRENCE AND HAVE KEPT ANY MENTION OUT OF THIS FCST. TREND FROM GFS/ECMWF OVER THE LAST FEW RUNS IS TO BECOME MORE AMPLIFIED WITH THE TROUGH AS IT PROCEEDS TO SLIDE ACROSS REST OF THE GREAT LAKES BY FRIDAY. CAN REALLY SEE THIS ON THE GFS LOOKING AT DPROG/DT OF H85 TEMPS OVER LK SUPERIOR AT 00Z FRIDAY. 00Z/12 RUN HAD TEMPS OF -2C WHILE LATEST RUN HAS -7C. THOUGH RECENT RUNS OF ECMWF ARE NOT AS COLD AS THE GFS...THE 12Z/11 RUN SHOWED A SIMILAR COLDER SOLUTION FOR THU NIGHT AND FRIDAY AND THE LATEST RUN HAS TRENDED COLDER AS WELL. AT THIS POINT...CANNOT COUNT OUT THE COLDER IDEA. MAY NOT REALLY MATTER THOUGH AS THE MARGINAL MOISTURE TO BEGIN WITH ON THURSDAY DIMINISHES FURTHER ON THURSDAY NIGHT. SPIKE OF 925MB MOISTURE ON GFS/ECMWF INDICATE SCT CLOUDS COULD OCCUR CLOSER TO LK SUPERIOR WITH SOME OVER-WATER INSTABILITY. ON THE FLIP SIDE...UPPER HEIGHTS RISING SHARPLY THROUGH FRIDAY RESULTS IN SYNOPTIC SUBSIDENCE SQUASHING INVERSION BLO H9 BY AFTN. DOES NOT APPEAR TO BE VERY GOOD SETUP TO SEE ANYTHING BUT SCT LAKE EFFECT CLOUDS ON THURSDAY NIGHT FOR A TIME. IN WAKE OF TROUGH HIGH PRESSURE BUILDS RIGHT BACK IN FOR FRIDAY THROUGH NEXT WEEKEND. EXPECT DRY WEATHER WITH TEMPS WARMING SLIGHTLY ABOVE NORMAL FOR DAYTIME HIGHS. FORECAST SOUNDINGS OFF GFS HINT AT LOW-LEVEL MOISTURE AND SHALLOWER INVERSION. IF THESE SIGNALS ARE CORRECT MAY EVEN SEE SOME FOG/STRATUS FRIDAY NIGHT. IF THESE SIGNALS ARE BOGUS THEN MAX TEMPS FROM SATURDAY THROUGH MONDAY COULD REACH UPR 40S TO LOW-MID 50S WHICH IS 10-15F DEGREES ABOVE NORMAL. NIGHTTIME LOWS ABOVE NORMAL TOO WITH READINGS MOSTLY ABOVE FREEZING. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1228 PM EST TUE NOV 13 2012 HIGH PRESSURE BUILDING INTO THE AREA FROM THE SOUTH WILL CONTINUE TO HELP ERODE THE CLOUD LAYER THAT HAS REMAINED IN PLACE THROUGH MUCH OF THE MORNING HOURS. ALL TAF SITES SHOULD REMAIN VFR THROUGH THE TAF PERIOD. IWD AND SAW HAVE CLEARED OUT AS OF 17Z AND SHOULD REMAIN THAT WAY THROUGH THE AFTERNOON HOURS. CMX WILL BEGIN TO CLEAR OUT BY 18Z AND REMAIN CLEAR THROUGH THE AFTERNOON HOURS AS WELL. INCREASING MOISTURE IN THE MID LEVEL WILL HELP TO INCREASE CLOUD COVER AT ALL TAF SITES TONIGHT THROUGH THE REMAINDER OF THE TAF PERIOD. THERE IS A SMALL CHANCE THAT -SHRA OR-SHSN COULD OCCUR...BUT LOW LEVEL DRYING COULD KEEP THIS FROM OCCURRING. AT THIS POINT HAVE INCREASED CLOUDS BUT KEPT CONDITIONS DRY. VISIBILITIES SHOULD REMAIN VFR. WIND SHOULD REMAIN LIGHT AND SOUTHERLY AT EACH TAF SITE. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 440 AM EST TUE NOV 13 2012 WESTERLY WINDS TO 30 KTS DIMINISH TO LESS THAN 25 KTS BY EVENING AS PRESSURE GRADIENT GRADUALLY RELAXES DUE TO HIGH PRESSURE BUILDING FROM THE OHIO VALLEY INTO THE GREAT LAKES. ON WEDNESDAY THE HIGH MOVES EAST WHILE SFC TROUGH MOVES ACROSS NORTHERN ONTARIO. EXPECT SOUTH WINDS TO INCREASE TO 30 KTS...MAINLY OVER EASTERN SECTIONS. SMALL RISK FOR GALE GUSTS. SOUTH TO SOUTHWEST WINDS REMAIN UP TO 25 KTS THROUGH THURSDAY. SFC TROUGH COMES ACROSS THURSDAY NIGHT. WINDS IN WAKE OF TROUGH SHIFT NORTH BY FRIDAY MORNING BUT QUICKLY DIMINISH TO LESS THAN 20 KTS BY FRIDAY AFTERNOON WITH HIGH PRESSURE BUILDING ACROSS REGION. EXPECT THE HIGH TO SLOWLY DRIFT TO THE NORTHEAST THROUGH THE FIRST PART OF NEXT WEEK KEEPING WINDS LESS THAN 20 KTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...JLA AVIATION...KEC MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
616 AM EST TUE NOV 13 2012 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 440 AM EST TUE NOV 13 2012 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR TROF OVER THE GREAT LAKES BTWN RDG OFF THE E COAST AND A MORE ZONAL FLOW OVER WRN NAMERICA. SINCE THE FASTEST WINDS ALF ARE ON THE E SIDE OF THE UPR TROF...THIS IS A STRONG SIGNAL THIS TROF IS WEAKENING AND LIFTING TO THE NE. IN FACT...12Z-24Z H5 HGT RISES IN EXCESS OF 100M AND EVEN 150M OCCURRED OVER MUCH OF THE NCENTRAL CONUS BEHIND THE UPR TROF. FAIRLY SHARP LLVL CYC WNW FLOW OVER THE GREAT LKS UNDER THE UPR TROF TRANSITIONS QUICKLY TO A SHARP SFC RDG AXIS OVER MN UNDER THESE HGT RISES/SUBSIDENCE. BUT QUITE A BIT OF LLVL MSTR LINGERS PER THE 00Z INL RAOB...SO A LO CLD OVC LINGERS ALL THE WAY W TO THE RDG AXIS. CLOSER TO HOME...LES RESPSONSIBLE FOR UP TO 6 INCHES OF SN LINGERS OVER THE W AS OF 06Z...WITH THE MORE PRONOUNCED REFLECTIVITIES FROM ONTAONGAON TOWARD THE HURON MTNS WHERE SHARP LLVL CNVGC BTWN LARGER SCALE WNW FLOW OVER THE KEWEENAW AND A MORE WSW LAND BREEZE FLOW OFF NW WI THAT IS INFLUENCING THE AREA CLOSER TO THE WI BORDER. LATEST TRENDS SHOW REFLECTIVITIES TENDING TO WEAKEN TO THE W...A SIGN THE STRONG SUBIDENCE MOVING IN FM THE W MIGHT BE HAVING AN IMPACT. AS FCST ISSUANCE APRCHS...THE RADAR REFLECTIVIES ARE DIMINISHING RAPIDLY TO THE W. THE DOMINANT LES BAND THAT WAS OVER ERN LK SUP HAS MOVED ONSHORE AS OF 09Z BUT HAS WEAKENED QUITE A BIT. WITH DOWNSLOPING FLOW OF UNMODIFIED AIR...SKIES OVER THE SCENTRAL ARE MOCLR. MAIN FCST CONCERNS IN THE SHORT TERM ARE LES TRENDS/GOING HEADLINES AND POSSIBLE NEED FOR AN ADVY OVER THE ERN CWA NEAR LK SUP THIS MRNG. TODAY...AREA OF SHARP HGT RISES/DEEP LYR QVECTOR DVGC/SUBSIDENCE TO THE W ARE FCST TO OVERSPREAD THE UPR GRT LKS AS TROF WEAKENS AND LIFTS OUT TO THE NE...LEAVING A ZONAL FLOW ALF OVER THE AREA BY LATE IN THE DAY. WITH ARRIVAL OF SHARP ACYC FLOW/LOWERING SUBSIDENCE INVRN/DRYING IN THE DGZ...THINK LES WL QUICKLY DIMINISH W-E. GIVEN THE RADAR TRENDS OVER THE W...OPTED TO CANX ADVY THAT WAS GOING TO EXPIRE AT 12Z ANYWAY. REMOVED ANY MENTION OF -FZDZ GIVEN SFC DEWPT DEPRESSIONS OF 5-10F EVEN THOUGH LINGERING LLVL MSTR WL BE CONFINED BLO THE DGZ. ALTHOUGH THE BANDS COMING ASHORE OVER THE E MIGHT DROP A COUPLE INCHES OF SN IN A FEW HRS EARLY THIS MRNG... LATEST FCST PROFILE FM THE LOCAL WRF-ARW FOR GRAND MARAIS IN ALGER COUNTY SHOWS INVRN BASE SINKING TO NEAR 5K FT BY 12Z WITH DRYING IN THE DGZ. SINCE THE DOMINANT BAND HAS WEAKENED ALREADY AND THE LES MODE WL TREND TOWARD A MULTIPLE BAND REGIME IN THE LLVL NW FLOW IN ADVANCE OF INCOMING SFC RDG AXIS...WL ISSUE SPS TO COVER SOME LOCALLY HEAVIER SN THIS MRNG AND NOT GO WITH AN ADVY. BY EARLY-MID AFTN... THE PROFILE OVER THE E IS FCST TO DRY OUT COMPLETELY WITH THE ARRIVAL OF THE SFC RDG AXIS. OTRW...LINGERING MRNG SC WL GIVE WAY TO MOSUNNY CONDITIONS WITH THE ARRIVAL OF THE SFC RDG. IN FACT... THE LLVL FLOW WL SHIFT TO THE SW LATER THIS AFT ONCE THE RDG AXIS SHIFTS TO THE E. TNGT...ALTHOUGH THE NGT WL START MOCLR...EXPECT INCRSG MID CLDS IN THE PREVAILING SW FLOW BTWM DEPARTING SFC RDG AXIS TO THE E AND A LO PRES TROF ASSOCIATED WITH A SHRTWV MOVING E THRU THE NRN PLAINS IN THE ZONAL FLOW ALF. THE ISENTROPIC ASCENT IS MOST PRONOUNCED ON THE 285-290K SFCS /H8-7/. WITH LINGERING DRY AIR BLO THE MID LVL MOISTENING AND ABSENCE OF ANY OTHER FORCING...EXPECT NO PCPN. EXPECT LO TEMPS TO OCCUR RELATIVELY EARLY BEFORE THE ARRIVAL OF THE MID CLD. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 440 AM EST TUE NOV 13 2012 UPPER LEVEL PATTERN BECOMING MORE ZONAL AND SPLIT ON WEDNESDAY AS LONG TERM BEGINS. NORTHERN STREAM TROUGH OVER WESTERN CANADA MOVES TO THE UPPER GREAT LAKES BY 12Z THURSDAY. GOOD AGREEMENT FROM NWP ON THE POSITION/DEPTH OF THIS RELATIVELY MINOR TROUGH. WEAK 1.5PVU ANAMOLY AHEAD OF TROUGH ALONG WITH STEADY H85-H7 WARM AIR ADVECTION AND A BIT OF MOISTURE ADVECTION AT H85-H7 MAY BE ENOUGH TO KICK OFF LGT PRECIP ON WEDNESDAY. AMOUNTS WILL BE LIGHT SO WILL ONLY HAVE A MENTION OF ISOLD RAIN/SNOW SHOWERS AND/OR FLURRIES/SPRINKLES. NO BIG DEAL AT ALL. MAIN ISSUE WILL BE A CLOUDY SKY LIMITING MAX TEMPS. PRIMARY LEAD PV ANAMOLY AND 300MB JET STREAK COME ACROSS UPR LAKES ON WEDNESDAY NIGHT. IF ENOUGH MOISTURE IS PRESENT...MAY BE ABLE TO SQUEEZE OUT ISOLD SNOW SHOWERS. WORTH A MENTION...ESPECIALLY WITH ELEVATED H7-H5 LAPSE RATES TOWARD 7 C/KM. SIMILAR FCST ON THURSDAY WITH TROUGH AXIS OVERHEAD AND BETTER AGREEMENT ON STEEPER MID-LEVEL LAPSE RATES. DAYTIME HEATING WILL NOT HURT CAUSE EITHER FOR POP-UP ISOLD RAIN/SNOW SHOWERS AHEAD OF ASSOCIATED SFC TROUGH THAT MOVES THROUGH THURSDAY EVENING. MOISTURE AVAILABLE TO THE TROUGH MAKES IT AN OVERALL LOW CHANCE OCCURRENCE AND HAVE KEPT ANY MENTION OUT OF THIS FCST. TREND FROM GFS/ECMWF OVER THE LAST FEW RUNS IS TO BECOME MORE AMPLIFIED WITH THE TROUGH AS IT PROCEEDS TO SLIDE ACROSS REST OF THE GREAT LAKES BY FRIDAY. CAN REALLY SEE THIS ON THE GFS LOOKING AT DPROG/DT OF H85 TEMPS OVER LK SUPERIOR AT 00Z FRIDAY. 00Z/12 RUN HAD TEMPS OF -2C WHILE LATEST RUN HAS -7C. THOUGH RECENT RUNS OF ECMWF ARE NOT AS COLD AS THE GFS...THE 12Z/11 RUN SHOWED A SIMILAR COLDER SOLUTION FOR THU NIGHT AND FRIDAY AND THE LATEST RUN HAS TRENDED COLDER AS WELL. AT THIS POINT...CANNOT COUNT OUT THE COLDER IDEA. MAY NOT REALLY MATTER THOUGH AS THE MARGINAL MOISTURE TO BEGIN WITH ON THURSDAY DIMINISHES FURTHER ON THURSDAY NIGHT. SPIKE OF 925MB MOISTURE ON GFS/ECMWF INDICATE SCT CLOUDS COULD OCCUR CLOSER TO LK SUPERIOR WITH SOME OVER-WATER INSTABILITY. ON THE FLIP SIDE...UPPER HEIGHTS RISING SHARPLY THROUGH FRIDAY RESULTS IN SYNOPTIC SUBSIDENCE SQUASHING INVERSION BLO H9 BY AFTN. DOES NOT APPEAR TO BE VERY GOOD SETUP TO SEE ANYTHING BUT SCT LAKE EFFECT CLOUDS ON THURSDAY NIGHT FOR A TIME. IN WAKE OF TROUGH HIGH PRESSURE BUILDS RIGHT BACK IN FOR FRIDAY THROUGH NEXT WEEKEND. EXPECT DRY WEATHER WITH TEMPS WARMING SLIGHTLY ABOVE NORMAL FOR DAYTIME HIGHS. FORECAST SOUNDINGS OFF GFS HINT AT LOW-LEVEL MOISTURE AND SHALLOWER INVERSION. IF THESE SIGNALS ARE CORRECT MAY EVEN SEE SOME FOG/STRATUS FRIDAY NIGHT. IF THESE SIGNALS ARE BOGUS THEN MAX TEMPS FROM SATURDAY THROUGH MONDAY COULD REACH UPR 40S TO LOW-MID 50S WHICH IS 10-15F DEGREES ABOVE NORMAL. NIGHTTIME LOWS ABOVE NORMAL TOO WITH READINGS MOSTLY ABOVE FREEZING. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 615 AM EST TUE NOV 13 2012 AS A HI PRES RDG MOVES IN FM MN...EXPECT LINGERING MVFR CIGS AT IWD/CMX TO BREAK BY LATE MRNG/EARLY AFTN. DOWNSLOPE WIND COMPONENT AT SAW WL RESULT IN VFR CONDITIONS THERE THRU THE WHOLE DAY. ALTHOUGH MORE CLDS WL ARRIVE TNGT IN THE SW FLOW ON THE WRN FLANK OF THE HI PRES RDG PASSING TO THE E...CIG HGTS WL BE VFR WITH DRY LLVL AIR LINGERING. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 440 AM EST TUE NOV 13 2012 WESTERLY WINDS TO 30 KTS DIMINISH TO LESS THAN 25 KTS BY EVENING AS PRESSURE GRADIENT GRADUALLY RELAXES DUE TO HIGH PRESSURE BUILDING FROM THE OHIO VALLEY INTO THE GREAT LAKES. ON WEDNESDAY THE HIGH MOVES EAST WHILE SFC TROUGH MOVES ACROSS NORTHERN ONTARIO. EXPECT SOUTH WINDS TO INCREASE TO 30 KTS...MAINLY OVER EASTERN SECTIONS. SMALL RISK FOR GALE GUSTS. SOUTH TO SOUTHWEST WINDS REMAIN UP TO 25 KTS THROUGH THURSDAY. SFC TROUGH COMES ACROSS THURSDAY NIGHT. WINDS IN WAKE OF TROUGH SHIFT NORTH BY FRIDAY MORNING BUT QUICKLY DIMINISH TO LESS THAN 20 KTS BY FRIDAY AFTERNOON WITH HIGH PRESSURE BUILDING ACROSS REGION. EXPECT THE HIGH TO SLOWLY DRIFT TO THE NORTHEAST THROUGH THE FIRST PART OF NEXT WEEK KEEPING WINDS LESS THAN 20 KTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...JLA AVIATION...KC MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
441 AM EST TUE NOV 13 2012 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 440 AM EST TUE NOV 13 2012 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR TROF OVER THE GREAT LAKES BTWN RDG OFF THE E COAST AND A MORE ZONAL FLOW OVER WRN NAMERICA. SINCE THE FASTEST WINDS ALF ARE ON THE E SIDE OF THE UPR TROF...THIS IS A STRONG SIGNAL THIS TROF IS WEAKENING AND LIFTING TO THE NE. IN FACT...12Z-24Z H5 HGT RISES IN EXCESS OF 100M AND EVEN 150M OCCURRED OVER MUCH OF THE NCENTRAL CONUS BEHIND THE UPR TROF. FAIRLY SHARP LLVL CYC WNW FLOW OVER THE GREAT LKS UNDER THE UPR TROF TRANSITIONS QUICKLY TO A SHARP SFC RDG AXIS OVER MN UNDER THESE HGT RISES/SUBSIDENCE. BUT QUITE A BIT OF LLVL MSTR LINGERS PER THE 00Z INL RAOB...SO A LO CLD OVC LINGERS ALL THE WAY W TO THE RDG AXIS. CLOSER TO HOME...LES RESPSONSIBLE FOR UP TO 6 INCHES OF SN LINGERS OVER THE W AS OF 06Z...WITH THE MORE PRONOUNCED REFLECTIVITIES FROM ONTAONGAON TOWARD THE HURON MTNS WHERE SHARP LLVL CNVGC BTWN LARGER SCALE WNW FLOW OVER THE KEWEENAW AND A MORE WSW LAND BREEZE FLOW OFF NW WI THAT IS INFLUENCING THE AREA CLOSER TO THE WI BORDER. LATEST TRENDS SHOW REFLECTIVITIES TENDING TO WEAKEN TO THE W...A SIGN THE STRONG SUBIDENCE MOVING IN FM THE W MIGHT BE HAVING AN IMPACT. AS FCST ISSUANCE APRCHS...THE RADAR REFLECTIVIES ARE DIMINISHING RAPIDLY TO THE W. THE DOMINANT LES BAND THAT WAS OVER ERN LK SUP HAS MOVED ONSHORE AS OF 09Z BUT HAS WEAKENED QUITE A BIT. WITH DOWNSLOPING FLOW OF UNMODIFIED AIR...SKIES OVER THE SCENTRAL ARE MOCLR. MAIN FCST CONCERNS IN THE SHORT TERM ARE LES TRENDS/GOING HEADLINES AND POSSIBLE NEED FOR AN ADVY OVER THE ERN CWA NEAR LK SUP THIS MRNG. TODAY...AREA OF SHARP HGT RISES/DEEP LYR QVECTOR DVGC/SUBSIDENCE TO THE W ARE FCST TO OVERSPREAD THE UPR GRT LKS AS TROF WEAKENS AND LIFTS OUT TO THE NE...LEAVING A ZONAL FLOW ALF OVER THE AREA BY LATE IN THE DAY. WITH ARRIVAL OF SHARP ACYC FLOW/LOWERING SUBSIDENCE INVRN/DRYING IN THE DGZ...THINK LES WL QUICKLY DIMINISH W-E. GIVEN THE RADAR TRENDS OVER THE W...OPTED TO CANX ADVY THAT WAS GOING TO EXPIRE AT 12Z ANYWAY. REMOVED ANY MENTION OF -FZDZ GIVEN SFC DEWPT DEPRESSIONS OF 5-10F EVEN THOUGH LINGERING LLVL MSTR WL BE CONFINED BLO THE DGZ. ALTHOUGH THE BANDS COMING ASHORE OVER THE E MIGHT DROP A COUPLE INCHES OF SN IN A FEW HRS EARLY THIS MRNG... LATEST FCST PROFILE FM THE LOCAL WRF-ARW FOR GRAND MARAIS IN ALGER COUNTY SHOWS INVRN BASE SINKING TO NEAR 5K FT BY 12Z WITH DRYING IN THE DGZ. SINCE THE DOMINANT BAND HAS WEAKENED ALREADY AND THE LES MODE WL TREND TOWARD A MULTIPLE BAND REGIME IN THE LLVL NW FLOW IN ADVANCE OF INCOMING SFC RDG AXIS...WL ISSUE SPS TO COVER SOME LOCALLY HEAVIER SN THIS MRNG AND NOT GO WITH AN ADVY. BY EARLY-MID AFTN... THE PROFILE OVER THE E IS FCST TO DRY OUT COMPLETELY WITH THE ARRIVAL OF THE SFC RDG AXIS. OTRW...LINGERING MRNG SC WL GIVE WAY TO MOSUNNY CONDITIONS WITH THE ARRIVAL OF THE SFC RDG. IN FACT... THE LLVL FLOW WL SHIFT TO THE SW LATER THIS AFT ONCE THE RDG AXIS SHIFTS TO THE E. TNGT...ALTHOUGH THE NGT WL START MOCLR...EXPECT INCRSG MID CLDS IN THE PREVAILING SW FLOW BTWM DEPARTING SFC RDG AXIS TO THE E AND A LO PRES TROF ASSOCIATED WITH A SHRTWV MOVING E THRU THE NRN PLAINS IN THE ZONAL FLOW ALF. THE ISENTROPIC ASCENT IS MOST PRONOUNCED ON THE 285-290K SFCS /H8-7/. WITH LINGERING DRY AIR BLO THE MID LVL MOISTENING AND ABSENCE OF ANY OTHER FORCING...EXPECT NO PCPN. EXPECT LO TEMPS TO OCCUR RELATIVELY EARLY BEFORE THE ARRIVAL OF THE MID CLD. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 440 AM EST TUE NOV 13 2012 UPPER LEVEL PATTERN BECOMING MORE ZONAL AND SPLIT ON WEDNESDAY AS LONG TERM BEGINS. NORTHERN STREAM TROUGH OVER WESTERN CANADA MOVES TO THE UPPER GREAT LAKES BY 12Z THURSDAY. GOOD AGREEMENT FROM NWP ON THE POSITION/DEPTH OF THIS RELATIVELY MINOR TROUGH. WEAK 1.5PVU ANAMOLY AHEAD OF TROUGH ALONG WITH STEADY H85-H7 WARM AIR ADVECTION AND A BIT OF MOISTURE ADVECTION AT H85-H7 MAY BE ENOUGH TO KICK OFF LGT PRECIP ON WEDNESDAY. AMOUNTS WILL BE LIGHT SO WILL ONLY HAVE A MENTION OF ISOLD RAIN/SNOW SHOWERS AND/OR FLURRIES/SPRINKLES. NO BIG DEAL AT ALL. MAIN ISSUE WILL BE A CLOUDY SKY LIMITING MAX TEMPS. PRIMARY LEAD PV ANAMOLY AND 300MB JET STREAK COME ACROSS UPR LAKES ON WEDNESDAY NIGHT. IF ENOUGH MOISTURE IS PRESENT...MAY BE ABLE TO SQUEEZE OUT ISOLD SNOW SHOWERS. WORTH A MENTION...ESPECIALLY WITH ELEVATED H7-H5 LAPSE RATES TOWARD 7 C/KM. SIMILAR FCST ON THURSDAY WITH TROUGH AXIS OVERHEAD AND BETTER AGREEMENT ON STEEPER MID-LEVEL LAPSE RATES. DAYTIME HEATING WILL NOT HURT CAUSE EITHER FOR POP-UP ISOLD RAIN/SNOW SHOWERS AHEAD OF ASSOCIATED SFC TROUGH THAT MOVES THROUGH THURSDAY EVENING. MOISTURE AVAILABLE TO THE TROUGH MAKES IT AN OVERALL LOW CHANCE OCCURRENCE AND HAVE KEPT ANY MENTION OUT OF THIS FCST. TREND FROM GFS/ECMWF OVER THE LAST FEW RUNS IS TO BECOME MORE AMPLIFIED WITH THE TROUGH AS IT PROCEEDS TO SLIDE ACROSS REST OF THE GREAT LAKES BY FRIDAY. CAN REALLY SEE THIS ON THE GFS LOOKING AT DPROG/DT OF H85 TEMPS OVER LK SUPERIOR AT 00Z FRIDAY. 00Z/12 RUN HAD TEMPS OF -2C WHILE LATEST RUN HAS -7C. THOUGH RECENT RUNS OF ECMWF ARE NOT AS COLD AS THE GFS...THE 12Z/11 RUN SHOWED A SIMILAR COLDER SOLUTION FOR THU NIGHT AND FRIDAY AND THE LATEST RUN HAS TRENDED COLDER AS WELL. AT THIS POINT...CANNOT COUNT OUT THE COLDER IDEA. MAY NOT REALLY MATTER THOUGH AS THE MARGINAL MOISTURE TO BEGIN WITH ON THURSDAY DIMINISHES FURTHER ON THURSDAY NIGHT. SPIKE OF 925MB MOISTURE ON GFS/ECMWF INDICATE SCT CLOUDS COULD OCCUR CLOSER TO LK SUPERIOR WITH SOME OVER-WATER INSTABILITY. ON THE FLIP SIDE...UPPER HEIGHTS RISING SHARPLY THROUGH FRIDAY RESULTS IN SYNOPTIC SUBSIDENCE SQUASHING INVERSION BLO H9 BY AFTN. DOES NOT APPEAR TO BE VERY GOOD SETUP TO SEE ANYTHING BUT SCT LAKE EFFECT CLOUDS ON THURSDAY NIGHT FOR A TIME. IN WAKE OF TROUGH HIGH PRESSURE BUILDS RIGHT BACK IN FOR FRIDAY THROUGH NEXT WEEKEND. EXPECT DRY WEATHER WITH TEMPS WARMING SLIGHTLY ABOVE NORMAL FOR DAYTIME HIGHS. FORECAST SOUNDINGS OFF GFS HINT AT LOW-LEVEL MOISTURE AND SHALLOWER INVERSION. IF THESE SIGNALS ARE CORRECT MAY EVEN SEE SOME FOG/STRATUS FRIDAY NIGHT. IF THESE SIGNALS ARE BOGUS THEN MAX TEMPS FROM SATURDAY THROUGH MONDAY COULD REACH UPR 40S TO LOW-MID 50S WHICH IS 10-15F DEGREES ABOVE NORMAL. NIGHTTIME LOWS ABOVE NORMAL TOO WITH READINGS MOSTLY ABOVE FREEZING. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1228 AM EST TUE NOV 13 2012 KIWD...EXPECT MVFR LAKE CLOUDS TO LIFT BY LATE TUE MORNING AS WINDS SHIFT FROM WRLY TO SWRLY. VFR CONDITIONS ARE THEN EXPECTED THROUGH THE REST OF THE FCST PD. KCMX...BEST LES BANDS HAVE SHIFTED SOUTH OF THE KEWEENAW PENINSULA. LOOK FOR FLURRIES TONIGHT WITH PREVAILING VFR CONDITIONS AS DRIER AIR AND RDGG WILL BE MOVING IN FM NW OF THE LAKE. SOME LOWERING OF INVERSION HGTS MAY BRIEFLY BRING CIGS BACK DOWN TO MVFR AROUND SUNRISE BEFORE WINDS BACK FM WEST TO SOUTHWEST ALLOWING FOR VFR CONDITIONS FOR THE REST OF THE FCST PD. KSAW...EXPECT VFR CONDITIONS THROUGH THE FCST PD AS WINDS SHIFT FROM WSW TONIGHT TO SSW ON TUESDAY. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 440 AM EST TUE NOV 13 2012 WESTERLY WINDS TO 30 KTS DIMINISH TO LESS THAN 25 KTS BY EVENING AS PRESSURE GRADIENT GRADUALLY RELAXES DUE TO HIGH PRESSURE BUILDING FROM THE OHIO VALLEY INTO THE GREAT LAKES. ON WEDNESDAY THE HIGH MOVES EAST WHILE SFC TROUGH MOVES ACROSS NORTHERN ONTARIO. EXPECT SOUTH WINDS TO INCREASE TO 30 KTS...MAINLY OVER EASTERN SECTIONS. SMALL RISK FOR GALE GUSTS. SOUTH TO SOUTHWEST WINDS REMAIN UP TO 25 KTS THROUGH THURSDAY. SFC TROUGH COMES ACROSS THURSDAY NIGHT. WINDS IN WAKE OF TROUGH SHIFT NORTH BY FRIDAY MORNING BUT QUICKLY DIMINISH TO LESS THAN 20 KTS BY FRIDAY AFTERNOON WITH HIGH PRESSURE BUILDING ACROSS REGION. EXPECT THE HIGH TO SLOWLY DRIFT TO THE NORTHEAST THROUGH THE FIRST PART OF NEXT WEEK KEEPING WINDS LESS THAN 20 KTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...JLA AVIATION...VOSS MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1229 AM EST TUE NOV 13 2012 .UPDATE... ISSUED AT 924 PM EST MON NOV 12 2012 MAIN UPDATE CONCERN DEALS WITH HEAVIER SNOW BAND WHICH HAS REACHED INTO THE NORTHERN PORTION OF BARAGA COUNTY THIS EVENING PER MQT RADAR LOOP. SPOTTER REPORTS FROM NEAR PELKIE TO BARAGA HAVE COME IN WITH BETWEEN 2 AND 3 INCHES THUS FAR. GIVEN THAT RADAR CONTINUES TO SHOW 30 DBZ REFLECTIVITY RETURNS WITH SNOW BAND OVER NW BARAGA COUNTY AND THAT MESOSCALE MODELS SUGGEST POTENTIAL FOR THIS SNOW TO CONTINUE FOR AT LEAST A FEW MORE HRS...DECIDED TO INCLUDE BARAGA COUNTY IN WINTER WX ADVISORY FOR 2 TO 5 INCHES OF SNOW. HEAVIER SNOW HAS TAPERED OFF OVER THE KEWEENAW PENINSULA WITH MAIN BAND NOW SHIFTING SOUTH OVER NRN ONTONAGON...SRN HOUGHTON AND BARAGA COUNTIES. LOOK FOR SNOW TO TAPER OFF LATE TONIGHT AS RDGG MOVES IN FM THE WEST AND SUBSIDENCE INVERSION LOWERS FROM NEAR 8KFT TO BLO 5KFT. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 405 PM EST MON NOV 12 2012 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A HIGH AMPLITUDE BUT WEAKENING TROF EXTENDING FROM NRN ONTARIO THRU THE MISSISSIPPI VALLEY. UNDERNEATH TROF EARLIER TODAY...12Z SOUNDINGS AT KINL/KMPX SHOWED A DEEP MOISTURE PROFILE WITH 850MB TEMPS AROUND -15C WHICH WILL ALLOW FOR A NICE INTERSECTION OF LAKE CONVECTION THRU THE DGZ. SO...CONDITIONS ARE FAVORABLE FOR MDT/HVY LAKE EFFECT/LAKE ENHANCED SNOW AS MID LEVEL TROF CONTINUES TO MOVE ACROSS THE UPPER GREAT LAKES LATE THIS AFTN/EVENING. AS EXPECTED...A DOMINANT LES BAND DEVELOPED OVER WRN LAKE SUPERIOR EARLIER TODAY BTWN THE MN NORTH SHORE AND WISCONSIN`S BAYFIELD PENINSULA. WITH MID LEVEL TROF PASSING...WINDS OVER WRN LAKE SUPERIOR ARE NOW VEERING MORE WRLY... SO THIS DOMINANT LES BAND IS ADJUSTING TO THE CHANGING WIND...BUT IT IS ALSO BECOMING LESS ORGANIZED...WHICH MAY BE PARTLY DUE TO NEGATIVE DIURNAL AFFECTS. KMQT/KDLH AND ENVIRONMENT CANADA RADAR LOCATED JUST N OF THUNDER BAY ALL INDICATE AREAS OF HEAVY LES NOW NEARING THE WRN SHORE OF THE KEWEENAW. KDLH RADAR IS STILL SHOWING RETURNS AS HIGH AS AROUND 12KFT...SO LAKE EFFECT CONVECTION REMAINS DEEP WITH POCKETS OF VERY HVY SNOW. AHEAD OF THE HEAVIER SNOW...SHSN HAVE BEEN AFFECTING PORTIONS OF THE KEWEENAW TODAY. HOWEVER...ONLY WEBCAM THAT HAS CONSISTENTLY SHOWN SHARPLY REDUCED VIS AT TIMES IS LOCATED ALONG THE SHORE WEST OF EAGLE RIVER. FCST THINKING HASN`T CHANGED MUCH WITH REGARD TO LES AND HEADLINES TONIGHT. DEEP MOISTURE AND FAVORABLE TEMP PROFILE ARGUES FOR MDT TO HVY SNOW AT TIMES AS MID LEVEL TROF PASSES TONIGHT. BULK OF SNOW ACCUMULATIONS ON THE KEWEENAW PENINSULA WILL OCCUR OVER THE NEXT SEVERAL HRS AS WIND SHIFT/CONVERGENCE ZONE OVER THE WRN LAKE DROP S ACROSS THE PENINSULA. MAY SEE SNOWFALL RATES BRIEFLY AS HIGH AS 2-4IN/HR. AFTER THE CONVERGENCE ZONE PASSES...WIND PARALLEL BANDS WITH MUCH MORE VARIABLE SNOW INTENSITY WILL SET UP FOR THE REMAINDER OF THE EVENING. LES WILL THEN QUICKLY DIMINISH OVERNIGHT AS SHARP HEIGHT RISES OCCUR IN THE WAKE OF MID LEVEL TROF (180-200M HEIGHT RISES AT 500MB BTWN 00Z AND 12Z)...INVERSION QUICKLY DROPS TO 4-5KFT AND CONVECTIVE LAYER BEGINS TO FALL BLO THE DGZ. GIVEN THE SHORT RESIDENCE TIME OF THE CONVERGENCE ZONE OVER THE KEWEENAW...AND RATHER QUICK DIMINISHING TREND THRU THE NIGHT...HAVE LOWERED SNOW AMOUNTS BY AN INCH OR TWO. MAX AMOUNTS WILL PROBABLY BE IN THE 4-5 INCH RANGE OVER THE HIGH TERRAIN. FARTHER S...CONVERGENCE ZONE WILL SINK S AND AFFECT ONTONAGON/SRN HOUGHTON COUNTIES THIS EVENING. ALTHOUGH PREVIOUSLY DISCUSSED NEGATIVE FACTORS TAKE HOLD DURING THE NIGHT TO DIMINISH LES INTENSITY...LOW-LEVEL WINDS WILL MAINTAIN A CONVERGENT LOOK AS WSW LAND BREEZE ENHANCED WINDS OFF NW WI CONVERGE WITH WNW FLOW OVER LAKE SUPERIOR. THIS SHOULD HELP TO AT LEAST MAINTAIN MORE PERSISTENT THOUGH WEAKENING LES ACROSS ONTONAGON/SRN HOUGHTON COUNTIES AND PROBABLY A SMALL PART OF GOGEBIC COUNTY N OF M-28 THRU THE NIGHT. WILL RETAIN ADVY FOR ONTONAGON/SRN HOUGHTON COUNTIES TONIGHT. TO THE E...WIND SHIFT/CONVERGENT BAND WILL EVENTUALLY MOVE ONSHORE OVER THE NE FCST AREA TONIGHT. HOWEVER...BY THE TIME IT DOES...DEEP MOISTURE WILL BE EXITING WITH SHARP HEIGHT RISES OCCURRING. SO... WHILE THERE WILL LIKELY BE A BRIEF PERIOD OF MDT/HVY SNOW ON WIND SHIFT...LES THAT ORGANIZES BEHIND TROF WILL NOT BE SUBSTANTIAL. WILL PAINT 1-3 INCH ACCUMULATIONS ACROSS ALGER COUNTY E OF MUNISING AND NRN LUCE COUNTY TONIGHT. LINGERING LES WILL QUICKLY WIND DOWN/END FROM W TO E TUE. MIGHT SEE AN ADDITIONAL INCH OF SNOW OVER ERN ALGER/NRN LUCE COUNTY IN THE MORNING. OTHERWISE...LOOK FOR DECREASING CLOUDS FROM SW TO NE AS WINDS BACK TO THE SW. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 405 PM EST MON NOV 12 2012 UPPER TROUGH THAT HAS LED TO THE UNSETTLED WEATHER THIS WEEKEND AND TODAY WILL BE SHIFTING EAST OF THE UPPER GREAT LAKES ON TUESDAY NIGHT. THIS WILL LEAD TO THE START OF SPLIT FLOW ACROSS MUCH OF THE COUNTRY...WHICH WILL REALLY BECOME ESTABLISHED ON BY THE WEEKEND BEHIND A WEAKER TROUGH MOVING THROUGH THE NORTHERN STREAM WEDNESDAY INTO FRIDAY. THIS WILL LEAD TO A FAIRLY QUIET PATTERN ACROSS THE UPPER GREAT LAKES FOR THE LONG TERM PERIOD. HIGH PRESSURE RIDGE WILL BE OVER THE AREA AT THE START OF THE LONG TERM PERIOD FROM HIGH PRESSURE CENTERED OVER THE LOWER GREAT LAKES AND OHIO RIVER VALLEY. MOSTLY CLEAR SKIES TO START THE EVENING WILL QUICKLY GIVE WAY TO INCREASING CLOUDS OVER THE WEST/CENTRAL...WHILE ANY LINGERING LAKE EFFECT SHOWERS SHOULD BE PUSHING NE OVER EASTERN LAKE SUPERIOR. THESE CLOUDS ARE IN ADVANCE OF A WEAK SHORTWAVE AND WARM AIR ADVECTION THAT WILL MOVE ACROSS THE WESTERN CWA WEDNESDAY. MODELS ARE CONSISTENT ON MOST OF THE MOISTURE STAYING ABOVE H800...WITH BROAD AND WEAK LIFT ASSOCIATED WITH IT. THERE IS SOME DRY AIR BELOW H800...BUT NOTHING TOO SUBSTANTIAL...SO THINK THAT ANY PRECIPITATION THAT DOES FALL WILL MAKE IT TO THE SURFACE. WITH THE BEST FORCING OVER WESTERN LAKE SUPERIOR...EXPECT THAT AREA TO HAVE THE BEST CHANCE OF SHOWERS...SO HAVE SPREAD THE SLIGHT CHANCES FARTHER SOUTH TO COVER MUCH OF WESTERN LAKE SUPERIOR ON WEDNESDAY. OTHERWISE...THE MID CLOUDS WILL COVER THE REST OF THE CWA WITH ONLY AN ISOLATED FLURRY OVER WESTERN UPPER MICHIGAN. ONE OTHER ITEM OF NOTE FOR LATE TUESDAY NIGHT AND INTO WEDNESDAY IS THE POTENTIAL FOR LAKE EFFECT PRECIPITATION OFF LAKE MICHIGAN. DELTA T VALUES AROUND 15 WOULD SUPPORT LAKE ENHANCED PRECIPITATION UNDER THE SLOWLY BACKING WINDS FROM SW TO SOUTHERLY ON WEDNESDAY. MAIN LIMITING FACTOR APPEARS TO BE INVERSION HEIGHTS AROUND 4-5KFT. THERE ARE SOME HINTS IN THE MODELS THAT THIS INVERSION COULD WEAKEN AS THE DEEPER MOISTURE ARRIVES AND LEAD TO AN INCREASE IN INTENSITY. THIS LOOKS TO BE FAIRLY SHORT LIVED...AS DRIER AIR BETWEEN H875-700 AND WAA MOVES BACK IN DURING THE AFTERNOON AND DIMINISHES THE CHANCES AGAIN. WILL CONTINUE TO MENTION THE SLIGHT CHANCES FOR THIS POTENTIAL...BUT SEEMS TO BE FAIRLY LIMITED. THE SHORTWAVE MOVES AWAY FROM THE AREA WHILE A LOW PRESSURE SYSTEM MOVES INTO HUDSON BAY. THIS SHOULD LEAD TO INCREASING SOUTHERLY FLOW AHEAD OF A WEAK COLD FRONT MOVING INTO WESTERN ONTARIO. EXPECT MID CLOUDS TO INCREASE AHEAD OF THIS FRONT ON WEDNESDAY NIGHT...ESPECIALLY OVER THE NORTH HALF OF THE CWA. BOTH NAM/SREF INDICATING INCREASED PROBABILITIES OF FOG OVER THE WEST...BUT THE NAM HAS THINNER MID CLOUDS...WHICH WOULD LEAD BETTER RADIATIONAL COOLING AND FOG POTENTIAL. WITH THE DIFFERENCES DIFFERENCES IN THE MID CLOUDS...WILL LEAVE FOG MENTION OUT OF THE FORECAST DUE TO THE POTENTIAL FOR MID CLOUDS. DECAYING FRONTAL BOUNDARY WILL BE MOVING ACROSS THE NORTHERN HALF OF THE CWA ON THURSDAY. THIS WILL LARGELY BE MARKED BY A WIND SHIFT AND CLOUDS WHILE THE PRECIPITATION WILL STAY TO THE NORTH OF LAKE SUPERIOR AND CLOSER TO THE BETTER FORCING/MOISTURE. BEHIND THIS FRONTAL BOUNDARY AND WEAK UPPER TROUGH...SPLIT FLOW REALLY SETTLES OVER THE NORTHERN HALF OF THE CONUS. THE SOUTHERN STREAM JET LOOKS TO REMAIN OVER THE SOUTHERN TIER OF STATES...WHILE THE NORTHERN STREAM RIDGES OVER NORTHERN CANADA. THIS SHOULD LEAD TO A VERY QUIET AND LIKELY ABOVE NORMAL TEMPERATURE PERIOD FOR UPPER MICHIGAN INTO NEXT WEEK. AT THE SURFACE...HIGH PRESSURE WILL SETTLE OVER THE GREAT LAKES REGION FOR THURSDAY NIGHT INTO SATURDAY BEFORE MOVING EAST INTO QUEBEC FOR SUNDAY AND MONDAY. DRY AIR ASSOCIATED WITH THIS HIGH SHOULD PRODUCE DECREASING CLOUDS ON THURSDAY NIGHT AND FRIDAY AND THEN PARTLY CLOUDY TO MOSTLY CLEAR SKIES INTO NEXT WEEK. BIGGEST QUESTION WILL BE THE TEMPERATURES...AS THEY WILL DEPEND ON HOW DEEP THE MIXING WILL BE. BOTH GFS/ECMWF INDICATING H850 TEMPS RISING TOWARDS 1-2C THIS WEEKEND...BUT BOTH ARE STRUGGLING TO MIX THOSE TEMPS TO THE SURFACE. WILL GO WITH THE MIDDLE GROUND SINCE IT IS SO FAR OUT...HIGHS IN THE MID-UPPER 40S...BUT IF WE CAN TAP INTO THE WARMER TEMPS ALOFT...COULD EASILY SEE HIGHS IN THE 50S AT THE FIRST PART OF NEXT WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1228 AM EST TUE NOV 13 2012 KIWD...EXPECT MVFR LAKE CLOUDS TO LIFT BY LATE TUE MORNING AS WINDS SHIFT FROM WRLY TO SWRLY. VFR CONDITIONS ARE THEN EXPECTED THROUGH THE REST OF THE FCST PD. KCMX...BEST LES BANDS HAVE SHIFTED SOUTH OF THE KEWEENAW PENINSULA. LOOK FOR FLURRIES TONIGHT WITH PREVAILING VFR CONDITIONS AS DRIER AIR AND RDGG WILL BE MOVING IN FM NW OF THE LAKE. SOME LOWERING OF INVERSION HGTS MAY BRIEFLY BRING CIGS BACK DOWN TO MVFR AROUND SUNRISE BEFORE WINDS BACK FM WEST TO SOUTHWEST ALLOWING FOR VFR CONDITIONS FOR THE REST OF THE FCST PD. KSAW...EXPECT VFR CONDITIONS THROUGH THE FCST PD AS WINDS SHIFT FROM WSW TONIGHT TO SSW ON TUESDAY. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 405 PM EST MON NOV 12 2012 A TIGHT PRESSURE GRADIENT BETWEEN THE FRONT THAT MOVED THROUGH LAST NIGHT AND ANOTHER SURFACE TROUGH MOVING THROUGH NORTHERN MN WILL KEEP WINDS IN THE 20-30KT RANGE TONIGHT AS THEY SHIFT TO A MORE NORTHWESTERLY DIRECTION. THERE COULD ALSO BE A FEW GALE FORCE GUSTS TO 35 KNOTS TONIGHT...MAINLY OVER THE EASTERN HALF OF LAKE SUPERIOR. A WEAK HIGH PRESSURE RIDGE WILL MOVE ACROSS LAKE SUPERIOR ON TUESDAY NIGHT AND LEAD TO WINDS WEAKENING BELOW 25KTS. A LOW PRESSURE SYSTEM MOVING INTO HUDSON BAY WILL BRING A TIGHTENING PRESSURE GRADIENT OVER LAKE SUPERIOR...WHICH WILL INCREASE WINDS OUT OF THE SOUTHWEST TO 20-30KTS OVER EASTERN LAKE SUPERIOR ON WEDNESDAY INTO WEDNESDAY EVENING. HIGH PRESSURE WILL THEN SETUP OVER THE GREAT LAKES REGION ON THURSDAY NIGHT AND SLOWLY DRIFT TO THE NORTHEAST THROUGH THE FIRST PART OF NEXT WEEK. THIS WILL LEAD TO WINDS STAYING BELOW 20KTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR MIZ001>004-084. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ UPDATE...VOSS SHORT TERM...ROLFSON LONG TERM...SRF AVIATION...VOSS MARINE...SRF
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
248 PM EST TUE NOV 13 2012 .SYNOPSIS... CLOUDS WILL GRADUALLY DECREASE TONIGHT INTO WEDNESDAY WITH HIGH PRESSURE TAKING OVER. DRY WEATHER AND SEASONAL TEMPERATURES ARE EXPECTED ALL THE WAY THROUGH AT LEAST SUNDAY AS HIGH PRESSURE DOMINATES THE WEATHER PATTERN. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 12 PM UPDATE...LATEST SAT PICS CONTINUE TO SHOW WIDESPREAD STRATO CU ACROSS THE CWA WITH A FEW BREAKS IN THE WESTERN MOHAWK VALLEY AND WYOMING VALLEY. OTHER THAN ADJUSTING MAX TEMPS DOWN A BIT MORE FORECAST IN GOOD SHAPE. 10 AM UPDATE...PRECIP HAS MOVED EAST OF THE REGION WITH THE CURRENT WEAK LAKE RESPONSE NORTH OF THE FORECAST AREA ALONG THE LAKE ONTARIO EASTERN SHORE. SATELLITE SHOWS CLOUDY TO MOSTLY CLOUDY SKIES OVER THE ENTIRE REGION WITH 12Z RAOBS AND RAP MODEL SOUNDINGS INDICATING A VERY SHALLOW LAYER OF MOISTURE ABOUT 50 MB DEEP AT THE 850 MB LEVEL. THE MODEL SOUNDINGS INDICATE THIS LAYER WILL BE VERY STUBBORN TO ERODE UNDER A STRONG SUBSIDENCE INVERSION. ADJUSTED CLOUD GRIDS TO REFLECT THIS MORE PESSIMISTIC THINKING OF CLOUDY TO MOSTLY CLOUDY SKIES FOR MUCH OF THE DAY EXCEPT FOR THE FAR SE FA. DUE TO THIS INCREASED CLOUD COVER ADJUSTED MAX TEMPS DOWN SLIGHTLY. LOW LEVEL WINDS WILL GRADUALLY VEER TODAY WITH SCATTERED RAIN/SNOW SHOWERS FOR PRIMARILY NRN ONEIDA COUNTY POSSIBLY DROPPING INTO THE SYR AREA LATER THIS AFTERNOON. SNOW ACCUM OF ONLY A FEW TENTHS IN THE HIGHER TERRAIN OF ONEIDA COUNTY. 615 AM UPDATE... HV UPPED SNOWFALL TOTALS IN THE CATSKILLS THIS MRNG. AT THE BINGHAMTON AIRPORT WE MEASURED 1.4 INCHES AND NOT OUT OF THE QUESTION THAT HIGHER TERRAIN IN THE CATSKILLS MAY SEE UPWARDS OF 4 INCHES. HIGHER REFLECTIVITIES ON RADAR ALONG WITH DUAL-POL PRODUCTS AND WEBCAMS IN THE REGION SUPPORT THIS THINKING. HV ALSO TWEAKED HRLY TEMPS AS THEY DROPPED OFF QUICKLY THIS MRNG. HRLY POP/WX GRIDS LOOK TO BE FAIRLY WELL IN LINE WITH REALITY SO NO UPDATES NEEDED AT THIS TIME. PREV DISCUSSIONS BLO... 445 AM UPDATE... HOW QUICKLY THINGS CAN GO AWRY. JUST AS GRIDS WERE SENT, RAIN SWITCHED OVR TO SNOW HERE AT KBGM. UPDATED GRIDS THRU 14Z TO ADD SNOW IN AT ELEVATIONS > 1600 FT. VRY MINIMAL ACCUMS EXPECTED BUT OVR IN THE WRN CATS MAY SEE AMNTS UPWARDS OF AN INCH BTWN NOW AND 12Z. 4 AM UPDATE... AS OF 07Z CDFNT HAS MVD THRU CWA. BULK OF THE RAIN, AS EXPECTED, IS BHND THE FRONTAL BNDRY AS UL TROF AND ASSOC SPEED MAX ROTATE THRU THE REGION BY 15Z. BASED ON PROGRESS OF BACK EDGE OF MAIN AREA OF PCPN RAIN SHUD BE LOCATED OVR FAR ERN ZONES BY 12Z AS FCST. EXPECT THIS PCPN WL SHOVE EAST OF FA BY 15Z. WRLY FLOW BHND FNT AS WELL AS CLD TEMPS ALOFT MAY LEAD TO LK RESPONSE FOR A TIME THIS MRNG INTO EARLY AFTN. WITH TEMPS RAPIDLY FALLING INTO THE LOW-MID 30S BY 12Z LOCALES IN THE SRN TUG HILL PLATEAU MAY SEE A BRIEF SNOW SHOWER THIS MRNG BFR MIXING WITH RAIN BY 15Z. ANY LINGERING PCPN WL LKLY BE ALL RAIN BY LATE MRNG INTO THE AF TN HRS...WITH VRY MINIMAL SNOW ACCUMS EXPECTED. THAT IS, ASSUMING ANYTHING CAN DVLP WITH VRY LITTLE ACTIVITY EVIDENT ON KBUF RADAR AS OF 09Z COURTESY OF LOW-LVL DRYING WORKING IN FM THE WEST. SKIES WL GNRLY BEGIN AS MOCLDY THIS MRNG BFR CLRNG SOUTH OF THE I-88 CORRIDOR BY AFTN. SXNS WEST OF I-81 WL RMN PRTLY-MOCLDY THRU 00Z WED. THIS WL STUNT TEMPS FM RISING TOO MUCH. ON AVG, EXPECT MAXES TO BE SOME 20-25 DEGREES LWR THAN YDA WITH HIGHS IN THE MIDDLE-40S. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... HIPRES WL BUILD IN FM THE WEST TONIGHT WITH NRLY FLOW TAKING HOLD ACRS THE REGION. THIS WL KEEP LK CLDS IN ACRS PORTIONS OF THE AREA AS WINDS SWING ARND FM THE NW AT 00Z TO MORE OF A NRLY FLOW BY 06Z. LESS OF A FETCH ACRS THE LKS WL LEAD TO MOCLDY DIMINISHING TO PCLDY OVRNGT WITH MOST AREAS EXPERIENCING SKC. GIVEN VARYING CLD CONDS EXPECT THAT MIN TEMPS WL DIP WELL INTO THE 20S AT MOST LOCALES WITH THE EXCEPTION OF THE LK PLAIN. HIPRES WL SQUAT OVR THE REGION THRU THURSDAY AND BYND. MODERATING TEMPS CAN BE EXPECTED THRU MIDWEEK. SKIES EXPECTED TO CLD UP FM THE WEST ON THUR AFTN AS H5 L/WV TROF APPCHS FM THE WEST COURTESY OF UL LOW OVR HUDSON BAY. HWVR, THIS WL LKLY HV LITTLE IMPACT ON TEMPS WITH HIGHS EXPECTED IN THE MID-UPR 40S. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... 215 PM TUE UPDATE... MODELS ARE IN AGREEMENT ON CONTINUED QUIET PERIOD OF DRY WEATHER THROUGH THE WEEKEND...BUT THEN DEPART CONSIDERABLY ON HOW TO HANDLE LOCATION AND SIZE OF A SYSTEM HEADING UP OFFSHORE THE COAST EARLY NEXT WEEK...AND WHETHER WE GET ANY PERIPHERAL IMPACTS AT ALL FROM IT. REGARDLESS...NOT SEEING ANY SIGNS OF ANOMOLOUSLY WARM NOR COLD OUTBREAKS...STAYING PRETTY CLOSE TO CLIMATOLOGY OVERALL OR JUST A SHADE SHORT OF IT IF ANYTHING. UPPER TROUGH DIGGING INTO WESTERN GREAT LAKES FRIDAY...PINCHES OFF A SMALL UPPER LOW WHICH HEADS TO THE SOUTHERN APPALACHIAN REGION. FOR US...STRONG SURFACE HIGH STAYS IN CONTROL. PLENTY OF DRY AIR AND ONLY A TENUOUS AT BEST CONNECTION FROM THE UPPER LOW WELL TO OUR SOUTH...TO THE SHEARING OUT NORTHERN STREAM WAVE TO OUR NORTH. THE ASSOCIATED WEAKENING VORTICITY LOBE ALOFT DOES NOT EVEN QUITE MAKE IT THROUGH OUR REGION. AT THIS POINT...GFS AND ECMWF ARE STRUGGLING WITH THE SOUTHERN UPPER LOW. GFS SIMPLY OPENS IT BACK UP AND PUSHES IT WELL OFF THE CAROLINA COAST...WITH THE LARGE SURFACE HIGH/RIDGE ACROSS THE NORTHEAST DOMINANT. SO WITH THE GFS...NO PRECIPITION FORESEEN WITH NEAR CLIMATOLOGY DAYS AND CHILLY NIGHTS. THE ECMWF MEANWHILE MAINTAINS THE UPPER LOW...AND TAKES IT UP THE COAST ONCE MEETING THE GULF STREAM. IT HAS A GRADUAL EVOLUTION IN DEVELOPING A LARGE IN SIZE...YET INITIALLY NOT VERY DEEP...SURFACE LOW WHICH VERY SLOWLY SLOGS NORTHWARD AND PERHAPS RETROGRADES SOMEWHAT TO EVENTUALLY IMPACT OUR WEATHER. TEMPERATURES IN THIS SCENARIO IF IT WERE TO PAN OUT DO NOT LOOK SUPPORTIVE OF SNOW. THE BIG SURFACE HIGH TO THE NORTH...REMAINING DOMINANT IN THE GFS...SQUEEZES FARTHER EAST IN THE ECMWF AND ALLOWS MOISTURE/PERIPHERY OF LOW PRESSURE TO OOZE TOWARDS THE NORTHEAST EARLY NEXT WEEK. NOT SURE HOW MUCH STOCK TO PUT IN THE ECMWF SOLUTION...WITH THE ODD LOOK TO ITS EVOLUTION ESPECIALLY REGARDING THE SURFACE LOW. UNTIL THIS LARGER SCALE CONUNDRUM CAN BE RESOLVED...FOR NOW I PLACED ONLY SLIGHT TO LOW CHANCE POPS FOCUSED ON SOUTHERN TO EASTERN ZONES EARLY NEXT WEEK...SIMILAR TO HPC FORECAST. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... 18Z UPDATE... WIND DIRECTION WILL VEER MORE NORTHWESTERLY THIS AFTERNOON. MVFR TO LOW END MVFR CIGS ARE EXPECTED COURTESY OF LAKE EFFECT AND FAVORABLE WIND DIRECTION. THAT BEING SAID...NOT ENOUGH COLD AIR FOR ANY SIGNIFICANT LAKE EFFECT PRECIPITATION. CIGS WILL SCATTER OUT FOR SOME AS FLOW SLACKENS WHILE VEERING FURTHER TONIGHT...YET DEVELOP FOR OTHERS AS INVERSION COMPRESSES CLOSER TOT HE SURFACE...SEE INDIVIDUAL TAFS FOR SPECIFICS. DRY ATMOSPHERE AND LIGHT NNE TO NE FLOW EVENTUALLY WIN OUT OF WEDNESDAY MORNING WITH VFR AND HIGH PRESSURE. OUTLOOK... WED THROUGH SUN...VFR WITH HIGH PRESSURE OVER THE REGION. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...MDP NEAR TERM...PVN/RRM SHORT TERM...PVN LONG TERM...MDP AVIATION...MDP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1230 PM EST TUE NOV 13 2012 .SYNOPSIS... AFTERNOON HIGH TEMPERATURES WILL AVERAGE 15 TO 20 DEGREES COLDER THAN YESTERDAY COURTESY OF A STRONG COLD FRONT THAT PASSED THROUGH LAST NIGHT. DRY WEATHER AND SEASONAL TEMPERATURES ARE EXPECTED THROUGH THE END OF THE WEEK AS HIGH PRESSURE DOMINATES THE WEATHER PATTERN. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 12 PM UPDATE...LATEST SAT PICS CONTINUE TO SHOW WIDESPREAD STRATO CU ACROSS THE CWA WITH A FEW BREAKS IN THE WESTERN MOHAWK VALLEY AND WYOMING VALLEY. OTHER THAN ADJUSTING MAX TEMPS DOWN A BIT MORE FORECAST IN GOOD SHAPE. 10 AM UPDATE...PRECIP HAS MOVED EAST OF THE REGION WITH THE CURRENT WEAK LAKE RESPONSE NORTH OF THE FORECAST AREA ALONG THE LAKE ONTARIO EASTERN SHORE. SATELLITE SHOWS CLOUDY TO MOSTLY CLOUDY SKIES OVER THE ENTIRE REGION WITH 12Z RAOBS AND RAP MODEL SOUNDINGS INDICATING A VERY SHALLOW LAYER OF MOISTURE ABOUT 50 MB DEEP AT THE 850 MB LEVEL. THE MODEL SOUNDINGS INDICATE THIS LAYER WILL BE VERY STUBBORN TO ERODE UNDER A STRONG SUBSIDENCE INVERSION. ADJUSTED CLOUD GRIDS TO REFLECT THIS MORE PESSIMISTIC THINKING OF CLOUDY TO MOSTLY CLOUDY SKIES FOR MUCH OF THE DAY EXCEPT FOR THE FAR SE FA. DUE TO THIS INCREASED CLOUD COVER ADJUSTED MAX TEMPS DOWN SLIGHTLY. LOW LEVEL WINDS WILL GRADUALLY VEER TODAY WITH SCATTERED RAIN/SNOW SHOWERS FOR PRIMARILY NRN ONEIDA COUNTY POSSIBLY DROPPING INTO THE SYR AREA LATER THIS AFTERNOON. SNOW ACCUM OF ONLY A FEW TENTHS IN THE HIGHER TERRAIN OF ONEIDA COUNTY. 615 AM UPDATE... HV UPPED SNOWFALL TOTALS IN THE CATSKILLS THIS MRNG. AT THE BINGHAMTON AIRPORT WE MEASURED 1.4 INCHES AND NOT OUT OF THE QUESTION THAT HIGHER TERRAIN IN THE CATSKILLS MAY SEE UPWARDS OF 4 INCHES. HIGHER REFLECTIVITIES ON RADAR ALONG WITH DUAL-POL PRODUCTS AND WEBCAMS IN THE REGION SUPPORT THIS THINKING. HV ALSO TWEAKED HRLY TEMPS AS THEY DROPPED OFF QUICKLY THIS MRNG. HRLY POP/WX GRIDS LOOK TO BE FAIRLY WELL IN LINE WITH REALITY SO NO UPDATES NEEDED AT THIS TIME. PREV DISCUSSIONS BLO... 445 AM UPDATE... HOW QUICKLY THINGS CAN GO AWRY. JUST AS GRIDS WERE SENT, RAIN SWITCHED OVR TO SNOW HERE AT KBGM. UPDATED GRIDS THRU 14Z TO ADD SNOW IN AT ELEVATIONS > 1600 FT. VRY MINIMAL ACCUMS EXPECTED BUT OVR IN THE WRN CATS MAY SEE AMNTS UPWARDS OF AN INCH BTWN NOW AND 12Z. 4 AM UPDATE... AS OF 07Z CDFNT HAS MVD THRU CWA. BULK OF THE RAIN, AS EXPECTED, IS BHND THE FRONTAL BNDRY AS UL TROF AND ASSOC SPEED MAX ROTATE THRU THE REGION BY 15Z. BASED ON PROGRESS OF BACK EDGE OF MAIN AREA OF PCPN RAIN SHUD BE LOCATED OVR FAR ERN ZONES BY 12Z AS FCST. EXPECT THIS PCPN WL SHOVE EAST OF FA BY 15Z. WRLY FLOW BHND FNT AS WELL AS CLD TEMPS ALOFT MAY LEAD TO LK RESPONSE FOR A TIME THIS MRNG INTO EARLY AFTN. WITH TEMPS RAPIDLY FALLING INTO THE LOW-MID 30S BY 12Z LOCALES IN THE SRN TUG HILL PLATEAU MAY SEE A BRIEF SNOW SHOWER THIS MRNG BFR MIXING WITH RAIN BY 15Z. ANY LINGERING PCPN WL LKLY BE ALL RAIN BY LATE MRNG INTO THE AFTN HRS...WITH VRY MINIMAL SNOW ACCUMS EXPECTED. THAT IS, ASSUMING ANYTHING CAN DVLP WITH VRY LITTLE ACTIVITY EVIDENT ON KBUF RADAR AS OF 09Z COURTESY OF LOW-LVL DRYING WORKING IN FM THE WEST. SKIES WL GNRLY BEGIN AS MOCLDY THIS MRNG BFR CLRNG SOUTH OF THE I-88 CORRIDOR BY AFTN. SXNS WEST OF I-81 WL RMN PRTLY-MOCLDY THRU 00Z WED. THIS WL STUNT TEMPS FM RISING TOO MUCH. ON AVG, EXPECT MAXES TO BE SOME 20-25 DEGREES LWR THAN YDA WITH HIGHS IN THE MIDDLE-40S. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/... HIPRES WL BUILD IN FM THE WEST TONIGHT WITH NRLY FLOW TAKING HOLD ACRS THE REGION. THIS WL KEEP LK CLDS IN ACRS PORTIONS OF THE AREA AS WINDS SWING ARND FM THE NW AT 00Z TO MORE OF A NRLY FLOW BY 06Z. LESS OF A FETCH ACRS THE LKS WL LEAD TO MOCLDY DIMINISHING TO PCLDY OVRNGT WITH MOST AREAS EXPERIENCING SKC. GIVEN VARYING CLD CONDS EXPECT THAT MIN TEMPS WL DIP WELL INTO THE 20S AT MOST LOCALES WITH THE EXCEPTION OF THE LK PLAIN. HIPRES WL SQUAT OVR THE REGION THRU THURSDAY AND BYND. MODERATING TEMPS CAN BE EXPECTED THRU MIDWEEK. SKIES EXPECTED TO CLD UP FM THE WEST ON THUR AFTN AS H5 L/WV TROF APPCHS FM THE WEST COURTESY OF UL LOW OVR HUDSON BAY. HWVR, THIS WL LKLY HV LITTLE IMPACT ON TEMPS WITH HIGHS EXPECTED IN THE MID-UPR 40S. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... 1 AM UPDATE... ONLY MINOR CHANGES. SHOULD BE A QUIET PERIOD WITH DRY WEATHER AND STEADY TEMPERATURES AT OR SLIGHTLY BELOW SEASONAL NORMALS. PREVIOUS DISCUSSION... VERY LITTLE TO TALK ABOUT AGAIN THIS AFTERNOON AS MODELS CONTINUE TO ADVERTISE A VERY QUIET PERIOD WITH HIGH PRESSURE IN FIRM CONTROL THROUGH AT LEAST SATURDAY. NORTHERN HEMISPHERIC 500-MB TEMP/HEIGHT PROGS SHOW ZONAL FLOW PREVAILING THROUGH THE PERIOD TO OUR NORTH ACROSS CENTRAL/NORTHERN CANADA...EFFECTIVELY KEEPING ANY TRUE ARCTIC AIR ACROSS THE HIGHER LATITUDES. WITH THIS BEING THE CASE...NO SIGNIFICANT COOL DOWNS ARE ANTICIPATED FROM THIS VANTAGE POINT WITH NEAR NORMAL TEMPS EXPECTED THROUGH THE PERIOD. ONE FEATURE THAT DOES WARRANT SOME WATCHING WILL BE A SOUTHERN STREAM WAVE WORKING THROUGH THE SOUTHEAST/TENN RVR VLY TOWARDS LATE WEEK. THE GFS IN PARTICULAR DOES DEVELOP CYCLOGENESIS OFF THE SOUTHEAST COAST WITH THE MODEL THEN TAKING THE SFC LOW AND UPPER WAVE SLOWLY UP THE EAST COAST. EXTENT OF NORTHWARD PROGRESS REMAINS IN QUESTION THIS AFTERNOON AS BOTH GFS AND ECMWF SHOW STRONG LOWER TROPOSPHERIC RIDGING ACROSS THE NORTHEASTERN US THROUGH THE WEEKEND WHICH COULD SERVE TO BLOCK NORTHWARD PROGRESS OF THE DISTURBANCE. FOR NOW HAVE ELECTED TO LEAVE ANY MENTION OF PRECIP OUT OF THE FCST...HOWEVER IF TRENDS CONTINUE TO SHOW HIGH PRESSURE SHIFTING TO THE NORTH...SUBSEQUENT UPDATES MAY HAVE TO INTRODUCE POPS FOR EARLY NEXT WEEK. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... 18Z UPDATE... WIND DIRECTION WILL VEER MORE NORTHWESTERLY THIS AFTERNOON. MVFR TO LOW END MVFR CIGS ARE EXPECTED COURTESY OF LAKE EFFECT AND FAVORABLE WIND DIRECTION. THAT BEING SAID...NOT ENOUGH COLD AIR FOR ANY SIGNIFICANT LAKE EFFECT PRECIPITATION. CIGS WILL SCATTER OUT FOR SOME AS FLOW SLACKENS WHILE VEERING FURTHER TONIGHT...YET DEVELOP FOR OTHERS AS INVERSION COMPRESSES CLOSER TOT HE SURFACE...SEE INDIVIDUAL TAFS FOR SPECIFICS. DRY ATMOSPHERE AND LIGHT NNE TO NE FLOW EVENTUALLY WIN OUT OF WEDNESDAY MORNING WITH VFR AND HIGH PRESSURE. OUTLOOK... WED THROUGH SUN...VFR WITH HIGH PRESSURE OVER THE REGION. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...PVN/RRM NEAR TERM...PVN/RRM SHORT TERM...PVN LONG TERM...CMG/TAC AVIATION...MDP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1215 PM EST TUE NOV 13 2012 .SYNOPSIS... AFTER A COLD START THIS MORNING, AFTERNOON HIGH TEMPERATURES WILL AVERAGE 15 TO 20 DEGREES COLDER THAN YESTERDAY COURTESY OF A STRONG COLD FRONT. HIGH TEMPERATURES TODAY CAN BE EXPECTED TO REMAIN IN THE 40S. DRY WEATHER AND SEASONAL TEMPERATURES ARE EXPECTED THROUGH THE END OF THE WEEK AS HIGH PRESSURE DOMINATES THE WEATHER PATTERN. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 12 PM UPDATE...LATEST SAT PICS CONTINUE TO SHOW WIDESPREAD STRATO CU ACROSS THE CWA WITH A FEW BREAKS IN THE WESTERN MOHAWK VALLEY AND WYOMING VALLEY. OTHER THAN ADJUSTING MAX TEMPS DOWN A BIT MORE FORECAST IN GOOD SHAPE. 10 AM UPDATE...PRECIP HAS MOVED EAST OF THE REGION WITH THE CURRENT WEAK LAKE RESPONSE NORTH OF THE FORECAST AREA ALONG THE LAKE ONTARIO EASTERN SHORE. SATELLITE SHOWS CLOUDY TO MOSTLY CLOUDY SKIES OVER THE ENTIRE REGION WITH 12Z RAOBS AND RAP MODEL SOUNDINGS INDICATING A VERY SHALLOW LAYER OF MOISTURE ABOUT 50 MB DEEP AT THE 850 MB LEVEL. THE MODEL SOUNDINGS INDICATE THIS LAYER WILL BE VERY STUBBORN TO ERODE UNDER A STRONG SUBSIDENCE INVERSION. ADJUSTED CLOUD GRIDS TO REFLECT THIS MORE PESSIMISTIC THINKING OF CLOUDY TO MOSTLY CLOUDY SKIES FOR MUCH OF THE DAY EXCEPT FOR THE FAR SE FA. DUE TO THIS INCREASED CLOUD COVER ADJUSTED MAX TEMPS DOWN SLIGHTLY. LOW LEVEL WINDS WILL GRADUALLY VEER TODAY WITH SCATTERED RAIN/SNOW SHOWERS FOR PRIMARILY NRN ONEIDA COUNTY POSSIBLY DROPPING INTO THE SYR AREA LATER THIS AFTERNOON. SNOW ACCUM OF ONLY A FEW TENTHS IN THE HIGHER TERRAIN OF ONEIDA COUNTY. 615 AM UPDATE... HV UPPED SNOWFALL TOTALS IN THE CATSKILLS THIS MRNG. AT THE BINGHAMTON AIRPORT WE MEASURED 1.4 INCHES AND NOT OUT OF THE QUESTION THAT HIGHER TERRAIN IN THE CATSKILLS MAY SEE UPWARDS OF 4 INCHES. HIGHER REFLECTIVITIES ON RADAR ALONG WITH DUAL-POL PRODUCTS AND WEBCAMS IN THE REGION SUPPORT THIS THINKING. HV ALSO TWEAKED HRLY TEMPS AS THEY DROPPED OFF QUICKLY THIS MRNG. HRLY POP/WX GRIDS LOOK TO BE FAIRLY WELL IN LINE WITH REALITY SO NO UPDATES NEEDED AT THIS TIME. PREV DISCUSSIONS BLO... 445 AM UPDATE... HOW QUICKLY THINGS CAN GO AWRY. JUST AS GRIDS WERE SENT, RAIN SWITCHED OVR TO SNOW HERE AT KBGM. UPDATED GRIDS THRU 14Z TO ADD SNOW IN AT ELEVATIONS > 1600 FT. VRY MINIMAL ACCUMS EXPECTED BUT OVR IN THE WRN CATS MAY SEE AMNTS UPWARDS OF AN INCH BTWN NOW AND 12Z. 4 AM UPDATE... AS OF 07Z CDFNT HAS MVD THRU CWA. BULK OF THE RAIN, AS EXPECTED, IS BHND THE FRONTAL BNDRY AS UL TROF AND ASSOC SPEED MAX ROTATE THRU THE REGION BY 15Z. BASED ON PROGRESS OF BACK EDGE OF MAIN AREA OF PCPN RAIN SHUD BE LOCATED OVR FAR ERN ZONES BY 12Z AS FCST. EXPECT THIS PCPN WL SHOVE EAST OF FA BY 15Z. WRLY FLOW BHND FNT AS WELL AS CLD TEMPS ALOFT MAY LEAD TO LK RESPONSE FOR A TIME THIS MRNG INTO EARLY AFTN. WITH TEMPS RAPIDLY FALLING INTO THE LOW-MID 30S BY 12Z LOCALES IN THE SRN TUG HILL PLATEAU MAY SEE A BRIEF SNOW SHOWER THIS MRNG BFR MIXING WITH RAIN BY 15Z. ANY LINGERING PCPN WL LKLY BE ALL RAIN BY LATE MRNG INTO THE AFTN HRS...WITH VRY MINIMAL SNOW ACCUMS EXPECTED. THAT IS, ASSUMING ANYTHING CAN DVLP WITH VRY LITTLE ACTIVITY EVIDENT ON KBUF RADAR AS OF 09Z COURTESY OF LOW-LVL DRYING WORKING IN FM THE WEST. SKIES WL GNRLY BEGIN AS MOCLDY THIS MRNG BFR CLRNG SOUTH OF THE I-88 CORRIDOR BY AFTN. SXNS WEST OF I-81 WL RMN PRTLY-MOCLDY THRU 00Z WED. THIS WL STUNT TEMPS FM RISING TOO MUCH. ON AVG, EXPECT MAXES TO BE SOME 20-25 DEGREES LWR THAN YDA WITH HIGHS IN THE MIDDLE-40S. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/... HIPRES WL BUILD IN FM THE WEST TONIGHT WITH NRLY FLOW TAKING HOLD ACRS THE REGION. THIS WL KEEP LK CLDS IN ACRS PORTIONS OF THE AREA AS WINDS SWING ARND FM THE NW AT 00Z TO MORE OF A NRLY FLOW BY 06Z. LESS OF A FETCH ACRS THE LKS WL LEAD TO MOCLDY DIMINISHING TO PCLDY OVRNGT WITH MOST AREAS EXPERIENCING SKC. GIVEN VARYING CLD CONDS EXPECT THAT MIN TEMPS WL DIP WELL INTO THE 20S AT MOST LOCALES WITH THE EXCEPTION OF THE LK PLAIN. HIPRES WL SQUAT OVR THE REGION THRU THURSDAY AND BYND. MODERATING TEMPS CAN BE EXPECTED THRU MIDWEEK. SKIES EXPECTED TO CLD UP FM THE WEST ON THUR AFTN AS H5 L/WV TROF APPCHS FM THE WEST COURTESY OF UL LOW OVR HUDSON BAY. HWVR, THIS WL LKLY HV LITTLE IMPACT ON TEMPS WITH HIGHS EXPECTED IN THE MID-UPR 40S. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... 1 AM UPDATE... ONLY MINOR CHANGES. SHOULD BE A QUIET PERIOD WITH DRY WEATHER AND STEADY TEMPERATURES AT OR SLIGHTLY BELOW SEASONAL NORMALS. PREVIOUS DISCUSSION... VERY LITTLE TO TALK ABOUT AGAIN THIS AFTERNOON AS MODELS CONTINUE TO ADVERTISE A VERY QUIET PERIOD WITH HIGH PRESSURE IN FIRM CONTROL THROUGH AT LEAST SATURDAY. NORTHERN HEMISPHERIC 500-MB TEMP/HEIGHT PROGS SHOW ZONAL FLOW PREVAILING THROUGH THE PERIOD TO OUR NORTH ACROSS CENTRAL/NORTHERN CANADA...EFFECTIVELY KEEPING ANY TRUE ARCTIC AIR ACROSS THE HIGHER LATITUDES. WITH THIS BEING THE CASE...NO SIGNIFICANT COOL DOWNS ARE ANTICIPATED FROM THIS VANTAGE POINT WITH NEAR NORMAL TEMPS EXPECTED THROUGH THE PERIOD. ONE FEATURE THAT DOES WARRANT SOME WATCHING WILL BE A SOUTHERN STREAM WAVE WORKING THROUGH THE SOUTHEAST/TENN RVR VLY TOWARDS LATE WEEK. THE GFS IN PARTICULAR DOES DEVELOP CYCLOGENESIS OFF THE SOUTHEAST COAST WITH THE MODEL THEN TAKING THE SFC LOW AND UPPER WAVE SLOWLY UP THE EAST COAST. EXTENT OF NORTHWARD PROGRESS REMAINS IN QUESTION THIS AFTERNOON AS BOTH GFS AND ECMWF SHOW STRONG LOWER TROPOSPHERIC RIDGING ACROSS THE NORTHEASTERN US THROUGH THE WEEKEND WHICH COULD SERVE TO BLOCK NORTHWARD PROGRESS OF THE DISTURBANCE. FOR NOW HAVE ELECTED TO LEAVE ANY MENTION OF PRECIP OUT OF THE FCST...HOWEVER IF TRENDS CONTINUE TO SHOW HIGH PRESSURE SHIFTING TO THE NORTH...SUBSEQUENT UPDATES MAY HAVE TO INTRODUCE POPS FOR EARLY NEXT WEEK. && .AVIATION /17Z TUESDAY THROUGH SATURDAY/... 630 AM UPDATE... MIXED PRECIP ON THE WAY OUT WITH ONLY KAVP HAVING RAIN NOW. THIS SHOULD END BY 14Z. SOME MVFR CIGS AND MAYBE MVFR VSBYS AT KAVP ALSO UNTIL 14Z. BEHIND THE FRONT CIGS QUICKLY RISE TO VFR AND STAY THERE TODAY. KRME AND KBGM MAY ALSO HAVE AN HOUR OR TWO OF MVFR RIGHT AT THE START. DURING THE DAY TODAY CONTINUED BKN TO OVC SKIES BUT VFR. WEAK LAKE ENHANCEMENT WITH WEST LL FLOW SHIFTING TO NW. LATE THIS AFTN TO SUNSET SKIES WILL BECOME SCATTERED OR CLEAR AND REMAIN THAT WAY TONIGHT. BEST CHANCE OF CLOUDS CLOSER TO THE LAKE...BUT LOW LEVEL FLOW GOES AROUND TO NE WITH CONDITIONAL LAKE INSTABILITY. NOT EXPECTING MANY CLOUDS TONIGHT. W TO NW WINDS INCREASING TO 8 KTS THIS MORNING THEN CONTINUING INTO THE AFTN. TONIGHT WINDS LIGHT TO CALM...MOSTLY FROM THE NW TO N. OUTLOOK... WED THROUGH SAT...VFR WITH HIGH PRESSURE OVER THE REGION. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...PVN/RRM NEAR TERM...PVN/RRM SHORT TERM...PVN LONG TERM...CMG/TAC AVIATION...TAC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1017 AM EST TUE NOV 13 2012 .SYNOPSIS... AFTER A COLD START THIS MORNING, AFTERNOON HIGH TEMPERATURES WILL AVERAGE 15 TO 20 DEGREES COLDER THAN YESTERDAY COURTESY OF A STRONG COLD FRONT. HIGH TEMPERATURES TODAY CAN BE EXPECTED TO REMAIN IN THE 40S. DRY WEATHER AND SEASONAL TEMPERATURES ARE EXPECTED THROUGH THE END OF THE WEEK AS HIGH PRESSURE DOMINATES THE WEATHER PATTERN. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 10 AM UPDATE...PRECIP HAS MOVED EAST OF THE REGION WITH THE CURRENT WEAK LAKE RESPONSE NORTH OF THE FORECAST AREA ALONG THE LAKE ONTARIO EASTERN SHORE. SATELLITE SHOWS CLOUDY TO MOSTLY CLOUDY SKIES OVER THE ENTIRE REGION WITH 12Z RAOBS AND RAP MODEL SOUNDINGS INDICATING A VERY SHALLOW LAYER OF MOISTURE ABOUT 50 MB DEEP AT THE 850 MB LEVEL. THE MODEL SOUNDINGS INDICATE THIS LAYER WILL BE VERY STUBBORN TO ERODE UNDER A STRONG SUBSIDENCE INVERSION. ADJUSTED CLOUD GRIDS TO REFLECT THIS MORE PESSIMISTIC THINKING OF CLOUDY TO MOSTLY CLOUDY SKIES FOR MUCH OF THE DAY EXCEPT FOR THE FAR SE FA. DUE TO THIS INCREASED CLOUD OVER ADJUSTED MAX TEMPS DOWN SLIGHTLY. LOW LEVEL WINDS WILL GRADUALLY VEER TODAY WITH SCATTERED RAIN/SNOW SHOWERS FOR PRIMARILY NRN ONEIDA COUNTY POSSIBLY DROPPING INTO THE SYR AREA LATER THIS AFTERNOON. SNOW ACCUM OF ONLY A FEW TENTHS IN THE HIGHER TERRAIN OF ONEIDA COUNTY. 615 AM UPDATE... HV UPPED SNOWFALL TOTALS IN THE CATSKILLS THIS MRNG. AT THE BINGHAMTON AIRPORT WE MEASURED 1.4 INCHES AND NOT OUT OF THE QUESTION THAT HIGHER TERRAIN IN THE CATSKILLS MAY SEE UPWARDS OF 4 INCHES. HIGHER REFLECTIVITIES ON RADAR ALONG WITH DUAL-POL PRODUCTS AND WEBCAMS IN THE REGION SUPPORT THIS THINKING. HV ALSO TWEAKED HRLY TEMPS AS THEY DROPPED OFF QUICKLY THIS MRNG. HRLY POP/WX GRIDS LOOK TO BE FAIRLY WELL IN LINE WITH REALITY SO NO UPDATES NEEDED AT THIS TIME. PREV DISCUSSIONS BLO... 445 AM UPDATE... HOW QUICKLY THINGS CAN GO AWRY. JUST AS GRIDS WERE SENT, RAIN SWITCHED OVR TO SNOW HERE AT KBGM. UPDATED GRIDS THRU 14Z TO ADD SNOW IN AT ELEVATIONS > 1600 FT. VRY MINIMAL ACCUMS EXPECTED BUT OVR IN THE WRN CATS MAY SEE AMNTS UPWARDS OF AN INCH BTWN NOW AND 12Z. 4 AM UPDATE... AS OF 07Z CDFNT HAS MVD THRU CWA. BULK OF THE RAIN, AS EXPECTED, IS BHND THE FRONTAL BNDRY AS UL TROF AND ASSOC SPEED MAX ROTATE THRU THE REGION BY 15Z. BASED ON PROGRESS OF BACK EDGE OF MAIN AREA OF PCPN RAIN SHUD BE LOCATED OVR FAR ERN ZONES BY 12Z AS FCST. EXPECT THIS PCPN WL SHOVE EAST OF FA BY 15Z. WRLY FLOW BHND FNT AS WELL AS CLD TEMPS ALOFT MAY LEAD TO LK RESPONSE FOR A TIME THIS MRNG INTO EARLY AFTN. WITH TEMPS RAPIDLY FALLING INTO THE LOW-MID 30S BY 12Z LOCALES IN THE SRN TUG HILL PLATEAU MAY SEE A BRIEF SNOW SHOWER THIS MRNG BFR MIXING WITH RAIN BY 15Z. ANY LINGERING PCPN WL LKLY BE ALL RAIN BY LATE MRNG INTO THE AFTN HRS...WITH VRY MINIMAL SNOW ACCUMS EXPECTED. THAT IS, ASSUMING ANYTHING CAN DVLP WITH VRY LITTLE ACTIVITY EVIDENT ON KBUF RADAR AS OF 09Z COURTESY OF LOW-LVL DRYING WORKING IN FM THE WEST. SKIES WL GNRLY BEGIN AS MOCLDY THIS MRNG BFR CLRNG SOUTH OF THE I-88 CORRIDOR BY AFTN. SXNS WEST OF I-81 WL RMN PRTLY-MOCLDY THRU 00Z WED. THIS WL STUNT TEMPS FM RISING TOO MUCH. ON AVG, EXPECT MAXES TO BE SOME 20-25 DEGREES LWR THAN YDA WITH HIGHS IN THE MIDDLE-40S. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/... HIPRES WL BUILD IN FM THE WEST TONIGHT WITH NRLY FLOW TAKING HOLD ACRS THE REGION. THIS WL KEEP LK CLDS IN ACRS PORTIONS OF THE AREA AS WINDS SWING ARND FM THE NW AT 00Z TO MORE OF A NRLY FLOW BY 06Z. LESS OF A FETCH ACRS THE LKS WL LEAD TO MOCLDY DIMINISHING TO PCLDY OVRNGT WITH MOST AREAS EXPERIENCING SKC. GIVEN VARYING CLD CONDS EXPECT THAT MIN TEMPS WL DIP WELL INTO THE 20S AT MOST LOCALES WITH THE EXCEPTION OF THE LK PLAIN. HIPRES WL SQUAT OVR THE REGION THRU THURSDAY AND BYND. MODERATING TEMPS CAN BE EXPECTED THRU MIDWEEK. SKIES EXPECTED TO CLD UP FM THE WEST ON THUR AFTN AS H5 L/WV TROF APPCHS FM THE WEST COURTESY OF UL LOW OVR HUDSON BAY. HWVR, THIS WL LKLY HV LITTLE IMPACT ON TEMPS WITH HIGHS EXPECTED IN THE MID-UPR 40S. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... 1 AM UPDATE... ONLY MINOR CHANGES. SHOULD BE A QUIET PERIOD WITH DRY WEATHER AND STEADY TEMPERATURES AT OR SLIGHTLY BELOW SEASONAL NORMALS. PREVIOUS DISCUSSION... VERY LITTLE TO TALK ABOUT AGAIN THIS AFTERNOON AS MODELS CONTINUE TO ADVERTISE A VERY QUIET PERIOD WITH HIGH PRESSURE IN FIRM CONTROL THROUGH AT LEAST SATURDAY. NORTHERN HEMISPHERIC 500-MB TEMP/HEIGHT PROGS SHOW ZONAL FLOW PREVAILING THROUGH THE PERIOD TO OUR NORTH ACROSS CENTRAL/NORTHERN CANADA...EFFECTIVELY KEEPING ANY TRUE ARCTIC AIR ACROSS THE HIGHER LATITUDES. WITH THIS BEING THE CASE...NO SIGNIFICANT COOL DOWNS ARE ANTICIPATED FROM THIS VANTAGE POINT WITH NEAR NORMAL TEMPS EXPECTED THROUGH THE PERIOD. ONE FEATURE THAT DOES WARRANT SOME WATCHING WILL BE A SOUTHERN STREAM WAVE WORKING THROUGH THE SOUTHEAST/TENN RVR VLY TOWARDS LATE WEEK. THE GFS IN PARTICULAR DOES DEVELOP CYCLOGENESIS OFF THE SOUTHEAST COAST WITH THE MODEL THEN TAKING THE SFC LOW AND UPPER WAVE SLOWLY UP THE EAST COAST. EXTENT OF NORTHWARD PROGRESS REMAINS IN QUESTION THIS AFTERNOON AS BOTH GFS AND ECMWF SHOW STRONG LOWER TROPOSPHERIC RIDGING ACROSS THE NORTHEASTERN US THROUGH THE WEEKEND WHICH COULD SERVE TO BLOCK NORTHWARD PROGRESS OF THE DISTURBANCE. FOR NOW HAVE ELECTED TO LEAVE ANY MENTION OF PRECIP OUT OF THE FCST...HOWEVER IF TRENDS CONTINUE TO SHOW HIGH PRESSURE SHIFTING TO THE NORTH...SUBSEQUENT UPDATES MAY HAVE TO INTRODUCE POPS FOR EARLY NEXT WEEK. && .AVIATION /15Z TUESDAY THROUGH SATURDAY/... 630 AM UPDATE... MIXED PRECIP ON THE WAY OUT WITH ONLY KAVP HAVING RAIN NOW. THIS SHOULD END BY 14Z. SOME MVFR CIGS AND MAYBE MVFR VSBYS AT KAVP ALSO UNTIL 14Z. BEHIND THE FRONT CIGS QUICKLY RISE TO VFR AND STAY THERE TODAY. KRME AND KBGM MAY ALSO HAVE AN HOUR OR TWO OF MVFR RIGHT AT THE START. DURING THE DAY TODAY CONTINUED BKN TO OVC SKIES BUT VFR. WEAK LAKE ENHANCEMENT WITH WEST LL FLOW SHIFTING TO NW. LATE THIS AFTN TO SUNSET SKIES WILL BECOME SCATTERED OR CLEAR AND REMAIN THAT WAY TONIGHT. BEST CHANCE OF CLOUDS CLOSER TO THE LAKE...BUT LOW LEVEL FLOW GOES AROUND TO NE WITH CONDITIONAL LAKE INSTABILITY. NOT EXPECTING MANY CLOUDS TONIGHT. W TO NW WINDS INCREASING TO 8 KTS THIS MORNING THEN CONTINUING INTO THE AFTN. TONIGHT WINDS LIGHT TO CALM...MOSTLY FROM THE NW TO N. OUTLOOK... WED THROUGH SAT...VFR WITH HIGH PRESSURE OVER THE REGION. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...PVN/RRM NEAR TERM...PVN/RRM SHORT TERM...PVN LONG TERM...CMG/TAC AVIATION...TAC
AREA FORECAST DISCUSSION
NWS RALEIGH NC
930 PM EST WED NOV 14 2012 .SYNOPSIS... AN UPPER LEVEL DISTURBANCE WILL CROSS THE AREA ON THURSDAY. HIGH PRESSURE WILL RETURN FOR FRIDAY BEFORE A COASTAL STORM DEVELOPS OFF THE SOUTHEAST COAST ON SATURDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 930 PM WEDNESDAY... COOL SURFACE HIGH CENTERED OVER SE ONTARIO WILL CONTINUE TO EXTEND DOWN THE EASTERN SEABOARD AND INTO THE CAROLINAS OVERNIGHT. MEANWHILE...A COMPACT POTENT MID/UPPER LEVEL SHORTWAVE OVER THE DEEP SOUTH WILL CONTINUE TO PROGRESS EAST...IN A NEGATIVE TILT FASHION...REACHING THE SAVANNA RIVER VALLEY BY DAYBREAK. LIFT WILL STRENGTHEN THROUGHOUT THE NIGHT WITH THE APPROACH OF THE SYSTEM AS 30 TO 40 METER H5 FALLS AND DPVA OVERSPREAD THE AREA. WHILE THE SYSTEM CURRENTLY LACKS DEEP MOISTURE...IT WILL BEGIN TO TAP INTO THE HIGHER PWATS(1.1-1.2")ALONG THE STALLED FRONTAL ZONE ALONG THE SOUTHEAST COAST. MOIST UPGLIDE WILL INCREASE IN THE 290K-295K LAYER TONIGHT OVER FAR SOUTH CENTRAL AND SW NC... ALTHOUGH IT NEVER BECOMES PARTICULARLY STRONG... AND THE SURFACE RIDGE WILL LEAD TO A SHALLOW BUT DRY SUBCLOUD LAYER... LIMITING PRECIP AMOUNTS. FORECAST POPS LOOK GOOD WITH A LATE SURGE TOWARDS DAYBREAK ACROSS THE SOUTHERN ZONES...WITH RAINFALL AMOUNTS AROUND A TENTH OF AN INCH. AS YOU HEAD NORTH...THE DRY SURFACE BASED AIR WILL REPEL MEASURABLE PRECIP WITH ONLY TRACE AMOUNTS EXPECTED. IT DOES APPEAR THAT THE FORECAST LOWS MAY BE A GOOD CATEGORY TOO COOL OVER SOUTHERN AND CENTRAL PORTIONS OF THE FORECAST AREA GIVEN ROBUST AND OPAQUE CLOUD COVER ALREADY OVER THE AREA WITH CEILINGS BETWEEN 2 TO 5KFT. LOWS IN THE LOWER TO MID 30 NORTHEAST TO LOWER 40S SOUTH. && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... AS OF 255 PM WEDNESDAY... ANOTHER CHILLY DAY THURSDAY WITH A GOOD CHANCE OF RAIN MAINLY SOUTH OF HIGHWAY 64. THE MID LEVEL SHORTWAVE TROUGH STARTS THE DAY RATHER POTENT AND NEGATIVELY TILTED OVER GA... THEN PROGRESSES EASTWARD ACROSS THE CAROLINAS WHILE DAMPENING IN FAVOR OF A BROAD TROUGH DROPPING THROUGH THE MIDWEST AND CENTRAL PLAINS. STRONG UPPER DIVERGENCE JUST OFF THE CAROLINA COAST... IN THE RIGHT ENTRANCE REGION OF A STRENGTHENING SRLY JET OVER THE ST LAWRENCE VALLEY... ALSO WEAKENS AS THE JET SHIFTS TO THE NE. THIS WANING FORCING ALOFT COMBINED WITH DIMINISHING LOWER LEVEL MOIST UPGLIDE AT 290K-295K AND THE CONTINUED SHALLOW BUT DRY SUBCLOUD LAYER WITH THE SURFACE RIDGE NOSING IN FROM THE NORTH SHOULD LIMIT THE NORTHWARD EXTENT OF THE MEASURABLE PRECIP. THE SREF PROBABILITIES SUPPORT THIS... INDICATING A LOW CHANCE OF MEASURABLE PRECIP IN THE VA BORDER COUNTIES OF CENTRAL NC. LATEST MODEL OUTPUT FOLLOWS OUR EARLIER FORECASTS FAIRLY CLOSELY... AND WILL HOLD ONTO LIKELY POPS OVERSPREADING THE SOUTH BUT WILL LOWER RAIN CHANCES IN THE FAR NORTH. LOW LEVEL COOL AIR ADVECTION WEDGING INTO THE AREA WITH OVERRUNNING ATOP IT AND LITTLE TO NO SUNSHINE WILL NOT ALLOW MUCH HEATING... AND EXPECT MUCH BELOW NORMAL HIGHS... 48-52. EXPECT QUICKLY WANING COVERAGE AND AMOUNTS AS THE MID LEVEL TROUGH MOVES EAST OF THE FORECAST AREA THURSDAY NIGHT... WITH CLEARING SKIES IN THE WEST LATE. GFS FORECAST SOUNDINGS -- WHICH FAVOR A WEAKER SHORTWAVE TROUGH AND THUS A FASTER CLEARING -- SUGGEST THAT WE COULD SEE PATCHY GROUND FOG LATE THURSDAY NIGHT. LOWS 33-40. -GIH && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... AS OF 300 PM WEDNESDAY... EXPECTED FOR MUCH OF THE EXTENDED PERIOD. NWP GUIDANCE IS GENERALLY CONSISTENT WITH THEIR DEPICTION OF THE MAIN PLAYERS THROUGH MUCH OF THE EXTENDED RANGE. DIFFERENCES ARE NOTED IN THE DETAILS OF THE EVOLUTION OF A LOW PRESSURE SYSTEM OFF THE SOUTHEAST COAST AND THE EVENTUAL DEPARTURE OF A CLOSED LOW OFF THE CAROLINA COAST LATE IN THE PERIOD. A LOW AMPLITUDE POSITIVELY TILTED MID LEVEL TROUGH ACROSS THE OHIO AND LOWER MISSISSIPPI VALLEY ON FRIDAY MORNING WILL DEEPEN AND CLOSE OFF OVER THE SOUTHERN APPALACHIANS ON SATURDAY MORNING. THE UPPER TROUGH WILL INTERACT WITH A BROAD AREA OF LOW PRESSURE OFF THE SOUTHEAST COAST AS A STRENGTHENING SURFACE HIGH PRESSURE SYSTEM BUILDS INTO THE NORTHEAST. THESE FEATURES WILL COMBINE TO STRENGTHEN A LOW LEVEL NORTHEAST FLOW ACROSS THE CAROLINAS AND GRADUALLY MOISTEN THE LOW AND MID LEVELS ON SATURDAY AND ESPECIALLY SATURDAY NIGHT. AS THE CLOSED LOW SLIPS EASTWARD AND DEEP LAYER MOISTURE INCREASES...EXPECT AREAS OF RAIN TO DEVELOP AND SHIFT NORTHWARD INTO THE SOUTHERN COASTAL PLAIN/SANDHILLS ON LATE SATURDAY AND THEN SPREAD NORTHWARD INTO THE REST OF THE COASTAL PLAIN AND EASTERN PIEDMONT ON SATURDAY NIGHT AND SUNDAY. THE THREAT OF LIGHT RAIN ACROSS THE WESTERN PIEDMONT AND TRIAD AREA WILL BE VERY LIMITED. RECENT RUNS OF THE GFS AND ECMWF HAVE TRENDED BOTH CLOSER/FARTHER AWAY FROM THE COAST AND RESULTED IN WETTER/DRIER CONDITIONS. GIVEN THE UNCERTAINTY REGARDING THE LIKELIHOOD AND AMOUNT OF PRECIPITATION...HAVE OPTED TO INCREASE POPS SLIGHTLY BUT CONFINE THEM TO THE MID CHANCE RANGE. THE THREAT OF PRECIPITATION... ESPECIALLY ACROSS EASTERN PORTIONS OF THE FORECAST AREA CONTINUES INTO MONDAY NIGHT. THE CONSIDERABLE AMOUNTS OF CLOUD COVER AND COOL SURFACE HIGH TO THE NORTH WILL RESULT IN HIGH TEMPERATURES AROUND 10 DEGREES BELOW NORMAL WITH A NORTHEAST WIND ADDING TO THE CHILL. THE CLOSED LOW WILL EVENTUALLY SHIFT EAST AND OFF THE COAST LATE MONDAY AND TUESDAY AS A MID LEVEL TROUGH APPROACHES FROM THE WEST. THE INTERACTION OF THIS TROUGH WITH THE SLOWLY DEPARTING CLOSED LOW OFF THE COAST IS UNCLEAR AT THIS TIME BUT THERE IS SOME LIMITED POTENTIAL FOR LIGHT PRECIPITATION ON WEDNESDAY. AT THIS POINT HAVE OPTED TO KEEP FORECAST DRY WITH SLIGHTLY BELOW NORMAL TEMPERATURES. -BLAES && .AVIATION /00Z THURSDAY THROUGH MONDAY/... AS OF 740 PM WEDNESDAY... 24 HOUR TAF PERIOD: VFR CONDITIONS EXPECTED THROUGH THE 24 HOUR TAF PERIOD AT KINT... KGSO...AND KRDU. THE NAM SHOWS THE POTENTIAL FOR A PERIOD OF SOME HIGH END MVFR CIGS AT THESE TERMINALS AFTER 12Z THURSDAY...HOWEVER THE GFS AND RUC ARE NOT AS PESSIMISTIC. AS SUCH...CONFIDENCE OF SUB VFR CIGS OCCURRING AT THOSE TERMINALS IS LOW AT THIS TIME AND HAVE NOT INCLUDED THEM IN THIS ISSUANCE. MODELS SHOW BEST ISENTROPIC UPGLIDE AT OR ABOVE 5 KFT AT ALL TERMINALS EXCEPT KFAY...WHERE THERE IS GOOD UPGLIDE AT OR BELOW 3 KFT. CIGS AT KFAY HAVE ALREADY FALLEN BELOW VFR AND WILL LIKELY REMAIN THERE THROUGH THE TAF PERIOD. THE BEST CHANCE FOR PRECIP TO DEVELOP IS ACROSS THE SOUTH (KFAY) MAINLY AFTER 12Z. THERE IS STILL A GOOD DEAL OF UNCERTAINTY WITH REGARD TO EXTENT AND TIMING BUT IT IS POSSIBLE THE RAIN COULD SPREAD FURTHER NORTH DURING THE DAY THURSDAY. KRWI SHOULD REMAIN LOW END VFR THROUGH 12Z THURSDAY WITH MVFR CIGS FROM 12Z THROUGH THE REMAINDER OF THE TAF PERIOD. SURFACE WINDS WILL BE MAINLY NE AROUND 5 KTS AND VEERING WITH HEIGHT. -KC LOOKING AHEAD: CIGS WILL LIFT/DISSIPATE OVERNIGHT THURSDAY INTO FRIDAY...WITH FAY THE LAST TO SEE THESE CLOUDS BREAK UP. PATCHY IFR FOG IS POSSIBLE RIGHT AROUND DAYBREAK FRIDAY. VFR CONDITIONS ARE EXPECTED FRIDAY/FRIDAY NIGHT... THEN MVFR/IFR SHOULD DEVELOP FROM EAST (FAY/RWI/RDU) TO WEST (GSO/INT) DURING SATURDAY... LASTING AT LEAST THROUGH SUNDAY NIGHT IF NOT MONDAY AS A STRONG SLOW-MOVING STORM SYSTEM APPROACHES AND DEEPENS JUST TO OUR WEST AND DRIFTS OVER THE CAROLINAS. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CBL/HARTFIELD NEAR TERM...CBL/HARTFIELD SHORT TERM...HARTFIELD LONG TERM...BLAES AVIATION...KC/HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
743 PM EST WED NOV 14 2012 .SYNOPSIS... COOL HIGH PRESSURE WILL EXTEND SOUTHWARD INTO THE CAROLINAS THROUGH TONIGHT. AN UPPER LEVEL DISTURBANCE WILL CROSS THE AREA ON THURSDAY... BRINGING CLOUDS AND UNSETTLED WEATHER. HIGH PRESSURE WILL THEN RETURN FOR FRIDAY. ANOTHER STORM SYSTEM WILL SLOWLY APPROACH FROM THE WEST OVER THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 205 PM WEDNESDAY... COOL SURFACE AIR WILL CONTINUE TO FILTER INTO NC TONIGHT FROM THE HIGH PRESSURE AREA CENTERED TO OUR NORTH OVER SE ONTARIO... AS CLOUDS STEADILY FILL IN ACROSS CENTRAL NC OVERNIGHT. IN ADDITION TO THE HIGH PRESSURE... THE LATEST SURFACE ANALYSIS SHOWS A DIFFUSE FRONTAL ZONE IN THE FORM OF A THETA-E GRADIENT ACROSS NRN FL/SE GA AND JUST OFF THE CAROLINA COAST. THE 925-850 MB FRONTAL ZONE REMAINS FARTHER NW... ACROSS THE SOUTHEAST PORTION OF THE CWA... AND THIS FRONTAL ZONE IS EXPECTED TO WAVER BACK AND FORTH A BIT BUT HOLD FAIRLY STATIONARY ACROSS SRN AND SE NC THROUGH TONIGHT... AS THE 925 MB LOW ATTACHED TO THE FRONT DRIFTS NORTHWARD OVER THE FL PANHANDLE. MEANWHILE... THE MID LEVEL SHORTWAVE TROUGH OVER THE LOWER MISS VALLEY THIS AFTERNOON DIGS AND STRENGTHENS AS IT MOVES EAST WITH A NEGATIVE TILT OVER GA BY DAYBREAK. MOIST UPGLIDE INCREASES IN THE 290K-295K LAYER TONIGHT OVER FAR SOUTH CENTRAL AND SW NC... ALTHOUGH IT NEVER BECOMES PARTICULARLY STRONG... AND THE SURFACE RIDGE WILL LEAD TO A SHALLOW BUT DRY SUBCLOUD LAYER... LIMITING PRECIP AMOUNTS. FORCING FOR ASCENT WILL INCREASE WITH MID LEVEL HEIGHT FALLS AND DPVA IN ADDITION TO THE BRIEF WEAK MOIST UPGLIDE ROOTED LOWER IN THE TROPOSPHERE... ALTHOUGH THE BETTER UPPER DIVERGENCE WILL HOLD JUST OFF THE CAROLINA COAST. SEE NO REASON TO MAKE MAJOR CHANGES TO THE EXISTING FORECAST OF GOOD CHANCE POPS SPREADING INTO THE FAR SW CWA LATE TONIGHT. THE MORE SUBSTANTIAL AMOUNTS SHOULD BE CONFINED TO ANSON COUNTY AND POINTS SOUTH AND WEST GIVEN THE CONSENSUS OF OPERATIONAL MODELS AS WELL AS QPF PROBABILITIES FROM THE SREF WHICH SUPPORT AMOUNTS OF A TENTH OF AN INCH OR LESS. ELSEWHERE... THE DRY SURFACE BASED AIR WILL REPEL MEASURABLE PRECIP... ALTHOUGH BROKEN TO OVERCAST SKIES WILL SPREAD OVER ALL OF CENTRAL NC FROM THE SOUTHEAST AND WEST THROUGH THE NIGHT. LOWS FROM 32 NORTH (WHERE CLOUDS WILL BE LAST TO FILL IN) TO NEAR 40 SOUTH. -GIH && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... AS OF 255 PM WEDNESDAY... ANOTHER CHILLY DAY THURSDAY WITH A GOOD CHANCE OF RAIN MAINLY SOUTH OF HIGHWAY 64. THE MID LEVEL SHORTWAVE TROUGH STARTS THE DAY RATHER POTENT AND NEGATIVELY TILTED OVER GA... THEN PROGRESSES EASTWARD ACROSS THE CAROLINAS WHILE DAMPENING IN FAVOR OF A BROAD TROUGH DROPPING THROUGH THE MIDWEST AND CENTRAL PLAINS. STRONG UPPER DIVERGENCE JUST OFF THE CAROLINA COAST... IN THE RIGHT ENTRANCE REGION OF A STRENGTHENING SRLY JET OVER THE ST LAWRENCE VALLEY... ALSO WEAKENS AS THE JET SHIFTS TO THE NE. THIS WANING FORCING ALOFT COMBINED WITH DIMINISHING LOWER LEVEL MOIST UPGLIDE AT 290K-295K AND THE CONTINUED SHALLOW BUT DRY SUBCLOUD LAYER WITH THE SURFACE RIDGE NOSING IN FROM THE NORTH SHOULD LIMIT THE NORTHWARD EXTENT OF THE MEASURABLE PRECIP. THE SREF PROBABILITIES SUPPORT THIS... INDICATING A LOW CHANCE OF MEASURABLE PRECIP IN THE VA BORDER COUNTIES OF CENTRAL NC. LATEST MODEL OUTPUT FOLLOWS OUR EARLIER FORECASTS FAIRLY CLOSELY... AND WILL HOLD ONTO LIKELY POPS OVERSPREADING THE SOUTH BUT WILL LOWER RAIN CHANCES IN THE FAR NORTH. LOW LEVEL COOL AIR ADVECTION WEDGING INTO THE AREA WITH OVERRUNNING ATOP IT AND LITTLE TO NO SUNSHINE WILL NOT ALLOW MUCH HEATING... AND EXPECT MUCH BELOW NORMAL HIGHS... 48-52. EXPECT QUICKLY WANING COVERAGE AND AMOUNTS AS THE MID LEVEL TROUGH MOVES EAST OF THE FORECAST AREA THURSDAY NIGHT... WITH CLEARING SKIES IN THE WEST LATE. GFS FORECAST SOUNDINGS -- WHICH FAVOR A WEAKER SHORTWAVE TROUGH AND THUS A FASTER CLEARING -- SUGGEST THAT WE COULD SEE PATCHY GROUND FOG LATE THURSDAY NIGHT. LOWS 33-40. -GIH && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... AS OF 300 PM WEDNESDAY... EXPECTED FOR MUCH OF THE EXTENDED PERIOD. NWP GUIDANCE IS GENERALLY CONSISTENT WITH THEIR DEPICTION OF THE MAIN PLAYERS THROUGH MUCH OF THE EXTENDED RANGE. DIFFERENCES ARE NOTED IN THE DETAILS OF THE EVOLUTION OF A LOW PRESSURE SYSTEM OFF THE SOUTHEAST COAST AND THE EVENTUAL DEPARTURE OF A CLOSED LOW OFF THE CAROLINA COAST LATE IN THE PERIOD. A LOW AMPLITUDE POSITIVELY TILTED MID LEVEL TROUGH ACROSS THE OHIO AND LOWER MISSISSIPPI VALLEY ON FRIDAY MORNING WILL DEEPEN AND CLOSE OFF OVER THE SOUTHERN APPALACHIANS ON SATURDAY MORNING. THE UPPER TROUGH WILL INTERACT WITH A BROAD AREA OF LOW PRESSURE OFF THE SOUTHEAST COAST AS A STRENGTHENING SURFACE HIGH PRESSURE SYSTEM BUILDS INTO THE NORTHEAST. THESE FEATURES WILL COMBINE TO STRENGTHEN A LOW LEVEL NORTHEAST FLOW ACROSS THE CAROLINAS AND GRADUALLY MOISTEN THE LOW AND MID LEVELS ON SATURDAY AND ESPECIALLY SATURDAY NIGHT. AS THE CLOSED LOW SLIPS EASTWARD AND DEEP LAYER MOISTURE INCREASES...EXPECT AREAS OF RAIN TO DEVELOP AND SHIFT NORTHWARD INTO THE SOUTHERN COASTAL PLAIN/SANDHILLS ON LATE SATURDAY AND THEN SPREAD NORTHWARD INTO THE REST OF THE COASTAL PLAIN AND EASTERN PIEDMONT ON SATURDAY NIGHT AND SUNDAY. THE THREAT OF LIGHT RAIN ACROSS THE WESTERN PIEDMONT AND TRIAD AREA WILL BE VERY LIMITED. RECENT RUNS OF THE GFS AND ECMWF HAVE TRENDED BOTH CLOSER/FARTHER AWAY FROM THE COAST AND RESULTED IN WETTER/DRIER CONDITIONS. GIVEN THE UNCERTAINTY REGARDING THE LIKELIHOOD AND AMOUNT OF PRECIPITATION...HAVE OPTED TO INCREASE POPS SLIGHTLY BUT CONFINE THEM TO THE MID CHANCE RANGE. THE THREAT OF PRECIPITATION... ESPECIALLY ACROSS EASTERN PORTIONS OF THE FORECAST AREA CONTINUES INTO MONDAY NIGHT. THE CONSIDERABLE AMOUNTS OF CLOUD COVER AND COOL SURFACE HIGH TO THE NORTH WILL RESULT IN HIGH TEMPERATURES AROUND 10 DEGREES BELOW NORMAL WITH A NORTHEAST WIND ADDING TO THE CHILL. THE CLOSED LOW WILL EVENTUALLY SHIFT EAST AND OFF THE COAST LATE MONDAY AND TUESDAY AS A MID LEVEL TROUGH APPROACHES FROM THE WEST. THE INTERACTION OF THIS TROUGH WITH THE SLOWLY DEPARTING CLOSED LOW OFF THE COAST IS UNCLEAR AT THIS TIME BUT THERE IS SOME LIMITED POTENTIAL FOR LIGHT PRECIPITATION ON WEDNESDAY. AT THIS POINT HAVE OPTED TO KEEP FORECAST DRY WITH SLIGHTLY BELOW NORMAL TEMPERATURES. -BLAES && .AVIATION /00Z THURSDAY THROUGH MONDAY/... AS OF 740 PM WEDNESDAY... 24 HOUR TAF PERIOD: VFR CONDITIONS EXPECTED THROUGH THE 24 HOUR TAF PERIOD AT KINT... KGSO...AND KRDU. THE NAM SHOWS THE POTENTIAL FOR A PERIOD OF SOME HIGH END MVFR CIGS AT THESE TERMINALS AFTER 12Z THURSDAY...HOWEVER THE GFS AND RUC ARE NOT AS PESSIMISTIC. AS SUCH...CONFIDENCE OF SUB VFR CIGS OCCURRING AT THOSE TERMINALS IS LOW AT THIS TIME AND HAVE NOT INCLUDED THEM IN THIS ISSUANCE. MODELS SHOW BEST ISENTROPIC UPGLIDE AT OR ABOVE 5 KFT AT ALL TERMINALS EXCEPT KFAY...WHERE THERE IS GOOD UPGLIDE AT OR BELOW 3 KFT. CIGS AT KFAY HAVE ALREADY FALLEN BELOW VFR AND WILL LIKELY REMAIN THERE THROUGH THE TAF PERIOD. THE BEST CHANCE FOR PRECIP TO DEVELOP IS ACROSS THE SOUTH (KFAY) MAINLY AFTER 12Z. THERE IS STILL A GOOD DEAL OF UNCERTAINTY WITH REGARD TO EXTENT AND TIMING BUT IT IS POSSIBLE THE RAIN COULD SPREAD FURTHER NORTH DURING THE DAY THURSDAY. KRWI SHOULD REMAIN LOW END VFR THROUGH 12Z THURSDAY WITH MVFR CIGS FROM 12Z THROUGH THE REMAINDER OF THE TAF PERIOD. SURFACE WINDS WILL BE MAINLY NE AROUND 5 KTS AND VEERING WITH HEIGHT. -KC LOOKING AHEAD: CIGS WILL LIFT/DISSIPATE OVERNIGHT THURSDAY INTO FRIDAY...WITH FAY THE LAST TO SEE THESE CLOUDS BREAK UP. PATCHY IFR FOG IS POSSIBLE RIGHT AROUND DAYBREAK FRIDAY. VFR CONDITIONS ARE EXPECTED FRIDAY/FRIDAY NIGHT... THEN MVFR/IFR SHOULD DEVELOP FROM EAST (FAY/RWI/RDU) TO WEST (GSO/INT) DURING SATURDAY... LASTING AT LEAST THROUGH SUNDAY NIGHT IF NOT MONDAY AS A STRONG SLOW-MOVING STORM SYSTEM APPROACHES AND DEEPENS JUST TO OUR WEST AND DRIFTS OVER THE CAROLINAS. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...HARTFIELD NEAR TERM...HARTFIELD SHORT TERM...HARTFIELD LONG TERM...BLAES AVIATION...KC/HARTFIELD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1219 PM EST TUE NOV 13 2012 .SYNOPSIS... A STRONG COLD FRONT WILL PUSH OFFSHORE THIS AFTERNOON...FOLLOWED BY CHILLY CANADIAN AIR. HIGH PRESSURE WILL BUILD TO OUR NORTH THIS WEEK...EXTENDING INTO THE CAROLINAS. A WEAK LOW PRESSURE SYSTEM WILL DEVELOP OFFSHORE THURSDAY AND MOVE NORTHEAST. ANOTHER LOW WILL DEVELOP OFFSHORE THIS WEEKEND WITH INCREASING CHANCES FOR RAIN. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1215 PM TUESDAY...THE COLD FRONT HAS BEEN LOCATED BY RADAR AND SURFACE OBSERVATIONS ON THE PENDER COUNTY COASTLINE...EXTENDING SOUTHWEST THROUGH WILMINGTON AND TO ABOUT 5 MILES WEST OF NORTH MYRTLE BEACH. THE FRONT SHOULD CONTINUE MOVING STEADILY OFF THE COAST THIS AFTERNOON. A HEALTHY CLUSTER OF SURFACE-BASED CONVECTION (SHOWERS) WILL MOVE ACROSS WILMINGTON WITHIN THE NEXT HOUR...WITH LIGHTER SHOWERS FROM ELEVATED INSTABILITY CONTINUING INLAND ESPECIALLY IN THE LUMBERTON AND DILLON VICINITY. TEMPERATURES HAVE PEAKED AT ALL LOCATIONS AND STEADY TO SLOWLY FALLING TEMPERATURES ARE EXPECTED DUE TO COLD ADVECTION THROUGH THE AFTERNOON. PREVIOUS DISCUSSION FROM 10 AM FOLLOWS... THE SURFACE COLD FRONT EXTENDS FROM NEAR ELIZABETHTOWN TO WHITEVILLE...ACROSS THE WESTERN PORTIONS OF HORRY COUNTY TO NEAR KINGSTREE IN SOUTH CAROLINA. THE 11Z HRRR WAS ABOUT ONE HOUR FAST WITH THE FRONT BUT OTHERWISE LOOKED TO BE A GOOD FIT FOR THE SHAPE AND FORWARD SPEED OF THE BOUNDARY...PRESSING IT OFFSHORE BY 18-19Z IN ALL AREAS. VISIBLE SATELLITE SHOWS A NARROW ZONE OF MAINLY CLEAR SKIES JUST IN ADVANCE OF THE FRONT WITH TEMPERATURES RISING INTO THE LOWER 70S ALONG THE SC COAST. THESE WARMER TEMPERATURES MAY EXTEND INTO EXTREME SE NORTH CAROLINA IN THE NEXT 1-2 HOURS BEFORE THE FRONT SWEEPS THROUGH AND MUCH COLDER AIR BUILDS IN. HIGH TEMPERATURES HAVE ALREADY BEEN RECORDED INLAND AND STEADY TEMPERATURES ARE ANTICIPATED FOR THE REMAINDER OF THE DAY NEAR AND WEST OF I-95. RADAR SHOWS ONE BATCH OF SHOWERS NEAR AND EAST OF CAPE FEAR ASSOCIATED WITH UNSTABLE AIR ADVECTING NORTH FROM THE WESTERN EDGE OF THE GULF STREAM. SHOWERS ACROSS THE CENTRAL CAROLINAS APPEAR TO BE LINKED TO SMALL ELEVATED INSTABILITY IN THE 900-700 MB LAYER ASSISTED BY SYNOPTIC-SCALE LIFT FROM THE RIGHT-ENTRANCE REGION OF A FAVORABLY POSITIONED 300 MB JET ACROSS THE MID-ATLANTIC AND EASTERN GREAT LAKES. THIS REGION OF ENHANCED SHOWER ACTIVITY SHOULD ADVECT SLOWLY NORTHEASTWARD THROUGH THE AFTERNOON. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 AM TUESDAY...A LARGE AREA OF HIGH PRESSURE WILL BE CENTERED NORTH OF NY STATE ON WEDNESDAY WITH A RIDGE AXIS/COOL AIR WEDGE EXTENDING DOWN INTO THE CAROLINAS. THIS VERY SHALLOW COOL AIR MASS WILL KEEP TEMPS WELL BELOW CLIMO, THE EXTENT TO WHICH WILL DEPEND ON HOW EXTENSIVE CLOUD COVER ENDS UP BEING. AS IT IS CLOUD COVER SHOULD BE QUITE EXTENSIVE BUT A FEW BREAKS DURING PEAK HEATING COULD REALLY ADD SEVERAL DEGREES TO HIGH TEMPS. AS THE DAY WEARS ON HOWEVER LOW LEVEL FLOW INCREASES JUST ATOP THE SURFACE AIRMASS IN RESPONSE TO AN APPROACHING SHORTWAVE. THIS FEATURE SWINGS THROUGH BY THURSDAY MORNING AND COULD TOUCH OFF WIDELY SCATTERED VERY LIGHT SHOWERS. WEAK SUBSIDENCE THURSDAY AFTERNOON BRINGS BACK THE ORIGINAL FORECAST ISSUE OF FIGURING OUT HOW CLOUDY THE DAY ENDS UP (STILL LIKELY WITHIN `MOSTLY CLOUDY`) AND THE EXTENT TO WHICH THIS ENDS UP KEEPING HIGH TEMPS BELOW CLIMO. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 3 AM TUESDAY...HIGH PRESSURE CENTERED OVER NY STATE RIDGING INTO THE CAROLINAS WILL MERGE WITH ANOTHER HIGH MOVING IN FROM THE WEST OVER THE WEEKEND. END RESULT WILL BE SURFACE PRESSURES CONTINUING TO ADVECT IN FROM POINTS NORTH KEEPING TEMPS BELOW CLIMO ESPECIALLY BY DAY. A NORTHERN BRANCH TROUGH WILL ALSO BECOME INCREASINGLY BAGGY AND EVENTUALLY CUTOFF WEAKLY OVER GULF STATES OVER THE WEEKEND. THE RESULTING ASCENT AHEAD OF THIS FEATURE WILL CAUSE PRESSURES TO FALL WELL OFF THE COAST ALONG THE OLD FRONTAL BOUNDARY. THIS WILL INITIALLY BE A VERY GRADUAL PROCESS THROUGH SATURDAY NIGHT INTO MOST OF SUNDAY. LATER SUNDAY AS THE UPPER WAVE GETS CLOSER TO THE COAST/FRONT BAROCLINIC INSTABILITY LEADS TO FEEDBACK THAT STRENGTHENS THE FEATURES BOTH SURFACE AND ALOFT. HOW MUCH RAINFALL THIS ENDS UP LEADING TO IS TOUGH TO SAY SINCE MODELS DIVERGE ON THE STRENGTH AND THE LATITUDE OF THE SYSTEMS EVOLUTION. THE EC, WHICH HAS BEEN QUITE ACCURATE ALONG THE EAST COAST AS OF LATE, IS THE STRONGEST AND FURTHEST TO THE SOUTH AND WOULD IMPLY SOME DECENT RAINS LOCALLY. THIS SOLUTION IS NOW GETTING SUPPORT FROM THE 00Z CANADIAN MODEL. THE GFS HAS BEEN VERY CONSISTENT IN A FLATTER AND FURTHER NORTH CYCLOGENESIS KEEPING RAINFALL CONFINED TO THE IMMEDIATE (MAINLY NC) COAST THIS FAR SOUTH. THIS HAS BEEN THE PREFERRED SOLUTION BUT THE AGREEMENT BETWEEN THE OTHERS IS GETTING HARD TO IGNORE AND THE WEEKEND FORECAST WILL BE TWEAKED IN A MORE PESSIMISTIC DIRECTION. MONDAYS FORECAST IS EVEN MORE UNCERTAIN AS THE FASTER SOLUTIONS IMPLY DRY AND COOL AIR ADVECTION WHEREAS THE SLOWEST POSSIBILITIES COULD STILL MEAN WRAPAROUND MOISTURE. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... AS OF 18Z...WIDESPREAD MVFR/IFR CIGS ACROSS THE INLAND COUNTIES WITH NNE WINDS 10 TO 15 KNOTS BEHIND THE COLD FRONT THAT PASSED THROUGH THIS MORNING. THE FRONT IS EXPECTED TO REACH THE COASTAL SITES AROUND 18Z...WHERE CIGS HAVE ALREADY LOWERED TO MVFR LEVELS AHEAD OF THE FRONT. MORE SHOWERS ARE DEVELOPING ALONG THE BOUNDARY...AND THE BEST RAIN CHANCES THIS AFTERNOON APPEAR TO BE AT THE COASTAL TERMS...ESPECIALLY KILM. HOWEVER...THE BIGGEST AVIATION IMPACT IN THIS TAF PERIOD IS THE REDUCED CIGS ACROSS THE CWA. MVFR/IFR STRATUS IS EXPECTED ALONG THE COAST TONIGHT...WHILE PREDOMINANTLY MVFR CIGS ARE LIKELY AT THE INLAND TERMS. LOW LEVEL CLOUD COVER WILL LINGER THROUGH THE REST OF THE VALID PERIOD...BUT SHOULD LIFT TO MVFR/VFR LEVELS BY LATE WED MORNING. NNE WINDS 10 TO 12 KNOTS ARE EXPECTED THROUGH WED AFTERNOON. EXTENDED OUTLOOK...POST FRONTAL STRATUS POSSIBLE WED AND EARLY THURS. OCCASIONAL LIGHT PRECIP IS POSSIBLE THURS THROUGH SAT. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1215 PM TUESDAY...NO SIGNIFICANT CHANGES NEEDED FROM THE PREVIOUS UPDATE. THE FRONT IS MOVING OFF THE PENDER COUNTY COAST CURRENTLY AND SHOULD SWEEP ACROSS THE REMAINDER OF THE COASTAL WATERS WITHIN THE NEXT 2 HOURS. NORTH WINDS WILL INCREASE TOWARD 15 KNOTS WITH SOME HIGHER GUSTS LATE IN THE DAY. PREVIOUS DISCUSSION FROM 10 AM FOLLOWS... THE COLD FRONT IS CURRENTLY 40-60 MILES INLAND FROM THE COAST AND SHOULD REACH THE BEACHES EARLY THIS AFTERNOON...ACCOMPANIED BY A RAPID SHIFT TO NORTH WINDS AND AN INCREASE IN SPEEDS TO AROUND 15 KNOTS. WINDS WILL STEADILY INCREASE THIS EVENING AND SMALL CRAFT ADVISORY CONDITIONS STILL APPEAR LIKELY OVERNIGHT. SHOWERS ARE MOST NUMEROUS NEAR AND EAST OF CAPE FEAR THIS MORNING ALTHOUGH THERE IS ENOUGH INSTABILITY IN THE ATMOSPHERE TO SUPPORT SHOWER DEVELOP ALMOST ANYWHERE THIS AFTERNOON INTO TONIGHT. SEAS CURRENTLY RANGE FROM 2 FT AT THE OCEAN CREST PIER ON OAK ISLAND TO AROUND 4 FT AT THE FRYING PAN SHOALS BUOY OFFSHORE. LITTLE CHANGE WILL OCCUR UNTIL AFTER THE FRONT PUSHES OFFSHORE THIS AFTERNOON...AT WHICH POINT SEAS WILL GRADUALLY BUILD TO 3-6 FT TONIGHT...HIGHEST OFFSHORE. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 AM TUESDAY...PINCHED GRADIENT IN A POST FRONTAL NORTHEASTERLY FLOW REGIME ON WEDNESDAY. A SMALL CRAFT ADVISORY APPEARS LIKELY FOR MOST OF THE AREA. SOME WAVE SHADOWING MAY CALL FOR JUST A SCEC HOWEVER OVER HORRY COUNTY WATERS. A SMALL DECREASE IN THE WINDS IS EXPECTED EITHER THURSDAY OR THURSDAY NIGHT AS THE FRONT SLIPS FURTHER OFFSHORE AND THIS MAY LEAD TO A BRIEF WINDOW WHERE SCA IS NO LONGER NEEDED. AT A MINIMUM IT SEEMS LIKELY THAT SCEC CAUTIONARY HEADLINES WILL CONTINUE. LONG TERM /FRIDAY THROUGH SATURDAY/... AS OF 3 AM TUESDAY...HEADLINES ANTICIPATED THE ENTIRE PERIOD. FRONTAL BOUNDARY STAYS WELL OFFSHORE WITH SURFACE HIGH PRESSURE RIDGING DOWN INTO THE CAROLINAS FROM POINTS WELL TO THE NORTH. COASTAL WASTERS FORECAST ZONES LIE IN THE GRADIENT BETWEEN. ON SATURDAY GRADUAL FALLING PRESSURE ALONG THE FRONT WILL BOLSTER THE GRADIENT AND ANY WATERS THAT HAD BEEN TEETERING NEAR THE SCEC/SCA THRESHOLDS WILL BE PUSHED INTO ADVISORY REALM BY BOTH WIND AND SEAS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 7 PM EST WEDNESDAY FOR AMZ250-252. && $$ SYNOPSIS...TRA NEAR TERM...TRA SHORT TERM...MBB LONG TERM...MBB AVIATION...BJR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1002 AM EST TUE NOV 13 2012 .SYNOPSIS... A STRONG COLD FRONT WILL PUSH OFFSHORE THIS AFTERNOON...FOLLOWED BY CHILLY CANADIAN AIR. HIGH PRESSURE WILL BUILD TO OUR NORTH THIS WEEK...EXTENDING INTO THE CAROLINAS. A WEAK LOW PRESSURE SYSTEM WILL DEVELOP OFFSHORE THURSDAY AND MOVE NORTHEAST. ANOTHER LOW WILL DEVELOP OFFSHORE THIS WEEKEND WITH INCREASING CHANCES FOR RAIN. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1000 AM TUESDAY...THE SURFACE COLD FRONT EXTENDS FROM NEAR ELIZABETHTOWN TO WHITEVILLE...ACROSS THE WESTERN PORTIONS OF HORRY COUNTY TO NEAR KINGSTREE IN SOUTH CAROLINA. THE 11Z HRRR WAS ABOUT ONE HOUR FAST WITH THE FRONT BUT OTHERWISE LOOKED TO BE A GOOD FIT FOR THE SHAPE AND FORWARD SPEED OF THE BOUNDARY...PRESSING IT OFFSHORE BY 18-19Z IN ALL AREAS. VISIBLE SATELLITE SHOWS A NARROW ZONE OF MAINLY CLEAR SKIES JUST IN ADVANCE OF THE FRONT WITH TEMPERATURES RISING INTO THE LOWER 70S ALONG THE SC COAST. THESE WARMER TEMPERATURES MAY EXTEND INTO EXTREME SE NORTH CAROLINA IN THE NEXT 1-2 HOURS BEFORE THE FRONT SWEEPS THROUGH AND MUCH COLDER AIR BUILDS IN. HIGH TEMPERATURES HAVE ALREADY BEEN RECORDED INLAND AND STEADY TEMPERATURES ARE ANTICIPATED FOR THE REMAINDER OF THE DAY NEAR AND WEST OF I-95. RADAR SHOWS ONE BATCH OF SHOWERS NEAR AND EAST OF CAPE FEAR ASSOCIATED WITH UNSTABLE AIR ADVECTING NORTH FROM THE WESTERN EDGE OF THE GULF STREAM. SHOWERS ACROSS THE CENTRAL CAROLINAS APPEAR TO BE LINKED TO SMALL ELEVATED INSTABILITY IN THE 900-700 MB LAYER ASSISTED BY SYNOPTIC-SCALE LIFT FROM THE RIGHT-ENTRANCE REGION OF A FAVORABLY POSITIONED 300 MB JET ACROSS THE MID-ATLANTIC AND EASTERN GREAT LAKES. THIS REGION OF ENHANCED SHOWER ACTIVITY SHOULD ADVECT SLOWLY NORTHEASTWARD THROUGH THE AFTERNOON. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 AM TUESDAY...A LARGE AREA OF HIGH PRESSURE WILL BE CENTERED NORTH OF NY STATE ON WEDNESDAY WITH A RIDGE AXIS/COOL AIR WEDGE EXTENDING DOWN INTO THE CAROLINAS. THIS VERY SHALLOW COOL AIR MASS WILL KEEP TEMPS WELL BELOW CLIMO, THE EXTENT TO WHICH WILL DEPEND ON HOW EXTENSIVE CLOUD COVER ENDS UP BEING. AS IT IS CLOUD COVER SHOULD BE QUITE EXTENSIVE BUT A FEW BREAKS DURING PEAK HEATING COULD REALLY ADD SEVERAL DEGREES TO HIGH TEMPS. AS THE DAY WEARS ON HOWEVER LOW LEVEL FLOW INCREASES JUST ATOP THE SURFACE AIRMASS IN RESPONSE TO AN APPROACHING SHORTWAVE. THIS FEATURE SWINGS THROUGH BY THURSDAY MORNING AND COULD TOUCH OFF WIDELY SCATTERED VERY LIGHT SHOWERS. WEAK SUBSIDENCE THURSDAY AFTERNOON BRINGS BACK THE ORIGINAL FORECAST ISSUE OF FIGURING OUT HOW CLOUDY THE DAY ENDS UP (STILL LIKELY WITHIN `MOSTLY CLOUDY`) AND THE EXTENT TO WHICH THIS ENDS UP KEEPING HIGH TEMPS BELOW CLIMO. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 3 AM TUESDAY...HIGH PRESSURE CENTERED OVER NY STATE RIDGING INTO THE CAROLINAS WILL MERGE WITH ANOTHER HIGH MOVING IN FROM THE WEST OVER THE WEEKEND. END RESULT WILL BE SURFACE PRESSURES CONTINUING TO ADVECT IN FROM POINTS NORTH KEEPING TEMPS BELOW CLIMO ESPECIALLY BY DAY. A NORTHERN BRANCH TROUGH WILL ALSO BECOME INCREASINGLY BAGGY AND EVENTUALLY CUTOFF WEAKLY OVER GULF STATES OVER THE WEEKEND. THE RESULTING ASCENT AHEAD OF THIS FEATURE WILL CAUSE PRESSURES TO FALL WELL OFF THE COAST ALONG THE OLD FRONTAL BOUNDARY. THIS WILL INITIALLY BE A VERY GRADUAL PROCESS THROUGH SATURDAY NIGHT INTO MOST OF SUNDAY. LATER SUNDAY AS THE UPPER WAVE GETS CLOSER TO THE COAST/FRONT BAROCLINIC INSTABILITY LEADS TO FEEDBACK THAT STRENGTHENS THE FEATURES BOTH SURFACE AND ALOFT. HOW MUCH RAINFALL THIS ENDS UP LEADING TO IS TOUGH TO SAY SINCE MODELS DIVERGE ON THE STRENGTH AND THE LATITUDE OF THE SYSTEMS EVOLUTION. THE EC, WHICH HAS BEEN QUITE ACCURATE ALONG THE EAST COAST AS OF LATE, IS THE STRONGEST AND FURTHEST TO THE SOUTH AND WOULD IMPLY SOME DECENT RAINS LOCALLY. THIS SOLUTION IS NOW GETTING SUPPORT FROM THE 00Z CANADIAN MODEL. THE GFS HAS BEEN VERY CONSISTENT IN A FLATTER AND FURTHER NORTH CYCLOGENESIS KEEPING RAINFALL CONFINED TO THE IMMEDIATE (MAINLY NC) COAST THIS FAR SOUTH. THIS HAS BEEN THE PREFERRED SOLUTION BUT THE AGREEMENT BETWEEN THE OTHERS IS GETTING HARD TO IGNORE AND THE WEEKEND FORECAST WILL BE TWEAKED IN A MORE PESSIMISTIC DIRECTION. MONDAYS FORECAST IS EVEN MORE UNCERTAIN AS THE FASTER SOLUTIONS IMPLY DRY AND COOL AIR ADVECTION WHEREAS THE SLOWEST POSSIBILITIES COULD STILL MEAN WRAPAROUND MOISTURE. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... AS OF 12Z...GENERALLY VFR/MVFR CIGS AND MVFR/IFR VSBYS ACROSS THE AREA AHEAD OF AN APPROACHING COLD FRONT...WITH SHOWER ACTIVITY APPROACHING KILM. RADAR AND SURFACE OBS INDICATE THE FRONT IS CURRENTLY JUST WEST OF OUR CWA...AND IT SHOULD MOVE THROUGH THE INLAND TERMS WITHIN THE NEXT HOUR OR SO. THE FRONT IS EXPECTED TO REACH THE COASTAL SITES AROUND 14/15Z. LOWERING CIGS AND SCATTERED LIGHT PRECIP WILL BE THE STORY FOR MUCH OF TODAY. WIDESPREAD IFR CIGS APPEAR LIKELY THIS AFTERNOON/EVENING AS SHALLOW CAA AND A STRONG LOW LEVEL INVERSION PROMOTE STRATUS DEVELOPMENT BEHIND THE FRONT. LIGHT W/SW WINDS AHEAD OF THE FRONT WILL BECOME NORTHERLY 10 TO 12 KNOTS TODAY. LOW CIGS WILL PERSIST INTO THE OVERNIGHT HOURS ALONG THE COAST...BUT THE MODEL SOUNDINGS INDICATE CIGS SHOULD LIFT TO MVFR/VFR LEVELS TOWARDS THE END OF THE TAF PERIOD FOR THE INLAND TERMS. EXTENDED OUTLOOK...POST FRONTAL STRATUS POSSIBLE WED INTO THURS. OCCASIONAL OVERRUNNING LIGHT PRECIP IS POSSIBLE THURS THROUGH SAT. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1000 AM TUESDAY...THE COLD FRONT IS CURRENTLY 40-60 MILES INLAND FROM THE COAST AND SHOULD REACH THE BEACHES EARLY THIS AFTERNOON...ACCOMPANIED BY A RAPID SHIFT TO NORTH WINDS AND AN INCREASE IN SPEEDS TO AROUND 15 KNOTS. WINDS WILL STEADILY INCREASE THIS EVENING AND SMALL CRAFT ADVISORY CONDITIONS STILL APPEAR LIKELY OVERNIGHT. SHOWERS ARE MOST NUMEROUS NEAR AND EAST OF CAPE FEAR THIS MORNING ALTHOUGH THERE IS ENOUGH INSTABILITY IN THE ATMOSPHERE TO SUPPORT SHOWER DEVELOP ALMOST ANYWHERE THIS AFTERNOON INTO TONIGHT. SEAS CURRENTLY RANGE FROM 2 FT AT THE OCEAN CREST PIER ON OAK ISLAND TO AROUND 4 FT AT THE FRYING PAN SHOALS BUOY OFFSHORE. LITTLE CHANGE WILL OCCUR UNTIL AFTER THE FRONT PUSHES OFFSHORE THIS AFTERNOON...AT WHICH POINT SEAS WILL GRADUALLY BUILD TO 3-6 FT TONIGHT...HIGHEST OFFSHORE. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 AM TUESDAY...PINCHED GRADIENT IN A POST FRONTAL NORTHEASTERLY FLOW REGIME ON WEDNESDAY. A SMALL CRAFT ADVISORY APPEARS LIKELY FOR MOST OF THE AREA. SOME WAVE SHADOWING MAY CALL FOR JUST A SCEC HOWEVER OVER HORRY COUNTY WATERS. A SMALL DECREASE IN THE WINDS IS EXPECTED EITHER THURSDAY OR THURSDAY NIGHT AS THE FRONT SLIPS FURTHER OFFSHORE AND THIS MAY LEAD TO A BRIEF WINDOW WHERE SCA IS NO LONGER NEEDED. AT A MINIMUM IT SEEMS LIKELY THAT SCEC CAUTIONARY HEADLINES WILL CONTINUE. LONG TERM /FRIDAY THROUGH SATURDAY/... AS OF 3 AM TUESDAY...HEADLINES ANTICIPATED THE ENTIRE PERIOD. FRONTAL BOUNDARY STAYS WELL OFFSHORE WITH SURFACE HIGH PRESSURE RIDGING DOWN INTO THE CAROLINAS FROM POINTS WELL TO THE NORTH. COASTAL WASTERS FORECAST ZONES LIE IN THE GRADIENT BETWEEN. ON SATURDAY GRADUAL FALLING PRESSURE ALONG THE FRONT WILL BOLSTER THE GRADIENT AND ANY WATERS THAT HAD BEEN TEETERING NEAR THE SCEC/SCA THRESHOLDS WILL BE PUSHED INTO ADVISORY REALM BY BOTH WIND AND SEAS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 7 PM EST WEDNESDAY FOR AMZ250-252. && $$ SYNOPSIS...TRA NEAR TERM...TRA SHORT TERM...MBB LONG TERM...MBB AVIATION...BJR
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1139 PM EST MON NOV 12 2012 .SYNOPSIS... HIGH PRESSURE WILL BEGIN BUILDING INTO THE AREA FROM THE SOUTHWEST TONIGHT AND THEN MOVE OVER THE AREA TUESDAY AND WEDNESDAY. THE HIGH PRESSURE CENTER WILL MOVE NORTHEAST OF THE AREA...BUT WILL CONTINUE TO RIDGE OVER THE AREA THROUGH THE SECOND HALF OF THE WEEK. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... UPDATE...WILL UPDATE ONE MORE TIME FOR CLOUD AND PRECIP TRENDS. PREVIOUS...THE COLD FRONT THAT MOVED THROUGH THE AREA TODAY IS MOVING OUT OF THE FORECAST AREA AS OF 20Z. RAIN WILL CONTINUE ESPECIALLY ACROSS THE EASTERN HALF OF THE AREA THROUGH THE REMAINDER OF THE AFTERNOON AND EVENING. MEANWHILE...THERE IS A SHARP CUTOFF TO BOTH PRECIP AND CLOUDS ACROSS THE WEST WITH SATELLITE SHOWING CLEARING MOVING INTO NW OH ALREADY THIS AFTERNOON. OBS HAVE SHOWN A MIX OF RAIN AND SNOW ACROSS WESTERN COUNTIES BUT RAIN ELSEWHERE. MADE ONLY SMALL ADJUSTMENTS TO POPS THROUGH EARLY TONIGHT WITH THE RAIN CONTINUING TO PUSH EASTWARD AND DECREASING POPS FROM WEST TO EAST. WITH THAT MENTION ONLY CHC POPS ACROSS THE WEST FOR EARLY TONIGHT...THEN DRY AFTER MIDNIGHT. ONCE THIS AREA OF SHOWERS DEPARTS TO THE EAST THE FOCUS WILL BE ON LAKE EFFECT SNOW SHOWERS. WITH H850 TEMPS DROPPING DOWN TO -8C OR SO AND INVERSIONS SHOWN ON BUFKIT SOUNDING STILL A BIT HIGH EXPECTING LINGERING CLOUDS WITH WEST WINDS ACROSS NE OH AND NW PA AFTER MIDNIGHT TONIGHT. THINKING THAT WITH THE AMOUNT OF DRIER AIR BUILDING IN THIS WILL LIMIT LAKE EFFECT SNOW DEVELOPMENT AND WILL HAVE TO WAIT FOR SOME ADDITIONAL SUPPORT LATE OVERNIGHT. WATER VAPOR AND MODELS SHOWING SHARPER UPPER TROUGH THAT IS EXPECTED TO SWING ACROSS THE SOUTHERN GREAT LAKES LATE OVERNIGHT AND TUESDAY MORNING. EXPECTING THIS TO HELP IN GETTING SOME LAKE EFFECT SNOW ACROSS NE OH AND NW PA. ELSEWHERE EXPECTING PARTLY CLOUDY SKIES. USED A BLEND OF MET AND MAV TEMPS WITH HRRR TRENDS IN THE VERY SHORT TERM ON HOURLY TEMPS. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/... GUIDANCE POPS NOT INDICATING MUCH WITH LAKE EFFECT SNOW SHOWERS...BUT WENT WITH AT LEAST HIGH CHC POPS ACROSS NE OH AND NW PA TUESDAY MORNING. WITH THE WEST FLOW NOT EXPECTING MUCH ACROSS GREATER CLEVELAND AREA...WITH BEST ACCUMS STRETCHING FROM CENTRAL ASHTABULA COUNTY INTO INTERIOR ERIE COUNTY. THINKING FURTHER SOUTH THROUGH CRAWFORD COUNTIES AMOUNTS WILL DIMINISH. BETTER SFC CONVERGENCE OFF THE LAKE APPEARS TO BE IN THIS AREA ALSO. OVERALL THOUGH THINKING ACCUMS WILL RANGE AROUND AN INCH OR SO ACROSS INTERIOR NW PA TO LESS THAN AN INCH BACK INTO FAR NE OH COUNTIES. BY AFTERNOON THE TROUGH PUSHES TO THE EAST AND DRIER AIR OVERCOMES THE LAKE EFFECT POTENTIAL. SOME LINGERING CLOUDS AND PERHAPS SOME FLURRIES POSSIBLE ACROSS HIGHER ELEVATIONS OF NW PA...BUT NOT EXPECTING ANY FURTHER ACCUMS. FOR THE REMAINDER OF THE AREA HIGH PRESSURE INFLUENCE WILL HELP ALLOW FOR SUNSHINE. TEMPS EXPECTED TO RANGE IN MID TO UPPER 30S ACROSS THE NORTHEAST WITH CLOUDS AND AM SNOW SHOWERS...TO LOWER 40S ACROSS THE SOUTH AND WEST. FROM TUESDAY NIGHT THROUGH THURSDAY NIGHT HIGH PRESSURE IS EXPECTED TO BE IN CONTROL ACROSS THE AREA WITH DRY CONDITIONS. SOME ISSUES WITH CLOUD COVER THROUGH THE PERIOD AS MODELS CONTINUING TO SHOW SOME WEAK UPPER TROUGHS MOVING THROUGH THE UPPER FLOW DURING THE PERIOD. DESPITE THAT MAINLY QUIET WEATHER WITH TEMPS TRENDING TOWARD NORMAL ARE EXPECTED. LEANED TOWARD A BLEND OF MET MAV AND MEX NUMBER THROUGH THE PERIOD AS SEEING NO REASON TO DEVIATE MUCH WITH HIGH PRESSURE INFLUENCE. && .LONG TERM /FRIDAY THROUGH MONDAY/... HIGH PRESSURE WILL BE THE DOMINANT FEATURE THROUGH THE EXTENDED EVEN AS THE CENTER OF IT DRIFTS INTO EASTERN QUEBEC PROVINCE. SO AT THIS POINT WE EXPECT TO SEE DRY CONDITIONS. THERE MAY BE A SLIGHT INCREASE IN CLOUD COVER ON SUNDAY AS A STORM SYSTEM TAKES SHAPE OFF THE MIDDLE ATLANTIC COAST. OTHERWISE EXPECT TO SEE TEMPERATURES NEAR TO SLIGHTLY BELOW AVERAGE THROUGH THE PERIOD. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... WRAP AROUND MOISTURE AND UPPER TROUGH WILL MAINTAIN CLOUDY SKIES INTO TUESDAY AFTERNOON. FORTUNATELY EXPECTING THESE TO PRIMARILY BE LOW END VFR. EXCEPTION WOULD BE WITH ANY SCATTERED LAKE EFFECT/ENHANCED SNOW SHOWERS ACROSS THE HIGHER TERRAIN LOCATIONS EAST OF CLEVELAND. NEAR THE IMMEDIATE LAKESHORE LIKELY STILL RAIN. BUT THE BEST MOISTURE STAYS TO OUR NORTH. WILL MENTION A SNRA MIX FOR ERIE IN A TEMPO...BUT THAT IS IT. FORECAST SOUNDING PROFILES ARE NOT SUGGESTING MUCH WITH THE LACK OF DEEPER MOISTURE. WINDS SHIFT TO THE NORTHWEST TUESDAY AFTERNOON. HIGH PRESSURE FOLLOWS FOR TUESDAY NIGHT. OUTLOOK...SOME NON-VFR POSSIBLE FRIDAY. && .MARINE... THE COLD FRONT IS JUST EAST OF THE FORECAST AREA. WINDS DIE DOWN BEHIND THE FRONT BUT AS THE MUCH COLDER AIR MOVES OVER THE LAKE INCREASED MIXING WILL OCCUR OVER THE LAKE. THE 850MB TEMPS FORECAST TO DIP TO MINUS 10C BY DAYBREAK TUESDAY. AS A RESULT THE SMALL CRAFT WILL BE NEEDED OVER THE LAKE THROUGH THE OVERNIGHT HOURS. THE WINDS WILL DIE DOWN SIGNIFICANTLY BY TOMORROW AFTERNOON AS HIGH PRESSURE BUILDS OVER THE LAKE. EXPECT CONDITIONS TO REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA THROUGH THE WEEKEND AS HIGH PRESSURE WILL REMAIN OVER THE LAKE. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EST TUESDAY FOR LEZ145>149. SMALL CRAFT ADVISORY UNTIL 4 AM EST TUESDAY FOR LEZ142>144. && $$ SYNOPSIS...ABE NEAR TERM...ABE/TK SHORT TERM...ABE LONG TERM...MULLEN AVIATION...OUDEMAN MARINE...DJB/OUDEMAN
AREA FORECAST DISCUSSION
NWS NORMAN OK
1155 AM CST TUE NOV 13 2012 .AVIATION... VFR WILL CONTINUE TO APPLY THROUGH THE FORECAST PERIOD. EXPECT SOUTH WINDS AROUND 10 TO 15 KT WITH SLIGHTLY STRONGER GUSTS THROUGH THIS AFTERNOON. A FEW HIGH CLOUDS WILL PASS OVERHEAD. THE WINDS WILL DECREASE NEAR SUNSET TONIGHT. && .PREV DISCUSSION... /ISSUED 1049 AM CST TUE NOV 13 2012/ UPDATE... INCREASED THE SOUTHERN WINDS A LITTLE ACROSS WESTERN HALF OF OKLAHOMA BASED ON CURRENT TRENDS AND NEW RUC OUTPUT. ALSO LOWERED DEWPOINTS WHERE DEEPER MIXING WILL OCCUR. ELEVATED FIRE DANGER ACROSS FAR WESTERN OKLAHOMA AND ADJACENT PARTS OF NORTH TEXAS PRIMARILY DUE TO THE INCREASED WIND. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 32 58 34 62 / 0 0 0 0 HOBART OK 29 59 33 62 / 0 0 0 0 WICHITA FALLS TX 32 63 36 66 / 0 0 0 0 GAGE OK 24 60 30 61 / 0 0 0 0 PONCA CITY OK 29 58 32 59 / 0 0 0 0 DURANT OK 33 59 35 61 / 0 0 0 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 11/03/03
AREA FORECAST DISCUSSION
NWS NORMAN OK
1049 AM CST TUE NOV 13 2012 .UPDATE... INCREASED THE SOUTHERN WINDS A LITTLE ACROSS WESTERN HALF OF OKLAHOMA BASED ON CURRENT TRENDS AND NEW RUC OUTPUT. ALSO LOWERED DEWPOINTS WHERE DEEPER MIXING WILL OCCUR. ELEVATED FIRE DANGER ACROSS FAR WESTERN OKLAHOMA AND ADJACENT PARTS OF NORTH TEXAS PRIMARILY DUE TO THE INCREASED WIND. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 58 32 58 34 / 0 0 0 0 HOBART OK 57 29 59 33 / 0 0 0 0 WICHITA FALLS TX 58 32 63 36 / 0 0 0 0 GAGE OK 58 24 60 30 / 0 0 0 0 PONCA CITY OK 56 29 58 32 / 0 0 0 0 DURANT OK 58 33 59 35 / 0 0 0 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 11/03
AREA FORECAST DISCUSSION
NWS MEDFORD OR
824 PM PST MON NOV 12 2012 .DISCUSSION...A COLD FRONT REMAINS OVER SW OREGON AND NORTHERN CALIFORNIA THIS EVENING. IT IS WEAKENING AND WASHING OUT AS EXPECTED, BUT LIGHT RAIN CONTINUES AT MANY LOCATIONS, ESPECIALLY THE CURRY COAST, WESTERN SISKIYOU COUNTY, AND IN THE CASCADES. THE MOISTURE IS CONFINED TO THE LOW LEVELS AND THUS THE RADAR IS OVERSHOOTING MUCH OF IT, BUT THERE ARE CERTAINLY STILL SHOWERS FLOATING AROUND OTHER LOCATIONS AS WELL. THE 13/00Z RUNS OF THE NAM AND RAP SHOW THIS CONTINUING FOR A WHILE TONIGHT. AS A RESULT, I HAVE ALREADY UPDATED THE FORECAST TO INCREASE POPS FOR THIS EVENING THROUGH EARLY TOMORROW MORNING, MOSTLY CASCADES AND SISKIYOUS WESTWARD. I`VE CONFINED THE HIGHEST POPS TO THE COAST AND MOUNTAINS BUT IT SHOULD NOT COME AS A SURPRISE TO SEE A BRIEF SHOWER OR TWO NEARLY ANYWHERE THIS EVENING. RAIN IS FAIRLY LIGHT (ONLY A FEW HUNDREDTHS AN HOUR AT MOST), AND SO, DESPITE INCREASING POPS, I ACTUALLY DECREASED AMOUNTS. THE REST OF THE FORECAST STILL LOOKS GOOD. -WRIGHT && .AVIATION...A FRONT IS STALLING AND WEAKENING OVER SOUTHWESTERN OREGON...AND BRINGING A MIX OF MVFR...IFR...AND VFR CEILINGS TO AREAS ALONG AND WEST OF THE CASCADES. MOUNTAIN OBSCURATION WILL IMPACT ALL AREAS TONIGHT. FOG AND IFR CEILINGS WILL LIKELY AFFECT WEST SIDE VALLEYS LATE TONIGHT...WITH VFR CONDITIONS AT MOST EAST SIDE TERMINALS. CONDITIONS SHOULD TRANSITION TO VFR ALL AREAS BY EARLY TUESDAY AFTERNOON. SK && .PREV DISCUSSION... /ISSUED 300 PM PST MON NOV 12 2012/ SHORT TERM...TONIGHT THROUGH THURSDAY NOVEMBER 15TH. A WARM FRONT LIFTED NORTHEAST ACROSS THE AREA THIS MORNING AND THE TRAILING COLD FRONT HAS GENERATED LIGHT TO MODERATE RAIN AND HIGH ELEVATION SNOW THIS AFTERNOON. AT THE TOP OF THE HOUR, MODERATE RAIN RATES WERE STILL REPORTED OVER THE COASTAL RANGE AND THE HIGHER TERRAIN OF EASTERN DOUGLAS COUNTY. THERE WAS AROUND A DUSTING TO AN INCH OF SNOW AT MOST MOUNTAIN PASSES ABOVE 4000 FEET EARLY THIS MORNING. BUT, THE SNOW LEVEL HAS RISEN TO AROUND 6500 FEET. THE CRATER LAKE VISITOR CENTER IS THE ONLY ROAD CAM STILL SHOWING SNOW ON THE ROADWAY. PRECIPITATION WILL TAPER OFF OVERNIGHT WITH THE FRONT DISSIPATING OVER THE CASCADES, AND A WEAK BUT BROAD UPPER RIDGE BUILDING INTO CALIFORNIA. SKIES ARE EXPECTED TO REMAIN MOSTLY CLOUDY TO CLOUDY OVERNIGHT WITH PATCHY LATE NIGHT AND MORNING VALLEY FOG. BREAKS IN THE CLOUD COVER ARE EXPECTED BY TUESDAY AFTERNOON. BUT, THESE WILL BE SHORT-LIVED WITH A VERY WEAK WARM FRONT EXPECTED TO MOVE NORTHEAST ACROSS CAPE MENDOCINO INTO SISKIYOU COUNTY LATE IN THE DAY. THIS WILL BRING AN INCREASE OF MID AND HIGH LEVEL CLOUDS INTO TUESDAY NIGHT WITH A CHANCE OF VERY LIGHT RAIN IN WESTERN SISKIYOU COUNTY AND A SLIGHT CHANCE FOR MOST OF THE REMAINDER OF OUR AREA THROUGH TUESDAY NIGHT. THE GFS, NAM AND ECMWF MODELS HAVE ALL TRENDED STRONGER WITH RIDGING WEDNESDAY INTO THURSDAY. AS A RESULT, POPS HAVE BEEN LOWERED ON WEDNESDAY AND THE MENTION OF ANY PROBABILITY OF PRECIPITATION REMOVED FROM WEDNESDAY NIGHT AND THURSDAY. THE PATTERN WILL BEGIN TO CHANGE THURSDAY NIGHT WITH A TROUGH STILL OFFSHORE BUT HEADED EAST TO NORTHEAST TOWARD NORTHERN CALIFORNIA. BY LATE THURSDAY NIGHT...THERE IS A SLIGHT CHANCE TO CHANCE OF RAIN ON THE WESTERN EDGES OF OUR AREA WITH A SNOW LEVEL NEAR 6000 FEET. LONG TERM...FRIDAY NOVEMBER 16TH THROUGH TUEDAY NOVEMBER 20TH. AN ACTIVE AND WET PATTERN IS SHAPING UP FOR LATE IN THE WEEK THROUGH EARLY NEXT WEEK. MODELS HAVE COME INTO BETTER AGREEMENT FOR THIS PERIOD. FRIDAY AND FRIDAY NIGHT, MODELS SHOW A TROUGH MOVING INLAND, CENTERED TO THE SOUTH. THIS TROUGH IS EXPECTED TO BRING SOUTHERLY MOISTURE INTO THE AREA. ALSO, ADDITIONAL SHORTWAVES MAY MOVE INTO THE AREA AS THE TROUGH SHIFTS INLAND TO THE SOUTH. I HAVE KEPT CHANCE TO LIKELY POPS OVER THE AREA FOR THIS PERIOD. MODELS HAVE COME INTO BETTER AGREEMENT FOR THE SATURDAY THROUGH MONDAY TIME PERIOD SHOWING A STRONG FRONTAL SYSTEM AND TROUGH MOVING OUT OF THE GULF OF ALASKA SATURDY INTO SUNDAY WHILE A STRONG RIDGE REMAINS INLAND EAST OF THE AREA. THE GFS IS ABOUT 6 HOURS FASTER WITH THE FRONT PUSHING INLAND SATURDAY NIGHT WHILE THE ECMWF BRINGS IT INLAND ON SUNDAY. GIVEN THE IMPROVED CONFIDENCE HAVE INCREASED POPS FOR THIS PERIOD. SNOW LEVELS ARE FORECAST ABOVE 6000 FEET SATURDAY...LOWERING BEHIND THE FRONT TO 4500 TO 5000 FEET SUNDAY NIGHT. MODELS SHIFT THE TROUGH AXIS INLAND LATE SUNDAY WITH A SHORTWAVE MOVING INTO THE PACNW COAST SUNDAY NIGHT INTO MONDAY. THIS IS EXPECTED TO KEEP A HIGH CHANCE FOR RAIN AND SNOW OVER THE AREA SATURDAY INTO MONDAY. SNOW LEVELS ARE EXPECTED TO REMAIN ARUOND 4500 TO 5000 FEET MONDAY MORNING THEN INCREASE TO ABOVE 5000 FEET DURING THE DAY. MID LEVEL WINDS ALSO INCREASE LATE SATURDAY INTO MONDAY AND ARE EXPECTED TO BRING PERIODS OF BREEZY AND GUSTY WINDS, ESPECIALLY SATURDAY NIGHT INTO SUNDAY AND AGAIN ON MONDAY. POTENTIAL AREAS AFFECTED INCLUDE THE HIGHER TERRAIN AS WELL AS THE SHASTA VALLEY AND SUMMER LAKE AREA. ON TUESDAY THE GFS AND ECMWF SHOW THE POTENTIAL FOR A STRONG JET ALOFT TO DEVELOP AND NOSE INTO THE PACNW. THIS COMBINED WITH A LOW PERSISTING IN THE GULF OF ALASKA AND SHORTWAVES AND FRONTS ROTATING AROUND THE LOW AND MOVING INTO THE AREA, WOULD ALLOW FOR A CONTINUED ACTIVE AND WET PATTERN. /CC && .MFR WATCHES/WARNINGS/ADVISORIES... OR...NONE. CA...NONE. PZ...NONE. $$
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
955 AM MST TUE NOV 13 2012 .UPDATE...16Z SURFACE ANALYSIS HAD WEAK TROUGH OVER THE CWA...A REFLECTION OF WEAK SHORTWAVE OVER WESTERN SD/EASTERN WY PER WATER VAPOUR. SYSTEM MOISTURE STARVED...WITH RETURNS ON RADAR MOSTLY ALOFT. BEST REFLECTIVITY LIKELY REACHING THE GROUND...BUT IN LIGHT FASHION OVER SOUTH CENTRAL SD THROUGH THIS AFTERNOON. WILL ADJUST POPS TO MATCH CURRENT RADAR TRENDS AND TWEAK TEMPERATURES FOR 12Z KUNR SOUNDING. && .AVIATION...18Z TAFS VFR CONDITIONS CAN BE EXPECTED THROUGH TONIGHT AS A WEAK UPPER LEVEL DISTURBANCE MOVES EAST OF THE REGION THIS AFTERNOON. A FEW LIGHT RAIN SHOWERS/SPRINKLES ARE STILL POSSIBLE ACROSS SOUTH CENTRAL SD THROUGH EARLY AFTERNOON. && .PREV DISCUSSION... /ISSUED 403 AM MST TUE NOV 13 2012/ WENT AHEAD AND REMOVED ZR CHANCES THIS MORNING. RELATIVELY WEAK LIFT IS SUPPORTING MAINLY OVERCAST SKY WITH AREAS OF VIRGA. IF PRECIP DOES MATERIALIZE...EXPECT IT WOULD BE IN THE FORM OF FLURRIES THIS MORNING GIVEN A DIMINISHING WARM NOSE. THIS IS IN LINE WITH THE LATEST RAP PROFILES. ALL ELSE IN GOOD SHAPE. PREV DISCUSSION... /ISSUED 257 AM MST TUE NOV 13 2012/ FAST DISTURBED WESTERLY FLOW WILL REMAIN IN PLACE IN THE PERIOD WITH 36 HOUR PHASE VELOCITY FAVORED IN MODEL CONSENSUS. MID LEVEL DISTURBANCE IN THE PROCESS OF ADVECTING EAST TROUGH MT/WY/CO AS OF 09Z. THIS SYSTEM WILL QUICKLY ADVANCE EAST THROUGH THE NORTHERN PLAINS TODAY...BRINGING ONLY A SLIGHT CHANCE FOR PRECIP TO THE AREA. ANOTHER DISTURBANCE NOW ENTERING THE PAC NW WILL AFFECT THE AREA WED...WITH INCREASED LIFT SUPPORTING INCREASING CLOUDS ACROSS THE REGION. LACK OF MOISTURE WITH BOTH SYSTEMS WILL SUPPORT A MAINLY DRY FORECAST /ESP WED/ WITH QUIET WEATHER EXPECTED IN THE PERIOD. TODAY...FAST MOVING IMPULSE WILL CONTINUE TO SUPPORT BROAD ASCENT OVERT THE REGION INTO THE AFTERNOON. THIS WILL SUPPORT OVERCAST CONDITIONS FOR MOST OF THE FA...WITH CLEARING WEST TO EAST DURING THE AFTERNOON. DISMAL MOISTURE PROFILES WITH OVERALL WEAK WAA/FRONTOGENETICAL RESPONSE WILL SUPPORT VERY SMALL PRECIP CHANCES...WITH MOST NUMERICAL GUIDANCE NOT SUPPORTING MUCH IN THE WAY OF QPF. DID RETAIN LOW POPS ACROSS THE NORTHERN 2/3 ENACTING A TIME SHIFT FOR THE AFTERNOON. IF PRECIP DOES MATERIALIZE THIS MORNING...THERMAL PROFILES WOULD SUPPORT MAINLY SNOW WITH THE POSSIBILITY OF SOME ZR GIVEN SFC T/S BELOW 32F AND A WARM NOSE JUST OFF THE SFC GREATER THAN 2.5C. THIS LINES UP WITH SREF PRECIP TYPE PROBS AND GFS DOMINANT PROGS. CLEARING EXPECTED THIS EVENING WITH INCREASING HIGH CLOUDS W-E LATE IN THE NIGHT PER THE NEXT ADVANCING UPPER IMPULSE. THIS IMPULSE WILL ALSO HELP TO KEEP THE BL PARTIALLY MIXED WITH WARM PROFILES JUST OFF THE SFC...HELPING TO QUELL T FALLS SOME. WED/THUR...NEXT IMPULSE WILL ADV THROUGH THE NORTHERN PLAINS WITH THE BULK OF FORCING REMAINING WELL NORTH OF THE REGION. THUS...ONLY AN INCREASE IN CLOUDS EXPECTED. CAA ON THE BACKSIDE OF THIS SYSTEM IS PROGGED TO BE A LITTLE MORE AGGRESSIVE WITH THE LATEST MODEL RUNS...A CONTINUED TREND IN THE 06Z NAM. THUS...HAVE COOLED NORTHERN AREAS DOWN WED NIGHT GIVEN FROPA AND CLEARING SKIES. HIGH PRESSURE WILL SETTLE OVER THE REGION THUR...AS LL FLOW VEERS AROUND TO E-SE PER THE NEXT MID LEVEL DISTURBANCE. STAUNCH PRESSURE FALLS AND WAA THUR NIGHT WILL SUPPORT BREEZY CONDITIONS...ESP OVER NE WY. HAVE BUMPED WINDS UP AND ADJUSTED MIN T/S PER EXPECTED TURBULENT MIXING. EXTENDED...WILL KEEP DRY FORECAST FOR THE EXTENDED PERIOD AS NEAR ZONAL FLOW PERSISTS ACROSS THE REGION. WEAK DISTURBANCES IN THE FLOW WILL LIKELY BRING SOME CLOUDINESS FROM TIME TO TIME...BUT CHANCES FOR PCPN LOOK TO BE MINIMAL. TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE AVERAGE THROUGH THE PERIOD...WITH HIGHS EXPECTED TO MOSTLY BE IN THE MID 40S TO MID 50S. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ SHORT TERM...WFO UNR LONG TERM...WFO UNR AVIATION...26 UPDATE...HELGESON
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
403 AM MST TUE NOV 13 2012 .UPDATE...WENT AHEAD AND REMOVED ZR CHANCES THIS MORNING. RELATIVELY WEAK LIFT IS SUPPORTING MAINLY OVERCAST SKY WITH AREAS OF VIRGA. IF PRECIP DOES MATERIALIZE...EXPECT IT WOULD BE IN THE FORM OF FLURRIES THIS MORNING GIVEN A DIMINISHING WARM NOSE. THIS IS IN LINE WITH THE LATEST RAP PROFILES. ALL ELSE IN GOOD SHAPE. && .AVIATION...12Z TAFS VFR CONDITIONS WILL CONTINUE THROUGH WEDNESDAY MORNING FOR MOST LOCATIONS. A WEAK UPPER LEVEL DISTURBANCE WILL CROSS THE NORTHERN PLAINS TODAY...BRINGING A PERIOD OF MID LEVEL CLOUDINESS AND SOME MVFR CIGS ACROSS THE HIGHER ELEVATIONS OF NORTHEAST WYOMING AND THE BLACK HILLS. SOME ISOLATED LIGHT RAIN AND SNOW SHOWERS ARE EXPECTED WITH THIS BAND OF CLOUDS...WITH ISOLATED LIGHT FREEZING RAIN SHOWERS POSSIBLE EARLY IN THE DAY. && .PREV DISCUSSION... /ISSUED 257 AM MST TUE NOV 13 2012/ DISCUSSION... FAST DISTURBED WESTERLY FLOW WILL REMAIN IN PLACE IN THE PERIOD WITH 36 HOUR PHASE VELOCITY FAVORED IN MODEL CONSENSUS. MID LEVEL DISTURBANCE IN THE PROCESS OF ADVECTING EAST TROUGH MT/WY/CO AS OF 09Z. THIS SYSTEM WILL QUICKLY ADVANCE EAST THROUGH THE NORTHERN PLAINS TODAY...BRINGING ONLY A SLIGHT CHANCE FOR PRECIP TO THE AREA. ANOTHER DISTURBANCE NOW ENTERING THE PAC NW WILL AFFECT THE AREA WED...WITH INCREASED LIFT SUPPORTING INCREASING CLOUDS ACROSS THE REGION. LACK OF MOISTURE WITH BOTH SYSTEMS WILL SUPPORT A MAINLY DRY FORECAST /ESP WED/ WITH QUIET WEATHER EXPECTED IN THE PERIOD. TODAY...FAST MOVING IMPULSE WILL CONTINUE TO SUPPORT BROAD ASCENT OVERT THE REGION INTO THE AFTERNOON. THIS WILL SUPPORT OVERCAST CONDITIONS FOR MOST OF THE FA...WITH CLEARING WEST TO EAST DURING THE AFTERNOON. DISMAL MOISTURE PROFILES WITH OVERALL WEAK WAA/FRONTOGENETICAL RESPONSE WILL SUPPORT VERY SMALL PRECIP CHANCES...WITH MOST NUMERICAL GUIDANCE NOT SUPPORTING MUCH IN THE WAY OF QPF. DID RETAIN LOW POPS ACROSS THE NORTHERN 2/3 ENACTING A TIME SHIFT FOR THE AFTERNOON. IF PRECIP DOES MATERIALIZE THIS MORNING...THERMAL PROFILES WOULD SUPPORT MAINLY SNOW WITH THE POSSIBILITY OF SOME ZR GIVEN SFC T/S BELOW 32F AND A WARM NOSE JUST OFF THE SFC GREATER THAN 2.5C. THIS LINES UP WITH SREF PRECIP TYPE PROBS AND GFS DOMINANT PROGS. CLEARING EXPECTED THIS EVENING WITH INCREASING HIGH CLOUDS W-E LATE IN THE NIGHT PER THE NEXT ADVANCING UPPER IMPULSE. THIS IMPULSE WILL ALSO HELP TO KEEP THE BL PARTIALLY MIXED WITH WARM PROFILES JUST OFF THE SFC...HELPING TO QUELL T FALLS SOME. WED/THUR...NEXT IMPULSE WILL ADV THROUGH THE NORTHERN PLAINS WITH THE BULK OF FORCING REMAINING WELL NORTH OF THE REGION. THUS...ONLY AN INCREASE IN CLOUDS EXPECTED. CAA ON THE BACKSIDE OF THIS SYSTEM IS PROGGED TO BE A LITTLE MORE AGGRESSIVE WITH THE LATEST MODEL RUNS...A CONTINUED TREND IN THE 06Z NAM. THUS...HAVE COOLED NORTHERN AREAS DOWN WED NIGHT GIVEN FROPA AND CLEARING SKIES. HIGH PRESSURE WILL SETTLE OVER THE REGION THUR...AS LL FLOW VEERS AROUND TO E-SE PER THE NEXT MID LEVEL DISTURBANCE. STAUNCH PRESSURE FALLS AND WAA THUR NIGHT WILL SUPPORT BREEZY CONDITIONS...ESP OVER NE WY. HAVE BUMPED WINDS UP AND ADJUSTED MIN T/S PER EXPECTED TURBULENT MIXING. EXTENDED...WILL KEEP DRY FORECAST FOR THE EXTENDED PERIOD AS NEAR ZONAL FLOW PERSISTS ACROSS THE REGION. WEAK DISTURBANCES IN THE FLOW WILL LIKELY BRING SOME CLOUDINESS FROM TIME TO TIME...BUT CHANCES FOR PCPN LOOK TO BE MINIMAL. TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE AVERAGE THROUGH THE PERIOD...WITH HIGHS EXPECTED TO MOSTLY BE IN THE MID 40S TO MID 50S. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ SHORT TERM...JC LONG TERM...15 AVIATION...15 UPDATE...JC
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1000 PM CST WED NOV 14 2012 .UPDATE... MADE MINOR CHANGES TO THE ONGOING FORECAST PACKAGE TO ACCOUNT FOR CURRENT AND REST OF TONIGHT WEATHER TRENDS. LATEST 00Z NAM12 AND 03Z RUC13 AREA FORECAST SOUNDINGS SUGGEST/MAINTAIN A 850MB BKN/OVC CLOUD LAYER TONIGHT INTO THURSDAY ACROSS THE SOUTHERN HALF OF SOUTH CENTRAL TEXAS. HILL COUNTRY WILL REMAIN MOSTLY CLEAR THIS EVENING WITH SOME CLOUDS RETURNING OVERNIGHT. ACROSS THE RIO GRANDE PLAINS/EDWARDS PLATEAU AREA...EXPECT CLOUDS TO INCREASE OVERNIGHT AS SURFACE DEWPOINTS AUGMENT AND MID TO UPPER LEVEL MOISTURE MOVES FROM WEST TEXAS AND NORTHEAST MEXICO. && .PREV DISCUSSION... /ISSUED 553 PM CST WED NOV 14 2012/ DISCUSSION... SEE AVIATION FOR 00Z TAFS. AVIATION... A MID LEVEL CLOUD DECK EXTENDS FROM SOUTHEAST OF DEL RIO TO SAN ANTONIO TO LA GRANGE AND SOUTH TO THE COAST. CIGS ACROSS THIS AREA ARE VFR. TO THE NORTH SKIES ARE MAINLY CLEAR. THESE CLOUDS ARE EXPECTED TO SLOWLY ERODE THROUGH THE EVENING. KAUS, KSAT, KSSF AND KDRT WILL BE VFR THROUGH THE EVENING. AS S/W ENERGY MOVES FROM THE NORTHERN ROCKIES TO JUST WEST OF THE GREAT LAKES AND THE CENTRAL U.S. ON THURSDAY...THE WEAK SFC RIDGE OVER SOUTH CENTRAL TEXAS WILL MOVE FURTHER EAST...PROVIDING A MORE CONSISTENT E TO SE SFC WIND PATTERN FOR THE DAY ON THURSDAY. THIS COULD CAUSE CIGS AROUND 2500 TO 6000 FT TO FORM NEAR THE RIO GRANDE TONIGHT THROUGH THURSDAY MORNING IN VCNTY OF KDRT. VFR CONDITIONS ARE EXPECTED TO CONTINUE AT KAUS, KSAT AND KSSF THURSDAY MORNING. SCT TO BKN CLOUDS AOB 10 THSD FT WILL SLOWLY INCREASE FROM THE WEST THROUGH THURSDAY AND THURSDAY NIGHT. BY THURSDAY EVENING SFC WINDS WILL BECOME E TO NE...AS THE S/W FROM WEST OF THE GREAT LAKES TO THE CENTRAL U.S. MOVES TO THE MS VALLEY AND CAUSES A WEAK RIDGE TO FORM ACROSS THE NORTHEAST TO EASTERN PART OF SOUTH CENTRAL TEXAS. THESE TYPE OF WEATHER PATTERNS WILL FAVOR VFR CONDITIONS ON THURSDAY AFTERNOON AND EVENING. PREV DISCUSSION... /ISSUED 312 PM CST WED NOV 14 2012/ DISCUSSION... CLOUDS HAVE BEEN SLOW TO CLEAR/ERODE OVER THE SRN HALF OF THE CWA TODAY. OVERRUNNING WAS OCCURRING IN THE SWLY FLOW 5-8K FEET ABOVE THE COOL DRY SURFACE RIDGE. SOME PARTIAL CLEARING WILL CONTINUE THIS EVENING...HOWEVER ADDITIONAL MID-UPPER LEVEL CLOUDS WERE MOVING IN FROM THE WEST AS WELL AS INCREASING LOW LEVEL RETURN MOISTURE UP THE RIO GRANDE. THE COOL SURFACE RIDGE OVER S TX WILL SLOWLY RETREAT EASTWARD THURSDAY WITH RETURN FLOW ALL AREAS. A BRIEF WEAK BACKDOOR COLD FRONT WILL AFFECT MAINLY NERN CWA THURSDAY NIGHT/EARLY FRIDAY AND BRIEFLY SHIFT WINDS TO THE NE-E. THIS WEAK FRONT COULD TRIGGER A FEW SHOWERS OVER THE FAR SWRN CWA AS WELL. WINDS WILL QUICKLY RETURN TO SELY BY SATURDAY INTO SUNDAY AS THE NWLY FLOW BECOMES MORE ZONAL FLOW. MINOR DISTURBANCES IN THE WESTERLY FLOW COULD GENERATE ISOLATED SHOWERS/SPRINKLES SUNDAY INTO SUNDAY NIGHT WITH PARTLY TO MOSTLY CLOUDY SKIES PREVAILING. A MORE POTENT TROUGH/COLD FRONT WILL MOVE INTO SOUTHWEST TX MONDAY AND ACROSS SOUTH TX MONDAY NIGHT AND TUESDAY...RESULTING IN BETTER CHANCES OF CONVECTION. HAVE TONED DOWN GFS MOS POPS TO 20-30 PERCENT MORE IN LINE WITH THE DRIER ECWMF AND PREVIOUS THINKING. CLEARING TUESDAY NIGHT INTO WEDNESDAY BEHIND THE COLD FRONT. MILD HIGH TEMPERATURES AND COOL NIGHTS AS AN UPPER LEVEL RIDGE BUILDS IN FROM THE WEST. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 40 68 44 68 40 / 0 0 0 0 0 AUSTIN BERGSTROM INTL AIRPORT 34 68 40 67 34 / 0 0 0 0 0 NEW BRAUNFELS MUNI AIRPORT 40 67 45 67 38 / 0 0 - 0 0 BURNET MUNI AIRPORT 35 66 41 66 37 / 0 0 0 0 0 DEL RIO INTL AIRPORT 48 68 51 65 48 / - 0 - - - GEORGETOWN MUNI AIRPORT 35 67 37 66 36 / 0 0 0 0 0 HONDO MUNI AIRPORT 45 66 49 67 42 / 0 0 - - 0 SAN MARCOS MUNI AIRPORT 40 66 44 67 39 / 0 0 - 0 0 LA GRANGE - FAYETTE REGIONAL 37 68 42 67 39 / 0 0 - - - SAN ANTONIO INTL AIRPORT 44 65 49 66 43 / 0 0 - - 0 STINSON MUNI AIRPORT 46 66 51 66 44 / 0 0 - - 0 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...08 SYNOPTIC/GRIDS...17 PUBLIC SERVICE/DATA COLLECTION...31
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1228 PM CST TUE NOV 13 2012 .DISCUSSION...QUICK UPDATE...BASED ON TIDE LEVELS OVER THE NORTHEAST (WHERE WITH NORTHEAST WINDS PILING UP OF WATER HAS NOT BEEN AS GREAT)...DROPPED THE COASTAL FLOOD ADVISORY FOR THE NORTHERN AREAS BUT KEPT FOR NUECES AND KLEBERG COUNTIES. BOB HALL PIER WILL BE CLOSE TO 2 FEET SO HAVE KEPT IT. EXPECTING LESS OF A PROBLEM TOMORROW WITH LIGHTER WINDS AND DIMINISHED SWELLS. FINALLY...DID NUDGE TEMPERATURES DOWN A BIT MAINLY AWAY FROM THE COAST (AND STILL MAY BE A BIT HIGH). RAIN ENTERING AREA IS COOLING THINGS A BIT AND CONTINUED CLOUD COVER WILL NOT BRING MUCH INCREASE IN TEMPERATURES. STILL LIKE THE 20 POPS GOING AS STILL ARE HAVING TROUBLE FINDING SOMEONE WITH MEASURABLE RAINFALL (ALTHOUGH RADAR IS SHOWING SOME AREAS WITH MORE THAN 1/10 INCH WHICH IS PLAUSIBLE GIVEN 45-55 DBZ CELLS AT TIMES. PRODUCTS OUT AGAIN. && .PREV DISCUSSION... /ISSUED 1137 AM CST TUE NOV 13 2012/ DISCUSSION...SEE 18Z AVIATION DISCUSSION. AVIATION...VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD...WITH SOME CIGS THROUGH THE PERIOD EXCEPT AT KVCT WHERE WILL SEE SOME CLEARING WEDNESDAY BEFORE SUNRISE. SOME AREAS OF LIGHT TO MODERATE RAINFALL SOUTH OF TERMINALS BETWEEN NOW AND 06Z...ENDING FROM WEST TO EAST. MOST OF THE ACTIVITY SHOULD BE VERY LIGHT SO ONLY HAVE PUT IN VCSH IN ALL BUT KVCT TERMINAL (NO VCSH). WILL UPDATE ON THIS IF NEEDED...ESPECIALLY IF LIGHTNING BECOMES AN ISSUE AT KLRD OR IF RAIN MORE MEASURABLE AND SCATTERED IN NATURE. OTHERWISE...NE TO E WINDS TODAY 11 KNOTS OR LESS (BIT HIGHER AT KCRP DUE TO PROXIMATE TO BAY). CIGS DECREASE A BIT THIS AFTERNOON WITH APPROACH OF RAIN...THEN INCREASE OVERNIGHT WITH PASSAGE OF JET AND DRIER AIR COMING IN FROM THE NORTHEAST. PREV DISCUSSION... /ISSUED 949 AM CST TUE NOV 13 2012/ DISCUSSION...EXTENDED MEASURABLE RAINFALL MORE NORTH FOR TODAY...BUT FOR NOW KEPT THE 20 POPS. BET PART OF RAIN CELL WENT JUST SOUTH OF KCOT WHERE THEY GOT A TRACE OF RAIN (AREAS SOUTH PROBABLY GOT A HUNDREDTH OR TWO). DID PUT THUNDER IN FOR THE WESTERN AREAS SINCE IT HAS BEEN A BIT OBSERVED FROM TIME TO TIME (PRETTY COOL ALOFT). OTHERWISE...MINOR CHANGES TO FIRST/SECOND PERIODS. MARINE...EXTENDED SCA FOR THE NEARSHORE TIL 3 PM. RUC13 AND NAM IS KEEPING 20-25 KNOT WINDS OVER THE NORTHEASTERN NEARSHORE THROUGH EARLY AFTERNOON...SO HAVE EXTENDED IT. LEFT SCA FOR OFFSHORE AS-IS. DID MENTION RAIN FOR LATE AFTERNOON/TONIGHT BUT NO THUNDER YET. WILL TAKE A LOOK AT LATER. PREV DISCUSSION... /ISSUED 832 AM CST TUE NOV 13 2012/ DISCUSSION...BASED ON RADAR TRENDS AND 4 KM MODEL OUTPUT FROM SPC AND TEX-TECH...HAVE DECIDED TO MENTION MEASURABLE RAINFALL IN THE FORECAST. RADAR IS SHOWING SOME 40-50 DBZ ECHOES IN THE BRUSH COUNTRY AND RIO GRANDE PLAINS HEADING TOWARD COTULLA. 4KM MODELS SHOWING SOME QPF (ISOLATED OVER 1/4 INCH...AM NOT SURE IT WILL BE THAT MUCH). THIS RAIN/SHOWERS IS FROM AN UPPER JET STREAK AND SUFFICIENT MOISTURE. GIVEN THE FACT THAT PWATS GET ABOVE 1 INCH LATER THIS AFTERNOON OVER THE SOUTHEAST...WILL GO WITH SOME LIGHT RAIN AND PUT SPRINKLES FARTHER NORTH WHERE MOISTURE IS MORE LIMITED. HAVE EVEN SEEN AN OCCASIONAL LIGHTNING STRIKE NW OF COTULLA BUT THINK THAT OUR AREA WILL SEE ESSENTIALLY ALL RAIN OR SPRINKLES AND THAT ELEVATED CONVECTION TOO LIMITED TO MENTION THUNDER AT THIS TIME (HOWEVER WILL MONITOR). PRODUCTS ARE OUT. PREV DISCUSSION... /ISSUED 537 AM CST TUE NOV 13 2012/ DISCUSSION...UPDATED FOR 12Z AVIATION. AVIATION...BROKEN/OVERCAST CEILINGS BETWEEN 8K AND 10K FEET ARE ANTICIPATED THROUGH THE MAJORITY OF THE TAF CYCLE. WINDS WILL GENERALLY BE LESS THAN 10 KNOTS...WITH A NORTHEASTERLY COMPONENT. LOW CONFIDENCE ON LIGHT RAIN/SPRINKLES LATER TODAY WILL PRECLUDE A MENTION IN THE TAFS ATTM. VFR FORECAST CONTINUES THE NEXT 24 HOURS. PREV DISCUSSION... /ISSUED 438 AM CST TUE NOV 13 2012/ SHORT TERM (TODAY THROUGH WEDNESDAY)...MORNING SATELLITE IMAGERY HAS STREAM OF MID AND LEVEL HIGH CLOUDS MOVING ACROSS SOUTH TEXAS. TEMPERATURES CURRENTLY ARE IN THE 40S AND 50 THIS MORNING AND DO NOT THINK TEMPS WILL FALL TOO MUCH MORE. WEAK SHORTWAVE/UPPER JET APPROACHES THE AREA TODAY...KEEPING MOSTLY CLOUDY CONDITIONS ACROSS SOUTH TEXAS. WITH NORTHEAST WINDS CONTINUING...TEMPS WILL ONLY CLIMB INTO THE 60S THIS AFTERNOON IN MOST LOCATIONS. DESPITE WEAK ISENTROPIC LIFT OVER THE AREA TODAY...THINK MEASURABLE PRECIP MAY BE DIFFICULT TO COME BY. ALSO...06Z MAV POPS HAVE COME IN LOWER THAN 00Z GUIDANCE AS WELL. PREFER TO CONTINUE WITH THE MENTION OF SPRINKLES INSTEAD OF LOW END POPS. UPPER DISTURBANCE TO PASS EAST OF THE AREA TODAY...WITH DRY NORTHWEST FLOW OVER THE REGION ON WEDNESDAY. SOME CLOUD COVER MAY LINGER INTO WEDNESDAY... BUT TEMPS SHOULD REBOUND A FEW DEGREES WITH UPPER 60S TO LOWER 70S FOR HIGHS. ALSO OF NOTE...MODERATE TO STRONG NORTHEAST WINDS WILL PERSIST TODAY OVER THE GULF WATERS. WITH SEAS STILL RUNNING 7 TO 9 FEET AND TIDE LEVEL RUNNING SLIGHTLY ABOVE PREDICTED...MINOR TIDAL OVERFLOW MAY OCCUR AT HIGH TIDE ALONG GULF BEACHES TODAY AND HAVE ISSUED A COASTAL FLOOD ADVISORY. MARINE...STRONG OFFSHORE FLOW WILL PERSIST OVER THE GULF WATERS THIS MORNING...WITH SCA CONDITIONS OVER THE NEAR AND OFFSHORE WATERS. WINDS WILL SLOWLY DECREASE BY THIS AFTERNOON TO BELOW SCA OVER THE NEAR SHORE WATERS...BUT SCA CONDITIONS WILL CONTINUE OVER THE OFFSHORE WATERS THROUGH TONIGHT AS SEAS REMAIN AROUND 7 FEET. LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...SLIGHTLY WARMER TEMPS CAN BE EXPECTED WED NIGHT AND THU AS THE AIRMASS BEGINS TO MODIFY. THE SRN EXTENT OF THE SFC HIGH IS PROGD TO REMAIN DRAPED ACROSS S TX THROUGH FRI RESULTING IN A GENERALLY LIGHT NE FLOW ACROSS THE AREA AND A WEAK TO MOD FLOW OVER THE COASTAL WATERS. THE FLOW BEGINS TO VEER TO THE E AND SE THRU THE WEEKEND AND THEN STRENGTHENS MON/TUE IN RESPONSE TO A LOW PRESSURE SYSTEM MOVG ACROSS THE CENTRAL PLAINS. THE ONSHORE FLOW WILL CONTINUE THE WARMING TREND INTO THE WEEKEND WITH HIGHS APPROACHING THE UPPER 70S TO LOW 80S BY SUNDAY. HAVE KNOCKED THE FCSTD TEMPS DOWN A COUPLE OF DEGREES SAT/SUN DUE TO PERSISTENT CLOUDS AND THE WINDS BLOWING ACROSS THE COOLER WATERS. WEAK ISENTROPIC UPGLIDE IS PROGD TO DVLP ACROSS THE RIO GRANDE PLAINS FRI WITH DEEPER MOISTURE SURGING NWD ALONG THE RIO GRANDE. THIS WILL COMBINE WITH AN EMBEDDED SHORT WAVE ALOFT TO BRING A SLIGHT CHC OF -SHRA`S TO THE RIO GRANDE PLAINS. KEPT THE SLIGHT CHC ACROSS THE SRN COASTAL BEND AS WELL DUE TO SLIGHTLY DEEPER MOISTURE AND THE SHORT WAVE ALTHOUGH ISENTROPIC DOWNGLIDE MAY PRECLUDE RAIN FARTHER E. SATURDAY IS PROGD TO BE A TAD DRIER...THEN ANOTHER SURGE OF MOISTURE MOVES INTO S TX ON SUN/MON TIME FRAME ALONG WITH A SERIES OF WEAK SHORT WAVES. THE GFS WAS PREVIOUSLY SHOWING DEEPER MOISTURE WITH BETTER DYNAMICS ON SUNDAY BUT THE LATEST RUN HAS PUSHED IT BACK INTO MON. DECIDED TO KEEP A BROAD BRUSHED SLIGHT CHC FOR BOTH DAYS FOR NOW. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 65 52 71 53 73 / 20 20 10 10 10 VICTORIA 62 42 68 41 72 / 10 10 10 10 10 LAREDO 64 51 72 55 75 / 20 20 10 10 10 ALICE 63 48 71 48 75 / 20 20 10 10 10 ROCKPORT 63 52 69 57 73 / 10 20 10 10 10 COTULLA 60 45 68 49 72 / 20 10 10 10 10 KINGSVILLE 66 49 71 52 75 / 20 20 10 10 10 NAVY CORPUS 66 55 70 56 72 / 20 20 10 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...HIGH RIP CURRENT RISK UNTIL MIDNIGHT CST TONIGHT FOR THE FOLLOWING ZONES: ARANSAS...CALHOUN...KLEBERG...NUECES. COASTAL FLOOD ADVISORY UNTIL 9 PM CST THIS EVENING FOR THE FOLLOWING ZONES: KLEBERG...NUECES. GM...SMALL CRAFT ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR THE FOLLOWING ZONES: WATERS FROM BAFFIN BAY TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM. SMALL CRAFT ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR THE FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL OUT 20 NM. && $$ GW/86...SHORT TERM JM/75...LONG TERM
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1137 AM CST TUE NOV 13 2012 .DISCUSSION...SEE 18Z AVIATION DISCUSSION. && .AVIATION...VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD...WITH SOME CIGS THROUGH THE PERIOD EXCEPT AT KVCT WHERE WILL SEE SOME CLEARING WEDNESDAY BEFORE SUNRISE. SOME AREAS OF LIGHT TO MODERATE RAINFALL SOUTH OF TERMINALS BETWEEN NOW AND 06Z...ENDING FROM WEST TO EAST. MOST OF THE ACTIVITY SHOULD BE VERY LIGHT SO ONLY HAVE PUT IN VCSH IN ALL BUT KVCT TERMINAL (NO VCSH). WILL UPDATE ON THIS IF NEEDED...ESPECIALLY IF LIGHTNING BECOMES AN ISSUE AT KLRD OR IF RAIN MORE MEASURABLE AND SCATTERED IN NATURE. OTHERWISE...NE TO E WINDS TODAY 11 KNOTS OR LESS (BIT HIGHER AT KCRP DUE TO PROXIMATE TO BAY). CIGS DECREASE A BIT THIS AFTERNOON WITH APPROACH OF RAIN...THEN INCREASE OVERNIGHT WITH PASSAGE OF JET AND DRIER AIR COMING IN FROM THE NORTHEAST. && .PREV DISCUSSION... /ISSUED 949 AM CST TUE NOV 13 2012/ DISCUSSION...EXTENDED MEASURABLE RAINFALL MORE NORTH FOR TODAY...BUT FOR NOW KEPT THE 20 POPS. BET PART OF RAIN CELL WENT JUST SOUTH OF KCOT WHERE THEY GOT A TRACE OF RAIN (AREAS SOUTH PROBABLY GOT A HUNDREDTH OR TWO). DID PUT THUNDER IN FOR THE WESTERN AREAS SINCE IT HAS BEEN A BIT OBSERVED FROM TIME TO TIME (PRETTY COOL ALOFT). OTHERWISE...MINOR CHANGES TO FIRST/SECOND PERIODS. MARINE...EXTENDED SCA FOR THE NEARSHORE TIL 3 PM. RUC13 AND NAM IS KEEPING 20-25 KNOT WINDS OVER THE NORTHEASTERN NEARSHORE THROUGH EARLY AFTERNOON...SO HAVE EXTENDED IT. LEFT SCA FOR OFFSHORE AS-IS. DID MENTION RAIN FOR LATE AFTERNOON/TONIGHT BUT NO THUNDER YET. WILL TAKE A LOOK AT LATER. PREV DISCUSSION... /ISSUED 832 AM CST TUE NOV 13 2012/ DISCUSSION...BASED ON RADAR TRENDS AND 4 KM MODEL OUTPUT FROM SPC AND TEX-TECH...HAVE DECIDED TO MENTION MEASURABLE RAINFALL IN THE FORECAST. RADAR IS SHOWING SOME 40-50 DBZ ECHOES IN THE BRUSH COUNTRY AND RIO GRANDE PLAINS HEADING TOWARD COTULLA. 4KM MODELS SHOWING SOME QPF (ISOLATED OVER 1/4 INCH...AM NOT SURE IT WILL BE THAT MUCH). THIS RAIN/SHOWERS IS FROM AN UPPER JET STREAK AND SUFFICIENT MOISTURE. GIVEN THE FACT THAT PWATS GET ABOVE 1 INCH LATER THIS AFTERNOON OVER THE SOUTHEAST...WILL GO WITH SOME LIGHT RAIN AND PUT SPRINKLES FARTHER NORTH WHERE MOISTURE IS MORE LIMITED. HAVE EVEN SEEN AN OCCASIONAL LIGHTNING STRIKE NW OF COTULLA BUT THINK THAT OUR AREA WILL SEE ESSENTIALLY ALL RAIN OR SPRINKLES AND THAT ELEVATED CONVECTION TOO LIMITED TO MENTION THUNDER AT THIS TIME (HOWEVER WILL MONITOR). PRODUCTS ARE OUT. PREV DISCUSSION... /ISSUED 537 AM CST TUE NOV 13 2012/ DISCUSSION...UPDATED FOR 12Z AVIATION. AVIATION...BROKEN/OVERCAST CEILINGS BETWEEN 8K AND 10K FEET ARE ANTICIPATED THROUGH THE MAJORITY OF THE TAF CYCLE. WINDS WILL GENERALLY BE LESS THAN 10 KNOTS...WITH A NORTHEASTERLY COMPONENT. LOW CONFIDENCE ON LIGHT RAIN/SPRINKLES LATER TODAY WILL PRECLUDE A MENTION IN THE TAFS ATTM. VFR FORECAST CONTINUES THE NEXT 24 HOURS. PREV DISCUSSION... /ISSUED 438 AM CST TUE NOV 13 2012/ SHORT TERM (TODAY THROUGH WEDNESDAY)...MORNING SATELLITE IMAGERY HAS STREAM OF MID AND LEVEL HIGH CLOUDS MOVING ACROSS SOUTH TEXAS. TEMPERATURES CURRENTLY ARE IN THE 40S AND 50 THIS MORNING AND DO NOT THINK TEMPS WILL FALL TOO MUCH MORE. WEAK SHORTWAVE/UPPER JET APPROACHES THE AREA TODAY...KEEPING MOSTLY CLOUDY CONDITIONS ACROSS SOUTH TEXAS. WITH NORTHEAST WINDS CONTINUING...TEMPS WILL ONLY CLIMB INTO THE 60S THIS AFTERNOON IN MOST LOCATIONS. DESPITE WEAK ISENTROPIC LIFT OVER THE AREA TODAY...THINK MEASURABLE PRECIP MAY BE DIFFICULT TO COME BY. ALSO...06Z MAV POPS HAVE COME IN LOWER THAN 00Z GUIDANCE AS WELL. PREFER TO CONTINUE WITH THE MENTION OF SPRINKLES INSTEAD OF LOW END POPS. UPPER DISTURBANCE TO PASS EAST OF THE AREA TODAY...WITH DRY NORTHWEST FLOW OVER THE REGION ON WEDNESDAY. SOME CLOUD COVER MAY LINGER INTO WEDNESDAY... BUT TEMPS SHOULD REBOUND A FEW DEGREES WITH UPPER 60S TO LOWER 70S FOR HIGHS. ALSO OF NOTE...MODERATE TO STRONG NORTHEAST WINDS WILL PERSIST TODAY OVER THE GULF WATERS. WITH SEAS STILL RUNNING 7 TO 9 FEET AND TIDE LEVEL RUNNING SLIGHTLY ABOVE PREDICTED...MINOR TIDAL OVERFLOW MAY OCCUR AT HIGH TIDE ALONG GULF BEACHES TODAY AND HAVE ISSUED A COASTAL FLOOD ADVISORY. MARINE...STRONG OFFSHORE FLOW WILL PERSIST OVER THE GULF WATERS THIS MORNING...WITH SCA CONDITIONS OVER THE NEAR AND OFFSHORE WATERS. WINDS WILL SLOWLY DECREASE BY THIS AFTERNOON TO BELOW SCA OVER THE NEAR SHORE WATERS...BUT SCA CONDITIONS WILL CONTINUE OVER THE OFFSHORE WATERS THROUGH TONIGHT AS SEAS REMAIN AROUND 7 FEET. LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...SLIGHTLY WARMER TEMPS CAN BE EXPECTED WED NIGHT AND THU AS THE AIRMASS BEGINS TO MODIFY. THE SRN EXTENT OF THE SFC HIGH IS PROGD TO REMAIN DRAPED ACROSS S TX THROUGH FRI RESULTING IN A GENERALLY LIGHT NE FLOW ACROSS THE AREA AND A WEAK TO MOD FLOW OVER THE COASTAL WATERS. THE FLOW BEGINS TO VEER TO THE E AND SE THRU THE WEEKEND AND THEN STRENGTHENS MON/TUE IN RESPONSE TO A LOW PRESSURE SYSTEM MOVG ACROSS THE CENTRAL PLAINS. THE ONSHORE FLOW WILL CONTINUE THE WARMING TREND INTO THE WEEKEND WITH HIGHS APPROACHING THE UPPER 70S TO LOW 80S BY SUNDAY. HAVE KNOCKED THE FCSTD TEMPS DOWN A COUPLE OF DEGREES SAT/SUN DUE TO PERSISTENT CLOUDS AND THE WINDS BLOWING ACROSS THE COOLER WATERS. WEAK ISENTROPIC UPGLIDE IS PROGD TO DVLP ACROSS THE RIO GRANDE PLAINS FRI WITH DEEPER MOISTURE SURGING NWD ALONG THE RIO GRANDE. THIS WILL COMBINE WITH AN EMBEDDED SHORT WAVE ALOFT TO BRING A SLIGHT CHC OF -SHRA`S TO THE RIO GRANDE PLAINS. KEPT THE SLIGHT CHC ACROSS THE SRN COASTAL BEND AS WELL DUE TO SLIGHTLY DEEPER MOISTURE AND THE SHORT WAVE ALTHOUGH ISENTROPIC DOWNGLIDE MAY PRECLUDE RAIN FARTHER E. SATURDAY IS PROGD TO BE A TAD DRIER...THEN ANOTHER SURGE OF MOISTURE MOVES INTO S TX ON SUN/MON TIME FRAME ALONG WITH A SERIES OF WEAK SHORT WAVES. THE GFS WAS PREVIOUSLY SHOWING DEEPER MOISTURE WITH BETTER DYNAMICS ON SUNDAY BUT THE LATEST RUN HAS PUSHED IT BACK INTO MON. DECIDED TO KEEP A BROAD BRUSHED SLIGHT CHC FOR BOTH DAYS FOR NOW. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 65 52 71 53 73 / 20 20 10 10 10 VICTORIA 63 42 68 41 72 / 10 10 10 10 10 LAREDO 66 51 72 55 75 / 20 20 10 10 10 ALICE 65 48 71 48 75 / 20 20 10 10 10 ROCKPORT 65 52 69 57 73 / 10 20 10 10 10 COTULLA 63 45 68 49 72 / 20 10 10 10 10 KINGSVILLE 66 49 71 52 75 / 20 20 10 10 10 NAVY CORPUS 66 55 70 56 72 / 20 20 10 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...HIGH RIP CURRENT RISK THROUGH THIS EVENING FOR THE FOLLOWING ZONES: ARANSAS...CALHOUN...KLEBERG...NUECES. COASTAL FLOOD ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR THE FOLLOWING ZONES: ARANSAS...CALHOUN...KLEBERG...NUECES. GM...SMALL CRAFT ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR THE FOLLOWING ZONES: WATERS FROM BAFFIN BAY TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM. SMALL CRAFT ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR THE FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL OUT 20 NM. && $$ GW/86...SHORT TERM JM/75...LONG TERM
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
949 AM CST TUE NOV 13 2012 .DISCUSSION...EXTENDED MEASURABLE RAINFALL MORE NORTH FOR TODAY...BUT FOR NOW KEPT THE 20 POPS. BET PART OF RAIN CELL WENT JUST SOUTH OF KCOT WHERE THEY GOT A TRACE OF RAIN (AREAS SOUTH PROBABLY GOT A HUNDREDTH OR TWO). DID PUT THUNDER IN FOR THE WESTERN AREAS SINCE IT HAS BEEN A BIT OBSERVED FROM TIME TO TIME (PRETTY COOL ALOFT). OTHERWISE...MINOR CHANGES TO FIRST/SECOND PERIODS. && .MARINE...EXTENDED SCA FOR THE NEARSHORE TIL 3 PM. RUC13 AND NAM IS KEEPING 20-25 KNOT WINDS OVER THE NORTHEASTERN NEARSHORE THROUGH EARLY AFTERNOON...SO HAVE EXTENDED IT. LEFT SCA FOR OFFSHORE AS-IS. DID MENTION RAIN FOR LATE AFTERNOON/TONIGHT BUT NO THUNDER YET. WILL TAKE A LOOK AT LATER. && .PREV DISCUSSION... /ISSUED 832 AM CST TUE NOV 13 2012/ DISCUSSION...BASED ON RADAR TRENDS AND 4 KM MODEL OUTPUT FROM SPC AND TEX-TECH...HAVE DECIDED TO MENTION MEASURABLE RAINFALL IN THE FORECAST. RADAR IS SHOWING SOME 40-50 DBZ ECHOES IN THE BRUSH COUNTRY AND RIO GRANDE PLAINS HEADING TOWARD COTULLA. 4KM MODELS SHOWING SOME QPF (ISOLATED OVER 1/4 INCH...AM NOT SURE IT WILL BE THAT MUCH). THIS RAIN/SHOWERS IS FROM AN UPPER JET STREAK AND SUFFICIENT MOISTURE. GIVEN THE FACT THAT PWATS GET ABOVE 1 INCH LATER THIS AFTERNOON OVER THE SOUTHEAST...WILL GO WITH SOME LIGHT RAIN AND PUT SPRINKLES FARTHER NORTH WHERE MOISTURE IS MORE LIMITED. HAVE EVEN SEEN AN OCCASIONAL LIGHTNING STRIKE NW OF COTULLA BUT THINK THAT OUR AREA WILL SEE ESSENTIALLY ALL RAIN OR SPRINKLES AND THAT ELEVATED CONVECTION TOO LIMITED TO MENTION THUNDER AT THIS TIME (HOWEVER WILL MONITOR). PRODUCTS ARE OUT. PREV DISCUSSION... /ISSUED 537 AM CST TUE NOV 13 2012/ DISCUSSION...UPDATED FOR 12Z AVIATION. AVIATION...BROKEN/OVERCAST CEILINGS BETWEEN 8K AND 10K FEET ARE ANTICIPATED THROUGH THE MAJORITY OF THE TAF CYCLE. WINDS WILL GENERALLY BE LESS THAN 10 KNOTS...WITH A NORTHEASTERLY COMPONENT. LOW CONFIDENCE ON LIGHT RAIN/SPRINKLES LATER TODAY WILL PRECLUDE A MENTION IN THE TAFS ATTM. VFR FORECAST CONTINUES THE NEXT 24 HOURS. PREV DISCUSSION... /ISSUED 438 AM CST TUE NOV 13 2012/ SHORT TERM (TODAY THROUGH WEDNESDAY)...MORNING SATELLITE IMAGERY HAS STREAM OF MID AND LEVEL HIGH CLOUDS MOVING ACROSS SOUTH TEXAS. TEMPERATURES CURRENTLY ARE IN THE 40S AND 50 THIS MORNING AND DO NOT THINK TEMPS WILL FALL TOO MUCH MORE. WEAK SHORTWAVE/UPPER JET APPROACHES THE AREA TODAY...KEEPING MOSTLY CLOUDY CONDITIONS ACROSS SOUTH TEXAS. WITH NORTHEAST WINDS CONTINUING...TEMPS WILL ONLY CLIMB INTO THE 60S THIS AFTERNOON IN MOST LOCATIONS. DESPITE WEAK ISENTROPIC LIFT OVER THE AREA TODAY...THINK MEASURABLE PRECIP MAY BE DIFFICULT TO COME BY. ALSO...06Z MAV POPS HAVE COME IN LOWER THAN 00Z GUIDANCE AS WELL. PREFER TO CONTINUE WITH THE MENTION OF SPRINKLES INSTEAD OF LOW END POPS. UPPER DISTURBANCE TO PASS EAST OF THE AREA TODAY...WITH DRY NORTHWEST FLOW OVER THE REGION ON WEDNESDAY. SOME CLOUD COVER MAY LINGER INTO WEDNESDAY... BUT TEMPS SHOULD REBOUND A FEW DEGREES WITH UPPER 60S TO LOWER 70S FOR HIGHS. ALSO OF NOTE...MODERATE TO STRONG NORTHEAST WINDS WILL PERSIST TODAY OVER THE GULF WATERS. WITH SEAS STILL RUNNING 7 TO 9 FEET AND TIDE LEVEL RUNNING SLIGHTLY ABOVE PREDICTED...MINOR TIDAL OVERFLOW MAY OCCUR AT HIGH TIDE ALONG GULF BEACHES TODAY AND HAVE ISSUED A COASTAL FLOOD ADVISORY. MARINE...STRONG OFFSHORE FLOW WILL PERSIST OVER THE GULF WATERS THIS MORNING...WITH SCA CONDITIONS OVER THE NEAR AND OFFSHORE WATERS. WINDS WILL SLOWLY DECREASE BY THIS AFTERNOON TO BELOW SCA OVER THE NEAR SHORE WATERS...BUT SCA CONDITIONS WILL CONTINUE OVER THE OFFSHORE WATERS THROUGH TONIGHT AS SEAS REMAIN AROUND 7 FEET. LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...SLIGHTLY WARMER TEMPS CAN BE EXPECTED WED NIGHT AND THU AS THE AIRMASS BEGINS TO MODIFY. THE SRN EXTENT OF THE SFC HIGH IS PROGD TO REMAIN DRAPED ACROSS S TX THROUGH FRI RESULTING IN A GENERALLY LIGHT NE FLOW ACROSS THE AREA AND A WEAK TO MOD FLOW OVER THE COASTAL WATERS. THE FLOW BEGINS TO VEER TO THE E AND SE THRU THE WEEKEND AND THEN STRENGTHENS MON/TUE IN RESPONSE TO A LOW PRESSURE SYSTEM MOVG ACROSS THE CENTRAL PLAINS. THE ONSHORE FLOW WILL CONTINUE THE WARMING TREND INTO THE WEEKEND WITH HIGHS APPROACHING THE UPPER 70S TO LOW 80S BY SUNDAY. HAVE KNOCKED THE FCSTD TEMPS DOWN A COUPLE OF DEGREES SAT/SUN DUE TO PERSISTENT CLOUDS AND THE WINDS BLOWING ACROSS THE COOLER WATERS. WEAK ISENTROPIC UPGLIDE IS PROGD TO DVLP ACROSS THE RIO GRANDE PLAINS FRI WITH DEEPER MOISTURE SURGING NWD ALONG THE RIO GRANDE. THIS WILL COMBINE WITH AN EMBEDDED SHORT WAVE ALOFT TO BRING A SLIGHT CHC OF -SHRA`S TO THE RIO GRANDE PLAINS. KEPT THE SLIGHT CHC ACROSS THE SRN COASTAL BEND AS WELL DUE TO SLIGHTLY DEEPER MOISTURE AND THE SHORT WAVE ALTHOUGH ISENTROPIC DOWNGLIDE MAY PRECLUDE RAIN FARTHER E. SATURDAY IS PROGD TO BE A TAD DRIER...THEN ANOTHER SURGE OF MOISTURE MOVES INTO S TX ON SUN/MON TIME FRAME ALONG WITH A SERIES OF WEAK SHORT WAVES. THE GFS WAS PREVIOUSLY SHOWING DEEPER MOISTURE WITH BETTER DYNAMICS ON SUNDAY BUT THE LATEST RUN HAS PUSHED IT BACK INTO MON. DECIDED TO KEEP A BROAD BRUSHED SLIGHT CHC FOR BOTH DAYS FOR NOW. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 65 52 71 53 73 / 20 20 10 10 10 VICTORIA 63 42 68 41 72 / 10 10 10 10 10 LAREDO 66 51 72 55 75 / 20 20 10 10 10 ALICE 65 48 71 48 75 / 20 20 10 10 10 ROCKPORT 65 52 69 57 73 / 10 20 10 10 10 COTULLA 63 45 68 49 72 / 20 10 10 10 10 KINGSVILLE 66 49 71 52 75 / 20 20 10 10 10 NAVY CORPUS 66 55 70 56 72 / 20 20 10 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...HIGH RIP CURRENT RISK THROUGH THIS EVENING FOR THE FOLLOWING ZONES: ARANSAS...CALHOUN...KLEBERG...NUECES. COASTAL FLOOD ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR THE FOLLOWING ZONES: ARANSAS...CALHOUN...KLEBERG...NUECES. GM...SMALL CRAFT ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR THE FOLLOWING ZONES: WATERS FROM BAFFIN BAY TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM. SMALL CRAFT ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR THE FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL OUT 20 NM. && $$ GW/86...SHORT TERM JM/75...LONG TERM
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1258 PM EST TUE NOV 13 2012 .SYNOPSIS... A STRONG COLD FRONT EXTENDED FROM NEW ENGLAND INTO THE NORTHERN GULF OF MEXICO. THIS FRONT WILL MOVE OFFSHORE BY THIS EVENING WITH HIGH PRESSURE COVERING THE EASTERN HALF OF THE COUNTRY ON WEDNESDAY. ANOTHER LOW WILL DEVELOP ALONG THE OLD COLD FRONT ON FRIDAY AND SATURDAY OFF THE SOUTHEAST COAST. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1015 AM EST TUESDAY... SATELLITE IMAGERY INDICATES A VERY SHARP GRADIENT TO THE CLOUD COVER ACROSS THE PIEDMONTS THIS MORNING...WITH MOSTLY CLEAR SKIES WEST OF A STOKES COUNTY NC TO AMHERST COUNTY VA LINE...WHILE CLOUDY SKIES ARE OBSERVED TO THE EAST. THESE CLOUDS...AND THE LINGERING SHOWER ACTIVITY WITHIN...ARE MAKING STEADY PROGRESS TO THE EAST THIS MORNING...AND EXPECT THESE REMAINING CLOUDS TO BE OUT OF OUR AREA DURING EARLY AFTERNOON. WITH COLDER AIR CONTINUING TO BUILD IN WITH HIGH PRESSURE TO OUR WEST...AFTERNOON TEMPERATURES WILL BE SIGNIFICANTLY LOWER THAN YESTERDAY...AND EXPECT HIGHS FOR TODAY TO RANGE FROM THE LOW TO MID 40S ACROSS THE MOUNTAINS...TO THE UPPER 40S ACROSS THE PIEDMONTS. AS OF 445 AM EST TUESDAY... AT 4AM COLD FRONT EXTENDED FROM VERMONT INTO SOUTHEAST VIRGINIA. SURFACE DEW POINTS HAD DROPPED INTO THE 30S AND 40S ACROSS THE COUNTY WARNING AREA. DRY AIR WILL CONTINUE TO WORK INTO THE REGION SHORT WAVE AXIS CROSSING THROUGH THE OHIO VALLEY WILL LOWER 850 TEMPERATURES OVER THE MOUNTAINS TODAY AND WILL TURN SURFACE WINDS TO THE NORTH TONIGHT. 00Z LOCAL WRF ALONG WITH THE LATEST RUC AND SREF GUIDANCE HELD PRECIPITATION IN THE FAR SOUTHEAST COUNTY WARNING AREA THIS MORNING...BUT ALL MODELS SHOWED DRY WEATHER AFTER 18Z/1PM. NARROW BAND OF STRATUS IN THE WESTERN UPSLOPE AREA FROM WEST VIRGINIA INTO TENNESSEE IS ALSO FORECAST TO DISSIPATE BY THIS AFTERNOON. WITH THE WEAK COLD AIR ADVECTION AND STARTING OUT WITH EXTENSIVE CLOUD COVER THIS MORNING HAVE USED COOLER MAV GUIDANCE AS A STARTING POINT FOR MAXIMUM TEMPERATURES TODAY. HIGH PRESSURE BUILDS IN TONIGHT AND PRESSURE GRADIENT WEAKENS. WITH A CLEAR SKY AND SURFACE DEW POINTS IN THE 20S AND 30S...AGAIN TRENDED TOWARD COLDER MAV GUIDANCE FOR OVERNIGHT LOWS. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/... AS OF 310 AM EST TUESDAY... THE FORECAST CHALLENGE DURING THIS PORTION OF THE FORECAST IS CENTERED AROUND THE POTENTIAL IMPACTS OF A SHORTWAVE TROUGH MOVING NORTH ALONG THE BACK SIDE OF A COLD FRONT ALONG THE ATLANTIC COAST. THE ECMWF FOR A FEW DAYS NOW HAS HAD THE BOLDEST SOLUTION ON BRINGING A SWATH OF PRECIPITATION THROUGH THE SOUTHEAST PORTION OF THE FORECAST AREA LATE WEDNESDAY NIGHT...THURSDAY...AND EVEN EARLY THURSDAY EVENING. THE NAM HAS HAD NOTHING TO DO WITH THIS SCENARIO. UNTIL THE 12Z...7AM MONDAY SOLUTION...THE GFS KEPT ANY ASSOCIATED PRECIPITATION SOUTHEAST OF THE REGION. AT THIS TIME...IT TOO HINTED AT SOME PRECIPITATION SKIRTING THE SOUTHEAST PORTION OF THE FORECAST AREA...BUT NOT TO THE DEGREE THE ECWMF SOLUTION DID. THE 00Z...7PM MONDAY...SOLUTIONS HAVE SHOWN THE FOLLOWING TRENDS. THE NAM STILL HAS NOTHING TO DO WITH PRECIPITATION REACHING THE FORECAST AREA. THE GFS IS NOT AS IMPRESSIVE WITH ITS COVERAGE OF PRECIPITATION AND IS PRIMARILY A THURSDAY EVENT NOW. THE ECMWF IS STILL THE BOLDEST WITH THE PRECIPITATION...BUT IT HAS SHIFTED THE PRECIPITATION MAXIMA SOUTHEAST...WITH VERY LITTLE OF IT SKIRTING THE FAR SOUTHEAST PART OF THE FORECAST AREA. TO KEEP A LEVEL OF CONSISTENCY...I DO NOT WANT TO MAKE TOO DRASTIC OF A CHANGE TO THE FORECAST. HOWEVER...GIVEN THE TRENDS...THE FORECAST WILL REFLECT A SLIGHTLY SMALLER CONFIDENCE IS PRECIPITATION ACROSS THE SOUTHERN AND SOUTHEASTERN PORTIONS OF THE FORECAST AREA LATE WEDNESDAY NIGHT THROUGH THURSDAY EVENING. OTHERWISE...LITTLE CHANGES HAVE BEEN MADE TO THE REMAINDER OF THE FORECAST DURING THIS TIME PERIOD. WE WILL STILL HAVE A DRY AND COLDER WEDNESDAY WITH LIMITED CLOUD COVER HAS HIGH PRESSURE MOVES INTO THE AREA BEHIND THE COLD FRONT. FRIDAY WILL STILL BE REPRESENTED BY A DRY FORECAST...BUT WITH THE APPROACH OF AN UPPER TROUGH...AND THE POTENTIAL FOR SOME MOIST NE 850 MB FLOW...HAVE CONTINUE TO REMAIN ON THE HIGH SIDE FOR CLOUD COVER. && .LONG TERM /SATURDAY THROUGH MONDAY/... AS OF 353 PM EST MONDAY... ALTHOUGH NOT AS PRONOUNCED AS THEIR ENSEMBLES...THE ECMWF AND TO A LESSER DEGREE THE GFS...ARE FURTHER WEST WITH A REX BLOCK/CLOSED UPPER LOW THAT FIRST PINCHES APART FROM THE UPPER FLOW ALONG THE SOUTHERN GREAT LAKES FRIDAY. THE TRACK OF THE UPPER LOW DOES GO AROUND OUR REGION...BUT THIS STILL MEANS AT LEAST A CHANCE OF RAIN...NUMEROUS CLOUDS AND CHILLY AIR AROUND FOR MUCH OF THE WEEKEND. FOLLOWING ITS BIAS...THE ECMWF MAY BE TOO FAR WEST WITH THE TRACK OF THE LOW...HOWEVER EVEN THE OPERATIONAL GFS THROWS QPF EAST OF THE BLUE RIDGE BY SUNDAY, THIS IS AT LEAST WORTH MENTIONABLE POPS GREATER THAN 24 PERCENT IN THE FVX/LYH/DAN CORRIDOR. OVER THE NEXT COUPLE OF DAYS OF MODEL RUNS...ITS PROBABLY MORE LIKELY THAT THE RAIN SHIELD WILL END UP FURTHER WEST INTO SW VA. IN THIS WEDGY REGIME WITH ENOUGH H85 RH...BOTH THE ECMWF MOS AND THE MEX MOS LOOK SEVERAL DEGREES TOO WARM ON HIGHS AND SEVERAL TOO COLD ON MINS. THEREFORE REDUCED THE DIURNAL RANGE OF TEMPS...WITH SOME SPOTS STUCK IN THE 40S FOR MAX T BOTH SATURDAY AND SUNDAY. STRUGGLING TO FIND ENOUGH COLD AIR FOR SNOW...PERHAPS ENOUGH UPSLOPE COOLING LATE AT NIGHT FOR SOME SNOW TO MIX IN ACROSS THE HIGHEST ELEVATIONS OF SE WEST VA OR NW NC. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... AS OF 1245 PM EST TUESDAY... SHOWER ACTIVITY HAS ALL BUT EXITED THE AREA THIS AFTERNOON...WITH THE LAST OF THE LOW CLOUD COVER EXPECTED TO EXIT FROM DAN AOA 13/19Z. ALL OTHER AIRPORTS ARE REPORTING CLEAR SKIES WITH A NORTHWESTERLY WIND IN THE 5KT TO 10KT RANGE. EXPECT THESE VFR CONDITIONS TO CONTINUE THROUGH THE REMAINDER OF THE 13/18Z TAF PERIOD. DESPITE MOIST SOIL CONDITIONS FROM WIDESPREAD RAINFALL ON MONDAY NIGHT/EARLY TUESDAY...DRY AIR BUILDING IN WITH HIGH PRESSURE WILL PREVENT ALL BUT ISOLATED LIGHT FOG FROM DEVELOPING. EXPECT WINDS TO GRADUALLY BECOME NORTHEASTERLY THROUGH THE EVENING AS HIGH PRESSURE SLIDES EAST ACROSS THE LOWER GREAT LAKES. HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH WEDNESDAY NIGHT WITH VFR CONDITIONS. ANOTHER WEAK LOW PRESSURE SYSTEM OFF THE SOUTHEAST COAST MAY BRING MVFR CIGS BACK TO THE REGION BY THURSDAY MORNING. A MORE ORGANIZED LOW WILL DEVELOP OFF THE SOUTHEAST COAST FRIDAY AND SATURDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/NF SHORT TERM...DS LONG TERM...KM AVIATION...AMS/NF
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1030 AM EST TUE NOV 13 2012 .SYNOPSIS... A STRONG COLD FRONT EXTENDED FROM NEW ENGLAND INTO THE NORTHERN GULF OF MEXICO. THIS FRONT WILL MOVE OFFSHORE BY THIS EVENING WITH HIGH PRESSURE COVERING THE EASTERN HALF OF THE COUNTRY ON WEDNESDAY. ANOTHER LOW WILL DEVELOP ALONG THE OLD COLD FRONT ON FRIDAY AND SATURDAY OFF THE SOUTHEAST COAST. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1015 AM EST TUESDAY... SATELLITE IMAGERY INDICATES A VERY SHARP GRADIENT TO THE CLOUD COVER ACROSS THE PIEDMONTS THIS MORNING...WITH MOSTLY CLEAR SKIES WEST OF A STOKES COUNTY NC TO AMHERST COUNTY VA LINE...WHILE CLOUDY SKIES ARE OBSERVED TO THE EAST. THESE CLOUDS...AND THE LINGERING SHOWER ACTIVITY WITHIN...ARE MAKING STEADY PROGRESS TO THE EAST THIS MORNING...AND EXPECT THESE REMAINING CLOUDS TO BE OUT OF OUR AREA DURING EARLY AFTERNOON. WITH COLDER AIR CONTINUING TO BUILD IN WITH HIGH PRESSURE TO OUR WEST...AFTERNOON TEMPERATURES WILL BE SIGNIFICANTLY LOWER THAN YESTERDAY...AND EXPECT HIGHS FOR TODAY TO RANGE FROM THE LOW TO MID 40S ACROSS THE MOUNTAINS...TO THE UPPER 40S ACROSS THE PIEDMONTS. AS OF 445 AM EST TUESDAY... AT 4AM COLD FRONT EXTENDED FROM VERMONT INTO SOUTHEAST VIRGINIA. SURFACE DEW POINTS HAD DROPPED INTO THE 30S AND 40S ACROSS THE COUNTY WARNING AREA. DRY AIR WILL CONTINUE TO WORK INTO THE REGION SHORT WAVE AXIS CROSSING THROUGH THE OHIO VALLEY WILL LOWER 850 TEMPERATURES OVER THE MOUNTAINS TODAY AND WILL TURN SURFACE WINDS TO THE NORTH TONIGHT. 00Z LOCAL WRF ALONG WITH THE LATEST RUC AND SREF GUIDANCE HELD PRECIPITATION IN THE FAR SOUTHEAST COUNTY WARNING AREA THIS MORNING...BUT ALL MODELS SHOWED DRY WEATHER AFTER 18Z/1PM. NARROW BAND OF STRATUS IN THE WESTERN UPSLOPE AREA FROM WEST VIRGINIA INTO TENNESSEE IS ALSO FORECAST TO DISSIPATE BY THIS AFTERNOON. WITH THE WEAK COLD AIR ADVECTION AND STARTING OUT WITH EXTENSIVE CLOUD COVER THIS MORNING HAVE USED COOLER MAV GUIDANCE AS A STARTING POINT FOR MAXIMUM TEMPERATURES TODAY. HIGH PRESSURE BUILDS IN TONIGHT AND PRESSURE GRADIENT WEAKENS. WITH A CLEAR SKY AND SURFACE DEW POINTS IN THE 20S AND 30S...AGAIN TRENDED TOWARD COLDER MAV GUIDANCE FOR OVERNIGHT LOWS. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/... AS OF 310 AM EST TUESDAY... THE FORECAST CHALLENGE DURING THIS PORTION OF THE FORECAST IS CENTERED AROUND THE POTENTIAL IMPACTS OF A SHORTWAVE TROUGH MOVING NORTH ALONG THE BACK SIDE OF A COLD FRONT ALONG THE ATLANTIC COAST. THE ECMWF FOR A FEW DAYS NOW HAS HAD THE BOLDEST SOLUTION ON BRINGING A SWATH OF PRECIPITATION THROUGH THE SOUTHEAST PORTION OF THE FORECAST AREA LATE WEDNESDAY NIGHT...THURSDAY...AND EVEN EARLY THURSDAY EVENING. THE NAM HAS HAD NOTHING TO DO WITH THIS SCENARIO. UNTIL THE 12Z...7AM MONDAY SOLUTION...THE GFS KEPT ANY ASSOCIATED PRECIPITATION SOUTHEAST OF THE REGION. AT THIS TIME...IT TOO HINTED AT SOME PRECIPITATION SKIRTING THE SOUTHEAST PORTION OF THE FORECAST AREA...BUT NOT TO THE DEGREE THE ECWMF SOLUTION DID. THE 00Z...7PM MONDAY...SOLUTIONS HAVE SHOWN THE FOLLOWING TRENDS. THE NAM STILL HAS NOTHING TO DO WITH PRECIPITATION REACHING THE FORECAST AREA. THE GFS IS NOT AS IMPRESSIVE WITH ITS COVERAGE OF PRECIPITATION AND IS PRIMARILY A THURSDAY EVENT NOW. THE ECMWF IS STILL THE BOLDEST WITH THE PRECIPITATION...BUT IT HAS SHIFTED THE PRECIPITATION MAXIMA SOUTHEAST...WITH VERY LITTLE OF IT SKIRTING THE FAR SOUTHEAST PART OF THE FORECAST AREA. TO KEEP A LEVEL OF CONSISTENCY...I DO NOT WANT TO MAKE TOO DRASTIC OF A CHANGE TO THE FORECAST. HOWEVER...GIVEN THE TRENDS...THE FORECAST WILL REFLECT A SLIGHTLY SMALLER CONFIDENCE IS PRECIPITATION ACROSS THE SOUTHERN AND SOUTHEASTERN PORTIONS OF THE FORECAST AREA LATE WEDNESDAY NIGHT THROUGH THURSDAY EVENING. OTHERWISE...LITTLE CHANGES HAVE BEEN MADE TO THE REMAINDER OF THE FORECAST DURING THIS TIME PERIOD. WE WILL STILL HAVE A DRY AND COLDER WEDNESDAY WITH LIMITED CLOUD COVER HAS HIGH PRESSURE MOVES INTO THE AREA BEHIND THE COLD FRONT. FRIDAY WILL STILL BE REPRESENTED BY A DRY FORECAST...BUT WITH THE APPROACH OF AN UPPER TROUGH...AND THE POTENTIAL FOR SOME MOIST NE 850 MB FLOW...HAVE CONTINUE TO REMAIN ON THE HIGH SIDE FOR CLOUD COVER. && .LONG TERM /SATURDAY THROUGH MONDAY/... AS OF 353 PM EST MONDAY... ALTHOUGH NOT AS PRONOUNCED AS THEIR ENSEMBLES...THE ECMWF AND TO A LESSER DEGREE THE GFS...ARE FURTHER WEST WITH A REX BLOCK/CLOSED UPPER LOW THAT FIRST PINCHES APART FROM THE UPPER FLOW ALONG THE SOUTHERN GREAT LAKES FRIDAY. THE TRACK OF THE UPPER LOW DOES GO AROUND OUR REGION...BUT THIS STILL MEANS AT LEAST A CHANCE OF RAIN...NUMEROUS CLOUDS AND CHILLY AIR AROUND FOR MUCH OF THE WEEKEND. FOLLOWING ITS BIAS...THE ECMWF MAY BE TOO FAR WEST WITH THE TRACK OF THE LOW...HOWEVER EVEN THE OPERATIONAL GFS THROWS QPF EAST OF THE BLUE RIDGE BY SUNDAY, THIS IS AT LEAST WORTH MENTIONABLE POPS GREATER THAN 24 PERCENT IN THE FVX/LYH/DAN CORRIDOR. OVER THE NEXT COUPLE OF DAYS OF MODEL RUNS...ITS PROBABLY MORE LIKELY THAT THE RAIN SHIELD WILL END UP FURTHER WEST INTO SW VA. IN THIS WEDGY REGIME WITH ENOUGH H85 RH...BOTH THE ECMWF MOS AND THE MEX MOS LOOK SEVERAL DEGREES TOO WARM ON HIGHS AND SEVERAL TOO COLD ON MINS. THEREFORE REDUCED THE DIURNAL RANGE OF TEMPS...WITH SOME SPOTS STUCK IN THE 40S FOR MAX T BOTH SATURDAY AND SUNDAY. STRUGGLING TO FIND ENOUGH COLD AIR FOR SNOW...PERHAPS ENOUGH UPSLOPE COOLING LATE AT NIGHT FOR SOME SNOW TO MIX IN ACROSS THE HIGHEST ELEVATIONS OF SE WEST VA OR NW NC. && .AVIATION /15Z TUESDAY THROUGH SATURDAY/... AS OF 710 AM EST TUESDAY... RADAR SHOWED BACK EDGE OF BAND OF LIGHT TO MODERATE SHOWERS THAT WERE ASSOCIATED WITH A COLD FRONT EAST OF A LINE FROM BUENA VISTA TO MARTINSVILLE. THE COLD FRONT AND SHOWERS WILL CONTINUE TO MOVE EAST THIS MORNING. MODELS WERE VERY SIMILAR WITH THE TIMING OF THE PRECIPITATION...ENDING IT AT LYH AND DAN BY 15Z/10AM. HIGH CONFIDENCE OF MVFR CEILINGS AND VISIBILITIES WITH THE SHOWERS. CLOUDS WILL CLEAR OUT QUICKLY BEHIND THE PRECIPITATION. EXPECT ROA/LYH AND DAN TO BE VFR BY 17Z/NOON. NORTHWEST SURFACE AND LOW LEVEL UPSLOPE WINDS IN THE MOUNTAINS WEAKEN TODAY AND TURN TO THE NORTH...SO EVEN BLF AND LWB WILL BE VFR BY 18Z/1PM. HIGH PRESSURE WILL BE OVER THE REGION TONIGHT THROUGH WEDNESDAY NIGHT WITH VFR CONDITIONS. ANOTHER WEAK LOW PRESSURE SYSTEM OFF THE SOUTHEAST COAST MAY BRING MVFR CIGS BACK TO THE REGION BY THURSDAY MORNING. A MORE ORGANIZED LOW WILL DEVELOP OFF THE SOUTHEAST COAST FRIDAY AND SATURDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/NF SHORT TERM...DS LONG TERM...KM AVIATION...AMS/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
717 AM EST TUE NOV 13 2012 .SYNOPSIS... A STRONG COLD FRONT EXTENDED FROM NEW ENGLAND INTO THE NORTHERN GULF OF MEXICO. THIS FRONT WILL MOVE OFFSHORE BY THIS EVENING WITH HIGH PRESSURE COVERING THE EASTERN HALF OF THE COUNTRY ON WEDNESDAY. ANOTHER LOW WILL DEVELOP ALONG THE OLD COLD FRONT ON FRIDAY AND SATURDAY OFF THE SOUTHEAST COAST. && .NEAR TERM /THROUGH TONIGHT/... AS OF 445 AM EST TUESDAY... AT 4AM COLD FRONT EXTENDED FROM VERMONT INTO SOUTHEAST VIRGINIA. SURFACE DEW POINTS HAD DROPPED INTO THE 30S AND 40S ACROSS THE COUNTY WARNING AREA. DRY AIR WILL CONTINUE TO WORK INTO THE REGION SHORT WAVE AXIS CROSSING THROUGH THE OHIO VALLEY WILL LOWER 850 TEMPERATURES OVER THE MOUNTAINS TODAY AND WILL TURN SURFACE WINDS TO THE NORTH TONIGHT. 00Z LOCAL WRF ALONG WITH THE LATEST RUC AND SREF GUIDANCE HELD PRECIPITATION IN THE FAR SOUTHEAST COUNTY WARNING AREA THIS MORNING...BUT ALL MODELS SHOWED DRY WEATHER AFTER 18Z/1PM. NARROW BAND OF STRATUS IN THE WESTERN UPSLOPE AREA FROM WEST VIRGINIA INTO TENNESSEE IS ALSO FORECAST TO DISSIPATE BY THIS AFTERNOON. WITH THE WEAK COLD AIR ADVECTION AND STARTING OUT WITH EXTENSIVE CLOUD COVER THIS MORNING HAVE USED COOLER MAV GUIDANCE AS A STARTING POINT FOR MAXIMUM TEMPERATURES TODAY. HIGH PRESSURE BUILDS IN TONIGHT AND PRESSURE GRADIENT WEAKENS. WITH A CLEAR SKY AND SURFACE DEW POINTS IN THE 20S AND 30S...AGAIN TRENDED TOWARD COLDER MAV GUIDANCE FOR OVERNIGHT LOWS. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/... AS OF 310 AM EST TUESDAY... THE FORECAST CHALLENGE DURING THIS PORTION OF THE FORECAST IS CENTERED AROUND THE POTENTIAL IMPACTS OF A SHORTWAVE TROUGH MOVING NORTH ALONG THE BACK SIDE OF A COLD FRONT ALONG THE ATLANTIC COAST. THE ECMWF FOR A FEW DAYS NOW HAS HAD THE BOLDEST SOLUTION ON BRINGING A SWATH OF PRECIPITATION THROUGH THE SOUTHEAST PORTION OF THE FORECAST AREA LATE WEDNESDAY NIGHT...THURSDAY...AND EVEN EARLY THURSDAY EVENING. THE NAM HAS HAD NOTHING TO DO WITH THIS SCENARIO. UNTIL THE 12Z...7AM MONDAY SOLUTION...THE GFS KEPT ANY ASSOCIATED PRECIPITATION SOUTHEAST OF THE REGION. AT THIS TIME...IT TOO HINTED AT SOME PRECIPITATION SKIRTING THE SOUTHEAST PORTION OF THE FORECAST AREA...BUT NOT TO THE DEGREE THE ECWMF SOLUTION DID. THE 00Z...7PM MONDAY...SOLUTIONS HAVE SHOWN THE FOLLOWING TRENDS. THE NAM STILL HAS NOTHING TO DO WITH PRECIPITATION REACHING THE FORECAST AREA. THE GFS IS NOT AS IMPRESSIVE WITH ITS COVERAGE OF PRECIPITATION AND IS PRIMARILY A THURSDAY EVENT NOW. THE ECMWF IS STILL THE BOLDEST WITH THE PRECIPITATION...BUT IT HAS SHIFTED THE PRECIPITATION MAXIMA SOUTHEAST...WITH VERY LITTLE OF IT SKIRTING THE FAR SOUTHEAST PART OF THE FORECAST AREA. TO KEEP A LEVEL OF CONSISTENCY...I DO NOT WANT TO MAKE TOO DRASTIC OF A CHANGE TO THE FORECAST. HOWEVER...GIVEN THE TRENDS...THE FORECAST WILL REFLECT A SLIGHTLY SMALLER CONFIDENCE IS PRECIPITATION ACROSS THE SOUTHERN AND SOUTHEASTERN PORTIONS OF THE FORECAST AREA LATE WEDNESDAY NIGHT THROUGH THURSDAY EVENING. OTHERWISE...LITTLE CHANGES HAVE BEEN MADE TO THE REMAINDER OF THE FORECAST DURING THIS TIME PERIOD. WE WILL STILL HAVE A DRY AND COLDER WEDNESDAY WITH LIMITED CLOUD COVER HAS HIGH PRESSURE MOVES INTO THE AREA BEHIND THE COLD FRONT. FRIDAY WILL STILL BE REPRESENTED BY A DRY FORECAST...BUT WITH THE APPROACH OF AN UPPER TROUGH...AND THE POTENTIAL FOR SOME MOIST NE 850 MB FLOW...HAVE CONTINUE TO REMAIN ON THE HIGH SIDE FOR CLOUD COVER. && .LONG TERM /SATURDAY THROUGH MONDAY/... AS OF 353 PM EST MONDAY... ALTHOUGH NOT AS PRONOUNCED AS THEIR ENSEMBLES...THE ECMWF AND TO A LESSER DEGREE THE GFS...ARE FURTHER WEST WITH A REX BLOCK/CLOSED UPPER LOW THAT FIRST PINCHES APART FROM THE UPPER FLOW ALONG THE SOUTHERN GREAT LAKES FRIDAY. THE TRACK OF THE UPPER LOW DOES GO AROUND OUR REGION...BUT THIS STILL MEANS AT LEAST A CHANCE OF RAIN...NUMEROUS CLOUDS AND CHILLY AIR AROUND FOR MUCH OF THE WEEKEND. FOLLOWING ITS BIAS...THE ECMWF MAY BE TOO FAR WEST WITH THE TRACK OF THE LOW...HOWEVER EVEN THE OPERATIONAL GFS THROWS QPF EAST OF THE BLUE RIDGE BY SUNDAY, THIS IS AT LEAST WORTH MENTIONABLE POPS GREATER THAN 24 PERCENT IN THE FVX/LYH/DAN CORRIDOR. OVER THE NEXT COUPLE OF DAYS OF MODEL RUNS...ITS PROBABLY MORE LIKELY THAT THE RAIN SHIELD WILL END UP FURTHER WEST INTO SW VA. IN THIS WEDGY REGIME WITH ENOUGH H85 RH...BOTH THE ECMWF MOS AND THE MEX MOS LOOK SEVERAL DEGREES TOO WARM ON HIGHS AND SEVERAL TOO COLD ON MINS. THEREFORE REDUCED THE DIURNAL RANGE OF TEMPS...WITH SOME SPOTS STUCK IN THE 40S FOR MAX T BOTH SATURDAY AND SUNDAY. STRUGGLING TO FIND ENOUGH COLD AIR FOR SNOW...PERHAPS ENOUGH UPSLOPE COOLING LATE AT NIGHT FOR SOME SNOW TO MIX IN ACROSS THE HIGHEST ELEVATIONS OF SE WEST VA OR NW NC. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... AS OF 710 AM EST TUESDAY... RADAR SHOWED BACK EDGE OF BAND OF LIGHT TO MODERATE SHOWERS THAT WERE ASSOCIATED WITH A COLD FRONT EAST OF A LINE FROM BUENA VISTA TO MARTINSVILLE. THE COLD FRONT AND SHOWERS WILL CONTINUE TO MOVE EAST THIS MORNING. MODELS WERE VERY SIMILAR WITH THE TIMING OF THE PRECIPITATION...ENDING IT AT LYH AND DAN BY 15Z/10AM. HIGH CONFIDENCE OF MVFR CEILINGS AND VISIBILITIES WITH THE SHOWERS. CLOUDS WILL CLEAR OUT QUICKLY BEHIND THE PRECIPITATION. EXPECT ROA/LYH AND DAN TO BE VFR BY 17Z/NOON. NORTHWEST SURFACE AND LOW LEVEL UPSLOPE WINDS IN THE MOUNTAINS WEAKEN TODAY AND TURN TO THE NORTH...SO EVEN BLF AND LWB WILL BE VFR BY 18Z/1PM. HIGH PRESSURE WILL BE OVER THE REGION TONIGHT THROUGH WEDNESDAY NIGHT WITH VFR CONDITIONS. ANOTHER WEAK LOW PRESSURE SYSTEM OFF THE SOUTHEAST COAST MAY BRING MVFR CIGS BACK TO THE REGION BY THURSDAY MORNING. A MORE ORGANIZED LOW WILL DEVELOP OFF THE SOUTHEAST COAST FRIDAY AND SATURDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS SHORT TERM...DS LONG TERM...KM AVIATION...AMS/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
459 AM EST TUE NOV 13 2012 .SYNOPSIS... A STRONG COLD FRONT EXTENDED FROM NEW ENGLAND INTO THE NORTHERN GULF OF MEXICO. THIS FRONT WILL MOVE OFFSHORE BY THIS EVENING WITH HIGH PRESSURE COVERING THE EASTERN HALF OF THE COUNTRY ON WEDNESDAY. ANOTHER LOW WILL DEVELOP ALONG THE OLD COLD FRONT ON FRIDAY AND SATURDAY OFF THE SOUTHEAST COAST. && .NEAR TERM /THROUGH TONIGHT/... AS OF 445 AM EST TUESDAY... AT 4AM COLD FRONT EXTENDED FROM VERMONT INTO SOUTHEAST VIRGINIA. SURFACE DEW POINTS HAD DROPPED INTO THE 30S AND 40S ACROSS THE COUNTY WARNING AREA. DRY AIR WILL CONTINUE TO WORK INTO THE REGION SHORT WAVE AXIS CROSSING THROUGH THE OHIO VALLEY WILL LOWER 850 TEMPERATURES OVER THE MOUNTAINS TODAY AND WILL TURN SURFACE WINDS TO THE NORTH TONIGHT. 00Z LOCAL WRF ALONG WITH THE LATEST RUC AND SREF GUIDANCE HELD PRECIPITATION IN THE FAR SOUTHEAST COUNTY WARNING AREA THIS MORNING...BUT ALL MODELS SHOWED DRY WEATHER AFTER 18Z/1PM. NARROW BAND OF STRATUS IN THE WESTERN UPSLOPE AREA FROM WEST VIRGINIA INTO TENNESSEE IS ALSO FORECAST TO DISSIPATE BY THIS AFTERNOON. WITH THE WEAK COLD AIR ADVECTION AND STARTING OUT WITH EXTENSIVE CLOUD COVER THIS MORNING HAVE USED COOLER MAV GUIDANCE AS A STARTING POINT FOR MAXIMUM TEMPERATURES TODAY. HIGH PRESSURE BUILDS IN TONIGHT AND PRESSURE GRADIENT WEAKENS. WITH A CLEAR SKY AND SURFACE DEW POINTS IN THE 20S AND 30S...AGAIN TRENDED TOWARD COLDER MAV GUIDANCE FOR OVERNIGHT LOWS. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/... AS OF 310 AM EST TUESDAY... THE FORECAST CHALLENGE DURING THIS PORTION OF THE FORECAST IS CENTERED AROUND THE POTENTIAL IMPACTS OF A SHORTWAVE TROUGH MOVING NORTH ALONG THE BACK SIDE OF A COLD FRONT ALONG THE ATLANTIC COAST. THE ECMWF FOR A FEW DAYS NOW HAS HAD THE BOLDEST SOLUTION ON BRINGING A SWATH OF PRECIPITATION THROUGH THE SOUTHEAST PORTION OF THE FORECAST AREA LATE WEDNESDAY NIGHT...THURSDAY...AND EVEN EARLY THURSDAY EVENING. THE NAM HAS HAD NOTHING TO DO WITH THIS SCENARIO. UNTIL THE 12Z...7AM MONDAY SOLUTION...THE GFS KEPT ANY ASSOCIATED PRECIPITATION SOUTHEAST OF THE REGION. AT THIS TIME...IT TOO HINTED AT SOME PRECIPITATION SKIRTING THE SOUTHEAST PORTION OF THE FORECAST AREA...BUT NOT TO THE DEGREE THE ECWMF SOLUTION DID. THE 00Z...7PM MONDAY...SOLUTIONS HAVE SHOWN THE FOLLOWING TRENDS. THE NAM STILL HAS NOTHING TO DO WITH PRECIPITATION REACHING THE FORECAST AREA. THE GFS IS NOT AS IMPRESSIVE WITH ITS COVERAGE OF PRECIPITATION AND IS PRIMARILY A THURSDAY EVENT NOW. THE ECMWF IS STILL THE BOLDEST WITH THE PRECIPITATION...BUT IT HAS SHIFTED THE PRECIPITATION MAXIMA SOUTHEAST...WITH VERY LITTLE OF IT SKIRTING THE FAR SOUTHEAST PART OF THE FORECAST AREA. TO KEEP A LEVEL OF CONSISTENCY...I DO NOT WANT TO MAKE TOO DRASTIC OF A CHANGE TO THE FORECAST. HOWEVER...GIVEN THE TRENDS...THE FORECAST WILL REFLECT A SLIGHTLY SMALLER CONFIDENCE IS PRECIPITATION ACROSS THE SOUTHERN AND SOUTHEASTERN PORTIONS OF THE FORECAST AREA LATE WEDNESDAY NIGHT THROUGH THURSDAY EVENING. OTHERWISE...LITTLE CHANGES HAVE BEEN MADE TO THE REMAINDER OF THE FORECAST DURING THIS TIME PERIOD. WE WILL STILL HAVE A DRY AND COLDER WEDNESDAY WITH LIMITED CLOUD COVER HAS HIGH PRESSURE MOVES INTO THE AREA BEHIND THE COLD FRONT. FRIDAY WILL STILL BE REPRESENTED BY A DRY FORECAST...BUT WITH THE APPROACH OF AN UPPER TROUGH...AND THE POTENTIAL FOR SOME MOIST NE 850 MB FLOW...HAVE CONTINUE TO REMAIN ON THE HIGH SIDE FOR CLOUD COVER. && .LONG TERM /SATURDAY THROUGH MONDAY/... AS OF 353 PM EST MONDAY... ALTHOUGH NOT AS PRONOUNCED AS THEIR ENSEMBLES...THE ECMWF AND TO A LESSER DEGREE THE GFS...ARE FURTHER WEST WITH A REX BLOCK/CLOSED UPPER LOW THAT FIRST PINCHES APART FROM THE UPPER FLOW ALONG THE SOUTHERN GREAT LAKES FRIDAY. THE TRACK OF THE UPPER LOW DOES GO AROUND OUR REGION...BUT THIS STILL MEANS AT LEAST A CHANCE OF RAIN...NUMEROUS CLOUDS AND CHILLY AIR AROUND FOR MUCH OF THE WEEKEND. FOLLOWING ITS BIAS...THE ECMWF MAY BE TOO FAR WEST WITH THE TRACK OF THE LOW...HOWEVER EVEN THE OPERATIONAL GFS THROWS QPF EAST OF THE BLUE RIDGE BY SUNDAY, THIS IS AT LEAST WORTH MENTIONABLE POPS GREATER THAN 24 PERCENT IN THE FVX/LYH/DAN CORRIDOR. OVER THE NEXT COUPLE OF DAYS OF MODEL RUNS...ITS PROBABLY MORE LIKELY THAT THE RAIN SHIELD WILL END UP FURTHER WEST INTO SW VA. IN THIS WEDGY REGIME WITH ENOUGH H85 RH...BOTH THE ECMWF MOS AND THE MEX MOS LOOK SEVERAL DEGREES TOO WARM ON HIGHS AND SEVERAL TOO COLD ON MINS. THEREFORE REDUCED THE DIURNAL RANGE OF TEMPS...WITH SOME SPOTS STUCK IN THE 40S FOR MAX T BOTH SATURDAY AND SUNDAY. STRUGGLING TO FIND ENOUGH COLD AIR FOR SNOW...PERHAPS ENOUGH UPSLOPE COOLING LATE AT NIGHT FOR SOME SNOW TO MIX IN ACROSS THE HIGHEST ELEVATIONS OF SE WEST VA OR NW NC. && .AVIATION /10Z TUESDAY THROUGH SATURDAY/... AS OF 745 PM EST MONDAY... FRONTAL SYSTEM AT THIS HOUR ROUGHLY ALONG A LINE FROM EKN-BLF-MKJ. SCT-BKN -SHRA ACTIVITY NOTED GENERALLY JUST AHEAD TO ABOUT 50 MILES BEHIND THE FRONT. ACTIVITY CONTINUES TO BREAK UP AS IT CROSSES THE MOUNTAINS. WOULD EXPECT THIS TREND TO CONTINUE...WITH ONLY SCT ACTIVITY REACHING THE LYH-DAN AREA. EXPECT MVFR CIGS FOR SEVERAL HOURS FOLLOWING FRONTAL PASSAGE...BUT ONLY A LIMITED PERIOD OF MVFR VSBYS EXPECTED IN -SHRA...AFTERWARD VFR VSBYS. FRONT SHOULD REACH BCB 02-03Z...ROA 03-04Z...AND LYH- DAN IN THE 05-06Z TIME FRAME. WINDS MOSTLY IN THE 170-190 RANGE AT 7-10KTS WITH SOME LOW END GUSTS IN ADVANCE OF THE FRONT...BECOMING W-NW BEHIND THE FRONT...MOSTLY 5-8KTS. SOME LOW END GUSTS AND SUSTAINED WINDS NEAR 10KTS EXPECTED FOR 1-2 HOURS BEHIND THE FRONTAL PASSAGE. LOW CLOUDS WILL BREAK UP LYH-DAN LATE TONIGHT/EARLY TUE...BUT SHOULD HANG ON MUCH OF THE DAY FROM UPSLOPE FLOW AND CAA LWB-BLF...BREAKING UP BY AFTERNOON. SOUTHERN STREAM SYSTEM WILL START TO SPREAD MID-HIGH CLOUDS ACROSS SE SECTIONS OF THE FORECAST AREA BY AFTERNOON. EXPECT VFR CONDITIONS THROUGH WEDNESDAY NIGHT AS HIGH PRESSURE RETURNS. ANOTHER WEAK LOW PRESSURE SYSTEM OFF THE SOUTHEAST COAST MAY BRING MVFR CIGS BACK TO THE REGION BY THURSDAY MORNING. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS SHORT TERM...DS LONG TERM...KM AVIATION...RAB
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
241 PM CST TUE NOV 13 2012 .SHORT TERM...THROUGH FRIDAY 241 PM CST TUE NOV 13 2012 MAIN FORECAST CONCERN REMAINS ON CLOUDS AND TEMPERATURES...ALONG WITH SMALL PRECIPITATION POTENTIAL...WITH THE GENERALLY QUIET WEATHER PATTERN IN PLACE NOW. CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHTS SHOWED NEARLY ZONAL FLOW ACROSS THE U.S....WITH A PERTURBATION IN THE FLOW OVER WESTERN PORTIONS OF NEBRASKA AND KANSAS ASSOCIATED WITH A SHORTWAVE TROUGH. ANOTHER WEAKER SHORTWAVE WAS NOTED OVER NORTH DAKOTA. THE ZONAL FLOW HAS HELPED TO SPREAD WARMER AIR INTO THE FORECAST AREA...REFLECTED BY THE 12Z MPX SOUNDING 850MB TEMP WHICH CLIMBED FROM -13C AT 00Z TO -6C AT 12Z. EVEN WARMER AIR WAS PRESENT TO THE WEST AT BIS AND ABR WHICH WERE AROUND -1C. THE COMBINATION OF THIS WARMER AIR ALOFT...FULL SUNSHINE FOR MUCH OF THE DAY...AND DRY AIR SHOWN TOO ON THE 12Z MPX SOUNDING HAS HELPED TEMPERATURES REBOUND INTO THE 30S AFTER A CHILLY DAY YESTERDAY. SATELLITE IMAGERY AND SURFACE OBS SHOWED A MASS OF MID AND HIGH CLOUDS SPREADING EAST FROM THE DAKOTAS INTO MINNESOTA AND IOWA....DOWNSTREAM OF THE TWO SHORTWAVES IN THE PLAINS. RADAR IMAGERY EVEN HAS SOME LIGHT DBZ ECHOES BUT ARE ALL JUST VIRGA DUE TO DRY LOW LEVEL AIR IN PLACE. AT THE SURFACE...A RIDGE OF HIGH PRESSURE EXTENDED FROM CHICAGO TO NORTHEAST TEXAS WHILE A SURFACE TROUGH EXTENDED FROM NORTHWEST ONTARIO TO PIERRE SOUTH DAKOTA. TONIGHT AND WEDNESDAY...THE WEAK SHORTWAVE OVER NORTH DAKOTA IS SLATED TO CROSS NORTHERN MINNESOTA AND INTO WESTERN LAKE SUPERIOR BY 12Z WEDNESDAY. GIVEN THE TRACK...BEST UPPER LEVEL PV ADVECTION STAYS OFF TO OUR NORTH. WE DO HAVE A WARM ADVECTION PATTERN IN PLACE...AND 285-295K ISENTROPIC LIFT PLOTS REFLECT THAT. THE BEST ISENTROPIC LIFT IS FORECAST TO OCCUR OVER THE FORECAST AREA...BUT THE LOWER CONDENSATION PRESSURE DEFICITS ARE MOSTLY TO THE NORTH OF THE LIFT. IF THERE IS ANY JUXTAPOSITION OF THE LIFT AND MOISTURE IS ALONG A STRETCH BETWEEN RED WING AND TAYLOR COUNTY INTO NORTHEAST WISCONSIN. MOST 13.12Z MODEL QPF OUTPUT FROM THE NAM...GFS AND ECMWF AS WELL AS THE 13.15Z SREF MEAN SUGGEST A DRY FORECAST LIKE WE HAD GOING...BUT THE 13.12Z GEM REGIONAL DOES HAVE LIGHT QPF. THINK THERE IS ENOUGH SUGGESTION FROM THE MODELS TO HAVE AT LEAST A FLURRY MENTION. NOTE...THOUGH...THERE IS A WARM LAYER AROUND 2000 FT WHICH COULD MELT THE FLURRIES INTO SPRINKLES. WET-BULBING IS POSSIBLE...BUT WOULD NOT BE APPROPRIATE GIVEN THE WEAK LIFT. MAY HAVE TO WATCH FOR THE SPRINKLES TO FREEZE IF THE SURFACE TEMPERATURE CANNOT CLIMB ABOVE FREEZING. OUTSIDE OF THIS VERY SMALL PRECIPITATION POTENTIAL...THE MID AND HIGH CLOUDS SEEN OVER THE DAKOTAS WILL SPREAD INTO THE AREA TONIGHT...THOUGH...WITH PARTIAL CLEARING PROGGED TO OCCUR WEST TO EAST DURING THE DAY WEDNESDAY IN THE WAKE OF THE SHORTWAVE. EXPECT WARMER TEMPERATURES TONIGHT THANKS TO THE CLOUDS...BUT THE SLIGHTLY LATER ARRIVAL FOR THEM IN WISCONSIN COULD ALLOW THE TYPICAL COLD SPOTS TO DROP INTO THE MID 20S BEFORE CLIMBING. MOST OTHER LOCATIONS SHOULD BE NEAR 30 FOR LOWS. WARMER 850MB TEMPS ON WEDNESDAY OF 0-2C COMBINED WITH SOME SUNSHINE SHOULD YIELD WARMER HIGHS AS WELL. A BLEND OF GUIDANCE SEEMED REASONABLE...YIELDING MID 40S TO LOW 50S. WEDNESDAY NIGHT AND THURSDAY...MODELS DEPICT A POTENT SHORTWAVE TROUGH...CURRENTLY NEAR THE ALASKA/YUKON BORDER...TO DROP DOWN INTO SASKATCHEWAN AND MANITOBA BY LATE WEDNESDAY. THIS POTENT SHORTWAVE HEADS UP INTO HUDSON BAY BY LATE THURSDAY. ALTHOUGH THE SHORTWAVE IS FAR FROM US...THERE IS A WEAKER SOUTHERN EXTENSION OF THE SHORTWAVE THAT DROPS SOUTHEAST THROUGH THE AREA ON THURSDAY. A WEAK COLD FRONT LOOKS TO ACCOMPANY THIS SHORTWAVE AT THE SURFACE. SIMILAR TO THE SHORTWAVE CROSSING NORTH DAKOTA TONIGHT...THERE IS A WARM ADVECTION PATTERN IN PLACE WITH AN AREA OF MID AND HIGH CLOUDS LIKELY TO SPREAD ACROSS AHEAD OF THE SHORTWAVE. HOWEVER...ISENTROPIC LIFT FIELDS THIS TIME DO NOT DEPICT ANY LIFT. IN ADDITION...THE SUB-CLOUD LAYER REMAINS DRY ACCORDING TO FORECAST SOUNDINGS. THUS...THE DRY FORECAST REMAINS. ALSO SIMILAR TO TONIGHT...THERE IS A PERIOD OF PARTIAL CLEARING WEDNESDAY EVENING BEFORE MORE EXTENSIVE CLOUDS COME IN TO ALLOW TEMPERATURES TO DROP OFF. THUS...SOME SITES IN WESTERN WISCONSIN AGAIN COULD DIP INTO THE UPPER 20S BEFORE CLIMBING WITH THE CLOUD INCREASE. LOWER TO MID 30S LOWS SHOULD BE TYPICAL ELSEWHERE. SOME AFTERNOON SUN ON THURSDAY COMBINED WITH 850MB TEMPS AGAIN IN THE 0-2C RANGE SHOULD ALLOW FOR HIGHS AGAIN IN THE MID 40S TO LOW 50S. THURSDAY NIGHT AND FRIDAY...IN THE WAKE OF THE WEDNESDAY NIGHT/THURSDAY SHORTWAVE TROUGH...GOOD MODEL AGREEMENT EXISTS OF STRENGTHENING UPPER AND SURFACE RIDGING BUILDING INTO THE FORECAST AREA. BY 12Z FRIDAY...MUCH OF THE AREA IS ENCOMPASSED BY A SURFACE HIGH PRESSURE RIDGE. CLEARING SKIES AND SUBSIDENCE IN THE WAKE OF THE SHORTWAVE TROUGH...COMBINED WITH DRY AIR NOTED BY PRECIPITABLE WATER VALUES FALLING TO NEAR ONE THIRD OF AN INCH AND LIGHT WINDS SHOULD SUPPORT GOOD RADIATIONAL COOLING CONDITIONS. THUS...STAYED TOWARDS THE LOW END OF GUIDANCE...ESPECIALLY AT THE TYPICAL COLD SPOTS IN WISCONSIN WHICH COULD DIP INTO THE LOWER 20S. SUNNY SKIES ON FRIDAY COMBINED WITH DRY AIR AND 850MB TEMPS AROUND 0C SHOULD LEAD TO A DECENT TEMPERATURE RISE. FOLLOWED A BLEND OF GUIDANCE WITH HIGHS IN THE 40S WHICH SEEMED REASONABLE...WARMEST OVER THE SOUTHERN HALF OF THE AREA WHERE SLIGHTLY WARMER 925MB TEMPS EXIST. .LONG TERM...FRIDAY NIGHT THROUGH TUESDAY 241 PM CST TUE NOV 13 2012 13.12Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES CONTINUE TO SHOW UPPER AND SURFACE RIDGING PRETTY MUCH DOMINATING THE AREA THROUGH THE WEEKEND. THIS IS AHEAD OF A DEEP EAST PACIFIC TROUGH AND SOME WEAK SUBTROPICAL SHORTWAVES LIFTING OUT OF THE FOUR CORNERS REGION AND INTO THE NORTHERN PLAINS. THIS SETUP SHOULD KEEP THE AREA DRY WITH TEMPERATURES GRADUALLY WARMING AS THE SURFACE HIGH FROM FRIDAY JUST SLOWLY SHIFTS EAST. 850MB TEMPS TOP OUT IN THE 2C EAST TO 4C WEST RANGE FOR THE WEEKEND WHICH SHOULD RESULT IN HIGHS IN THE MID 40S TO LOWER 50S. LOWS ARE A LITTLE TRICKY...ESPECIALLY OVER WISCONSIN WHERE LIGHT WINDS AT NIGHT ASSOCIATED WITH THE SURFACE RIDGE AND MOSTLY CLEAR SKIES COULD ALLOW FOR QUICK TEMPERATURE DROPS. FOR EARLY NEXT WEEK....THERE ARE ISSUES BEGINNING TO SHOW UP WITH THE HANDLING OF THAT DEEP EAST PACIFIC TROUGH. ALL MODELS HAVE THE TROUGH MOVING INLAND ON MONDAY...BUT THE 13.06Z/12Z GFS DRIVE MUCH OF IT INTO THE WESTERN U.S. AS A BROAD TROUGH. COMPARE THIS TO THE 13.00Z ECMWF AND 13.12Z CANADIAN WHICH ARE MORE LIFT A LOT UP INTO CANADA WHICH RESULTS IN A ZONAL FLOW PATTERN FROM THE PACIFIC NORTHWEST INTO THE NORTHERN PLAINS BY TUESDAY. INTERESTINGLY...THE NEW 13.12Z ECMWF HAS TRENDED TOWARDS THE GFS SCENARIO. GIVEN THE ECMWF TREND...HAVE LEANED A LITTLE MORE IN THE GFS/ECMWF DIRECTION. THIS SCENARIO WILL BRING A LOW PRESSURE SYSTEM AT US FROM THE PLAINS...WITH VARYING INTENSITY DEPENDING ON HOW MUCH OF THAT UPPER TROUGH DIGS INTO THE PLAINS. GULF OF MEXICO MOISTURE SHOULD RETURN AHEAD OF IT...THUS HAVE PRECIPITATION CHANCES IN FOR SOUTH OF I-90 MONDAY NIGHT AND AREA WIDE ON TUESDAY. THE GENERAL WARM AIRMASS SHOULD KEEP THE TYPE AS RAIN. REGARDING TEMPS...850MB TEMPS HOLD IN THE 2-4C RANGE...YIELDING HIGHS STILL IN THE MID 40S TO LOW 50S. LOOKING AHEAD TO THANKSGIVING...WITH THE MODEL TREND ON THE EAST PACIFIC TROUGH NOW DIGGING INTO THE PLAINS...POTENTIAL EXISTS FOR A LOW PRESSURE SYSTEM TO BE HANGING AROUND THE AREA WEDNESDAY INTO THURSDAY. SOME PRECIPITATION THUS LOOKS ON TAP...WITH EITHER RAIN OR A RAIN AND SNOW MIX THE TYPE. STAY TUNED TO LATER FORECASTS AS THINGS IRON THEMSELVES OUT. && .AVIATION...THROUGH 18Z WEDNESDAY 1047 AM CST TUE NOV 13 2012 FOCUS IS ON A MID-LEVEL SHORTWAVE TROUGH MOVING ACROSS THE UPPER MISSISSIPPI RIVER VALLEY REGION OVER THE NEXT 24 HOURS. CURRENTLY THIS WAVE WAS PRODUCING VFR ALTOCUMULUS ACROSS THE DAKOTAS/NEBRASKA. THERE WERE ALSO A FEW RADAR RETURNS OUT OF THESE CLOUDS BUT APPEARS THE PRECIPITATION WAS EVAPORATING BELOW THE CLOUD BASE PER SURFACE OBSERVATIONS. AS THIS WAVE MOVES TOWARD THE AREA THIS EVENING...LOOK FOR AN INCREASE IN ALTOCUMULUS AT THE KRST/KLSE AIRPORTS...BECOMING BROKEN-OVERCAST OVERNIGHT. CLOUDS BASES EXPECTED TO REMAIN AOA 8KFT AT BOTH SITES. ALTOCUMULUS IS THEN EXPECTED TO SCATTER OUT WEDNESDAY MORNING IN THE 13-15Z TIME FRAME. OTHERWISE...LOOK FOR A LIGHT SOUTHERLY SURFACE WIND IN THE 8-10KT RANGE. && .ARX WATCHES/WARNINGS/ADVISORIES... 241 PM CST TUE NOV 13 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...DAS
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1013 PM CST MON NOV 12 2012 .UPDATE... SUBSIDENCE AND DRY AIR WORKING IN BETWEEN MAIN VORT MAX OVER ERN U.P. OF MICHIGAN AND WEAKER VORT OVER NRN IN/SRN LOWER MI BORDER ON WATER VAPOR IMAGERY HAVE SCOURED OUT CLOUDS OVER A PORTION OF SOUTHERN WISCONSIN. LOOKING FOR STRATOCU DECK WRAPPING AROUND STRONGER NORTHERN VORT MAX TO CROSS THE NORTHERN HALF TO TWO- THIRDS OF THE CWA OVERNIGHT. EXTRAPOLATION OF BACK EDGE HAS CLOUDS OUT OF ALL BUT THE LAKESHORE COUNTIES FROM WIND POINT NORTH AROUND 12Z TUESDAY...WITH ALL CLOUDS GONE BY 1330Z TUESDAY. AS A RESULT OF SLOWER CLEARING...HAVE RAISED LOWS A FEW DEGREES IN THE FAR EAST AND NORTHEAST. STILL EXPECT WESTERN AREAS TO COOL WITH CLEARING SKIES AND DECOUPLING WINDS. && .AVIATION/06Z TAFS/... DRY AIR AND SUBSIDENCE HAVE PUSHED A WEDGE OF CLEARING ACROSS A PORTION OF SOUTHERN WISCONSIN. LOOKING FOR VFR STRATOCU DECK WRAPPING AROUND NORTHERN VORT MAX TO CROSS THE NORTHERN HALF TO TWO-THIRDS OF THE CWA OVERNIGHT...COVERING ALL THE TAF SITES EXCEPT KENW. EXTRAPOLATION OF BACK EDGE HAS IT REACHING KMSN BETWEEN 06Z AND 07Z...KUES BETWEEN 1130Z AND 12Z...AND KMKE AROUND 1230Z. WINDS WILL DECOUPLE WITH CLEARING...BUT GUSTY NATURE OF WINDS WILL CONTINUE WITH CLOUDS AT EASTERN SITES THOUGH SLOWLY DIMINISHING. VFR CONDITIONS FOR THE REMAINDER OF THE PERIOD...WITH WARM-AIR ADVECTION CLOUDS AT OR ABOVE 6K FT POSSIBLY REACHING KMSN BY 06Z AND KMKE BY 12Z WEDNESDAY. && .MARINE... EXTENDED SMALL CRAFT ADVISORY UNTIL 12 MIDNIGHT WITH MID-LAKE BUOY STILL REPORTING 7-FOOT WAVES AND SHORELINE OB WINDS STILL GUSTING TO 20 KNOTS SUPPORTING 5 FOOT WAVES TOWARD OPEN WATERS. 00Z NAM ...RAP AS WELL AS HRRR SHOW WINDS DIMINISHING BETWEEN 03Z AND 06Z ENOUGH FOR WAVES TO FALL TO 4 FEET OR LESS BY MIDNIGHT. && .PREV DISCUSSION... /ISSUED 326 PM CST MON NOV 12 2012/ TONIGHT AND TUESDAY...FORECAST CONFIDENCE IS MEDIUM TO HIGH. BROKEN AND NARROW BAND OF SNOW SHOWERS EXTENDING FROM NORTH OF WISCONSIN DELLS TO NORTHWEST OF BOSCOBEL CURRENTLY SHIFTING EAST SOUTHEAST TOWARD THE WESTERN COUNTIES. THIS BAND...IF IT HOLDS TOGETHER...WOULD SHIFT EAST SOUTHEAST THROUGH PORTIONS OF THE AREA INTO EARLY THIS EVENING. THIS AND OTHER SCATTERED FLURRIES/LIGHT SNOW SHOWERS BEING DRIVEN BY SHORTWAVE TROUGH WITHIN BROAD MID/UPPER TROUGH PASSING THROUGH THE REGION. THE BAND MENTIONED EARLIER HAS PRODUCED LOW VISIBILITIES EARLIER THIS AFTERNOON TO THE NORTHWEST...AND COULD BRING A DUSTING OF SNOW. HOWEVER...DID NOT MENTION ANY ACCUMULATIONS...AS THIS AREA IS BROKEN AND SKINNY AND MAY NOT HOLD TOGETHER AS IT MOVES THROUGH. WILL HAVE TO BE WATCHED BY EVENING SHIFT. GUSTY WEST WINDS AND THE LOW CLOUDS WILL LINGER INTO THE EVENING AS WELL. DRIER AIRMASS MOVING INTO THE REGION SHOULD BRING GRADUALLY CLEARING SKIES LATER THIS EVENING AND OVERNIGHT...THOUGH THERE ARE MORE CLOUDS UPSTREAM OF THE AREA. THINKING THAT THE THIN NATURE OF THE CLOUDS SHOULD ALLOW FOR THEM TO CLEAR OUT. CHILLY LOWS SHOULD TUMBLE INTO THE UPPER TEENS TO LOWER 20S. HIGH PRESSURE RIDGE TO THE SOUTH WILL BRING QUIET WEATHER FOR TUESDAY. DRY AIRMASS WILL LEAD TO MOSTLY SUNNY SKIES...WITH COOL TEMPERATURES CONTINUING. HIGHS IN THE MID TO UPPER 30S ARE EXPECTED PER NAM 925MB TEMPERATURES. WEDNESDAY THROUGH MONDAY...FORECAST CONFIDENCE IS HIGH. WE WILL BE UNDER AN EXCEPTIONALLY STABLE PATTERN FOR A TIME OF YEAR THAT CHARACTERISTICALLY ISN/T. BLOCKING HIGH PRESSURE WILL RESIDE FROM NEW ENGLAND SOUTHWEST THROUGH THE GREAT LAKES. A WEAK TROF COMES OVERHEAD ON WEDNESDAY...BUT MOISTURE AND FORCING IS MINIMAL AND WILL KEEP IT DRY. TEMPERATURES WILL BE FAIRLY STABLE AND NEAR NORMAL WITH HIGHS IN THE MID 40S TO AROUND 50 AND LOWS IN THE UPPER 20S TO LOWER 30S. AVIATION/00Z TAFS/...MVFR/VFR CEILINGS ARE EXPECTED TO LINGER ACROSS TAF SITES THROUGH MID EVENING...AS TROUGH OF LOW PRESSURE SHIFTS EAST THROUGH THE REGION. ONE BROKEN BAND OF MODERATE SNOW SHOWERS WITH MVFR/IFR VISIBILITIES SHOULD REMAIN JUST NORTH OF TAF SITES. OTHERWISE...SCATTERED FLURRIES AND LIGHT SNOW SHOWERS ARE EXPECTED INTO EARLY THIS EVENING. NO ACCUMULATIONS ARE EXPECTED...AND VISIBILITIES SHOULD REMAIN VFR CATEGORY. GUSTY WEST WINDS WILL CONTINUE INTO EARLY EVENING. SHOULD SEE GRADUALLY CLEARING SKIES/VFR CONDITIONS LATER TONIGHT...AS THE TROUGH OF LOW PRESSURE MOVES EAST. MOSTLY SUNNY SKIES ARE EXPECTED TUESDAY. WINDS WILL WEAKEN LATER THIS EVENING AND OVERNIGHT...SHIFTING SOUTHWEST TUESDAY AFTERNOON. MARINE...SMALL CRAFT ADVISORY HAS BEEN EXTENDED UNTIL 04Z TUESDAY ACROSS THE NEARSHORE WATERS. GUSTY WEST WINDS OF 15 TO 25 KNOTS WILL CONTINUE UNTIL THIS TIME...AS A TIGHT PRESSURE GRADIENT LINGERS ACROSS THE AREA. THE OFFSHORE WINDS WILL KEEP THE HIGHEST WAVES TOWARD THE OPEN WATERS. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR LMZ643>646. && $$ UPDATE...REM TONIGHT/TUESDAY AND AVIATION/MARINE...WOOD TUESDAY NIGHT THROUGH MONDAY...DAVIS
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1136 PM CST WED NOV 14 2012 ...UPDATE TO AVIATION... .DISCUSSION... SHORT TERM FORECAST - TONIGHT AND THURSDAY... 21Z RAP SURFACE ANALYSIS INDICATES A WEAK AREA OF BROAD LOW PRESSURE OVER THE HIGH PLAINS WITH ANOTHER BROAD AREA OF HIGH PRESSURE OVER THE SE CONUS. BETWEEN THESE TWO FEATURES A WEAK SURFACE PRESSURE GRADIENT HAS CAUSED SOUTHERLY WINDS AROUND 5 TO 10 MPH TO PERSIST THROUGHOUT THE DAY. EXPECT THESE SOUTHERLY WINDS TO PERSIST OVERNIGHT AROUND 5 MPH...WHICH MAY HELP TO KEEP TEMPS SLIGHTLY WARMER THAN TUESDAY NIGHT AS LOWS ARE EXPECTED TO STAY IN THE LOWER TO MID 30S. THURSDAY WILL LIKELY BE A REPEAT OF WEDNESDAY WITH SUNNY SKIES...HOWEVER WINDS MAY BE SLIGHTLY MORE OUT OF THE WEST THAN WEDNESDAY AND THIS MAY ALLOW FOR TEMPS TO RISE SLIGHTLY HIGHER THAN WEDNESDAY...WITH HIGHS EXPECTED TO BE IN THE LOWER 60S. JL LONG TERM - THURSDAY NIGHT THROUGH WEDNESDAY... THE LONG TERM PERIOD WILL BE ON THE QUIET SIDE WITH A RATHER DRY AIRMASS REMAINING ENTRENCHED ACROSS THE PLAINS. THE FLOW PATTERN ALOFT WILL SEE A FEW DISTURBANCES MOVE THROUGH THE REGION. THE FIRST MOVES THROUGH ON THURSDAY NIGHT BUT IS A FAST MOVING SYSTEM THROUGH A MOISTURE STARVED REGION...WHICH WILL RESULT IN A DRY FRONTAL PASSAGE AND A SLIGHTLY COOLER AIRMASS FOR FRIDAY AND SATURDAY. THE UPPER FLOW WILL BECOME MORE SOUTHWESTERLY FOR THE WEEKEND WITH WARM ADVECTION ALOFT AND A WEAK DISTURBANCE SCHEDULED TO AFFECT THE AREA BY SUNDAY EVENING. TEMPERATURES WILL BE ABOVE NORMAL INTO SUNDAY NIGHT...AND CURRENT INDICATIONS SUGGEST THAT SUFFICIENT MOISTENING WILL OCCUR IN ADVANCE OF THIS DISTURBANCE TO PROVIDE A CHANCE FOR SCATTERED SHOWERS ON SUNDAY NIGHT AND EARLY MONDAY IN A ZONE OF DEEP ASCENT IMMEDIATELY IN ADVANCE OF THE SHORT WAVE. A SLIGHTLY DEEPER TROUGH WILL QUICKLY FOLLOW AND MERGE WITH THE INITIAL SHORT WAVE TROUGH BY MONDAY NIGHT. WHILE THIS WILL BE A DEEPER SYSTEM...ANY PRECIPITATION WILL LIKELY HOLD OFF UNTIL THE TWO WAVES MERGE AND STRENGTHEN...EAST OF THE FORECAST AREA. SO HAVE A DRY FORECAST BEYOND MONDAY WITH CONTINUED ABOVE NORMAL TEMPERATURES AS UPPER RIDGING AND WARM ADVECTION BUILD INTO THE REGION THROUGH MID WEEK. BARJENBRUCH && .AVIATION... VFR TO CONTINUE THROUGH THE PERIOD. WINDS UNDER 10 KTS EXPECTED THROUGH THE PERIOD. WINDS WILL BECOME NORTH BETWEEN 19Z-23Z. 53 && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
328 AM EST THU NOV 15 2012 .SYNOPSIS... SURFACE HIGH PRESSURE CENTERED OVER EASTERN CANADA WILL RIDGE SOUTHWARD TOWARD THE MID-ATLANTIC STATES TODAY. A SECONDARY AREA OF HIGH PRESSURE WILL THEN BUILD IN FROM THE GREAT LAKES FRIDAY. LOW PRESSURE DEVELOPING OFF THE SOUTHEAST COAST THIS WEEKEND IS EXPECTED TO REMAIN WELL SOUTH AND EAST OF THE REGION AS HIGH PRESSURE REMAINS IN CONTROL THROUGH EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... 08Z SFC ANALYSIS SHOWS A 1037-MB HIGH CENTERED OVER ERN QUEBEC. THIS HIGH WILL CONTINUE TO RIDGE SWD INTO THE MID-ATLANTIC REGION TDA. AN UPPER SHORTWAVE TROUGH WILL CROSS THE SRN APPALACHIANS THIS MRNG AND MOVE ACROSS THE CAROLINAS THIS AFTN/TNGT. HI-LVL CS STREAMING AHEAD OF THE TROUGH WILL PROVIDE MSTLY CLOUDY TO CLOUDY SKIES FOR MOST OF TDA. FCST MODEL SOUNDINGS SHOW A STRONG SUBSIDENCE INVERSION PERSISTING AROUND 4KFT TDA. BENEATH THIS INVERSION...MOISTURE BETWEEN 3-4 KFT AGL WILL REMAIN TRAPPED WHILE LGT ELY FLOW WILL CONTINUE TO ADVECT STRATUS DECK INLAND THIS MRNG. THE STRATUS DECK...WHICH HAS SPREAD WEST OF I-95 AS OF 08Z...WILL ENHANCE CLOUD COVER TDA FROM THE BLUE RIDGE-EWD. CLEARING SHOULD OCCUR IN THE MTS LATER THIS MRNG AND AFTN AS THE UPPER TROUGH AND BACK EDGE OF CS PROGRESS EWD. DESPITE WAA IN THE LLVLS...CLOUD COVER WILL KEEP TEMPS THIS AFTN NOT MUCH WARMER THAN YDA...MID 40S TO LOWER 50S. MIN TEMPS TNGT RANGE FROM THE MID 20S ALONG THE ALLEGHENY FRONT TO UPPER 30S IN THE CITIES AND ALONG WRN SHORE OF THE BAY. && .SHORT TERM /FRIDAY THROUGH SATURDAY/... A S/WV AXIS WL CROSS THE CWFA FRI. FUNCTIONALLY...ITS MERELY A DIVIDER BTWN TWO AREAS OF HIPRES DOMINATING THE GRTLKS AND NEW ENGLAND. IT APPEARS TO BE RELATIVELY MSTR-STARVED...AND SHUD SUPPORT VARYING AMTS OF MID-HIGH LVL CLDS. THE LATTER RDG WL BE OVER THE NERN CONUS BY SAT. H8 TEMPS CHG LTL THRU THE PD...BUT H10-8 TKNS VALUES SUGGEST MODERATION OF THE LLVLS. THAT/LL PERMIT MAXT TO COME CLSR TO CLIMO...AS REFLECTED IN LTST MOS. MIN-T A LTL TRICKIER...AS DEWPTS LOW. CLDCVR WL DICTATE HOW LOW MIN-T CAN GET. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... GDNC CONTG TO PLACE INCRSG EMPHASIS ON HIPRES RDG IN THE NERN CONUS INFLUENCING WX IN THE MID ATLC. THEREFORE...ANY CYCLOGENESIS WL BE WEAKER AND FURTHER TO THE S. LCLLY...THAT MEANS IMPACTS WL BE LESS...AND WL CONT TREND FM YDA OF SCALING POPS BACK SAT NGT-MON. WUDNT BE SURPRISED TO SEE ENTIRE WKND DRY...BUT ATTM WL MAINTAIN AT LEAST A 20-30 PCT CHC RA E OF I-95 SUN NGT-MON. THAT TOO CAN BE RMVD IF CURRENT TRENDS PERSIST. ONE THING THAT CANT BE DISCOUNTED JUST YET THO IS THE EXTENT OF LLVL CLDS/DZ WORKING INLAND DEPENDING ON HOW MUCH OF A NELY FLOW CAN BE MAINTAINED. WL HV MOCLDY SKIES SHEN VLY EWD SUN NGT-MON AS A CONSEQUENCE. TEMPS REMAIN AOB NRML GIVEN N/NELY FLOW. && .AVIATION /09Z THURSDAY THROUGH MONDAY/... BKN-OVC STRATUS BETWEEN 3 AND 4 KFT HAS MOVED WWD ERY THIS MRNG INTO DCA/BWI/MTN/IAD. LATEST HRRR AND LAMP GUIDANCE HAS STRATUS REMAINING EAST OF MRB/CHO. LOWER CLOUDS SHOULD ERODE FROM NW TO SE DURING THE MID TO LATE AFTN. LGT NLY WINDS AROUND 5 KT THIS MRNG WILL VEER SLIGHTLY TO NELY THIS AFTN AND TNGT. VFR CONDS XPCTD THRU SAT UNDER HIPRES. HIPRES OVER NEW ENGLND SUN-MON COMBINED W/ WK DVLPG LOPRES OFF THE SE CONUS WL LEAD TO NELY FLOW. ITS STILL TBD HOW MUCH MSTR CAN WORK INLAND. AT LEAST OCNL FLGT RESTRICTIONS SEEM PLAUSIBLE...W/ IFR CIGS PSBL. && .MARINE... LGT N-NE FLOW GENERALLY AOB 10 KT TDA AND TNGT...ALTHOUGH A FEW HIGHER GUSTS TO 15 KT LIKELY IN THE MAIN STEM OF THE CHSPK BAY. NLY FLOW GNLY AOB 10 KT THRU SAT...ALTHO MID BAY MAY BE CLSR TO 10-15 KT. ANY GUSTS SHUD REMAIN BLO SCA CRITERIA. SUN-MON A BIT MORE QSTNBL...DEPENDING ON STRENGTH OF P-GRAD BTWN HIPRES OVR NEW ENGLAND AND DVLPG LOPRES OFF THE SERN CONUS. IF SCA WERE TO BE REQD...MID BAY/TANGIER SOUND/MOUTH OF THE PTMC APPEAR MORE FVRBL. WL CARRY THAT POTL IN THE HWO. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ SYNOPSIS...JRK NEAR TERM...JRK SHORT TERM...HTS LONG TERM...HTS AVIATION...JRK/HTS MARINE...JRK/HTS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
426 AM EST THU NOV 15 2012 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 423 AM EST THU NOV 15 2012 00Z RAOBS AND RUC ANALYSIS SHOW PRETTY QUIET WESTERLY SPLIT FLOW ALOFT WITH MINIMAL H5 HEIGHT FALLS OR RISES NOTED UPSTREAM. STRONGEST SHORTWAVE WITHIN THE FLOW IS IN THE NORTHERN STREAM PUSHING ACROSS MANITOBA INTO NORTHERN ONTARIO. COLD FRONT ASSOCIATED WITH THIS WAVE IS STRONG. TEMPS HAVE FALLEN INTO THE TEENS IN CENTRAL MANITOBA AND INTO SINGLE NUMBERS BACK OVR SASKATCHEWAN. BATCH OF HEAVIER SNOW IS ACCOMPANYING THE FRONT IN NORTHERN MANITOBA...BUT NOT MUCH IS OCCURRING FARTHER SOUTH ALONG THE COLD FRONT. ONLY OTHER SHORTWAVE RELATIVELY CLOSE BY IS MOVING ACROSS CENTRAL MINNESOTA. DESPITE DRY LOW-LEVELS SEEN OVER AREA LAST DAY...THIS WAVE IS STRONG ENOUGH TO PRODUCE SOME LGT SHRA OVER ECNTRL MN WITHIN LAST 2 HOURS. OVER UPR MICHIGAN IT IS ANOTHER NIGHT WITH A LOT OF MID CLOUDS BUT NO PRECIP. TEMPS IN MANY AREAS EARLY THIS MORNING ARE CLOSE TO WHAT IS A TYPICAL NORMAL HIGH TEMP FOR 15 NOVEMBER AKA THE FIRE ARM RIFLE DEER HUNTING OPENER FOR MICHIGAN. AS NORTHERN STREAM TROUGH PRESSES EAST TODAY...ASSOCIATED SFC LOW MOVES ACROSS HUDSON BAY AND SFC COLD FRONT TAKES AIM ON UPR MICHIGAN LATE TODAY. UNTIL ARRIVAL OF THE FRONT...DEPENDING ON EXTENT OF CLOUD COVER...APPEARS WE COULD HAVE MAKING OF FAIRLY WARM DAY. MID CLOUDS ALREADY TRYING TO SCT OUT OVER WESTERN UPR MICHIGAN AND AT LEAST PARTIAL SUNSHINE IS EXPECTED FOR MUCH OF WESTERN AND CENTRAL CWA THIS MORNING. WILL HAVE TO WATCH WI BORDER THOUGH AS SHORTWAVE OVR MN MAY PUSH CLOSE BY ENOUGH TO AT LEAST INCREASE CLOUDS AGAIN THIS MORNING AND EVEN PRODUCE A FEW SPRINKLES TOWARD KIMT. MIXING TO 925MB SUPPORTS TEMPS WELL INTO THE 40S BY MID AFTN WITH DOWNSLOPE SW WINDS PUSHING READINGS INTO LOWER 50S NEAR LK SUPERIOR NCNTRL IF CLOUDS ARE DELAYED. BY MID AFTN...EXPECT MID CLOUDS /H8-H7 RH/ TO BUILD BACK OVER CWA FROM THE SOUTHWEST WHILE BATCH OF CLOUDS JUST AHEAD OF COLD FRONT SLIDE INTO CWA FROM ONTARIO. FORECAST SOUNDINGS INDICATE THERE WILL BE ENOUGH DEEPER MOISTURE AND UVM WITHIN ICE NUCLEATION ZONE TO GENERATE A FEW SHOWERS AFT 21Z. SREF/HIGHER RES MODELS FROM NCEP AND NAM/LOCAL WRF-ARW AGREE PRECIP MAINLY AFFECTS ALGER/SCHOOLCRAFT/LUCE. DAYTIME HEATING INCREASES 1000-H85 LAPSE RATES OVR MUCH OF EAST HALF AHEAD OF FRONT...SO ALSO ADDED ISOLD MENTION AS FAR WEST AS MARQUETTE/DELTA COUNTIES. PTYPE ONLY RAIN AS WBZERO HEIGHTS ARE WELL ABOVE 1KFT AGL. ONLY POSSIBILITY OF SEEING SOME SNOW MIXING IN WOULD BE OVER HIGHER TERRAIN OF MQT COUNTY IN EVENING...BUT MOST OF SYNOPTIC PRECIP SHOULD DONE BY THIS TIME. ONCE FRONT MOVES THROUGH...A PORTION OF COLD AIR SEEN UPSTREAM WILL MAKE RUN ACROSS LK SUPERIOR AND INTO UPR MICHIGAN. IT IS A SHALLOW COLDER AIRMASS OVR MANITOBA AS 925MB TEMPS ARE COLDER THAN THOSE AT 850MB. SETUP TONIGHT OVER UPR MICHIGAN NO DIFFERENT. NORTHWEST WINDS IN WAKE OF FRONT EVENTUALLY TURN MORE NORTHERLY AS SFC HIGH CURRENTLY OVR NORTHERN ROCKIES AND NORTHERN PLAINS EXTENDS A RIDGE INTO NORTHERN ONTARIO AND NORTHERN LK SUPERIOR. NORTH LOW-LEVEL WINDS ALONG WITH INCREASING SUB H85 MOISTURE SEEN ON UPSTREAM SOUNDINGS AT YQD /CNTRL MANITOBA/ AND YSM /NORTHWEST TERRITORIES/ ALONG WITH LOWERING SUBSIDENCE INVERSION /TEMPS AT INVERSION TOP AROUND -7C/ CONTINUE TO SUPPORT GOING FCST OF FZDZ OR FLURRIES OVR HIGHLANDS OF NCNTRL UPR MICHIGAN. DESPITE INCREASING CLOUDS...PREFER TO GO COLDER WITH MINS TONIGHT WITH SHALLOW INVERSION/STABLE TEMP PROFILE. MOST AREAS WILL FALL INTO THE 20S WEST/CNTRL WITH NEAR 30 FOR EASTERN CWA. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 423 AM EST THU NOV 15 2012 A FAIRLY QUIET PERIOD OF WX IS IN STORE THRU THIS WEEKEND AS A ZONAL FLOW OF RELATIVELY MILD PACIFIC AIR DOMINATES. FRI...SFC HI PRES RDG AXIS IS FCST TO MOVE FM MN INTO NW ONTARIO TO AN A LINE FM UPR MI INTO ONTARIO BY 00Z SAT AS H5 RDG BUILDS OVER THE UPR LKS. PREFER THE CLOUDIER NAM DEPICTION OF EVENTS GIVEN FCST SHARP INVNR ARND 3K FT ENHANCED BY SHALLOW COLD INFUSION AND TRAPPING LLVL AIRMASS MOISTENED IN PASSAGE OVER LK SUP. ONCE THE HI PRES RDG PASSES TO THE E...EXPECT STUBBORN LO CLDS TO BREAK UP AS THE FLOW TURNS OFFSHORE. BUT OVER THE NCNTRL...THIS WSHFT IS NOT FCST TO OCCUR UNTIL LATE IN THE DAY. SO SUSPECT THE DAY WL BE MOCLDY IN THIS AREA...WITH SOME MRNG -FZDZ OVER THE HIER TERRAIN OF THE NCENTRAL WHERE LLVL N VEERING E WIND UPSLOPES AND LLVL MSTR REMAINS TRAPPED BLO SHARP INVRN BTWN H9-925 MAINTAINED BY DEEP LYR QVECTOR DVGC/SUBSIDENCE. EVEN OVER THE W... FCST LIGHT WINDS SUG THE LO CLD MAY BE QUITE TENACIOUS GIVEN SHARP LO INVRN BASE THAT TRAPS THE LLVL MSTR. AREAS FM IWD-ONTONAGON- KEWEENAW PROBABLY HAVE THE BEST SHOT AT SEEING SOME CLRG WITH A MORE PRONOUCNED DOWNSLOPE WIND COMPONENT. DVLPG E FLOW OFF LK MI WL ALSO BRING ABOUT MORE SC OVER THE SCENTRAL...BUT THERE MAY SOME PARTIAL CLRG OVER THE E WITH DOWNSLOPING OFF ONTARIO AND LOSS OF LK MOISTENING COMPONENT. WITH PLENTY OF CLD COVER LINGERING ALL DAY OVER THE NCENTRAL...MAX TEMPS MAY STRUGGLE TO RISE ABV 32 ACRS THE HIER TERRAIN IN THAT AREA. FRI NGT...AS HI SHIFTS TO THE E...THE LLVL WINDS WL VEER MORE TO THE S. IN CONCERT WITH INVRN SINKING CLOSER TO THE SFC AS SHOWN BY NAM FCST SDNGS...THIS FLOW SHOULD ALLOW THE SKY TO BECOME CLR TO PCLDY. DESPITE THE CLRG...INCRSG S WINDS WL TEND TO LIMIT THE DIURNAL TEMP FALL AT LEAST OVER THE W. THE LOWEST MIN TEMPS SHOULD BE OVER THE INTERIOR CENTRAL AND E WHERE THE H925 WINDS WL BE AOB 10 KTS MOST IF NOT ALL OF THE NGT. WITH PWAT AOB 0.25 INCH...TENDED AOB THE LO END OF GUIDANCE FOR MIN TEMPS IN THIS AREA EVEN THOUGH SOME HI CLDS MIGHT ARRIVE OVERNGT IN MORE WSW FLOW ALF. SAT THRU SUN...THE UPR GRT LKS WL BE DOMINATED BY STEADY SW FLOW BTWN HI PRES DRIFTING INTO NEW ENGLAND AND LO PRES TROF IN THE PLAINS DOWNWIND OF DEEPENING WRN TROF. DESPITE THE STRENGTHENING SSW LLVL FLOW...MODELS ADVERTISE LTL MOISTENING IN THE LO-MID LVLS. BUT WSW FLOW ALF WL BRING SCT-BKN HI CLDS. TEMPS WL AVG ABOVE NORMAL THRU THE WEEKEND WITH H85 TEMPS FCST FM 1 TO 4C. THE HIEST TEMPS SHOULD BE OVER THE DOWNSLOPE AREAS NEAR LK SUP ON SUN DESPITE SOME THICKER HI CLD. EXTENDED...GUIDANCE INDICATES THE PERSISTENT SW FLOW FM THE SRN PLAINS INTO THE UPR GRT LKS ON WRN FLANK OF HI PRES OVER THE NE CONUS MAY TAP MORE MOIST AIRMASS BY MON. AS DIFFICULT TO TIME SHRTWVS EJECT FM THE WRN TROF EWD TOWARD THE UPR GRT LKS EARLY NEXT WEEK...MODEL CONSENSUS INDICATES SCHC POPS ARE WARRANTED FOR MON THRU WED. GUIDANCE SEEMS TO HAVE TRENDED TOWARD KEEPING THE TROF OUT W LONGER...SO LATER UPDATES MAY TREND TOWARD DRIER WX. TEMPS WL REMAIN WELL ABV THE SEASONAL NORM WITH PACIFIC AIR DOMINATING UNDER WSW FLOW ALF. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1233 AM EST THU NOV 15 2012 VFR CONDITIONS WILL PERSIST AT ALL TAF SITES TONIGHT THROUGH THE DAY AS ONLY MID LEVEL CLOUDS ARE EXPECTED. HOWEVER...AS A COLD FRONT MOVES THROUGH THE REGION LATE THIS AFTERNOON AND WINDS VEER FROM SSW TO NNW BY EVENING EXPECT CIGS TO DROP INTO THE MVFR RANGE. THE LOWER CIGS WILL BE SUPPORTED BY AN INFLUX OF COLDER AIR...LOW LEVEL MOISTENING ACROSS LAKE SUPERIOR AND UPSLOPE FLOW INTO THE HIGHER TERRAIN. SOME DZ OR -FZDZ/FLURRIES MAY ALSO BE POSSIBLE MAINLY AT KSAW BUT PROBABILITY IS LOW AND ANY PCPN IS NOT EXPECTED TO AFFECT VSBY. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 423 AM EST THU NOV 15 2012 EXPECT S-SW WINDS UP TO 25-30 KTS TODAY IN ADVANCE OF APPROACHING COLD FNT TO SHIFT TO THE N-NW THIS AFTERNOON/EVENING ONCE THE FRONT PASSES W-E ACROSS THE LAKE. NOT OUT OF THE QUESTION THERE COULD BE A FEW GALE FORCE GUSTS JUST AHEAD OF THE FRONT MAINLY OVER THE NCENTRAL LAKE WITH TERRAIN BETWEEN ISLE ROYALE AND THE KEWEENAW ENHANCING EXPECTED WSW WIND. APPROACH OF TRAILING HI PRES WILL THEN CAUSE QUICKLY DIMINISHING WINDS BY FRI WHICH WILL CONTINUE THRU FRI NIGHT. OVER THE WEEKEND INTO EARLY NEXT WEEK...LAKE SUP WILL BE DOMINATED BY S WINDS BETWEEN HI PRES MOVING INTO NEW ENGLAND AND A LO PRES TROF IN THE PLAINS. THE STRONGEST S WINDS UP TO 25 KTS DURING THIS PERIOD ARE MOST LIKELY OVER THE E HALF OF THE LAKE. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLA LONG TERM...KC AVIATION...JLB MARINE...KC
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1148 PM CST WED NOV 14 2012 .DISCUSSION... SEE AVIATION FOR 06Z TAFS. && .AVIATION... AS S/W ENERGY MOVES FROM THE NORTHERN ROCKIES TO JUST WEST OF THE GREAT LAKES AND THE CENTRAL U.S. ON THURSDAY...THE WEAK SFC RIDGE OVER SOUTH CENTRAL TEXAS WILL MOVE FURTHER EAST...PROVIDING A MORE CONSISTENT E TO SE SFC WIND PATTERN DURING THE DAY ON THURSDAY. CIGS AROUND 3000 TO 6000 FT FROM VCNTY OF KDRT TO KUVA TONIGHT WILL SPREAD SLIGHTLY FURTHER EAST AFTER 09Z THROUGH 18Z TO NEAR AND WEST OF A LINE FROM KPEZ TO KSAT TO KERV. SCT TO BKN CLOUDS ABOVE 25 THSD FT ARE EXPECTED VCNTY OF KAUS THROUGH 18Z THURSDAY. AFTER 18Z ON THURSDAY SCT CLOUDS FROM 5 THSD TO 10 THSD FT ARE EXPECTED...WITH HIGHER CIRRUS SCT TO BKN AT OR ABOVE 25 THSD FT. BY THURSDAY EVENING SFC WINDS WILL BECOME E TO NE...AS THE S/W FROM WEST OF THE GREAT LAKES TO THE CENTRAL U.S. MOVES TO THE MISSISSIPPI VALLEY AND CAUSES A WEAK RIDGE TO FORM ACROSS THE NORTHEAST TO EASTERN PART OF SOUTH CENTRAL TEXAS. THESE TYPE OF WEATHER PATTERNS WILL FAVOR VFR CONDITIONS ON THURSDAY NIGHT... WITH SCT CLOUDS AROUND 10 THSD FT AND SCT TO BKN HIGHER CIRRUS AT OR ABOVE 25 THSD FT. && .PREV DISCUSSION... /ISSUED 1000 PM CST WED NOV 14 2012/ UPDATE... MADE MINOR CHANGES TO THE ONGOING FORECAST PACKAGE TO ACCOUNT FOR CURRENT AND REST OF TONIGHT WEATHER TRENDS. LATEST 00Z NAM12 AND 03Z RUC13 AREA FORECAST SOUNDINGS SUGGEST/MAINTAIN A 850MB BKN/OVC CLOUD LAYER TONIGHT INTO THURSDAY ACROSS THE SOUTHERN HALF OF SOUTH CENTRAL TEXAS. HILL COUNTRY WILL REMAIN MOSTLY CLEAR THIS EVENING WITH SOME CLOUDS RETURNING OVERNIGHT. ACROSS THE RIO GRANDE PLAINS/EDWARDS PLATEAU AREA...EXPECT CLOUDS TO INCREASE OVERNIGHT AS SURFACE DEWPOINTS AUGMENT AND MID TO UPPER LEVEL MOISTURE MOVES FROM WEST TEXAS AND NORTHEAST MEXICO. PREV DISCUSSION... /ISSUED 553 PM CST WED NOV 14 2012/ DISCUSSION... SEE AVIATION FOR 00Z TAFS. AVIATION... A MID LEVEL CLOUD DECK EXTENDS FROM SOUTHEAST OF DEL RIO TO SAN ANTONIO TO LA GRANGE AND SOUTH TO THE COAST. CIGS ACROSS THIS AREA ARE VFR. TO THE NORTH SKIES ARE MAINLY CLEAR. THESE CLOUDS ARE EXPECTED TO SLOWLY ERODE THROUGH THE EVENING. KAUS, KSAT, KSSF AND KDRT WILL BE VFR THROUGH THE EVENING. AS S/W ENERGY MOVES FROM THE NORTHERN ROCKIES TO JUST WEST OF THE GREAT LAKES AND THE CENTRAL U.S. ON THURSDAY...THE WEAK SFC RIDGE OVER SOUTH CENTRAL TEXAS WILL MOVE FURTHER EAST...PROVIDING A MORE CONSISTENT E TO SE SFC WIND PATTERN FOR THE DAY ON THURSDAY. THIS COULD CAUSE CIGS AROUND 2500 TO 6000 FT TO FORM NEAR THE RIO GRANDE TONIGHT THROUGH THURSDAY MORNING IN VCNTY OF KDRT. VFR CONDITIONS ARE EXPECTED TO CONTINUE AT KAUS, KSAT AND KSSF THURSDAY MORNING. SCT TO BKN CLOUDS AOB 10 THSD FT WILL SLOWLY INCREASE FROM THE WEST THROUGH THURSDAY AND THURSDAY NIGHT. BY THURSDAY EVENING SFC WINDS WILL BECOME E TO NE...AS THE S/W FROM WEST OF THE GREAT LAKES TO THE CENTRAL U.S. MOVES TO THE MS VALLEY AND CAUSES A WEAK RIDGE TO FORM ACROSS THE NORTHEAST TO EASTERN PART OF SOUTH CENTRAL TEXAS. THESE TYPE OF WEATHER PATTERNS WILL FAVOR VFR CONDITIONS ON THURSDAY AFTERNOON AND EVENING. PREV DISCUSSION... /ISSUED 312 PM CST WED NOV 14 2012/ DISCUSSION... CLOUDS HAVE BEEN SLOW TO CLEAR/ERODE OVER THE SRN HALF OF THE CWA TODAY. OVERRUNNING WAS OCCURRING IN THE SWLY FLOW 5-8K FEET ABOVE THE COOL DRY SURFACE RIDGE. SOME PARTIAL CLEARING WILL CONTINUE THIS EVENING...HOWEVER ADDITIONAL MID-UPPER LEVEL CLOUDS WERE MOVING IN FROM THE WEST AS WELL AS INCREASING LOW LEVEL RETURN MOISTURE UP THE RIO GRANDE. THE COOL SURFACE RIDGE OVER S TX WILL SLOWLY RETREAT EASTWARD THURSDAY WITH RETURN FLOW ALL AREAS. A BRIEF WEAK BACKDOOR COLD FRONT WILL AFFECT MAINLY NERN CWA THURSDAY NIGHT/EARLY FRIDAY AND BRIEFLY SHIFT WINDS TO THE NE-E. THIS WEAK FRONT COULD TRIGGER A FEW SHOWERS OVER THE FAR SWRN CWA AS WELL. WINDS WILL QUICKLY RETURN TO SELY BY SATURDAY INTO SUNDAY AS THE NWLY FLOW BECOMES MORE ZONAL FLOW. MINOR DISTURBANCES IN THE WESTERLY FLOW COULD GENERATE ISOLATED SHOWERS/SPRINKLES SUNDAY INTO SUNDAY NIGHT WITH PARTLY TO MOSTLY CLOUDY SKIES PREVAILING. A MORE POTENT TROUGH/COLD FRONT WILL MOVE INTO SOUTHWEST TX MONDAY AND ACROSS SOUTH TX MONDAY NIGHT AND TUESDAY...RESULTING IN BETTER CHANCES OF CONVECTION. HAVE TONED DOWN GFS MOS POPS TO 20-30 PERCENT MORE IN LINE WITH THE DRIER ECWMF AND PREVIOUS THINKING. CLEARING TUESDAY NIGHT INTO WEDNESDAY BEHIND THE COLD FRONT. MILD HIGH TEMPERATURES AND COOL NIGHTS AS AN UPPER LEVEL RIDGE BUILDS IN FROM THE WEST. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 40 68 44 68 40 / 0 0 0 0 0 AUSTIN BERGSTROM INTL AIRPORT 34 68 40 67 34 / 0 0 0 0 0 NEW BRAUNFELS MUNI AIRPORT 40 67 45 67 38 / 0 0 - 0 0 BURNET MUNI AIRPORT 35 66 41 66 37 / 0 0 0 0 0 DEL RIO INTL AIRPORT 48 68 51 65 48 / - 0 - - - GEORGETOWN MUNI AIRPORT 35 67 37 66 36 / 0 0 0 0 0 HONDO MUNI AIRPORT 45 66 49 67 42 / 0 0 - - 0 SAN MARCOS MUNI AIRPORT 40 66 44 67 39 / 0 0 - 0 0 LA GRANGE - FAYETTE REGIONAL 37 68 42 67 39 / 0 0 - - - SAN ANTONIO INTL AIRPORT 44 65 49 66 43 / 0 0 - - 0 STINSON MUNI AIRPORT 46 66 51 66 44 / 0 0 - - 0 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...08 SYNOPTIC/GRIDS...17
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
751 AM MST THU NOV 15 2012 .UPDATE... && .SHORT TERM...CLOUD DECK HAS BECOME MORE EXTENSIVE OVER THE PLAINS THIS MORNING AND EVEN LIGHT SNOW AND FLURRY BAND HAS SAGGED A BIT FURTHER SOUTH INTO BOULDER AND NORTHERN JEFFERSON COUNTY. DON`T EXPECT ANY ACCUMULATION THOUGH EXCEPT SOME DUSTING OVER NORTHERN WELD COUNTY. CHANGES TO FORECAST INCLUDE MORE CLOUDS AND GRADUAL CLEARING DURING THE EARLY AFTERNOON. ADDED LIGHT SNOW A BIT FURTHER SOUTH THAN CURRENT FORECAT. .AVIATION...SOLID STRATUS DECK IN PLACE OVER LOCAL TERMINALS AND MAY EVEN SEE A FEW FLURRIES AT BJC AND DEN OVER THE NEXT FEW HOURS. NO ACCUMULATION EXPECTED THOUGH. WILL CONTINUE THE TREND OF LATER CLEARING AND MAY SEE ILS CONDITIONS AT DEN THROUGH EARLY AFTERNOON. && .PREV DISCUSSION... /ISSUED 717 AM MST THU NOV 15 2012/ UPDATE... AVIATION...STRATUS DECK HAS BECOME RATHER WIDESPREAD AND IS NOW COVERING ALL THE LOCAL TERMINALS WITH CEILINGS BETWEEN 2000 AND 4000 FEET AGL. WILL DELAY CLEARING INTO THE 17Z-19Z TIME FRAME GIVEN LATEST SOUNDINGS AND PER RUC FORECAST. PREV DISCUSSION... /ISSUED 547 AM MST THU NOV 15 2012/ UPDATE... AVIATION... AN AREA OF LOW CLOUDS HAS FORMED ON THE SOUTH SIDE OF THE SHOWER BAND...PROBABLY DUE TO COOLING FROM THE SHOWER OUTFLOW. CEILINGS BETWEEN 025 AND 040 LIKELY AT KDEN FOR THE NEXT COUPLE OF HOURS...IT MAY GET INTO KBJC BUT EXPECT THESE CLOUDS TO NOT MAKE IT TO KAPA. EXPECT THIS LAYER TO BREAK UP IN THE 14Z-16Z TIME FRAME AS THE SHOWERS FADE AND THE SURFACE WARMS. PREV DISCUSSION... /ISSUED 326 AM MST THU NOV 15 2012/ SHORT TERM...LITTLE SNOW BAND IN A WEAK FRONTOLYSIS ZONE THAT WAS PARKED OVER THE LARAMIE AND CHEYENNE AREAS MOST OF THE NIGHT HAS STARTED TO SAG SOUTH A BIT AS THE TROUGH AXIS GETS EAST OF US...BUT IS ALSO STARTING TO FALL APART AND SHRINK AT BOTH THE EASTERN AND WESTERN ENDS. THIS SHOULD CONTINUE TO DIMINISH AS THE QG LIFT GOES AWAY AND DRIER AIR UNDERCUTS THE MID LEVEL LIFT. CURRENT FORECAST HAS THESE SHOWERS ENDING BY 15Z WHICH IS PROBABLY ALRIGHT...I DID KEEP A FEW SHOWERS IN THE NORTHERN MOUNTAINS LATER THIS MORNING AS THE CLOUDS ON THE TAIL END OF THE BAND WILL LIKELY STILL BE OUT THERE. I ALSO SLOWED THE CLEARING ON THE PLAINS JUST A LITTLE...BUT EXPECT MOST OF THE CLOUDS TO BE GONE BY LATE AFTERNOON. NO CHANGES TO THE REST OF THE FORECAST...WEAK NORTHERLY WIND SURGE AND COOLER HIGHS TODAY APPEAR WELL HANDLED. LONG TERM...NOT MUCH TO CONTEND WITH THROUGH MONDAY. THE FLOW ALOFT WILL REMAIN SOUTHWESTERLY WITH A SERIES OF WEAK EMBEDDED DISTURBANCES SLIPPING ACROSS COLORADO. THERE WILL BE ENOUGH MOISTURE TO PRODUCE A SLIGHT CHANCE OF SNOW IN THE HIGH COUNTRY...BUT LIMITED MOISTURE AND PREVAILING DOWNSLOPE WILL KEEP THE LOWER ELEVATION MILD AND DRY. OVERALL...AFTERNOON TEMPERATURES WILL REMAIN SLIGHTLY ABOVE SEASONAL NORMALS. AVIATION...VFR CONDITIONS EXPECTED OVER THE DENVER AREA THROUGH TONIGHT...WITH LIGHT SNOW SHOWERS THIS MORNING REMAINING NORTH OF DENVER. WITH HIGH PRESSURE SHIFTING OVER THE NORTHERN PLAINS...EXPECT THE CURRENT WIND PATTERN TO BREAK DOWN WITH NORTH TO NORTHEAST WINDS DEVELOPING IN THE DENVER AREA BY SUNRISE. WINDS MAY STILL BE LIGHT AND SOMEWHAT VARIABLE THIS MORNING...BUT BY MIDDAY EXPECT STEADIER NE-E WINDS THAT WILL ROTATE TO SLY DRAINAGE WINDS THIS EVENING. EXPECT A DENVER CYCLONE TO DEVELOP TONIGHT SO SOME UNCERTAINTY ABOUT WIND DIRECTION AT KDEN/KAPA FOR FRIDAY MORNING...BUT FOG THREAT APPEARS LOW. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...ENTREKIN LONG TERM....COOPER AVIATION...ENTREKIN
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
717 AM MST THU NOV 15 2012 .UPDATE... && .AVIATION...STRATUS DECK HAS BECOME RATHER WIDESPREAD AND IS NOW COVERING ALL THE LOCAL TERMINALS WITH CEILINGS BETWEEN 2000 AND 4000 FEET AGL. WILL DELAY CLEARING INTO THE 17Z-19Z TIME FRAME GIVEN LATEST SOUNDINGS AND PER RUC FORECAST. && .PREV DISCUSSION... /ISSUED 547 AM MST THU NOV 15 2012/ UPDATE... AVIATION... AN AREA OF LOW CLOUDS HAS FORMED ON THE SOUTH SIDE OF THE SHOWER BAND...PROBABLY DUE TO COOLING FROM THE SHOWER OUTFLOW. CEILINGS BETWEEN 025 AND 040 LIKELY AT KDEN FOR THE NEXT COUPLE OF HOURS...IT MAY GET INTO KBJC BUT EXPECT THESE CLOUDS TO NOT MAKE IT TO KAPA. EXPECT THIS LAYER TO BREAK UP IN THE 14Z-16Z TIME FRAME AS THE SHOWERS FADE AND THE SURFACE WARMS. PREV DISCUSSION... /ISSUED 326 AM MST THU NOV 15 2012/ SHORT TERM...LITTLE SNOW BAND IN A WEAK FRONTOLYSIS ZONE THAT WAS PARKED OVER THE LARAMIE AND CHEYENNE AREAS MOST OF THE NIGHT HAS STARTED TO SAG SOUTH A BIT AS THE TROUGH AXIS GETS EAST OF US...BUT IS ALSO STARTING TO FALL APART AND SHRINK AT BOTH THE EASTERN AND WESTERN ENDS. THIS SHOULD CONTINUE TO DIMINISH AS THE QG LIFT GOES AWAY AND DRIER AIR UNDERCUTS THE MID LEVEL LIFT. CURRENT FORECAST HAS THESE SHOWERS ENDING BY 15Z WHICH IS PROBABLY ALRIGHT...I DID KEEP A FEW SHOWERS IN THE NORTHERN MOUNTAINS LATER THIS MORNING AS THE CLOUDS ON THE TAIL END OF THE BAND WILL LIKELY STILL BE OUT THERE. I ALSO SLOWED THE CLEARING ON THE PLAINS JUST A LITTLE...BUT EXPECT MOST OF THE CLOUDS TO BE GONE BY LATE AFTERNOON. NO CHANGES TO THE REST OF THE FORECAST...WEAK NORTHERLY WIND SURGE AND COOLER HIGHS TODAY APPEAR WELL HANDLED. LONG TERM...NOT MUCH TO CONTEND WITH THROUGH MONDAY. THE FLOW ALOFT WILL REMAIN SOUTHWESTERLY WITH A SERIES OF WEAK EMBEDDED DISTURBANCES SLIPPING ACROSS COLORADO. THERE WILL BE ENOUGH MOISTURE TO PRODUCE A SLIGHT CHANCE OF SNOW IN THE HIGH COUNTRY...BUT LIMITED MOISTURE AND PREVAILING DOWNSLOPE WILL KEEP THE LOWER ELEVATION MILD AND DRY. OVERALL...AFTERNOON TEMPERATURES WILL REMAIN SLIGHTLY ABOVE SEASONAL NORMALS. AVIATION...VFR CONDITIONS EXPECTED OVER THE DENVER AREA THROUGH TONIGHT...WITH LIGHT SNOW SHOWERS THIS MORNING REMAINING NORTH OF DENVER. WITH HIGH PRESSURE SHIFTING OVER THE NORTHERN PLAINS...EXPECT THE CURRENT WIND PATTERN TO BREAK DOWN WITH NORTH TO NORTHEAST WINDS DEVELOPING IN THE DENVER AREA BY SUNRISE. WINDS MAY STILL BE LIGHT AND SOMEWHAT VARIABLE THIS MORNING...BUT BY MIDDAY EXPECT STEADIER NE-E WINDS THAT WILL ROTATE TO SLY DRAINAGE WINDS THIS EVENING. EXPECT A DENVER CYCLONE TO DEVELOP TONIGHT SO SOME UNCERTAINTY ABOUT WIND DIRECTION AT KDEN/KAPA FOR FRIDAY MORNING...BUT FOG THREAT APPEARS LOW. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...GIMMESTAD LONG TERM....COOPER AVIATION...ENTREKIN
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1025 AM EST THU NOV 15 2012 .SYNOPSIS... HIGH PRESSURE OVER THE CANADIAN MARITIMES BUILDS EAST INTO THE NORTH ATLANTIC LATER TODAY. ANOTHER STRONG AREA OF HIGH PRESSURE APPROACHES FROM THE WEST ON FRIDAY. THE HIGH BUILDS TO THE NORTH OF THE AREA OVER THE WEEKEND. A BROAD AREA OF LOW PRESSURE WILL THEN DEVELOP OFF THE SOUTHEAST COAST LATE IN THE WEEKEND AND TRACKS NORTHEAST WELL OFFSHORE INTO EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... CLOUD COVER IS THE FORECAST ISSUE OF THE DAY. FIRST...VARIABLE AMOUNTS OF CIRRUS IN THE SOUTHWEST FLOW THROUGH THE DAY. BASED ON TRENDS LATEST RAP SOUNDING...A GENERAL THICKENING OF THE CIRRUS IS FORECAST THROUGH THE DAY. SECOND...IS A LAYER OF STRATOCU OVER LONG ISLAND AND EASTERN CT. THIS LAYER SHOULD STAY IN PLACE THROUGH THE DAY...THOUGH IT MAY SLIDE SLIGHTLY TO THE WEST THROUGH THE DAY. THUS...GOING WITH A CLOUDY DAY EAST AND A PARTLY SUNNY DAY WEST. OTHERWISE...TEMPS WERE ADJUSTED SLIGHTLY LOWER AND KEPT IN THE 40S. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... HIGH PRESSURE REMAINS SITUATED TO THE NORTH AND WEST...WHILE A SHORT WAVE TROF AND DISSIPATING COLD FRONT PUSH ACROSS THE GREAT LAKES AND EASTERN CANADA TONIGHT. THE LATTER OF WHICH DISSIPATES WELL TO THE NORTH AND WEST OF THE AREA. A MUCH STRONGER AREA OF HIGH PRESSURE APPROACHES FROM THE UPPER MIDWEST ON FRIDAY. A DRY...NORTHERLY FLOW WILL CONTINUE ON FRI WITH TEMPERATURES WARMING UP INTO THE LOWER 50S...WHICH IS NEARLY SEASONABLE. UPPER LEVEL CLOUDS MAY CONTINUE TO IMPACT THE REGION...ESPECIALLY FOR THE FIRST HALF OF THE DAY. FOLLOWED THE MOS GUIDANCE CLOSELY FOR BOTH THE MORNING LOWS AND AFT HIGHS. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... FAIRLY PERSISTENT AND QUIET PATTERN IN PLACE THROUGH THE LONG TERM OUTSIDE OF A LOW POTENTIAL FOR A COASTAL SYSTEM EARLY NEXT WEEK. BROAD AREA OF HIGH PRESSURE OVER MUCH OF THE EASTERN SEABOARD STAYS IN PLACE THROUGH THE PERIOD KEEPING TEMPERATURES NEAR NORMAL AND A PERSISTENT NORTH TO NORTHEAST FLOW ACROSS THE REGION. INTO SUNDAY AND MONDAY...THE ZONAL FLOW SPLITS WITH THE SOUTHERN STREAM DIGGING INTO THE SOUTHEAST STATES AS THE NORTHERN STREAM MOVES THROUGH SOUTHERN CANADA. AS THE SOUTHERN STREAM DIPS INTO THE SOUTHEAST...MODELS INDICATING IT CUTS OFF NEAR THE SE COAST...ON SUNDAY WITH THE GFS/NAM AND INTO MONDAY WITH THE ECMWF. THIS IS THE FORCING FOR THE COASTAL LOW DEVELOPMENT THAT TRACKS NORTHEAST. THERE IS STILL A LOW POSSIBILITY OF A COASTAL STORM DEVELOPING EARLY NEXT WEEK. HOWEVER...ALL GLOBAL MODELS HAVE BEEN TRENDING EAST WITH THE SURFACE LOW PRESSURE THROUGH THE LAST FEW RUNS AND HAVE CONTINUED TO SHOW STRONG HIGH PRESSURE TO OUR NORTH. 18Z GFS/GEFS AND THE 00Z ECMWF ALL DEVELOP A VERY WEAK SURFACE LOW OFF THE EAST COAST AND KEEPS IT WELL OFFSHORE. 00Z GFS ALSO SHOWS THIS WEAK LOW FOR EARLY IN THE WEEK BUT THEN ALSO DEVELOPS ANOTHER SURFACE LOW AROUND THURSDAY...ALSO KEEPING THAT WELL OFFSHORE. SINCE THIS IS THE FIRST SET OF MODEL RUNS SHOWING SOME CONSISTENCY WITH THE WEAKER LOW...HAVE NOT COMPLETELY REMOVED THE POPS AND GUSTY WINDS FROM THE FORECAST FOR THE MON THROUGH WED TIME FRAME. OUTSIDE OF THIS SLIGHT SCALE DOWN IN WINDS/POPS...LITTLE CHANGES WERE MADE TO THE EXTENDED FORECAST FROM THE PREVIOUS ONE. && .AVIATION /15Z THURSDAY THROUGH MONDAY/... HIGH PRESSURE CENTERED OVER EASTERN CANADA WEAKENS LATE TODAY AND THIS EVENING...THEN IS REPLACED BY STRONGER HIGH PRESSURE BUILDING TO THE WEST LATE TONIGHT. MARGINAL VFR CEILINGS WITH STRATO CU HAVE DEVELOPED UNDER A LOW LEVEL INVERSION. CEILINGS HAVE SLOWLY BEEN DEVELOPING TOWARDS THE WEST...AND HAVE MADE IT TO KFRG AND KBDR. CONFIDENCE LOW ON JUST HOW FAR WEST THE MVFR CIGS WILL MAKE IT. WILL TEMPO THE CIGS IN A KJFK AND KLGA FOR A FEW HOURS LATE THIS MORNING AND EARLY AFTERNOON FOR THE MVFR CIGS. THE STRATO CU IS EXPECTED TO MIX OUT EARLY THIS AFTERNOON. THESE MVFR CIGS MAY BECOME DIFFICULT TO TRACK ON SATELLITE AS HIGHER CLOUDS WILL MOVE OVER THE LOWER DECK. WINDS WILL BE FROM THE NORTH TO NORTHEAST AND GENERALLY 10 KT OR LESS. SOME GUSTS WILL BE POSSIBLE ESPECIALLY ACROSS EASTERN TERMINALS. ...NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR A PERIOD OF MVFR CIGS LATE THIS MORNING EARLY AFTERNOON. IF CIGS DEVELOP...EXPECT HEIGHTS BETWEEN 2-3KFT. KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR A PERIOD OF MVFR CIGS LATE THIS MORNING EARLY AFTERNOON. IF CIGS DEVELOP...EXPECT HEIGHTS BETWEEN 2-3KFT. KEWR FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KTEB FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED. KHPN FCSTER COMMENTS: OCCASIONAL GUSTS INTO THE UPPER TEENS POSSIBLE TODAY. KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR MARGINAL VFR CEILINGS. OCCASIONAL GUSTS INTO THE UPPER TEENS POSSIBLE. .OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY... .FRIDAY-SUNDAY...VFR. .MONDAY...MOST LIKELY VFR...SMALL CHANCE OF MVFR. && .MARINE... MARGINAL SCA CONDITIONS CONTINUE ON THE OCEAN WATERS INTO FRI...PRIMARILY FOR HAZARDOUS SEAS AROUND 5 FT. A PERSISTENT N/NE FLOW AND A SE SWELL FROM OFFSHORE LOW PRESSURE ARE THE REASONS FOR THE HIGH SEAS. A GRADUALLY STRENGTHENING NE FLOW THROUGH THE WEEKEND INTO EARLY NEXT WEEK WILL RESULT IN BUILDING SEAS ON THE OCEAN WATERS...WHICH ARE EXPECTED TO REMAIN ABOVE SCA CRITERIA INTO EARLY NEXT WEEK. AS A COASTAL LOW PRESSURE FORMS OFF THE SOUTHEAST COAST...THE GRADIENT STRENGTHENS BETWEEN IT AND HIGH PRESSURE TO THE NORTH. WINDS INCREASE TO ABOVE SCA CRITERIA BUT NOT QUITE GALE STRENGTH. WAVES ALSO INCREASE AHEAD OF THE COASTAL SYSTEM AND WILL LIKELY STAY ABOVE SCA CRITERIA THROUGH THE PERIOD. IF THE STORM TRACKS CLOSER TO THE COAST THEN CURRENTLY FORECAST...WAVES COULD BE A FEW FEET HIGHER AND WINDS COULD POTENTIALLY REACH GALE FORCE. && .HYDROLOGY... DRY WEATHER IS EXPECTED THROUGH EARLY NEXT WEEK. && .TIDES/COASTAL FLOODING... HIGH ASTRONOMICAL TIDES WITH SLIGHTLY ANOMALOUS HIGH WATER LEVELS AND A LIGHT TO MODERATE NORTHEASTERLY FLOW RESULTED IN ANOTHER ROUND OF MINOR COASTAL FLOODING THIS MORNING WITH LEVELS A FEW INCHES HIGHER THAN THOSE OBSERVED WEDNESDAY MORNING. A PROLONGED NE FLOW THROUGH THE WEEKEND INTO EARLY NEXT MAY LEAD TO ADDITIONAL EPISODES OF MAINLY MINOR COASTAL FLOODING IN HISTORICALLY VULNERABLE LOCATIONS. THE THREAT OF A STRONG COASTAL STORM EARLY NEXT WEEK SEEMS MORE UNLIKELY BASED ON LATEST GUIDANCE. && .EQUIPMENT... THE NATIONAL WEATHER SERVICE DOPPLER WEATHER RADAR AT UPTON NEW YORK /KOKX/ IS UNAVAILABLE. THE RADAR MAY BE OUT OF SERVICE FOR UP TO 2 WEEKS. ADDITIONAL UPDATES WILL BE MADE AVAILABLE AS MORE INFORMATION BECOMES AVAILABLE. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ350-353-355. && $$ SYNOPSIS...LN/DW NEAR TERM...JST SHORT TERM...DW LONG TERM...LN AVIATION...BC/MET MARINE...LN/DW HYDROLOGY...DW TIDES/COASTAL FLOODING... EQUIPMENT...
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1058 AM EST THU NOV 15 2012 .DISCUSSION... LATEST RAP ANALYSIS SHOWS A WEAK H100-H85 TROF CENTERED OFF THE GA/SC COAST TRAILING BACK ACRS THE N GULF COAST...RESULTING IN A W/NW LOW/MID LVL FLOW ACRS CENTRAL FL. MOISTURE POOLING WITHIN THE TROF HAS ALLOWED A DENSE LYR OF STRATUS TO PERSIST ACRS THE CENTRAL PENINSULA. MORNING RAOBS SHOWED PWAT VALUES ACRS THE STATE BTWN 0.8"-1.1"...BUT WITH WIDE VARIANCE IN DISTRIBUTION THRU THE COLUMN THAT WELL DEPICT THE LATEST SAT IMAGERY. KJAX/KTAE MORNING RAOBS SHOW A STOUT INVERSION IN THE H100-H95 LYR...BOTH SATURATED THRU THE H80 LYR. INVERSION DISAPPEARS ON THE KTBW-KXMR SOUNDINGS THOUGH HIGH MOISTURE LVLS ARE APPARENT THRU THE H100-H70 LYR. KMFL SHOWED LITTLE IN THE WAY OF LOW LVL MOISTURE...SHOULD SEE DRIER AIR MIX DOWN OVER S FL THAT WILL ERODE THE STRATUS FROM SOUTH TO NORTH THRU THE AFTN. MID MORNING TEMPS REFLECT THE EXTENT OF THE CLOUD COVER...L/M70S ALONG THE TREASURE COAST WHERE CLOUDS HAVE BROKEN UP...L/M60S WHERE THE CLOUDS REMAIN. WITH DENSE LOW LVL CLOUDS HOLDING FIRM OVER MUCH OF THE CWA...HAD TO REWORK POPS TO REFLECT HIGHER CHANCES WHERE THE CLOUDS HAVE BROKEN UP AND LOW LVL HEATING WILL MOST LIKELY OCCUR. W/NW FLOW THRU THE LOW/MID LVLS WILL LIMIT THE POTENTIAL FOR TSRA...WILL GO WITH SHRAS INSTEAD. DROPPED MAX TEMPS A FEW DEGS TO REFLECT CLOUD AS WELL. && .AVIATION... THRU 15/18Z...IFR CIGS/MVFR VSBYS IN LOW STRATUS/MIST/FOG N OF KVRB/KOBE...PREVAILING VFR S OF KVRB WITH TEMPO IFR CIGS. BTWN 15/18Z-15/20Z...P6SM ALL SITES...AREAS MVFR CIGS BTWN FL020-030 N OF KTIX-KISM. BTWN 15/20Z-16/04Z...VFR ALL SITES...PREVAILING CIGS BTWN FL035-050. AFT 16/04Z...IFR CIGS/MVFR VSBYS DVLPG ALL SITES. && .MARINE... NNW WINDS TO 15 TO 20 KNOTS ACROSS THE NRN WATERS AND SEAS TO 7 FT OFFSHORE WILL NECESSITATE A SMALL CRAFT ADVISORY FOR THE VOLUSIA AND BREVARD COUNTY COASTAL WATERS. STRONGEST WINDS/HIGHEST SEAS ARE NORTH OF CAPE CANAVERAL ACROSS THE NRN BREVARD/VOLUSIA WATERS BUT HAVE DECIDED TO RAISE ADVISORY FOR CENTRAL AND NRN MARINE AREAS BASED ON RECENT 41009 WIND/SEA TRENDS THE LAST SEVERAL HOURS. WILL CONTINUE ADVISORY INTO THIS EVENING BUT WILL LIKELY NEED TO BE EXTENDED FOR PORTIONS OF THE NORTHERN WATERS INTO TONIGHT AND FRIDAY. && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ SHORT TERM/AVIATION...BRAGAW MARINE/IMPACT WX......VOLKMER
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
800 AM EST THU NOV 15 2012 .UPDATE (REST OF TODAY AND TONIGHT)... 13Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A NORTHERN STREAM FLOW CARVING OUT A BROAD TROUGH ACROSS THE CENTRAL/EASTERN PORTION OF THE CONUS. SHORTWAVE TROUGH EMBEDDED WITHIN THE LARGE SCALE FLOW HAS BEEN PASSING TO OUR NORTH EARLY THIS MORNING AND HAS NOW PASSED OUR LONGITUDE AS IT TAKES ON A NEGATIVE TILT AND BEGINS TO PIVOT UP THE EASTERN SEABOARD. 12Z KTBW SOUNDING SHOWS A MOIST BOUNDARY LAYER UNDER INCREASINGLY DRY MID-LEVELS IN ASSOCIATION WITH THE DEEP LAYER SUBSIDENCE IN THE WAKE OF THE PASSING SHORTWAVE. THIS SUBSIDENCE OVER-TOP THE MOIST BOUNDARY LAYER HAS PROVIDED A GOOD SETUP FOR THE DEVELOPMENT OF THE WIDESPREAD LOW STRATUS/FOG SEEN ACROSS THE REGION THIS MORNING. THE WEAKER MID-NOVEMBER SUN ANGLE WILL NOT AID IN ANY RAPID DISSIPATION OF THIS LAYER...AND WOULD EXPECT MOSTLY CLOUDY SKIES TO PERSIST IN SPOTS LIKELY INTO THE LATER MORNING HOURS BEFORE ANY SIGNIFICANT BURN OFF COMMENCES. LATEST NARRE (NORTH AMERICAN RAPID REFRESH ENSEMBLE) CEILING PROBABILITIES ARE IN LINE WITH THIS THINKING AND 12Z TAF PACKAGE HAS BEEN PREPARED ACCORDINGLY. ONCE THE LOW STRATUS BURNS OFF...WILL BE LOOKING FOR A FAIR AND GENERALLY DRY DAY UNDER PARTLY CLOUDY SKIES. TEMPERATURES WILL BE A BIT TRICKY DEPENDING ON JUST WHEN WE SEE THE SUN BREAK THROUGH AND THE RESULTING POTENTIAL LOSS IN TOTAL INSOLATION THROUGH THE DAY. WITH A LATE MORNING/MIDDAY BURN OFF EXPECTED...SHOULD STILL BE ABLE TO MIX OUT TO AFTERNOON HIGHS IN THE LOW 80S SOUTH OF I-4 AND MID/UPPER 70S FURTHER NORTH. WILL CONTINUE TO MONITOR THE PROGRESS OF THE STRATUS ON THE GOES-E CLOUD THICKNESS HEIGHT ANALYSIS AND MAKE ANY ADJUSTMENT TO THE TEMPS/SKY COVER GRIDS AS NECESSARY. FOR TONIGHT...A GENERAL ZONAL FLOW WILL BE DOMINANT IN THE MID/UPPER LEVELS OVER THE FLORIDA PENINSULA AS LARGE SCALE TROUGHING DIGS SOUTH INTO THE WESTERN/CENTRAL GULF OF MEXICO. ANY SYNOPTIC LIFT/SUPPORT ASSOCIATED WITH THIS FEATURE SHOULD NOT ARRIVE FOR OUR AREA UNTIL DURING THE DAY ON FRIDAY...AND EVEN THEN BE WEAK. THEREFORE STILL ANTICIPATE A DRY OVERNIGHT PERIOD. RESIDUAL BOUNDARY LAYER MOISTURE MAY AGAIN RESULT IN AREAS OF LOW STRATUS AFTER MIDNIGHT...HOWEVER THE COVERAGE/EXTENT SHOULD NOT BE AS GREAT AS WHAT IS BEING OBSERVED THIS MORNING. LOW TEMPS WILL BE SEASONABLE WITH GENERALLY MID/UPPER 50S AWAY FROM THE COAST. NORTH OF BROOKSVILLE THE TEMPS MAY BRIEFLY REACH THE LOWER 50S...ESPECIALLY IF THE STRATUS COVERAGE IS MINIMAL. && .AVIATION... PREVAILING IFR/LIFR CEILINGS AND VISIBILITIES FROM LOW CLOUDS AND FOG EARLY THIS MORNING WILL LIFT AFTER 15/16Z WITH VFR CONDITIONS DEVELOPING AT ALL TERMINALS. THERE WILL BE A SLIGHT CHANCE OF A SHOWER MAINLY IN THE VICINITY OF LAL...PGD...RSW AND FMY DURING THE AFTERNOON. NORTHEAST WINDS IN THE 5 TO 8 KNOT RANGE THIS MORNING WILL BECOME NORTH TO NORTHWEST AT 8 TO 10 KNOTS AFTER 15/18Z. && .MARINE... SURFACE HIGH PRESSURE WILL CONTINUE TO RIDGE SOUTH SOUTHWEST FROM NEW ENGLAND INTO THE GULF OF MEXICO WITH NORTHERLY FLOW TODAY BECOMING NORTHEASTERLY AND INCREASING OVER THE WEEKEND INTO EARLY NEXT WEEK. WINDS COULD REACH EXERCISE CAUTION...POSSIBLY ADVISORY CRITERIA OVER THE WEEKEND. && .PRELIMINARY POINT TEMPS/POPS... TPA 78 61 78 61 / 10 10 20 20 FMY 82 62 81 62 / 10 10 20 20 GIF 79 58 77 59 / 20 10 20 20 SRQ 79 60 79 61 / 10 10 20 20 BKV 77 54 77 55 / 10 10 20 20 SPG 78 63 78 63 / 10 10 20 20 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ UPDATE...MROCZKA AVIATION...MCMICHAEL
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1014 AM EST THU NOV 15 2012 .SYNOPSIS... A WEAK AREA OF LOW PRESSURE WILL TRACK ACROSS THE CAROLINAS AND OFF THE COAST TODAY INTO EARLY FRIDAY MORNING. A LARGE AREA OF HIGH PRESSURE WILL BUILD ACROSS THE GREAT LAKES AND INTO NEW ENGLAND FRIDAY AFTERNOON THROUGH SATURDAY. LOW PRESSURE WILL DEVELOP OFF THE SOUTHEAST COAST SATURDAY NIGHT THROUGH SUNDAY...THEN SLOWLY TRACK EAST NORTHEAST OUT TO SEA MONDAY INTO TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WDSPRD CLDNS OVR THE RGN RIGHT NOW...AND LIKELY TO CONT THROUGH THE REST OF THE DAY. WK/DE-AMPLIFYING S/W TRACKING THROUGH THE CAROLINAS W/ WK SFC LO PRES OFFSHR CONTG TO SPREAD MSTR NWD INTO THE RGN. LGT RA HAVING DIFFICULTY SPREADING N THROUGH CNTRL/ERN NC. LATEST RUC FOLLOWS CURRENT FCST IN KEEPING RA MNLY S OF THE VA/NC BRDR LATER TDA INTO TNGT AS SYS EXITS OFF THE CST. MINOR ADJSTMNTS MADE TO TEMPS...W/ HI TEMPS FM THE U40S-ARND 50F W OF I95...TO RANGING THROUGH THE 50S TO THE E. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... BEST LO LVL MOISTURE/LIFT FCST RMN INVOF SE VA AND NE NC WHERE CURRENT POPS OF 30-40% STILL LUK GOOD FOR TNGT INTO EARLY FRI MORNG. SLGT CHC POPS OF 20% WILL COME INTO A LINE EXTENDING FM AVC-JGG-OXB. LOWS TNGT RANGING FM THE LWR 30S TO THE LWR 40S. A LARGE AREA OF HI PRES WILL BLD ACRS THE GRT LKS AND INTO NEW ENGLAND FRI AFTN THRU SAT. WHILE MOISTURE RIBBON WILL LINGER INVOF THE CSTL CAROLINAS FM FRI AFTN THRU SAT...THE HI PRES SHOULD KEEP OUR WX DRY DURING THE PERIOD...WITH MORE CLOUDINESS POSSIBLE OVER NE NC. OTHRWISE...EXPECT A PRTLY OR MSTLY SNY SKY ACRS MUCH OF THE REGION BOTH DAYS...WITH HI TEMPS IN THE LWR TO MID 50S. LOWS FRI NGT RANGING THRU THE 30S TO ARND 40. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... MODELS STILL HAVING DIFFICULTY RESOLVING PROGRESS OF UPPER LEVEL TROUGH THROUGH THE MEDIUM RANGE PERIOD. GOOD AGREEMENT WITH UPPER LEVEL FEATURES INITIALLY AS MAJORITY OF ENSEMBLES AND OPERATIONAL GFS/ECMWF SHOW SPLIT FLOW DEVELOPING, WITH A PIECE OF UPPER SHORTWAVE ENERGY SPLITTING OFF FROM NORTHERN STREAM AND DROPPING ACROSS THE SOUTHEAST US SAT-SUN, EVENTUALLY DEVELOPING INTO A AMPLIFYING/DIGGING CLOSED UPPER LOW OVER THE SOUTHEAST BY LATE IN THE WEEKEND. DIFFERENCES SPRING FROM THERE, WITH BULK OF UNCERTAINTY IN THIS FORECAST PERTAINING TO EXTENT OF DIGGING AND THE POTENTIAL FOR SFC CYCLOGENESIS (DEVELOPING SFC LOW) ALONG THE SE COAST BY LATE IN THE WEEKEND. OPERATIONAL ECMWF (12Z) REMAINS A BIT FARTHER WEST WITH THE DEVELOPING UPPER TROUGH, WHICH WOULD SERVE TO BRING POTENTIAL DEVELOPING LOW PRESSURE CENTER CLOSER TO THE EAST COAST THAN THE FARTHER OFFSHORE GFS SOLUTION. STILL, APPEARS AS IF MODELS DO AGREE THAT BULK OF HEAVIER PCPN WILL REMAIN CONFINED OFFSHORE. FORECAST CONFIDENCE IS HIGH ENOUGH ATTM TO CONTINUE RAMPING RAIN CHCS SUNDAY, WITH HIGHEST (~50%) POP ACROSS COASTAL ZONES SUNDAY AND SUNDAY NIGHT, WITH LOWER (SLIGHT TO LOW CHC AT BEST) RAIN CHCS SUN/SUN NIGHT WEST OF I-95. LATER IN THE PERIOD, ECMWF ALSO SHOWING SIGNS OF DEVELOPING A RATHER SHARP REX BLOCKING TYPE SIGNATURE IN THE NORTHERN ATLANTIC EARLY NEXT WEEK. WHILE THE UPPER LOW ITSELF WOULD SLIDE OFF THE EAST COAST MON-TUE, SLIDING BEST RAIN CHCS OFFSHORE WITH IT, THE PROGRESS OF NEXT MID-UPPER TROUGH ARRIVING FROM THE MIDWEST WOULD LIKELY LEAD TO A PROLONGED PERIOD OF COOL NE FLOW. ACCORDINGLY, WENT WITH MOSTLY CLDY CONDITIONS PERSISTING FOR MUCH OF EARLY NEXT WEEK IN DIGITAL DB, WITH LOW RAIN CHCS ACROSS COASTAL ZONES (DRY INLAND). CLOUDS WOULD KEEP TEMPS AVERAGING BELOW NORMAL THROUGH THE PERIOD. HIGHS GENERALLY IN THE 50S, LOWS IN THE 30S INLAND TO L40S AT THE COAST. && .AVIATION /15Z THURSDAY THROUGH MONDAY/... BKN/OVC CONDITIONS IN PLACE ACRS THE REGION...WITH 2-3 K FT CIGS EXPECTED TO SLOWLY LOWER TO 1-2 K FT BETWEEN 09-15Z. SOUNDINGS AND CURRENT OBS DO NOT SHOW MUCH CHANCE FOR CIGS TO DROP BELOW 1 K FT (IFR) BUT IT COULD BE CLOSE ALONG THE COAST. WINDS TODAY WILL BE N/NE AVERAGING 10-15 KT AT KORF/KECG AND 10 KT OR LESS ELSEWHERE. HAVE ADDED -RA TO KECG FOR MUCH OF THE DAY...CHANCE FOR -RA ELSEWHERE AS WELL BUT GENLY SHOULD NOT HAVE MUCH AFFECT ON VSBYS. OUTLOOK...WEAK SYSTEM SLIDES OFF THE COASTAL CAROLINAS TONIGHT AND MAINLY DRY CONDITIONS WILL PREVAIL ALTHOUGH LOW CLOUDS PERSIST ESPECIALLY SE VA/NE NC. CLEARING/VFR FRI...WITH ANOTHER PERIOD OF LOWER CIGS AND A CHANCE FOR RAIN LATE SAT-SUN. N/NE FLOW PREVAILS THROUGHOUT...AND WILL TEND TO INCREASE AGAIN SUN/MON CLOSER TO THE COAST. && .MARINE... LATEST OBS REFLECT N/NE FLOW 15 TO 20 KT ACROSS THE MAJORITY OF THE WATERS...WITH SOMEWHAT LOWER WIND SPEEDS IN THE UPPER BAY AND RIVERS OUTSIDE OF THE LOWER JAMES. SEAS OVER ATLANTIC COAST ZONES STILL AVG 5-7 FT...WAVES OVER THE CENTRAL/SOUTHERN BAY 3-4 FT. LATER TODAY/TONIGHT...MODELS ALL GENLY AGREE THAT THE SURGE AND PRESSURE GRADIENT SLACKENS OFF A LITTLE MORE SO SCA`S OVER BAY/SND SLATED TO COME DOWN THIS EVENING...WHILE SCA`S REMAIN IN EFFECT FOR THE COAST AS SEAS ARE EXPECTED TO REMAIN 4-5 FT OR HIGHER. A BIT OF A LULL IN THE GRADIENT FRI-SAT...BUT STILL WITH CONDITIONS THAT ARE AT LEAST CLOSE TO SCA LEVELS IN THE BAY/RIVERS/SOUND SO IT WILL BE LESS THAN IDEAL BOATING THROUGHOUT THE REGION (SCA`S WILL LIKELY NEED TO BE EXTENDED FOR THE COASTAL WATERS FOR 4-5 FT SEAS). LATER SAT INTO SUN SUN/MON...STRONG HIGH PRESSURE BUILDS INTO NEW ENGLAND...AS ANOTHER AREA OF SFC LOW PRESSURE IS EXPECTED TO DEVELOP OFF THE COASTAL CAROLINAS BY LATE IN THE WEEKEND. RE-TIGHTENING OF PRESSURE GRADIENT BETWEEN THESE FEATURES IS LIKELY TO RESULT IN ANOTHER PERIOD OF STRONG SCA CONDITIONS (POSSIBLY RAMPING UP TO LOW END GALES BY LATE SUNDAY ON THE COAST). WHILE THE SYSTEM APPEARS WEAKER THAN PREVIOUS MODEL RUNS...SCA CONDITIONS ARE STILL VERY LIKELY TO PERSIST THROUGH THE MUCH OF THE FIRST HALF OF NEXT WEEK. SEAS AVG 6-9 FT ON THE COAST...WITH WAVES IN THE BAY 3-5 FT SUN-MON. && .TIDES/COASTAL FLOODING... CONTINUED N/NE WINDS 15-20 KT TODAY ACRS MUCH OF THE MARINE AREA...AND HAVE HOISTED A COASTAL FLOOD ADSY FOR PORTIONS OF THE OCEAN SIDE OF THE ERN SHORE FOR VERY MARGINAL MINOR FLOODING W/ THE UPCOMING LATE MORNING TIDE CYCLE (SEE CFWAKQ FOR DETAILS). THE ANOMALIES ARE ONLY ABOUT 1 FOOT BUT THE ASTRONOMICAL TIDES ARE RATHER HIGH DUE TO THE NEW MOON CYCLE. FARTHER SOUTH ANOMALIES ARE RUNNING 0.5 TO 1 FOOT ABOVE NORMAL BUT THE WATER LEVELS LOOK TO STAY ABOUT 0.5 FT BELOW THRESHOLDS (WILL MENTION PORTIONS OF HAMPTON ROADS IN THE HWO FOR NUISANCE FLOODING POSSIBLE RIGHT AT THE TIME OF HIGH TIDE THIS MORNING). THE NEXT HIGH TIDE CYCLE THAT MAY BE CLOSE TO MINOR FLOODING THRESHOLDS WILL BE LATE THIS EVENING/TONIGHT. WINDS GENLY LOOK TO SLACKEN OFF THOUGH SO AGAIN IT WILL BE VERY MARGINAL SO WILL LET NEXT SHIFT EVALUATE NEED FOR THIS LATER TODAY. FOR THE WEEKEND/EARLY NEXT WEEK...PATTERN OF A VERY STRONG/1040 MB SFC HIGH BUILDING INTO NEW ENGLAND AND A TROUGH OFF THE SE COAST WOULD MAKE WINDS TURN MORE TO THE NE (RATHER THAN N)...LEADING TO THE POTENTIAL FOR MORE TIDAL FLOODING. LATEST MODEL TRENDS ARE A LITTLE SLOWER...WEAKER...AND MORE OFFSHORE WITH THE TRACK OF THE EVENTUAL COASTAL SYSTEM...WHICH WOULD SUGGEST LESS OF A FLOODING IMPACT THAN WHAT WAS PREVIOUSLY ANTICIPATED. THERE IS STILL TOO MUCH UNCERTAINTY AND THE FACT THAT THE GFS-BASED MDL GUIDANCE IS NOT SHOWING MUCH OF AN ANOMALY ON SUNDAY COULD JUST BE DUE TO THE GUIDANCE BEING UNDERDONE THIS FAR OUT IN THE PERIOD. IN ANY EVENT...WILL NEED TO CONTINUE TO MONITOR AND WOULD EXPECT AT LEAST SOME MINOR TIDAL FLOODING ACRS PORTIONS OF THE AREA SUN/MON. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...COASTAL FLOOD ADVISORY UNTIL NOON EST TODAY FOR MDZ024-025. NC...NONE. VA...COASTAL FLOOD ADVISORY UNTIL NOON EST TODAY FOR VAZ099. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ632>634. SMALL CRAFT ADVISORY UNTIL NOON EST TODAY FOR ANZ631-638. SMALL CRAFT ADVISORY UNTIL 6 PM EST FRIDAY FOR ANZ654-656-658. SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ650-652. && $$ SYNOPSIS...ALB/TMG NEAR TERM...ALB/TMG SHORT TERM...ALB/TMG LONG TERM...MAM AVIATION...LKB MARINE...LKB TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
651 AM EST THU NOV 15 2012 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 423 AM EST THU NOV 15 2012 00Z RAOBS AND RUC ANALYSIS SHOW PRETTY QUIET WESTERLY SPLIT FLOW ALOFT WITH MINIMAL H5 HEIGHT FALLS OR RISES NOTED UPSTREAM. STRONGEST SHORTWAVE WITHIN THE FLOW IS IN THE NORTHERN STREAM PUSHING ACROSS MANITOBA INTO NORTHERN ONTARIO. COLD FRONT ASSOCIATED WITH THIS WAVE IS STRONG. TEMPS HAVE FALLEN INTO THE TEENS IN CENTRAL MANITOBA AND INTO SINGLE NUMBERS BACK OVR SASKATCHEWAN. BATCH OF HEAVIER SNOW IS ACCOMPANYING THE FRONT IN NORTHERN MANITOBA...BUT NOT MUCH IS OCCURRING FARTHER SOUTH ALONG THE COLD FRONT. ONLY OTHER SHORTWAVE RELATIVELY CLOSE BY IS MOVING ACROSS CENTRAL MINNESOTA. DESPITE DRY LOW-LEVELS SEEN OVER AREA LAST DAY...THIS WAVE IS STRONG ENOUGH TO PRODUCE SOME LGT SHRA OVER ECNTRL MN WITHIN LAST 2 HOURS. OVER UPR MICHIGAN IT IS ANOTHER NIGHT WITH A LOT OF MID CLOUDS BUT NO PRECIP. TEMPS IN MANY AREAS EARLY THIS MORNING ARE CLOSE TO WHAT IS A TYPICAL NORMAL HIGH TEMP FOR 15 NOVEMBER AKA THE FIRE ARM RIFLE DEER HUNTING OPENER FOR MICHIGAN. AS NORTHERN STREAM TROUGH PRESSES EAST TODAY...ASSOCIATED SFC LOW MOVES ACROSS HUDSON BAY AND SFC COLD FRONT TAKES AIM ON UPR MICHIGAN LATE TODAY. UNTIL ARRIVAL OF THE FRONT...DEPENDING ON EXTENT OF CLOUD COVER...APPEARS WE COULD HAVE MAKING OF FAIRLY WARM DAY. MID CLOUDS ALREADY TRYING TO SCT OUT OVER WESTERN UPR MICHIGAN AND AT LEAST PARTIAL SUNSHINE IS EXPECTED FOR MUCH OF WESTERN AND CENTRAL CWA THIS MORNING. WILL HAVE TO WATCH WI BORDER THOUGH AS SHORTWAVE OVR MN MAY PUSH CLOSE BY ENOUGH TO AT LEAST INCREASE CLOUDS AGAIN THIS MORNING AND EVEN PRODUCE A FEW SPRINKLES TOWARD KIMT. MIXING TO 925MB SUPPORTS TEMPS WELL INTO THE 40S BY MID AFTN WITH DOWNSLOPE SW WINDS PUSHING READINGS INTO LOWER 50S NEAR LK SUPERIOR NCNTRL IF CLOUDS ARE DELAYED. BY MID AFTN...EXPECT MID CLOUDS /H8-H7 RH/ TO BUILD BACK OVER CWA FROM THE SOUTHWEST WHILE BATCH OF CLOUDS JUST AHEAD OF COLD FRONT SLIDE INTO CWA FROM ONTARIO. FORECAST SOUNDINGS INDICATE THERE WILL BE ENOUGH DEEPER MOISTURE AND UVM WITHIN ICE NUCLEATION ZONE TO GENERATE A FEW SHOWERS AFT 21Z. SREF/HIGHER RES MODELS FROM NCEP AND NAM/LOCAL WRF-ARW AGREE PRECIP MAINLY AFFECTS ALGER/SCHOOLCRAFT/LUCE. DAYTIME HEATING INCREASES 1000-H85 LAPSE RATES OVR MUCH OF EAST HALF AHEAD OF FRONT...SO ALSO ADDED ISOLD MENTION AS FAR WEST AS MARQUETTE/DELTA COUNTIES. PTYPE ONLY RAIN AS WBZERO HEIGHTS ARE WELL ABOVE 1KFT AGL. ONLY POSSIBILITY OF SEEING SOME SNOW MIXING IN WOULD BE OVER HIGHER TERRAIN OF MQT COUNTY IN EVENING...BUT MOST OF SYNOPTIC PRECIP SHOULD DONE BY THIS TIME. ONCE FRONT MOVES THROUGH...A PORTION OF COLD AIR SEEN UPSTREAM WILL MAKE RUN ACROSS LK SUPERIOR AND INTO UPR MICHIGAN. IT IS A SHALLOW COLDER AIRMASS OVR MANITOBA AS 925MB TEMPS ARE COLDER THAN THOSE AT 850MB. SETUP TONIGHT OVER UPR MICHIGAN NO DIFFERENT. NORTHWEST WINDS IN WAKE OF FRONT EVENTUALLY TURN MORE NORTHERLY AS SFC HIGH CURRENTLY OVR NORTHERN ROCKIES AND NORTHERN PLAINS EXTENDS A RIDGE INTO NORTHERN ONTARIO AND NORTHERN LK SUPERIOR. NORTH LOW-LEVEL WINDS ALONG WITH INCREASING SUB H85 MOISTURE SEEN ON UPSTREAM SOUNDINGS AT YQD /CNTRL MANITOBA/ AND YSM /NORTHWEST TERRITORIES/ ALONG WITH LOWERING SUBSIDENCE INVERSION /TEMPS AT INVERSION TOP AROUND -7C/ CONTINUE TO SUPPORT GOING FCST OF FZDZ OR FLURRIES OVR HIGHLANDS OF NCNTRL UPR MICHIGAN. DESPITE INCREASING CLOUDS...PREFER TO GO COLDER WITH MINS TONIGHT WITH SHALLOW INVERSION/STABLE TEMP PROFILE. MOST AREAS WILL FALL INTO THE 20S WEST/CNTRL WITH NEAR 30 FOR EASTERN CWA. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 423 AM EST THU NOV 15 2012 A FAIRLY QUIET PERIOD OF WX IS IN STORE THRU THIS WEEKEND AS A ZONAL FLOW OF RELATIVELY MILD PACIFIC AIR DOMINATES. FRI...SFC HI PRES RDG AXIS IS FCST TO MOVE FM MN INTO NW ONTARIO TO AN A LINE FM UPR MI INTO ONTARIO BY 00Z SAT AS H5 RDG BUILDS OVER THE UPR LKS. PREFER THE CLOUDIER NAM DEPICTION OF EVENTS GIVEN FCST SHARP INVNR ARND 3K FT ENHANCED BY SHALLOW COLD INFUSION AND TRAPPING LLVL AIRMASS MOISTENED IN PASSAGE OVER LK SUP. ONCE THE HI PRES RDG PASSES TO THE E...EXPECT STUBBORN LO CLDS TO BREAK UP AS THE FLOW TURNS OFFSHORE. BUT OVER THE NCNTRL...THIS WSHFT IS NOT FCST TO OCCUR UNTIL LATE IN THE DAY. SO SUSPECT THE DAY WL BE MOCLDY IN THIS AREA...WITH SOME MRNG -FZDZ OVER THE HIER TERRAIN OF THE NCENTRAL WHERE LLVL N VEERING E WIND UPSLOPES AND LLVL MSTR REMAINS TRAPPED BLO SHARP INVRN BTWN H9-925 MAINTAINED BY DEEP LYR QVECTOR DVGC/SUBSIDENCE. EVEN OVER THE W... FCST LIGHT WINDS SUG THE LO CLD MAY BE QUITE TENACIOUS GIVEN SHARP LO INVRN BASE THAT TRAPS THE LLVL MSTR. AREAS FM IWD-ONTONAGON- KEWEENAW PROBABLY HAVE THE BEST SHOT AT SEEING SOME CLRG WITH A MORE PRONOUCNED DOWNSLOPE WIND COMPONENT. DVLPG E FLOW OFF LK MI WL ALSO BRING ABOUT MORE SC OVER THE SCENTRAL...BUT THERE MAY SOME PARTIAL CLRG OVER THE E WITH DOWNSLOPING OFF ONTARIO AND LOSS OF LK MOISTENING COMPONENT. WITH PLENTY OF CLD COVER LINGERING ALL DAY OVER THE NCENTRAL...MAX TEMPS MAY STRUGGLE TO RISE ABV 32 ACRS THE HIER TERRAIN IN THAT AREA. FRI NGT...AS HI SHIFTS TO THE E...THE LLVL WINDS WL VEER MORE TO THE S. IN CONCERT WITH INVRN SINKING CLOSER TO THE SFC AS SHOWN BY NAM FCST SDNGS...THIS FLOW SHOULD ALLOW THE SKY TO BECOME CLR TO PCLDY. DESPITE THE CLRG...INCRSG S WINDS WL TEND TO LIMIT THE DIURNAL TEMP FALL AT LEAST OVER THE W. THE LOWEST MIN TEMPS SHOULD BE OVER THE INTERIOR CENTRAL AND E WHERE THE H925 WINDS WL BE AOB 10 KTS MOST IF NOT ALL OF THE NGT. WITH PWAT AOB 0.25 INCH...TENDED AOB THE LO END OF GUIDANCE FOR MIN TEMPS IN THIS AREA EVEN THOUGH SOME HI CLDS MIGHT ARRIVE OVERNGT IN MORE WSW FLOW ALF. SAT THRU SUN...THE UPR GRT LKS WL BE DOMINATED BY STEADY SW FLOW BTWN HI PRES DRIFTING INTO NEW ENGLAND AND LO PRES TROF IN THE PLAINS DOWNWIND OF DEEPENING WRN TROF. DESPITE THE STRENGTHENING SSW LLVL FLOW...MODELS ADVERTISE LTL MOISTENING IN THE LO-MID LVLS. BUT WSW FLOW ALF WL BRING SCT-BKN HI CLDS. TEMPS WL AVG ABOVE NORMAL THRU THE WEEKEND WITH H85 TEMPS FCST FM 1 TO 4C. THE HIEST TEMPS SHOULD BE OVER THE DOWNSLOPE AREAS NEAR LK SUP ON SUN DESPITE SOME THICKER HI CLD. EXTENDED...GUIDANCE INDICATES THE PERSISTENT SW FLOW FM THE SRN PLAINS INTO THE UPR GRT LKS ON WRN FLANK OF HI PRES OVER THE NE CONUS MAY TAP MORE MOIST AIRMASS BY MON. AS DIFFICULT TO TIME SHRTWVS EJECT FM THE WRN TROF EWD TOWARD THE UPR GRT LKS EARLY NEXT WEEK...MODEL CONSENSUS INDICATES SCHC POPS ARE WARRANTED FOR MON THRU WED. GUIDANCE SEEMS TO HAVE TRENDED TOWARD KEEPING THE TROF OUT W LONGER...SO LATER UPDATES MAY TREND TOWARD DRIER WX. TEMPS WL REMAIN WELL ABV THE SEASONAL NORM WITH PACIFIC AIR DOMINATING UNDER WSW FLOW ALF. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 649 AM EST THU NOV 15 2012 SCT-BKN MID CLOUDS /VFR CONDITIONS/ EXPECTED THROUGH EARLY AFTN AT ALL TAF SITES. SW WINDS MAY GUST TO 20 KTS MID MORNING THROUGH EARLY AFTN. COLD FRONT CURRENTLY OVER SOUTHERN MANITOBA ARRIVES MID-LATE AFTERNOON AT IWD AND CMX THEN BY EVENING AT SAW. MVFR CIGS LIKELY THROUGH TONIGHT IN WAKE OF THE FRONT. AT SAW...WINDS BECOMING NORTHERLY AND ADDITIONAL MOISTURE FROM LK SUPERIOR COULD SUPPORT IFR CIGS AND FLURRIES/FZDZ LATE TONIGHT. JUST HINTED AT THIS POSSIBILITY IN THE TAF DUE TO UNCERTAINTY OF EXTENT OF LOW-LEVEL MOISTURE. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 423 AM EST THU NOV 15 2012 EXPECT S-SW WINDS UP TO 25-30 KTS TODAY IN ADVANCE OF APPROACHING COLD FNT TO SHIFT TO THE N-NW THIS AFTERNOON/EVENING ONCE THE FRONT PASSES W-E ACROSS THE LAKE. NOT OUT OF THE QUESTION THERE COULD BE A FEW GALE FORCE GUSTS JUST AHEAD OF THE FRONT MAINLY OVER THE NCENTRAL LAKE WITH TERRAIN BETWEEN ISLE ROYALE AND THE KEWEENAW ENHANCING EXPECTED WSW WIND. APPROACH OF TRAILING HI PRES WILL THEN CAUSE QUICKLY DIMINISHING WINDS BY FRI WHICH WILL CONTINUE THRU FRI NIGHT. OVER THE WEEKEND INTO EARLY NEXT WEEK...LAKE SUP WILL BE DOMINATED BY S WINDS BETWEEN HI PRES MOVING INTO NEW ENGLAND AND A LO PRES TROF IN THE PLAINS. THE STRONGEST S WINDS UP TO 25 KTS DURING THIS PERIOD ARE MOST LIKELY OVER THE E HALF OF THE LAKE. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLA LONG TERM...KC AVIATION...JLA MARINE...KC
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1258 PM MST THU NOV 15 2012 .UPDATE...STRATUS DECK GRADUALLY BREAKING UP. CLOUDS WILL BE MOST PERSISTENT AGAINST THE FOOTHILLS FROM BOULDER TO FORT COLLINS BUT EVEN THERE SHOULD CLEAR BY LATE AFTERNOON. && .AVIATION...SOME STRATOCUMULUS HAD DEVELOPED WHERE CEILINGS HAD BROKEN UP AT KDEN...ENOUGH FOR TEMPO BROKEN NEAR 4000 FT AGL TIL 21Z-22Z. MEANWHILE...KAPA SHOULD ONLY SEE SCT CLOUDS...WHILE KBJC SHOULD FINALLY SEE ORIGINAL STRATUS DECK BREAK UP AROUND 22Z. OTHERWISE VISUAL LANDING CONDITIONS WILL PREVAIL THROUGH FRIDAY WITH LIGHT WINDS. && .PREV DISCUSSION... /ISSUED 751 AM MST THU NOV 15 2012/ UPDATE... SHORT TERM...CLOUD DECK HAS BECOME MORE EXTENSIVE OVER THE PLAINS THIS MORNING AND EVEN LIGHT SNOW AND FLURRY BAND HAS SAGGED A BIT FURTHER SOUTH INTO BOULDER AND NORTHERN JEFFERSON COUNTY. DON`T EXPECT ANY ACCUMULATION THOUGH EXCEPT SOME DUSTING OVER NORTHERN WELD COUNTY. CHANGES TO FORECAST INCLUDE MORE CLOUDS AND GRADUAL CLEARING DURING THE EARLY AFTERNOON. ADDED LIGHT SNOW A BIT FURTHER SOUTH THAN CURRENT FORECAT. AVIATION...SOLID STRATUS DECK IN PLACE OVER LOCAL TERMINALS AND MAY EVEN SEE A FEW FLURRIES AT BJC AND DEN OVER THE NEXT FEW HOURS. NO ACCUMULATION EXPECTED THOUGH. WILL CONTINUE THE TREND OF LATER CLEARING AND MAY SEE ILS CONDITIONS AT DEN THROUGH EARLY AFTERNOON. PREV DISCUSSION... /ISSUED 717 AM MST THU NOV 15 2012/ UPDATE... AVIATION...STRATUS DECK HAS BECOME RATHER WIDESPREAD AND IS NOW COVERING ALL THE LOCAL TERMINALS WITH CEILINGS BETWEEN 2000 AND 4000 FEET AGL. WILL DELAY CLEARING INTO THE 17Z-19Z TIME FRAME GIVEN LATEST SOUNDINGS AND PER RUC FORECAST. PREV DISCUSSION... /ISSUED 547 AM MST THU NOV 15 2012/ UPDATE... AVIATION... AN AREA OF LOW CLOUDS HAS FORMED ON THE SOUTH SIDE OF THE SHOWER BAND...PROBABLY DUE TO COOLING FROM THE SHOWER OUTFLOW. CEILINGS BETWEEN 025 AND 040 LIKELY AT KDEN FOR THE NEXT COUPLE OF HOURS...IT MAY GET INTO KBJC BUT EXPECT THESE CLOUDS TO NOT MAKE IT TO KAPA. EXPECT THIS LAYER TO BREAK UP IN THE 14Z-16Z TIME FRAME AS THE SHOWERS FADE AND THE SURFACE WARMS. PREV DISCUSSION... /ISSUED 326 AM MST THU NOV 15 2012/ SHORT TERM...LITTLE SNOW BAND IN A WEAK FRONTOLYSIS ZONE THAT WAS PARKED OVER THE LARAMIE AND CHEYENNE AREAS MOST OF THE NIGHT HAS STARTED TO SAG SOUTH A BIT AS THE TROUGH AXIS GETS EAST OF US...BUT IS ALSO STARTING TO FALL APART AND SHRINK AT BOTH THE EASTERN AND WESTERN ENDS. THIS SHOULD CONTINUE TO DIMINISH AS THE QG LIFT GOES AWAY AND DRIER AIR UNDERCUTS THE MID LEVEL LIFT. CURRENT FORECAST HAS THESE SHOWERS ENDING BY 15Z WHICH IS PROBABLY ALRIGHT...I DID KEEP A FEW SHOWERS IN THE NORTHERN MOUNTAINS LATER THIS MORNING AS THE CLOUDS ON THE TAIL END OF THE BAND WILL LIKELY STILL BE OUT THERE. I ALSO SLOWED THE CLEARING ON THE PLAINS JUST A LITTLE...BUT EXPECT MOST OF THE CLOUDS TO BE GONE BY LATE AFTERNOON. NO CHANGES TO THE REST OF THE FORECAST...WEAK NORTHERLY WIND SURGE AND COOLER HIGHS TODAY APPEAR WELL HANDLED. LONG TERM...NOT MUCH TO CONTEND WITH THROUGH MONDAY. THE FLOW ALOFT WILL REMAIN SOUTHWESTERLY WITH A SERIES OF WEAK EMBEDDED DISTURBANCES SLIPPING ACROSS COLORADO. THERE WILL BE ENOUGH MOISTURE TO PRODUCE A SLIGHT CHANCE OF SNOW IN THE HIGH COUNTRY...BUT LIMITED MOISTURE AND PREVAILING DOWNSLOPE WILL KEEP THE LOWER ELEVATION MILD AND DRY. OVERALL...AFTERNOON TEMPERATURES WILL REMAIN SLIGHTLY ABOVE SEASONAL NORMALS. AVIATION...VFR CONDITIONS EXPECTED OVER THE DENVER AREA THROUGH TONIGHT...WITH LIGHT SNOW SHOWERS THIS MORNING REMAINING NORTH OF DENVER. WITH HIGH PRESSURE SHIFTING OVER THE NORTHERN PLAINS...EXPECT THE CURRENT WIND PATTERN TO BREAK DOWN WITH NORTH TO NORTHEAST WINDS DEVELOPING IN THE DENVER AREA BY SUNRISE. WINDS MAY STILL BE LIGHT AND SOMEWHAT VARIABLE THIS MORNING...BUT BY MIDDAY EXPECT STEADIER NE-E WINDS THAT WILL ROTATE TO SLY DRAINAGE WINDS THIS EVENING. EXPECT A DENVER CYCLONE TO DEVELOP TONIGHT SO SOME UNCERTAINTY ABOUT WIND DIRECTION AT KDEN/KAPA FOR FRIDAY MORNING...BUT FOG THREAT APPEARS LOW. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BARJENBRUCH LONG TERM....COOPER AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
140 PM EST THU NOV 15 2012 .SYNOPSIS (REST OF TODAY AND TONIGHT)... 18Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS THE NORTHERN STREAM FLOW CARVING OUT A BROAD TROUGH ACROSS THE CENTRAL/EASTERN PORTION OF THE CONUS. SHORTWAVE TROUGH EMBEDDED WITHIN THE LARGE SCALE FLOW PASSED TO OUR NORTH THIS MORNING AND IS NOW TAKING ON A NEGATIVE TILT AS THE FEATURE PIVOTS UP THE EASTERN SEABOARD. 12Z KTBW SOUNDING SHOWED A MOIST BOUNDARY LAYER UNDER INCREASINGLY DRY MID-LEVELS IN ASSOCIATION WITH THE DEEP LAYER SUBSIDENCE IN THE WAKE OF THE PASSING SHORTWAVE. THIS SUBSIDENCE OVER-TOP THE MOIST BOUNDARY LAYER PROVIDED A GOOD SETUP FOR THE DEVELOPMENT OF THE WIDESPREAD LOW STRATUS/FOG SEEN ACROSS THE REGION THIS MORNING. THE WEAKER MID-NOVEMBER SUN ANGLE SLOWED ANY RAPID DISSIPATION OF THIS LAYER. IT IS ONLY IN THE PAST HOUR OR SO THAT ANY VISIBLE THINNING OF THE STRATUS CAN BE SEEN IN SATELLITE IMAGERY. EXPECT THESE CLOUDS TO CONTINUE TO THIN OVER THE NEXT COUPLE OF HOURS WITH PARTLY CLOUDY SKIES BEING THE GENERAL RULE BY LATE AFTERNOON. AT THE SURFACE...A WEAK BOUNDARY IS NEARLY STATIONARY OVER THE SOUTHERN PORTION OF THE PENINSULA. GRADIENT BETWEEN THIS BOUNDARY AND 1030MB HIGH PRESSURE WELL TO OUR NORTHWEST IS FORCING A STEADY NORTH TO NORTHEAST LOW LEVEL FLOW ACROSS THE AREA. LOWERED PROJECTED HIGH TEMPS A COUPLE OF DEGREES OVER CENTRAL/NORTHERN ZONES THIS AFTERNOON AS THE STUBBORN CLOUDS HAVE LESSENED THE OVERALL INSOLATION THESE AREAS WILL SEE FOR THE DAY. && .SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)... TONIGHT...A GENERAL ZONAL FLOW WILL BE DOMINANT IN THE MID/UPPER LEVELS OVER THE FLORIDA PENINSULA AS LARGE SCALE TROUGHING DIGS SOUTH INTO THE WESTERN/CENTRAL GULF OF MEXICO. ANY SYNOPTIC LIFT/SUPPORT ASSOCIATED WITH THIS FEATURE SHOULD NOT ARRIVE FOR OUR AREA UNTIL DURING THE DAY ON FRIDAY...AND EVEN THEN BE WEAK. THEREFORE STILL ANTICIPATE A GENERALLY DRY OVERNIGHT PERIOD. RESIDUAL BOUNDARY LAYER MOISTURE SHOULD AGAIN ALLOW FOR THE DEVELOPMENT OF LOW STRATUS AFTER MIDNIGHT...HOWEVER THE COVERAGE/EXTENT SHOULD NOT BE AS GREAT AS WHAT WAS OBSERVED THIS MORNING. WILL FOLLOW CLOSELY WITH THE SREF CEILING PROBABILITIES WHICH SHOW THE HIGHEST CHANCES/COVERAGE FROM THE PUNTA GORDA AREA NORTHWARD. LOW TEMPS WILL BE SEASONABLE WITH GENERALLY MID/UPPER 50S AWAY FROM THE COAST. DEPENDING ON THE EXTENT OF THE CLOUD COVER...TEMPS NORTH OF BROOKSVILLE MAY BRIEFLY REACH THE UPPER 40S/LOWER 50S. IF STRATUS DEVELOPS EARLY/THICK ENOUGH...THEN LOW TEMPERATURES WILL BE WARMER. FRIDAY/FRIDAY NIGHT...AN AMPLIFICATION TO THE PATTERN WILL EVOLVE OVER THE SOUTHEASTERN CONUS AS LONGWAVE TROUGHING MIGRATES EASTWARD AND ATTEMPTS TO CLOSE OFF OVER AL/GA. DESPITE SOME WEAK SYNOPTIC SUPPORT FOR LIFT ASSOCIATED WITH THE APPROACHING HEIGHT FALLS...OVERALL COLUMN MOISTURE WILL NOT BE THAT IMPRESSIVE. FORECAST WILL SHOW SLIGHT CHANCES FOR SHOWERS DEVELOPING SOUTH OF TAMPA BAY DURING THE DAY...AND THEN EXPANDING OVER THE REST OF THE REGION FRIDAY NIGHT. SHOWERS WILL BE ISOLATED IN NATURE AND NOT ANTICIPATING MUCH IMPACT IN TERMS OF DURATION OR AMOUNT FOR ANY PLANNED OUTDOOR ACTIVITIES. SIMILAR TO THIS MORNING...AREAS OF LOWER STRATUS WILL LIKELY BE RATHER STUBBORN TO BURN OFF AND WILL KEEP SKIES MOSTLY CLOUDY IN THE GRIDS THROUGH THE MORNING. HIGH TEMPERATURES LOOK TO RANGE FROM AROUND 70 UP NEAR CHIEFLAND...TO AROUND 80 DOWN TOWARD FT. MYERS. SATURDAY/SATURDAY NIGHT...UPPER TROUGH AXIS MOVES OVER THE REGION. SOME INDICATION THAT THIS ENERGY MAY ATTEMPT TO CLOSE OFF AN AREA OF WEAK LOW PRESSURE OFF THE GA/NE FL COAST. IF THIS DOES OCCUR...THEN AN ENHANCEMENT TO THE ONSHORE FLOW MAY LEAD TO A BETTER CHANCE OF SHOWERS TO THE NORTH OF I-4 ASSOCIATED WITH SPEED CONVERGENCE FOCUS ORIGINATING ALONG THE NE FL COAST. ELSEWHERE...THE OVERALL WEAK SYNOPTIC FORCING AND COOLER TEMPERATURES ALOFT SHOULD BE ENOUGH TO LEAVE SLIGHT CHANCE POPS IN THE GRIDS. ONCE AGAIN THE IMPACTS OF ANY SHOWERS ARE EXPECTED TO BE MINOR WITH THE MAJORITY OF THE PERIOD BEING RAIN-FREE. && .LONG TERM (SUNDAY - WEDNESDAY)... SOUTHERN STREAM SHORTWAVE WILL PUSH ACROSS THE SOUTHEAST U.S. SUNDAY AND SUNDAY NIGHT...WITH UPPER LEVEL RIDGING BEHIND THE TROUGH OVER THE GULF OF MEXICO AND FLORIDA MONDAY AND MONDAY NIGHT. DIGGING TROUGH ALONG THE EASTERN SEABOARD TUESDAY AND WEDNESDAY WILL GENERATE A SURFACE LOW OFF THE SOUTHEAST COAST WEDNESDAY. STRONG SURFACE HIGH PRESSURE OVER THE NORTHEAST U.S. WILL EXTEND TO THE GULF COAST THROUGH TUESDAY WITH NORTHEAST BOUNDARY LAYER FLOW ACROSS THE FORECAST AREA. GRADIENT WILL REMAIN RATHER TIGHT WHICH SHOULD PRECLUDE LATE NIGHT FOG DEVELOPMENT...HOWEVER CONDITIONS WILL BE FAVORABLE FOR LATE NIGHT/EARLY MORNING LOW CLOUDS ACROSS MUCH OF THE REGION. SURFACE LOW OFF THE SOUTHEAST U.S. COAST WEDNESDAY WILL INCREASE THE CHANCE OF SHOWERS OVER THE REGION. TEMPERATURES WILL RUN NEAR TO SLIGHTLY ABOVE CLIMATIC NORMALS THROUGH THE PERIOD. && .AVIATION... LINGERING MVFR/IFR CEILINGS AT KTPA...KPIE...KSRQ...AND KLAL WILL GIVE WAY TO VFR AFTER 15/20Z AS THE LOW STRATUS CLOUD DECK ERODES. ADDITIONAL MVFR CEILINGS WILL REDEVELOP AT ALL TAF SITES AFTER 16/06Z TONIGHT WITH LOCAL IFR/LIFR CIGS POSSIBLE BETWEEN 16/08 16/12Z. VFR SHOULD RETURN TO ALL TERMINALS AFTER 16/16Z ON FRIDAY. NORTHWEST TO NORTH WINDS IN THE 6 TO 8 KNOT RANGE THIS AFTERNOON WILL BECOME NORTHEAST IN THE 4 TO 6 KNOT RANGE AFTER 16/02Z TONIGHT...INCREASING TO 6 TO 9 KNOTS AFTER 16/15Z ON FRIDAY. && .MARINE... WINDS WILL REMAIN OUT OF THE NORTHEAST THE NEXT COUPLE OF DAYS BETWEEN HIGH PRESSURE TO OUR NORTH AND A DEVELOPING SURFACE TROUGH TO OUR EAST. WINDS ARE EXPECTED TO APPROACH CAUTIONARY LEVELS AT TIMES THE NEXT COUPLE OF NIGHT...ESPECIALLY FROM TAMPA BAY NORTHWARD. && .FIRE WEATHER... NO SIGNIFICANT FIRE WEATHER CONCERNS ARE ANTICIPATED THROUGH AT LEAST THE FIRST HALF OF THE UPCOMING WEEKEND AS RELATIVE HUMIDITY VALUES WILL GENERALLY REMAIN ABOVE CRITICAL LEVELS. LOWER STRATUS CLOUDS ARE ONCE AGAIN EXPECTED ACROSS MUCH OF THE AREA FRIDAY MORNING AND THIS LAYER WILL KEEP DISPERSION INDICES VERY LOW UNTIL THE CLOUDS BURN OFF DURING THE LATE MORNING/EARLY AFTERNOON. && .PRELIMINARY POINT TEMPS/POPS... TPA 58 75 58 76 / 10 10 20 20 FMY 61 80 61 79 / 10 20 30 20 GIF 57 77 57 78 / 10 10 20 20 SRQ 59 77 60 77 / 10 10 20 20 BKV 50 74 52 74 / 10 10 20 20 SPG 62 74 61 75 / 10 10 20 20 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA AVIATION...MCMICHAEL LONG TERM...OGLESBY
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1258 PM EST THU NOV 15 2012 .SYNOPSIS... A WEAK AREA OF LOW PRESSURE WILL TRACK ACROSS THE CAROLINAS AND OFF THE COAST TODAY INTO EARLY FRIDAY MORNING. A LARGE AREA OF HIGH PRESSURE WILL BUILD ACROSS THE GREAT LAKES AND INTO NEW ENGLAND FRIDAY AFTERNOON THROUGH SATURDAY. LOW PRESSURE WILL DEVELOP OFF THE SOUTHEAST COAST SATURDAY NIGHT THROUGH SUNDAY...THEN SLOWLY TRACK EAST NORTHEAST OUT TO SEA MONDAY INTO TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WDSPRD CLDNS OVR THE RGN RIGHT NOW...AND LIKELY TO CONT THROUGH THE REST OF THE DAY. WK/DE-AMPLIFYING S/W TRACKING THROUGH THE CAROLINAS W/ WK SFC LO PRES OFFSHR CONTG TO SPREAD MSTR NWD INTO THE RGN. LGT RA HAVING DIFFICULTY SPREADING N THROUGH CNTRL/ERN NC. LATEST RUC FOLLOWS CURRENT FCST IN KEEPING RA MNLY S OF THE VA/NC BRDR LATER TDA INTO TNGT AS SYS EXITS OFF THE CST. MINOR ADJSTMNTS MADE TO TEMPS...W/ HI TEMPS FM THE U40S-ARND 50F W OF I95...TO RANGING THROUGH THE 50S TO THE E. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... BEST LO LVL MOISTURE/LIFT FCST RMN INVOF SE VA AND NE NC WHERE CURRENT POPS OF 30-40% STILL LUK GOOD FOR TNGT INTO EARLY FRI MORNG. SLGT CHC POPS OF 20% WILL COME INTO A LINE EXTENDING FM AVC-JGG-OXB. LOWS TNGT RANGING FM THE LWR 30S TO THE LWR 40S. A LARGE AREA OF HI PRES WILL BLD ACRS THE GRT LKS AND INTO NEW ENGLAND FRI AFTN THRU SAT. WHILE MOISTURE RIBBON WILL LINGER INVOF THE CSTL CAROLINAS FM FRI AFTN THRU SAT...THE HI PRES SHOULD KEEP OUR WX DRY DURING THE PERIOD...WITH MORE CLOUDINESS POSSIBLE OVER NE NC. OTHRWISE...EXPECT A PRTLY OR MSTLY SNY SKY ACRS MUCH OF THE REGION BOTH DAYS...WITH HI TEMPS IN THE LWR TO MID 50S. LOWS FRI NGT RANGING THRU THE 30S TO ARND 40. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... MODELS STILL HAVING DIFFICULTY RESOLVING PROGRESS OF UPPER LEVEL TROUGH THROUGH THE MEDIUM RANGE PERIOD. GOOD AGREEMENT WITH UPPER LEVEL FEATURES INITIALLY AS MAJORITY OF ENSEMBLES AND OPERATIONAL GFS/ECMWF SHOW SPLIT FLOW DEVELOPING, WITH A PIECE OF UPPER SHORTWAVE ENERGY SPLITTING OFF FROM NORTHERN STREAM AND DROPPING ACROSS THE SOUTHEAST US SAT-SUN, EVENTUALLY DEVELOPING INTO A AMPLIFYING/DIGGING CLOSED UPPER LOW OVER THE SOUTHEAST BY LATE IN THE WEEKEND. DIFFERENCES SPRING FROM THERE, WITH BULK OF UNCERTAINTY IN THIS FORECAST PERTAINING TO EXTENT OF DIGGING AND THE POTENTIAL FOR SFC CYCLOGENESIS (DEVELOPING SFC LOW) ALONG THE SE COAST BY LATE IN THE WEEKEND. OPERATIONAL ECMWF (12Z) REMAINS A BIT FARTHER WEST WITH THE DEVELOPING UPPER TROUGH, WHICH WOULD SERVE TO BRING POTENTIAL DEVELOPING LOW PRESSURE CENTER CLOSER TO THE EAST COAST THAN THE FARTHER OFFSHORE GFS SOLUTION. STILL, APPEARS AS IF MODELS DO AGREE THAT BULK OF HEAVIER PCPN WILL REMAIN CONFINED OFFSHORE. FORECAST CONFIDENCE IS HIGH ENOUGH ATTM TO CONTINUE RAMPING RAIN CHCS SUNDAY, WITH HIGHEST (~50%) POP ACROSS COASTAL ZONES SUNDAY AND SUNDAY NIGHT, WITH LOWER (SLIGHT TO LOW CHC AT BEST) RAIN CHCS SUN/SUN NIGHT WEST OF I-95. LATER IN THE PERIOD, ECMWF ALSO SHOWING SIGNS OF DEVELOPING A RATHER SHARP REX BLOCKING TYPE SIGNATURE IN THE NORTHERN ATLANTIC EARLY NEXT WEEK. WHILE THE UPPER LOW ITSELF WOULD SLIDE OFF THE EAST COAST MON-TUE, SLIDING BEST RAIN CHCS OFFSHORE WITH IT, THE PROGRESS OF NEXT MID-UPPER TROUGH ARRIVING FROM THE MIDWEST WOULD LIKELY LEAD TO A PROLONGED PERIOD OF COOL NE FLOW. ACCORDINGLY, WENT WITH MOSTLY CLDY CONDITIONS PERSISTING FOR MUCH OF EARLY NEXT WEEK IN DIGITAL DB, WITH LOW RAIN CHCS ACROSS COASTAL ZONES (DRY INLAND). CLOUDS WOULD KEEP TEMPS AVERAGING BELOW NORMAL THROUGH THE PERIOD. HIGHS GENERALLY IN THE 50S, LOWS IN THE 30S INLAND TO L40S AT THE COAST. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... BKN/OVC CONDITIONS IN PLACE ACRS THE REGION. WINDS TODAY WILL BE N/NE AVERAGING 10-15 KT AT KORF/KECG AND 10 KT OR LESS ELSEWHERE. EXPECT -RA AT KECG AROUND 23 Z BUT SHOULD NOT HAVE MUCH AFFECT ON VSBYS. WEAK SYSTEM SLIDES OFF THE COASTAL CAROLINAS TONIGHT AND MAINLY DRY CONDITIONS WILL PREVAIL ALTHOUGH LOW CLOUDS WILL PERSIST ESPECIALLY IN SE VA/NE NC. VFR CONDITIONS WILL PREVAIL BEGINNING FRI MORNING. EXPECT ANOTHER PERIOD OF LOWER CIGS AND A CHANCE FOR RAIN LATE SAT-SUN. N/NE FLOW PREVAILS THROUGHOUT...AND WILL TEND TO INCREASE AGAIN SUN/MON CLOSER TO THE COAST. && .MARINE... LATEST OBS REFLECT N/NE FLOW 15 TO 20 KT ACROSS THE MAJORITY OF THE WATERS...WITH SOMEWHAT LOWER WIND SPEEDS IN THE UPPER BAY AND RIVERS OUTSIDE OF THE LOWER JAMES. SEAS OVER ATLANTIC COAST ZONES STILL AVG 5-7 FT...WAVES OVER THE CENTRAL/SOUTHERN BAY 3-4 FT. LATER TODAY/TONIGHT...MODELS ALL GENLY AGREE THAT THE SURGE AND PRESSURE GRADIENT SLACKENS OFF A LITTLE MORE SO SCA`S OVER BAY/SND SLATED TO COME DOWN THIS EVENING...WHILE SCA`S REMAIN IN EFFECT FOR THE COAST AS SEAS ARE EXPECTED TO REMAIN 4-5 FT OR HIGHER. A BIT OF A LULL IN THE GRADIENT FRI-SAT...BUT STILL WITH CONDITIONS THAT ARE AT LEAST CLOSE TO SCA LEVELS IN THE BAY/RIVERS/SOUND SO IT WILL BE LESS THAN IDEAL BOATING THROUGHOUT THE REGION (SCA`S WILL LIKELY NEED TO BE EXTENDED FOR THE COASTAL WATERS FOR 4-5 FT SEAS). LATER SAT INTO SUN SUN/MON...STRONG HIGH PRESSURE BUILDS INTO NEW ENGLAND...AS ANOTHER AREA OF SFC LOW PRESSURE IS EXPECTED TO DEVELOP OFF THE COASTAL CAROLINAS BY LATE IN THE WEEKEND. RE-TIGHTENING OF PRESSURE GRADIENT BETWEEN THESE FEATURES IS LIKELY TO RESULT IN ANOTHER PERIOD OF STRONG SCA CONDITIONS (POSSIBLY RAMPING UP TO LOW END GALES BY LATE SUNDAY ON THE COAST). WHILE THE SYSTEM APPEARS WEAKER THAN PREVIOUS MODEL RUNS...SCA CONDITIONS ARE STILL VERY LIKELY TO PERSIST THROUGH THE MUCH OF THE FIRST HALF OF NEXT WEEK. SEAS AVG 6-9 FT ON THE COAST...WITH WAVES IN THE BAY 3-5 FT SUN-MON. && .TIDES/COASTAL FLOODING... CONTINUED N/NE WINDS 15-20 KT TODAY ACRS MUCH OF THE MARINE AREA...AND HAVE HOISTED A COASTAL FLOOD ADSY FOR PORTIONS OF THE OCEAN SIDE OF THE ERN SHORE FOR VERY MARGINAL MINOR FLOODING W/ THE UPCOMING LATE MORNING TIDE CYCLE (SEE CFWAKQ FOR DETAILS). THE ANOMALIES ARE ONLY ABOUT 1 FOOT BUT THE ASTRONOMICAL TIDES ARE RATHER HIGH DUE TO THE NEW MOON CYCLE. FARTHER SOUTH ANOMALIES ARE RUNNING 0.5 TO 1 FOOT ABOVE NORMAL BUT THE WATER LEVELS LOOK TO STAY ABOUT 0.5 FT BELOW THRESHOLDS (WILL MENTION PORTIONS OF HAMPTON ROADS IN THE HWO FOR NUISANCE FLOODING POSSIBLE RIGHT AT THE TIME OF HIGH TIDE THIS MORNING). THE NEXT HIGH TIDE CYCLE THAT MAY BE CLOSE TO MINOR FLOODING THRESHOLDS WILL BE LATE THIS EVENING/TONIGHT. WINDS GENLY LOOK TO SLACKEN OFF THOUGH SO AGAIN IT WILL BE VERY MARGINAL SO WILL LET NEXT SHIFT EVALUATE NEED FOR THIS LATER TODAY. FOR THE WEEKEND/EARLY NEXT WEEK...PATTERN OF A VERY STRONG/1040 MB SFC HIGH BUILDING INTO NEW ENGLAND AND A TROUGH OFF THE SE COAST WOULD MAKE WINDS TURN MORE TO THE NE (RATHER THAN N)...LEADING TO THE POTENTIAL FOR MORE TIDAL FLOODING. LATEST MODEL TRENDS ARE A LITTLE SLOWER...WEAKER...AND MORE OFFSHORE WITH THE TRACK OF THE EVENTUAL COASTAL SYSTEM...WHICH WOULD SUGGEST LESS OF A FLOODING IMPACT THAN WHAT WAS PREVIOUSLY ANTICIPATED. THERE IS STILL TOO MUCH UNCERTAINTY AND THE FACT THAT THE GFS-BASED MDL GUIDANCE IS NOT SHOWING MUCH OF AN ANOMALY ON SUNDAY COULD JUST BE DUE TO THE GUIDANCE BEING UNDERDONE THIS FAR OUT IN THE PERIOD. IN ANY EVENT...WILL NEED TO CONTINUE TO MONITOR AND WOULD EXPECT AT LEAST SOME MINOR TIDAL FLOODING ACRS PORTIONS OF THE AREA SUN/MON. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ632>634. SMALL CRAFT ADVISORY UNTIL 6 PM EST FRIDAY FOR ANZ654-656-658. SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ650-652. && $$ SYNOPSIS...ALB/TMG NEAR TERM...ALB/TMG SHORT TERM...ALB/TMG LONG TERM...MAM AVIATION...LKB/DAP MARINE...LKB TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1238 PM EST THU NOV 15 2012 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 423 AM EST THU NOV 15 2012 00Z RAOBS AND RUC ANALYSIS SHOW PRETTY QUIET WESTERLY SPLIT FLOW ALOFT WITH MINIMAL H5 HEIGHT FALLS OR RISES NOTED UPSTREAM. STRONGEST SHORTWAVE WITHIN THE FLOW IS IN THE NORTHERN STREAM PUSHING ACROSS MANITOBA INTO NORTHERN ONTARIO. COLD FRONT ASSOCIATED WITH THIS WAVE IS STRONG. TEMPS HAVE FALLEN INTO THE TEENS IN CENTRAL MANITOBA AND INTO SINGLE NUMBERS BACK OVR SASKATCHEWAN. BATCH OF HEAVIER SNOW IS ACCOMPANYING THE FRONT IN NORTHERN MANITOBA...BUT NOT MUCH IS OCCURRING FARTHER SOUTH ALONG THE COLD FRONT. ONLY OTHER SHORTWAVE RELATIVELY CLOSE BY IS MOVING ACROSS CENTRAL MINNESOTA. DESPITE DRY LOW-LEVELS SEEN OVER AREA LAST DAY...THIS WAVE IS STRONG ENOUGH TO PRODUCE SOME LGT SHRA OVER ECNTRL MN WITHIN LAST 2 HOURS. OVER UPR MICHIGAN IT IS ANOTHER NIGHT WITH A LOT OF MID CLOUDS BUT NO PRECIP. TEMPS IN MANY AREAS EARLY THIS MORNING ARE CLOSE TO WHAT IS A TYPICAL NORMAL HIGH TEMP FOR 15 NOVEMBER AKA THE FIRE ARM RIFLE DEER HUNTING OPENER FOR MICHIGAN. AS NORTHERN STREAM TROUGH PRESSES EAST TODAY...ASSOCIATED SFC LOW MOVES ACROSS HUDSON BAY AND SFC COLD FRONT TAKES AIM ON UPR MICHIGAN LATE TODAY. UNTIL ARRIVAL OF THE FRONT...DEPENDING ON EXTENT OF CLOUD COVER...APPEARS WE COULD HAVE MAKING OF FAIRLY WARM DAY. MID CLOUDS ALREADY TRYING TO SCT OUT OVER WESTERN UPR MICHIGAN AND AT LEAST PARTIAL SUNSHINE IS EXPECTED FOR MUCH OF WESTERN AND CENTRAL CWA THIS MORNING. WILL HAVE TO WATCH WI BORDER THOUGH AS SHORTWAVE OVR MN MAY PUSH CLOSE BY ENOUGH TO AT LEAST INCREASE CLOUDS AGAIN THIS MORNING AND EVEN PRODUCE A FEW SPRINKLES TOWARD KIMT. MIXING TO 925MB SUPPORTS TEMPS WELL INTO THE 40S BY MID AFTN WITH DOWNSLOPE SW WINDS PUSHING READINGS INTO LOWER 50S NEAR LK SUPERIOR NCNTRL IF CLOUDS ARE DELAYED. BY MID AFTN...EXPECT MID CLOUDS /H8-H7 RH/ TO BUILD BACK OVER CWA FROM THE SOUTHWEST WHILE BATCH OF CLOUDS JUST AHEAD OF COLD FRONT SLIDE INTO CWA FROM ONTARIO. FORECAST SOUNDINGS INDICATE THERE WILL BE ENOUGH DEEPER MOISTURE AND UVM WITHIN ICE NUCLEATION ZONE TO GENERATE A FEW SHOWERS AFT 21Z. SREF/HIGHER RES MODELS FROM NCEP AND NAM/LOCAL WRF-ARW AGREE PRECIP MAINLY AFFECTS ALGER/SCHOOLCRAFT/LUCE. DAYTIME HEATING INCREASES 1000-H85 LAPSE RATES OVR MUCH OF EAST HALF AHEAD OF FRONT...SO ALSO ADDED ISOLD MENTION AS FAR WEST AS MARQUETTE/DELTA COUNTIES. PTYPE ONLY RAIN AS WBZERO HEIGHTS ARE WELL ABOVE 1KFT AGL. ONLY POSSIBILITY OF SEEING SOME SNOW MIXING IN WOULD BE OVER HIGHER TERRAIN OF MQT COUNTY IN EVENING...BUT MOST OF SYNOPTIC PRECIP SHOULD DONE BY THIS TIME. ONCE FRONT MOVES THROUGH...A PORTION OF COLD AIR SEEN UPSTREAM WILL MAKE RUN ACROSS LK SUPERIOR AND INTO UPR MICHIGAN. IT IS A SHALLOW COLDER AIRMASS OVR MANITOBA AS 925MB TEMPS ARE COLDER THAN THOSE AT 850MB. SETUP TONIGHT OVER UPR MICHIGAN NO DIFFERENT. NORTHWEST WINDS IN WAKE OF FRONT EVENTUALLY TURN MORE NORTHERLY AS SFC HIGH CURRENTLY OVR NORTHERN ROCKIES AND NORTHERN PLAINS EXTENDS A RIDGE INTO NORTHERN ONTARIO AND NORTHERN LK SUPERIOR. NORTH LOW-LEVEL WINDS ALONG WITH INCREASING SUB H85 MOISTURE SEEN ON UPSTREAM SOUNDINGS AT YQD /CNTRL MANITOBA/ AND YSM /NORTHWEST TERRITORIES/ ALONG WITH LOWERING SUBSIDENCE INVERSION /TEMPS AT INVERSION TOP AROUND -7C/ CONTINUE TO SUPPORT GOING FCST OF FZDZ OR FLURRIES OVR HIGHLANDS OF NCNTRL UPR MICHIGAN. DESPITE INCREASING CLOUDS...PREFER TO GO COLDER WITH MINS TONIGHT WITH SHALLOW INVERSION/STABLE TEMP PROFILE. MOST AREAS WILL FALL INTO THE 20S WEST/CNTRL WITH NEAR 30 FOR EASTERN CWA. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 423 AM EST THU NOV 15 2012 A FAIRLY QUIET PERIOD OF WX IS IN STORE THRU THIS WEEKEND AS A ZONAL FLOW OF RELATIVELY MILD PACIFIC AIR DOMINATES. FRI...SFC HI PRES RDG AXIS IS FCST TO MOVE FM MN INTO NW ONTARIO TO AN A LINE FM UPR MI INTO ONTARIO BY 00Z SAT AS H5 RDG BUILDS OVER THE UPR LKS. PREFER THE CLOUDIER NAM DEPICTION OF EVENTS GIVEN FCST SHARP INVNR ARND 3K FT ENHANCED BY SHALLOW COLD INFUSION AND TRAPPING LLVL AIRMASS MOISTENED IN PASSAGE OVER LK SUP. ONCE THE HI PRES RDG PASSES TO THE E...EXPECT STUBBORN LO CLDS TO BREAK UP AS THE FLOW TURNS OFFSHORE. BUT OVER THE NCNTRL...THIS WSHFT IS NOT FCST TO OCCUR UNTIL LATE IN THE DAY. SO SUSPECT THE DAY WL BE MOCLDY IN THIS AREA...WITH SOME MRNG -FZDZ OVER THE HIER TERRAIN OF THE NCENTRAL WHERE LLVL N VEERING E WIND UPSLOPES AND LLVL MSTR REMAINS TRAPPED BLO SHARP INVRN BTWN H9-925 MAINTAINED BY DEEP LYR QVECTOR DVGC/SUBSIDENCE. EVEN OVER THE W... FCST LIGHT WINDS SUG THE LO CLD MAY BE QUITE TENACIOUS GIVEN SHARP LO INVRN BASE THAT TRAPS THE LLVL MSTR. AREAS FM IWD-ONTONAGON- KEWEENAW PROBABLY HAVE THE BEST SHOT AT SEEING SOME CLRG WITH A MORE PRONOUCNED DOWNSLOPE WIND COMPONENT. DVLPG E FLOW OFF LK MI WL ALSO BRING ABOUT MORE SC OVER THE SCENTRAL...BUT THERE MAY SOME PARTIAL CLRG OVER THE E WITH DOWNSLOPING OFF ONTARIO AND LOSS OF LK MOISTENING COMPONENT. WITH PLENTY OF CLD COVER LINGERING ALL DAY OVER THE NCENTRAL...MAX TEMPS MAY STRUGGLE TO RISE ABV 32 ACRS THE HIER TERRAIN IN THAT AREA. FRI NGT...AS HI SHIFTS TO THE E...THE LLVL WINDS WL VEER MORE TO THE S. IN CONCERT WITH INVRN SINKING CLOSER TO THE SFC AS SHOWN BY NAM FCST SDNGS...THIS FLOW SHOULD ALLOW THE SKY TO BECOME CLR TO PCLDY. DESPITE THE CLRG...INCRSG S WINDS WL TEND TO LIMIT THE DIURNAL TEMP FALL AT LEAST OVER THE W. THE LOWEST MIN TEMPS SHOULD BE OVER THE INTERIOR CENTRAL AND E WHERE THE H925 WINDS WL BE AOB 10 KTS MOST IF NOT ALL OF THE NGT. WITH PWAT AOB 0.25 INCH...TENDED AOB THE LO END OF GUIDANCE FOR MIN TEMPS IN THIS AREA EVEN THOUGH SOME HI CLDS MIGHT ARRIVE OVERNGT IN MORE WSW FLOW ALF. SAT THRU SUN...THE UPR GRT LKS WL BE DOMINATED BY STEADY SW FLOW BTWN HI PRES DRIFTING INTO NEW ENGLAND AND LO PRES TROF IN THE PLAINS DOWNWIND OF DEEPENING WRN TROF. DESPITE THE STRENGTHENING SSW LLVL FLOW...MODELS ADVERTISE LTL MOISTENING IN THE LO-MID LVLS. BUT WSW FLOW ALF WL BRING SCT-BKN HI CLDS. TEMPS WL AVG ABOVE NORMAL THRU THE WEEKEND WITH H85 TEMPS FCST FM 1 TO 4C. THE HIEST TEMPS SHOULD BE OVER THE DOWNSLOPE AREAS NEAR LK SUP ON SUN DESPITE SOME THICKER HI CLD. EXTENDED...GUIDANCE INDICATES THE PERSISTENT SW FLOW FM THE SRN PLAINS INTO THE UPR GRT LKS ON WRN FLANK OF HI PRES OVER THE NE CONUS MAY TAP MORE MOIST AIRMASS BY MON. AS DIFFICULT TO TIME SHRTWVS EJECT FM THE WRN TROF EWD TOWARD THE UPR GRT LKS EARLY NEXT WEEK...MODEL CONSENSUS INDICATES SCHC POPS ARE WARRANTED FOR MON THRU WED. GUIDANCE SEEMS TO HAVE TRENDED TOWARD KEEPING THE TROF OUT W LONGER...SO LATER UPDATES MAY TREND TOWARD DRIER WX. TEMPS WL REMAIN WELL ABV THE SEASONAL NORM WITH PACIFIC AIR DOMINATING UNDER WSW FLOW ALF. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1236 PM EST THU NOV 15 2012 A COLD FRONT WILL MOVE THROUGH NEAR OR SHORTLY AFTER 18Z TAF ISSUANCE AT IWD AND CMX...AND LATER IN THE DAY AT SAW. COLDER AIR BEHIND THE FRONT MAY BRING LOWER LAKE EFFECT CIGS AT ALL SITES TONIGHT...BUT MOISTURE SEEMS TO LIMITED FOR ANY PRECIP. HOWEVER...SAW WILL SEE THE BEST CHANCES FOR PRECIP LATE TONIGHT INTO EARLY FRI AS WIND DIRECTIONS WILL BE MORE FAVORABLE FOR PRECIP THERE...BUT VIS IS NOT EXPECTED TO DROP ALL THAT MUCH IN ANY LIGHT SNOW OR FREEZING DRIZZLE THAT DEVELOPS. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 423 AM EST THU NOV 15 2012 EXPECT S-SW WINDS UP TO 25-30 KTS TODAY IN ADVANCE OF APPROACHING COLD FNT TO SHIFT TO THE N-NW THIS AFTERNOON/EVENING ONCE THE FRONT PASSES W-E ACROSS THE LAKE. NOT OUT OF THE QUESTION THERE COULD BE A FEW GALE FORCE GUSTS JUST AHEAD OF THE FRONT MAINLY OVER THE NCENTRAL LAKE WITH TERRAIN BETWEEN ISLE ROYALE AND THE KEWEENAW ENHANCING EXPECTED WSW WIND. APPROACH OF TRAILING HI PRES WILL THEN CAUSE QUICKLY DIMINISHING WINDS BY FRI WHICH WILL CONTINUE THRU FRI NIGHT. OVER THE WEEKEND INTO EARLY NEXT WEEK...LAKE SUP WILL BE DOMINATED BY S WINDS BETWEEN HI PRES MOVING INTO NEW ENGLAND AND A LO PRES TROF IN THE PLAINS. THE STRONGEST S WINDS UP TO 25 KTS DURING THIS PERIOD ARE MOST LIKELY OVER THE E HALF OF THE LAKE. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLA LONG TERM...KC AVIATION...TITUS MARINE...KC