Forecast Discussions mentioning any of "HRRR" "RR" "RUC13" "RUC" received at GSD on 02/27/12


AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
407 PM EST SAT FEB 25 2012 .SYNOPSIS... AN INTENSE LOW OVER THE MARITIMES WILL BEGIN WEAKENING EARLY SUNDAY AS IT MOVES INTO THE NORTH ATLANTIC SOUTH OF GREENLAND. HIGH PRESSURE OVER THE LOWER MISSISSIPPI VALLEY WILL REACH THE MID ATLANTIC COAST SUNDAY AFTERNOON. LOW PRESSURE CROSSING NEW ENGLAND LATE MONDAY WILL SEND A COLD FRONT THROUGH THE MID ATLANTIC STATES MONDAY NIGHT...FOLLOWED BY CANADIAN HIGH PRESSURE BUILDING TO OUR NORTH ON TUESDAY. THAT COLD HIGH MAY LOCK IN OVER QUEBEC THURSDAY AND FRIDAY...SETTING THE STAGE FOR WINTRY WEATHER IN PORTIONS OF NEW JERSEY AND PENNSYLVANIA DURING MID WEEK. STRONG LOW PRESSURE IN THE UPPER MIDWEST ON WEDNESDAY WILL WEAKEN AS IT REDEVELOPS ALONG THE DELMARVA COAST THURSDAY AND THEN HEADS OUT TO SEA. THE CANADIAN HIGH REASSERTS CONTROL HERE FOR A PORTION OF FRIDAY BEFORE ANOTHER LOW PRESSURE SYSTEM ARRIVES TO START THE WEEKEND. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... A 19Z SURFACE ANALYSIS PLACED AN INTENSE LOW ACROSS THE CANADIAN MARITIMES. THE LOWEST SURFACE PRESSURE SO FAR WITH THIS WAS 966 MB. A TROUGH OR SECONDARY FRONT IS DRAPED ACROSS NEW YORK STATE TO LAKE MICHIGAN. HIGH PRESSURE WAS ACROSS THE MISSISSIPPI VALLEY. AN UPPER AIR ANALYSIS INDICATED A SHARP TROUGH AXIS FROM NEW ENGLAND TO THE UPPER OHIO VALLEY. A RIDGE WAS IN THE PLAINS WITH ANOTHER TROUGH IN THE NORTHERN ROCKIES. AN AREA OF FOCUSED WAA AT 850 MB WAS ACROSS THE CENTRAL AND NORTHERN PLAINS. A STRONG CYCLONICALLY CURVED 250 MB JET WAS FROM THE MIDWEST TO THE OHIO VALLEY THEN OFF THE NEW ENGLAND COAST. AS THE INTENSE STORM IN THE CANADIAN MARITIMES CONTINUES TO MOVE NORTHEASTWARD, HIGH PRESSURE WILL BEGIN TO EDGE CLOSER FROM THE WEST THROUGH TONIGHT. THE UPPER-LEVEL TROUGH AXIS HOWEVER IS FORECAST TO SWING ACROSS OUR AREA EARLY THIS EVENING. THE COMBINATION OF DEEP CYCLONIC FLOW, CAA AND STEEP LOW-LEVEL LAPSE RATES HAVE ALLOWED SNOW SHOWERS TO OCCUR MAINLY ACROSS THE NORTHERN HALF OF THE CWA. THESE ARE MORE CONVECTIVE, AND ANY STRONGER ACTIVITY COULD PRODUCE A BURST OF SNOW. ANY LOCAL SNOW ACCUMULATIONS ARE EXPECTED TO BE AN INCH OR LESS AS IT APPEARS THE SNOW SHOWERS WILL BE TRANSIENT. SOME OF THE HIGH RESOLUTION MODELS HOWEVER, SUCH AS THE HRRR AND THE SPC WRF-NMM, INDICATE THAT THERE COULD BE A COUPLE OF WEST TO EAST ORIENTATED SNOW BANDS MOVING THROUGH PARTS OF THE AREA THROUGH EARLY THIS EVENING. THIS WAS OBSERVED THIS MORNING, AND GIVEN THE TROUGH AXIS MOVING THROUGH IT CANNOT BE RULED OUT. THERE ARE TWO DISTINCT BANDS ON THE RADAR AS OF 20Z, ONE ACROSS CENTRAL PENNSYLVANIA AND THE OTHER ONE DROPPING SOUTHEASTWARD INTO NORTHEASTERN PENNSYLVANIA. THE LATTER LOOKS TO BE AHEAD OF A WEAK SURFACE TROUGH OR FRONT WITH SOME VEERING OF THE WINDS A BIT MORE TO THE NORTHWEST BEHIND IT. THE 12Z SPC WRF-NMM HAS PICKED UP ON THIS ACTIVITY AND IS DOING WELL AS OF 19Z. IT BRINGS THESE TWO BANDS ACROSS PORTIONS OF EASTERN PENNSYLVANIA AND THE NORTHERN HALF OF NEW JERSEY THROUGH ABOUT 23Z BEFORE WEAKENING THEM. WE LEANED OUR POPS CLOSER TO THIS, WITH SOME LIKELY VALUES ACROSS THE FAR NORTHWEST INTO THIS EVENING, AND SOME HIGHER CHC VALUES FARTHER SOUTH. IF THESE BANDS OCCUR, A BURST OF HEAVIER SNOW WILL FALL WHICH WILL GREATLY REDUCE THE VISIBILITY FOR A SHORT TIME. AS WE TAPERED THE POPS DOWN WITH A SOUTHEASTWARD EXTENT, DID CARRY SCATTERED FLURRIES ON THE SOUTHERN END FOR NOW WITH MOST OF THIS MENTION ALONG AND NORTH/WEST OF INTERSTATE 95. ANY ACTIVITY SHOULD WEAKEN AND THEN DISSIPATE DURING THE NIGHT AS SOME DRIER AIR AND SUBSIDENCE BEGINS TO WORK INTO THE AREA. THIS WILL ALSO ALLOW THE STRATOCUMULUS TO RETREAT NORTHWESTWARD THROUGH THE NIGHT. THE STRONG WINDS ACROSS THE AREA WILL CONTINUE INTO THIS EVENING AS THE 925 MB WINDS ARE FORECAST TO INCREASE SOME AS THE TROUGH AXIS SWINGS THROUGH. WE SHOULD START TO SHRINK THE VERTICAL MIXING EARLY THIS EVENING AS THE LOSS OF DAYTIME HEATING OCCURS, HOWEVER IT APPEARS WE SHOULD ACHIEVE SOME ADVISORY LEVEL GUSTS INTO THIS EVENING. THEREFORE, WE WILL CONTINUE THE WIND ADVISORY ACROSS THE ENTIRE CWA UNTIL 7 PM. AS FOR TEMPERATURES, WE GENERALLY USED A BLEND OF THE GFS/NAM MOS. THE WINDS SHOULD DROP OFF ENOUGH LATER TONIGHT TO ALLOW THE TEMPERATURES TO DROP MORE GIVEN THE LOW DEW POINTS. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/... AN UPPER-LEVEL TROUGH WILL BE WELL EAST OF OUR AREA SUNDAY AS A MID LEVEL RIDGE APPROACHES FROM THE WEST. THIS WILL DRIVE SURFACE HIGH PRESSURE OVER OUR AREA DURING THE COURSE OF THE DAY. THERE IS A LINGERING PRESSURE GRADIENT TO START THE MORNING, HOWEVER THIS WEAKENS FAIRLY QUICKLY AS THE SURFACE HIGH BEGINS TO CREST INTO OUR REGION. THIS WILL RESULT IN MUCH LESS WIND COMPARED TO TODAY. THERE APPEARS TO BE ENOUGH DRYING IN THE LOWER AND MIDDLE PORTIONS OF THE ATMOSPHERE AND SUBSIDENCE TO LIMIT ANY STRATOCUMULUS DEVELOPMENT. AN AREA OF WAA UP THROUGH THE OHIO VALLEY HOWEVER WILL TEND TO DRIVE A DEVELOPING WARM FRONT JUST TO OUR WEST. THE MAIN PUSH OF MILDER AIR IS FORECAST TO BE FOCUSED MORE TO OUR WEST. HOWEVER AS THE MID LEVEL RIDGE AXIS NEARS, SOME HIGH CLOUDS MAY START TO MOVE IN. THIS LOOKS MINIMAL AT THIS POINT, THEREFORE WE LEANED TOWARD A GOOD DEAL OF SUNSHINE DURING THE DAY. AS FOR TEMPERATURES, WE MAINLY WENT WITH A MOS BLEND. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... NORTHERN TIER OF USA SHOWS A SUCCESSION OF THREE STRENGTHENING SHORT WAVES IN THE UPPER MIDWEST TENDING TO GETTING SQUASHED AS THEY MOVE INTO CONFLUENCE ZONE OVER SOUTHEAST CANADA. THIS MAY EVENTUALLY BODE WELL FOR MUCH NE PA AND NW NJ SNOW/ICE ENTHUSIASTS MIDDLE OF THE WEEK AND NEXT WEEKEND. THE FIRST SHORT WAVE ASSOCIATED SFC LOW VICINITY OF LSUPR SUNDAY EVENING WEAKENS TO A NOVA SCOTIA PASSAGE TUESDAY MORNING. THE SECOND SHORT WAVE AND STRONGER LOW PRESSURE SYSTEM IN THE MIDWEST WEDNESDAY BECOMES A POTENTIALLY BIGGER PLAYER HERE AS IT EVENTUALLY MOVES OFF THE NJ OR DE COAST THURSDAY. PLS SEE THE 150 PM PMDEPD FROM HPC ON THIS. WHILE THE 12Z/25 GEFS CONTS TO INSIST ON A NORTH TRACK...AM WARY OF WARM SOLNS E OF THE APPALACHIANS WITH A MID LVL /500MB/ CONFLUENCE ZONE THAT IS IN SE CANADA/NORTHERN NEW ENGLAND. AS AN EXAMPLE OF BUST POTENTIAL...THE 12Z/23 NCEP MOS GUIDANCE FCST FOR PHL ON 12/24 WAS 68-71F. THE EC SCORCHED THE GUIDANCE WITH HIGHS NEAR 50. THE DAYTIME HIGH WAS 49. THINK THE BUST POTENTIAL MAY AGAIN BE PRETTY LARGE FOR WED/THU HERE IN OUR FA. AM APPROACHING WARM SOLNS WITH CAUTION AND COMPLETELY ADOPTING THE MUCH COLDER THAN NCEP GUIDANCE SOLN FOR WED-FRI. THE THIRD SHORT WAVE THAT WILL BECOME A PLAYER IS DEPARTING THE UPPER MIDWEST FRIDAY NIGHT. COULD SEE ICE OR SNOW TO START ON THAT ONE IN THE POCS AND FAR NW NJ. NOT CONCENTRATING ON THAT LATTER EVENT. THERE IS MUCH LESS CHC OF THIS INSIDE RUNNER GETTING SQUASHED SOUTH OF LONG ISLAND BUT WITH RELATIVELY COLD TEMPS TO START...AT LEAST A LITTLE ICE OR SNOW IS ENVISIONED FRI NIGHT. TEMPS IN THIS PATTERN WILL CONTINUE ABOVE NORMAL. 12Z/25 NCEP MODEL GUIDANCE APPEARS MUCH TOO WARM ON DAYTIME MAX`S IN NJ/PA IF PCPN IS OCCURRING ON WED-THU. USED HPC GUIDANCE TEMPS/WINDS. THE DAILIES... SUNDAY NIGHT AND MONDAY...FAIR WITH A DRY SW FLOW WAA BEHIND THE DEPARTING MID ATLC COAST SFC HIGH. A CHILLY RADIATIONAL COOLING START TO MONDAY MORNING WARMS QUICKLY TO WELL ABOVE NORMAL TEMPS IN THE AFTN WITH GUSTY SW WINDS 20-25 MPH. BLENDED MOS GUIDANCE. WILL THIS BE A FWX CONCERN FOR AN SPS AFTN? PROBABLY NOT BECAUSE OF YDYS RAINFALL AND CHILLY TEMPS OF THIS WEEKEND. MONDAY NIGHT...DRY CFP. BLENDED MOS GUIDANCE. TUESDAY...DRY HIGH PRES ARRIVES... WITH A TENDENCY OF MORE HIGH PRES OVER SE CANADA...IE A COLDER WET BULB LYING IN WAIT FOR THE NORTHERN ZONES. TUESDAY NIGHT-WEDNESDAY...COMPLEX. A MODEL BATTLE BETWEEN GEFS AND THE UKMET-GGEM-ECMWF. A WARM FRONT WILL PRODUCE PRECIPITATION WEDNESDAY..SOME OF IT EXPECTED TO BE SNOW FROM KABE- KSMQ REGION NORTH AND WHEN ALL IS SAID AND DONE THURSDAY...THIS SEASONABLE WINTER WX EVENT MAY BE RIVALING ONE OF THE MORE SIGNIFICANT SNOW EVENTS OF THIS EASY GOING WINTER. THE SOUTHERN EDGE OF WINTER WX IS NOT SET IN STONE BUT WAS THE BEST ESTIMATE I COULD OFFER AT THIS JUNCTURE FROM MODEL ENSEMBLING AND REALIZING WE ARE STILL IN MET WINTER. 12Z/25 HPC GUIDANCE TEMPS/WINDS. PTYPE WAS RUN OFF A BLEND OF 12Z ECMWF/GFS PARTIAL THICKNESSES AND BLV ITS BIAS`D TOO WARM AND TOO WET. LOW PROB OF THUNDER DE/MD IN THE MORNING ON THE NOSE OF THE LLJ. WEDNESDAY NIGHT-THURSDAY...THE CLOSED LOW ALOFT IN THE MIDWEST HAS NO WHERE TO GO BUT EAST OR ESE...FORCED BY THE CONFLUENCE ZONE IN MAINE. THAT MEANS PLENTY OF VORT RIDING OVER WHATEVER THE AXIS OF LEFTOVER DEEPER MOISTURE. IF THAT MOIST AXIS IS NORTH OF OUR FA...THEN VERY LITTLE PCPN. BUT IF THE WARM FRONTAL WAVE DEVELOPS EWD FROM NJ OR DE AS PER THE ECMWF FOR WED NIGHT...IT WILL HAVE THE BAROCLINIC ZONE AXIS SET UP FOR A NEW SFC LOW TO FORM OFF NJ/DE THURSDAY MORNING RAISING THE POTENTIAL FOR MORE SNOW IN NE PA AND NW NJ AND SOME COLD DRIZZLE OR A FEW SHOWERS ELSEWHERE S OF KSMQ- KABE. THERE IS A LOW PROB FOR HAZARDOUS WX ALL THE WAY DOWN TO PHIL. 12Z/25 HPC GUIDANCE TEMPS/WINDS. THE WIND FCST IS QUESTIONABLE AND BLV WE WILL NEED MORE NE IN THE NEXT FCST FOR NJ AND SIGNIFICANTLY STRONGER FOR NNJ. FRIDAY...DRY CANADIAN HIGH PRES BRIEFLY REASSERTS CONTROL HERE. HOWEVER THE NEXT LOW PRESSURE SYSTEM WILL BE APPROACHING...POSSIBLY SPREADING COLD PRECIPITATION INTO OUR AREA FRIDAY NIGHT. 12Z/25 HPC GUIDANCE WAS USED AND NOT MUCH ENERGY INTO MODIFYING THE DATA. APPEARS THAT 500MB CONFLUENCE SUPPRESSION IS MUCH LESS OF A RISK. THERE MIGHT BE A TRIPLE PT OCCLUSION AND PRES FALLS NEAR THE PT OF OCCLUSION HOLDING LEFTOVER COLD AIR IN LONG ENOUGH /NE SFC WIND/ FOR ICE AT THE START OVER NE PA AND NW NJ. && .AVIATION /21Z SATURDAY THROUGH THURSDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. AN INTENSE STORM IN THE CANADIAN MARITIMES WILL CONTINUE TO TRACK NORTHEASTWARD AND AWAY FROM OUR AREA. HIGH PRESSURE WILL THEN BUILD INTO OUR AREA DURING SUNDAY. A TIGHT PRESSURE GRADIENT BETWEEN THIS HIGH AND LOW PRESSURE TO OUR NORTHEAST WILL CONTINUE TO DRIVE GUSTY WEST TO NORTHWEST WINDS THROUGH ABOUT THE FIRST HALF OF THE NIGHT. THE PEAK GUSTS WILL GENERALLY BE AROUND 40 KNOTS INTO EARLY THIS EVENING, THEN THESE ARE EXPECTED TO DIMINISH THROUGH THE NIGHT AS THE VERTICAL MIXING SHRINKS AND HIGH PRESSURE EDGES CLOSER FROM THE WEST. A DECENT AMOUNT OF STRATOCUMULUS AROUND THE REGION THIS AFTERNOON WILL THIN OUT FROM SOUTHEAST TO NORTHWEST AS SOME DRYING WORKS IN AND HIGH PRESSURE GETS A BIT CLOSER DURING THE NIGHT. ANY SNOW SHOWERS ARE EXPECTED TO RETREAT BACK NORTHWESTWARD THROUGH THE EVENING, AND GENERALLY BE NORTH AND WEST FROM ABOUT KTTN TO KILG. A NARROW BAND OF HEAVIER SNOW MAY DEVELOP ACROSS PARTS OF THE REGION THROUGH EARLY THIS EVENING, THEREFORE SOME BRIEF BUT GREATLY REDUCED VISIBILITIES /AND SOME LOWER CEILINGS/ MAY OCCUR. SOME SHORT-FUSED AMENDMENTS MAY BE NEEDED TO ACCOUNT FOR ANY SNOW SHOWERS THAT LOOK TO IMPACT ANY LOCAL TERMINAL. FOR SUNDAY, A CALMER DAY IS EXPECTED AS HIGH PRESSURE SETTLES RIGHT OVER THE AREA. THIS WILL ALLOW FOR MUCH LESS WIND, THEREFORE A WESTERLY WIND SHOULD BE ON THE ORDER OF 10 TO 15 KNOTS BEFORE WEAKENING MORE BY LATER IN THE DAY. THERE APPEARS TO BE ENOUGH DRYING IN THE LOWER AND MIDDLE LEVELS OF THE ATMOSPHERE TO LIMIT AND STRATOCUMULUS DEVELOPMENT. THEREFORE, VFR IS EXPECTED. OUTLOOK... SUNDAY NIGHT-TUESDAY...VFR. SW GUSTS TO 20 KT POSSIBLE MON AFTN. WEDNESDAY/THURSDAY...MVFR CONDS IN SHOWERS EXCEPT MIXED WINTRY PCPN POSSIBLE KABE-KSMQ NORTHWARD WHERE CONDS SHOULD DETERIORATE TO OCNL IFR. LOW PROB THUNDER DE/MD WED MORNING. ENE WINDS IN COASTAL NE NJ MAY G25 KT ON THURSDAY. && .MARINE... THE PRESSURE GRADIENT REMAINS TIGHT ACROSS THE REGION DUE TO AN INTENSE STORM IN THE CANADIAN MARITIMES AND HIGH PRESSURE MOVING INTO THE OHIO VALLEY. THIS GRADIENT IS EXPECTED TO WEAKEN THROUGH THE NIGHT AS HIGH PRESSURE EDGES CLOSER. THE MODEL GUIDANCE INDICATES THAT THE 925 MB FLOW INCREASES SOME THROUGH EARLY THIS EVENING AS THE UPPER-LEVEL TROUGH AXIS MOVES ACROSS THE AREA. THIS SHOULD TEND TO KEEP THE LOWER LEVELS MIXED FAIRLY WELL WITH GUSTS TO NEAR 40 KNOTS. BASED ON THE FORECAST SOUNDINGS, WE WILL CONTINUE THE GALE WARNING FOR ALL OUR ZONES UNTIL 06Z TONIGHT. A SMALL CRAFT ADVISORY WILL THEN BE NEEDED FOLLOWING THE GALE AS WINDS WILL GUST TO NEAR 30 KNOTS FOR A TIME AND SEAS WILL HOLD UP ESPECIALLY ON THE OCEAN. FOR SUNDAY, HIGH PRESSURE WILL BE BUILDING IN THEREFORE ANY LINGERING GUSTY WINDS WILL BE ON A DIMINISHING TREND THROUGH THE DAY. THIS WILL ALSO ALLOW THE SEAS TO SUBSIDE. OUTLOOK... SUNDAY NIGHT...QUIET WITH LIGHT WIND. MONDAY...SCA SW GUSTS POSSIBLE IN THE AFTN. MONDAY NIGHT....NW SCA GUSTS POSSIBLE. TUESDAY...NO HEADLINE. WEDNESDAY/THURSDAY...SCA POSSIBLE...COMPLEX. UNCERTAINTY WHETHER A WFRONTAL WAVE DEVELOPS OFF NJ .. SIMILAR TO YESTERDAY THE 24TH. WIND COULD RANGE FROM E TO SW WITH A TENDENCY FOR E IN THE NNJ WATERS AND SW IN THE SRN WATERS BUT UNCERTAINTY EXISTS. WHILE UNCERTAIN...ON THE STRENGTH OF RECENT ECWMF PERFORMANCE.. ODDS SEEM TO FAVOR A MOSTLY NE FLOW WITH GUSTS 20-30 KTS AT TIMES BY WED NIGHT OR THURSDAY MORNING. && .TIDES/COASTAL FLOODING... THE STRONG WESTERLY FLOW CONTINUES TO DRIVE THE TIDAL DEPARTURES DOWN INTO THE NEGATIVE RANGE ESPECIALLY DURING LOW TIDE. THIS IS EXPECTED TO CONTINUE THROUGH THIS EVENING AT LEAST WITH LEVELS GETTING RATHER CLOSE TO BLOWOUT CRITERIA /-1.8 FEET MLLW/. FOR THIS REASON, A LOW WATER ADVISORY REMAINS IN EFFECT ALONG OUR NEW JERSEY AND DELAWARE COASTS UNTIL 6 PM AND ON DELAWARE BAY FROM 4 PM TO 9 PM. WATER LEVELS WILL REMAIN RATHER LOW WELL INTO TONIGHT AND IT REMAINS POSSIBLE THAT THE SUNDAY MORNING LOW TIDE CYCLE COULD ALSO SEE NEAR BLOWOUT CONDITIONS. FOR NOW THOUGH, WE WILL SEE HOW THE DEPARTURES BEHAVE AND THEREFORE NO CHANGES WERE MADE TO THE PREVIOUS HEADLINE. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ054-055- 060>062-067>071. NJ...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NJZ001-007>010- 012>027. DE...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR DEZ001>004. MD...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR MDZ008-012-015- 019-020. MARINE...LOW WATER ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ450>455. GALE WARNING UNTIL 1 AM EST SUNDAY FOR ANZ430-431-450>455. LOW WATER ADVISORY UNTIL 9 PM EST THIS EVENING FOR ANZ430-431. && $$ SYNOPSIS...DRAG NEAR TERM...GORSE SHORT TERM...GORSE LONG TERM...DRAG 407 AVIATION...DRAG/GORSE 407 MARINE...DRAG/GORSE 407 TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
305 PM EST SAT FEB 25 2012 .SYNOPSIS... AN INTENSE LOW OVER THE MARITIMES WILL BEGIN WEAKENING EARLY SUNDAY AS IT MOVES INTO THE NORTH ATLANTIC SOUTH OF GREENLAND. HIGH PRESSURE OVER THE LOWER MISSISSIPPI VALLEY WILL REACH THE MID ATLANTIC COAST SUNDAY AFTERNOON. LOW PRESSURE CROSSING NEW ENGLAND LATE MONDAY WILL SEND A COLD FRONT THROUGH THE MID ATLANTIC STATES MONDAY NIGHT...FOLLOWED BY CANADIAN HIGH PRESSURE BUILDING TO OUR NORTH ON TUESDAY. THAT COLD HIGH MAY LOCK IN OVER QUEBEC THURSDAY AND FRIDAY...SETTING THE STAGE FOR WINTRY WEATHER IN PORTIONS OF NEW JERSEY AND PENNSYLVANIA DURING MID WEEK. STRONG LOW PRESSURE IN THE UPPER MIDWEST ON WEDNESDAY WILL WEAKEN AS IT REDEVELOPS ALONG THE DELMARVA COAST THURSDAY AND THEN HEADS OUT TO SEA. THE CANADIAN HIGH REASSERTS CONTROL HERE FOR A PORTION OF FRIDAY BEFORE ANOTHER LOW PRESSURE SYSTEMS ARRIVES TO START THE WEEKEND. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... A 19Z SURFACE ANALYSIS PLACED AN INTENSE LOW ACROSS THE CANADIAN MARITIMES. THE LOWEST SURFACE PRESSURE SO FAR WITH THIS WAS 966 MB. A TROUGH OR SECONDARY FRONT IS DRAPED ACROSS NEW YORK STATE TO LAKE MICHIGAN. HIGH PRESSURE WAS ACROSS THE MISSISSIPPI VALLEY. AN UPPER AIR ANALYSIS INDICATED A SHARP TROUGH AXIS FROM NEW ENGLAND TO THE UPPER OHIO VALLEY. A RIDGE WAS IN THE PLAINS WITH ANOTHER TROUGH IN THE NORTHERN ROCKIES. AN AREA OF FOCUSED WAA AT 850 MB WAS ACROSS THE CENTRAL AND NORTHERN PLAINS. A STRONG CYCLONICALLY CURVED 250 MB JET WAS FROM THE MIDWEST TO THE OHIO VALLEY THEN OFF THE NEW ENGLAND COAST. AS THE INTENSE STORM IN THE CANADIAN MARITIMES CONTINUES TO MOVE NORTHEASTWARD, HIGH PRESSURE WILL BEGIN TO EDGE CLOSER FROM THE WEST THROUGH TONIGHT. THE UPPER-LEVEL TROUGH AXIS HOWEVER IS FORECAST TO SWING ACROSS OUR AREA EARLY THIS EVENING. THE COMBINATION OF DEEP CYCLONIC FLOW, CAA AND STEEP LOW-LEVEL LAPSE RATES HAVE ALLOWED SNOW SHOWERS TO OCCUR MAINLY ACROSS THE NORTHERN HALF OF THE CWA. THESE ARE MORE CONVECTIVE, AND ANY STRONGER ACTIVITY COULD PRODUCE A BURST OF SNOW. ANY LOCAL SNOW ACCUMULATIONS ARE EXPECTED TO BE AN INCH OR LESS AS IT APPEARS THE SNOW SHOWERS WILL BE TRANSIENT. SOME OF THE HIGH RESOLUTION MODELS HOWEVER, SUCH AS THE HRRR AND THE SPC WRF-NMM, INDICATE THAT THERE COULD BE A COUPLE OF WEST TO EAST ORIENTATED SNOW BANDS MOVING THROUGH PARTS OF THE AREA THROUGH EARLY THIS EVENING. THIS WAS OBSERVED THIS MORNING, AND GIVEN THE TROUGH AXIS MOVING THROUGH IT CANNOT BE RULED OUT. THERE ARE TWO DISTINCT BANDS ON THE RADAR AS OF 20Z, ONE ACROSS CENTRAL PENNSYLVANIA AND THE OTHER ONE DROPPING SOUTHEASTWARD INTO NORTHEASTERN PENNSYLVANIA. THE LATTER LOOKS TO BE AHEAD OF A WEAK SURFACE TROUGH OR FRONT WITH SOME VEERING OF THE WINDS A BIT MORE TO THE NORTHWEST BEHIND IT. THE 12Z SPC WRF-NMM HAS PICKED UP ON THIS ACTIVITY AND IS DOING WELL AS OF 19Z. IT BRINGS THESE TWO BANDS ACROSS PORTIONS OF EASTERN PENNSYLVANIA AND THE NORTHERN HALF OF NEW JERSEY THROUGH ABOUT 23Z BEFORE WEAKENING THEM. WE LEANED OUR POPS CLOSER TO THIS, WITH SOME LIKELY VALUES ACROSS THE FAR NORTHWEST INTO THIS EVENING, AND SOME HIGHER CHC VALUES FARTHER SOUTH. IF THESE BANDS OCCUR, A BURST OF HEAVIER SNOW WILL FALL WHICH WILL GREATLY REDUCE THE VISIBILITY FOR A SHORT TIME. AS WE TAPERED THE POPS DOWN WITH A SOUTHEASTWARD EXTENT, DID CARRY SCATTERED FLURRIES ON THE SOUTHERN END FOR NOW WITH MOST OF THIS MENTION ALONG AND NORTH/WEST OF INTERSTATE 95. ANY ACTIVITY SHOULD WEAKEN AND THEN DISSIPATE DURING THE NIGHT AS SOME DRIER AIR AND SUBSIDENCE BEGINS TO WORK INTO THE AREA. THIS WILL ALSO ALLOW THE STRATOCUMULUS TO RETREAT NORTHWESTWARD THROUGH THE NIGHT. THE STRONG WINDS ACROSS THE AREA WILL CONTINUE INTO THIS EVENING AS THE 925 MB WINDS ARE FORECAST TO INCREASE SOME AS THE TROUGH AXIS SWINGS THROUGH. WE SHOULD START TO SHRINK THE VERTICAL MIXING EARLY THIS EVENING AS THE LOSS OF DAYTIME HEATING OCCURS, HOWEVER IT APPEARS WE SHOULD ACHIEVE SOME ADVISORY LEVEL GUSTS INTO THIS EVENING. THEREFORE, WE WILL CONTINUE THE WIND ADVISORY ACROSS THE ENTIRE CWA UNTIL 7 PM. AS FOR TEMPERATURES, WE GENERALLY USED A BLEND OF THE GFS/NAM MOS. THE WINDS SHOULD DROP OFF ENOUGH LATER TONIGHT TO ALLOW THE TEMPERATURES TO DROP MORE GIVEN THE LOW DEW POINTS. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/... AN UPPER-LEVEL TROUGH WILL BE WELL EAST OF OUR AREA SUNDAY AS A MID LEVEL RIDGE APPROACHES FROM THE WEST. THIS WILL DRIVE SURFACE HIGH PRESSURE OVER OUR AREA DURING THE COURSE OF THE DAY. THERE IS A LINGERING PRESSURE GRADIENT TO START THE MORNING, HOWEVER THIS WEAKENS FAIRLY QUICKLY AS THE SURFACE HIGH BEGINS TO CREST INTO OUR REGION. THIS WILL RESULT IN MUCH LESS WIND COMPARED TO TODAY. THERE APPEARS TO BE ENOUGH DRYING IN THE LOWER AND MIDDLE PORTIONS OF THE ATMOSPHERE AND SUBSIDENCE TO LIMIT ANY STRATOCUMULUS DEVELOPMENT. AN AREA OF WAA UP THROUGH THE OHIO VALLEY HOWEVER WILL TEND TO DRIVE A DEVELOPING WARM FRONT JUST TO OUR WEST. THE MAIN PUSH OF MILDER AIR IS FORECAST TO BE FOCUSED MORE TO OUR WEST. HOWEVER AS THE MID LEVEL RIDGE AXIS NEARS, SOME HIGH CLOUDS MAY START TO MOVE IN. THIS LOOKS MINIMAL AT THIS POINT, THEREFORE WE LEANED TOWARD A GOOD DEAL OF SUNSHINE DURING THE DAY. AS FOR TEMPERATURES, WE MAINLY WENT WITH A MOS BLEND. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... NORTHERN TIER OF USA SHOWS A SUCCESSION OF THREE STRENGTHENING SHORT WAVES IN THE UPPER MIDWEST TENDING TO GETTING SQUASHED AS THEY MOVE INTO CONFLUENCE ZONE OVER SOUTHEAST CANADA. THIS MAY EVENTUALLY BODE WELL FOR MUCH NE PA AND NW NJ SNOW/ICE ENTHUSIASTS MIDDLE OF THE WEEK AND NEXT WEEKEND. THE FIRST SHORT WAVE ASSOCIATED SFC LOW VICINITY OF LSUPR SUNDAY EVENING WEAKENS TO A NOVA SCOTIA PASSAGE TUESDAY MORNING. THE SECOND SHORT WAVE STRONGER LOW PRESSURE SYSTEM IN THE MIDWEST WEDNESDAY BECOMES A POTENTIALLY BIGGER PLAYER HERE AS IT EVENTUALLY MOVES OFF THE NJ OR DE COAST THURSDAY. PLS SEE THE 150 PM PMDEPD FROM HPC ON THIS. WHILE THE 12Z/25 GEFS CONTS TO INSIST ON A NORTH TRACK...AM WARY OF WARM SOLNS E OF THE APPALACHIANS WITH A MID LVL /500MB/ CONFLUENCE ZONE THAT IS IN SE CANADA/NORTHERN NEW ENGLAND. AS AN EXAMPLE OF BUST POTENTIAL...THE 12Z/23 NCEP MOS GUIDANCE FCST FOR PHL ON 12/24 WAS 68-71F. THE EC SCORCHED THE GUIDANCE WITH HIGHS NEAR 50. THE DAYTIME HIGH WAS 49. THINK THE BUST POTENTIAL MAY AGAIN BE PRETTY LARGE FOR WED/THU HERE IN OUR FA. AM APPROACHING WARM SOLNS WITH CAUTION AND COMPLETELY ADOPTING THE MUCH COLDER THAN NCEP GUIDANCE SOLN FOR WED-FRI. THE THIRD SHORT WAVE THAT WILL BECOME A PLAYER IS DEPARTING THE UPPER MIDWEST FRIDAY NIGHT. COULD SEE ICE OR SNOW TO START ON THAT ONE IN THE POCS AND FAR NW NJ. NOT CONCENTRATING ON THAT LATTER EVENT. TEMPS IN THIS PATTERN WILL CONTINUE ABOVE NORMAL. NCEP MODEL GUIDANCE APPEARS MUCH TOO WARM ON DAYTIME MAX`S IN NJ/PA IF PCPN IS OCCURRING ON WED-THU. USED HPC GUIDANCE TEMPS. THE DAILIES... SUNDAY NIGHT AND MONDAY...FAIR IN DRY SW FLOW WAA BEHIND THE DEPARTING MID ATLC COAST SFC HIGH. A CHILLY RADIATIONAL COOLING START TO MONDAY MORNING WARMS QUICKLY TO ABOVE NORMAL TEMPS IN THE AFTN WITH GUSTY SW WINDS 20-25 MPH. BLENDED MOS GUIDANCE. WILL THIS BE A FWX CONCERN FOR AN SPS AFTN? MONDAY NIGHT...DRY CFP. BLENDED MOS GUIDANCE. TUESDAY...DRY HIGH PRES ARRIVES... WITH A TENDENCY OF MORE HIGH PRES OVER SE CANADA...IE A COLDER WET BULB LYING IN WAIT FOR THE NORTHERN ZONES. TUESDAY NIGHT-WEDNESDAY...COMPLEX BUT A WARM FRONT WILL PRODUCE A PERIOD OF PRECIPITATION WEDNESDAY..SOME OF IT EXPECTED TO BE SNOW FROM KABE-KSMQ REGION NORTH AND MAYBE RIVALING ONE OF THE MORE SIGNIFICANT SNOW EVENTS OF THE WINTER SO FAR. THAT SOUTHERN EDGE OF WINTER WX IS NOT SET IN STONE BUT THATS THE BEST ESTIMATE I CAN OFFER AT THIS JUNCTURE FROM MODEL ENSEMBLING AND REALIZING WE ARE STILL IN MET WINTER. 12Z/25 HPC GUIDANCE TEMPS/WINDS. WEDNESDAY NIGHT-THURSDAY...THE CLOSED LOW ALOFT IN THE MIDWEST HAS NO WHERE TO GO BUT E OR ESE FORCED BY THE CONFLUENCE ZONE IN MAINE. THAT MEANS PLENTY OF VORT RIDING OVER WHATEVER THE AXIS OF LEFTOVER DEEPER MOISTURE. IF THAT MOIST AXIS IS NORTH OF OUR FA...THEN VERY LITTLE PCPN. BUT IF THE WARM FRONTAL WAVE DEVELOPS EWD FROM NJ OR DE AS PER THE ECMWF ON WED NIGHT...IT WILL HAVE THE BAROCLINIC ZONE AXIS SET UP FOR A NEW SFC LOW TO FORM OFF NJ/DE THURSDAY MORNING RAISING THE POTENTIAL FOR MORE SNOW IN NE PA AND NW NJ AND SOME COLD DRIZZLE OR A FEW SHOWERS ELSEWHERE S OF KSMQ- KABE. THERE IS A LOW PROB FOR HAZARDOUS WX ALL THE WAY DOWN TO PHIL. 12Z/25 HPC GUIDANCE TEMPS/WINDS. FRIDAY...DRY CANADIAN HIGH PRES REASSERTS CONTROL HERE...BRIEFLY. HOWEVER THE NEXT LOW PRESSURE SYSTEM WILL BE APPROACHING...POSSIBLY SPREADING COLD PRECIPITATION INTO OUR AREA FRIDAY NIGHT. 12Z/25 HPC GUIDANCE AND NOT MUCH ENERGY INTO MODIFYING DATA FOR THIS DATE. && .AVIATION /20Z SATURDAY THROUGH THURSDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. AN INTENSE STORM IN THE CANADIAN MARITIMES WILL CONTINUE TO TRACK NORTHEASTWARD AND AWAY FROM OUR AREA. HIGH PRESSURE WILL THEN BUILD INTO OUR AREA DURING SUNDAY. A TIGHT PRESSURE GRADIENT BETWEEN THIS HIGH AND LOW PRESSURE TO OUR NORTHEAST WILL CONTINUE TO DRIVE GUSTY WEST TO NORTHWEST WINDS THROUGH ABOUT THE FIRST HALF OF THE NIGHT. THE PEAK GUSTS WILL GENERALLY BE AROUND 40 KNOTS INTO EARLY THIS EVENING, THEN THESE ARE EXPECTED TO DIMINISH THROUGH THE NIGHT AS THE VERTICAL MIXING SHRINKS AND HIGH PRESSURE EDGES CLOSER FROM THE WEST. A DECENT AMOUNT OF STRATOCUMULUS AROUND THE REGION THIS AFTERNOON WILL THIN OUT FROM SOUTHEAST TO NORTHWEST AS SOME DRYING WORKS IN AND HIGH PRESSURE GETS A BIT CLOSER DURING THE NIGHT. ANY SNOW SHOWERS ARE EXPECTED TO RETREAT BACK NORTHWESTWARD THROUGH THE EVENING, AND GENERALLY BE NORTH AND WEST FROM ABOUT KTTN TO KILG. A NARROW BAND OF HEAVIER SNOW MAY DEVELOP ACROSS PARTS OF THE REGION THROUGH EARLY THIS EVENING, THEREFORE SOME BRIEF BUT GREATLY REDUCED VISIBILITIES /AND SOME LOWER CEILINGS/ MAY OCCUR. SOME SHORT-FUSED AMENDMENTS MAY BE NEEDED TO ACCOUNT FOR ANY SNOW SHOWERS THAT LOOK TO IMPACT ANY LOCAL TERMINAL. FOR SUNDAY, A CALMER DAY IS EXPECTED AS HIGH PRESSURE SETTLES RIGHT OVER THE AREA. THIS WILL ALLOW FOR MUCH LESS WIND, THEREFORE A WESTERLY WIND SHOULD BE ON THE ORDER OF 10 TO 15 KNOTS BEFORE WEAKENING MORE BY LATER IN THE DAY. THERE APPEARS TO BE ENOUGH DRYING IN THE LOWER AND MIDDLE LEVELS OF THE ATMOSPHERE TO LIMIT AND STRATOCUMULUS DEVELOPMENT. THEREFORE, VFR IS EXPECTED. OUTLOOK... SUNDAY NIGHT-TUESDAY...VFR. SW GUSTS TO 20 KT POSSIBLE MON AFTN. WEDNESDAY/THURSDAY...MVFR CONDS IN SHOWERS EXCEPT MIXED WINTRY PCPN POSSIBLE KABE-KSMQ NORTHWARD WHERE CONDS SHOULD DETERIORATE TO OCNL IFR. && .MARINE... THE PRESSURE GRADIENT REMAINS TIGHT ACROSS THE REGION DUE TO AN INTENSE STORM IN THE CANADIAN MARITIMES AND HIGH PRESSURE MOVING INTO THE OHIO VALLEY. THIS GRADIENT IS EXPECTED TO WEAKEN THROUGH THE NIGHT AS HIGH PRESSURE EDGES CLOSER. THE MODEL GUIDANCE INDICATES THAT THE 925 MB FLOW INCREASES SOME THROUGH EARLY THIS EVENING AS THE UPPER-LEVEL TROUGH AXIS MOVES ACROSS THE AREA. THIS SHOULD TEND TO KEEP THE LOWER LEVELS MIXED FAIRLY WELL WITH GUSTS TO NEAR 40 KNOTS. BASED ON THE FORECAST SOUNDINGS, WE WILL CONTINUE THE GALE WARNING FOR ALL OUR ZONES UNTIL 06Z TONIGHT. A SMALL CRAFT ADVISORY WILL THEN BE NEEDED FOLLOWING THE GALE AS WINDS WILL GUST TO NEAR 30 KNOTS FOR A TIME AND SEAS WILL HOLD UP ESPECIALLY ON THE OCEAN. FOR SUNDAY, HIGH PRESSURE WILL BE BUILDING IN THEREFORE ANY LINGERING GUSTY WINDS WILL BE ON A DIMINISHING TREND THROUGH THE DAY. THIS WILL ALSO ALLOW THE SEAS TO SUBSIDE. OUTLOOK... SUNDAY NIGHT...QUIET WITH LIGHT WIND. MONDAY...SCA SW GUSTS POSSIBLE IN THE AFTN. MONDAY NIGHT....NW SCA GUSTS POSSIBLE. TUESDAY...NO HEADLINE. WEDNESDAY/THURSDAY...SCA POSSIBLE...COMPLEX. UNCERTAINTY WHETHER A WFRONTAL WAVE DEVELOPS OFF NJ .. SIMILAR TO YESTERDAY THE 24TH. WIND COULD RANGE FROM E TO SW WITH A TENDENCY FOR E IN THE NNJ WATERS AND SW IN THE SRN WATERS BUT UNCERTAINTY EXISTS. UNCERTAINTY BUT ODDS SEEM TO FAVOR A MOSTLY NE FLOW WITH GUSTS 20-30 KTS AT TIMES BY WED NIGHT AND THU. && .TIDES/COASTAL FLOODING... THE STRONG WESTERLY FLOW CONTINUES TO DRIVE THE TIDAL DEPARTURES DOWN INTO THE NEGATIVE RANGE ESPECIALLY DURING LOW TIDE. THIS IS EXPECTED TO CONTINUE THROUGH THIS EVENING AT LEAST WITH LEVELS GETTING RATHER CLOSE TO BLOWOUT CRITERIA /-1.8 FEET MLLW/. FOR THIS REASON, A LOW WATER ADVISORY REMAINS IN EFFECT ALONG OUR NEW JERSEY AND DELAWARE COASTS UNTIL 6 PM AND ON DELAWARE BAY FROM 4 PM TO 9 PM. WATER LEVELS WILL REMAIN RATHER LOW WELL INTO TONIGHT AND IT REMAINS POSSIBLE THAT THE SUNDAY MORNING LOW TIDE CYCLE COULD ALSO SEE NEAR BLOWOUT CONDITIONS. FOR NOW THOUGH, WE WILL SEE HOW THE DEPARTURES BEHAVE AND THEREFORE NO CHANGES WERE MADE TO THE PREVIOUS HEADLINE. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ054-055- 060>062-067>071. NJ...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NJZ001-007>010- 012>027. DE...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR DEZ001>004. MD...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR MDZ008-012-015- 019-020. MARINE...LOW WATER ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ450>455. GALE WARNING UNTIL 1 AM EST SUNDAY FOR ANZ430-431-450>455. LOW WATER ADVISORY UNTIL 9 PM EST THIS EVENING FOR ANZ430-431. && $$ SYNOPSIS...DRAG NEAR TERM...GORSE SHORT TERM...GORSE LONG TERM...DRAG AVIATION...DRAG/GORSE MARINE...DRAG/GORSE TIDES/COASTAL FLOODING...RPW/GORSE/ROBERTSON
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
214 PM EST SAT FEB 25 2012 .SYNOPSIS... AN INTENSE LOW OVER THE MARITIMES WILL BEGIN WEAKENING EARLY SUNDAY AS IT MOVES INTO THE NORTH ATLANTIC SOUTH OF GREENLAND. HIGH PRESSURE OVER THE LOWER MISSISSIPPI VALLEY WILL REACH THE MID ATLANTIC COAST SUNDAY AFTERNOON. LOW PRESSURE CROSSING NEW ENGLAND LATE MONDAY WILL SEND A COLD FRONT THROUGH THE MID ATLANTIC STATES MONDAY NIGHT...FOLLOWED BY CANADIAN HIGH PRESSURE BUILDING TO OUR NORTH ON TUESDAY. THAT COLD HIGH MAY LOCK IN OVER QUEBEC THURSDAY AND FRIDAY...SETTING THE STAGE FOR WINTRY WEATHER IN PORTIONS OF NEW JERSEY AND PENNSYLVANIA DURING MID WEEK. STRONG LOW PRESSURE IN THE UPPER MIDWEST ON WEDNESDAY WILL WEAKEN AS IT REDEVELOPS ALONG THE DELMARVA COAST THURSDAY AND THEN HEADS OUT TO SEA. THE CANADIAN HIGH REASSERTS CONTROL HERE FOR A PORTION OF FRIDAY BEFORE ANOTHER LOW PRESSURE SYSTEMS ARRIVES TO START THE WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE EARLIER NARROW BUT BRIEFLY INTENSE SNOW BAND HAS WEAKENED AS IT MOVED INTO PORTIONS OF SOUTHERN NEW JERSEY EARLIER. THIS PRODUCED LOCALLY UP TO 1.5 INCHES OF SNOW IN A SHORT PERIOD OF TIME IN PORTIONS OF SOUTHEASTERN PENNSYLVANIA. THE COMBINATION OF STEEPENING LOW-LEVEL LAPSE RATES, CAA AND A DEEP CYCLONIC FLOW IS ALLOWING ADDITIONAL SNOW SHOWERS TO DEVELOP. THESE TO MAY DEVELOP INTO EAST TO WEST TYPE BANDS. BASED ON THE SOUNDINGS AND OBSERVING VISIBLE SATELLITE IMAGERY, THE ACTIVITY DOES HAVE A CONVECTIVE LOOK. THEREFORE, SOME LOCAL BUT BRIEF BURSTS OF SNOW ARE POSSIBLE THROUGH THE AFTERNOON. THE CLOUDS HAVE EVEN CLEARED OUT BEHIND SOME OF THE HEAVIER SNOW SHOWERS AS THE AIRMASS STABILIZES FOR A TIME. WE WILL MAINLY CARRY CHC POPS ACROSS MOSTLY THE NORTHERN HALF OF THE CWA TO ACCOUNT FOR THIS ACTIVITY. THE HRRR APPEARS TO BE THE ONLY HIGH RESOLUTION GUIDANCE THAT HAS CAPTURED THE SNOW BANDS DECENTLY SO FAR. BASED ON THE FORECAST SOUNDINGS, THE STRONGER WINDS MAY ACTUALLY OCCUR LATER THIS AFTERNOON AS THE LAPSE RATES MAX OUT AND WE GET EVEN DEEPER MIXING ALONG WITH SOME STRONGER WINDS ALOFT. THE WINDS HAVE BEEN SHOWING SIGNS OF INCREASING SO FAR WITH SOME GUSTS TO AROUND 45 MPH ACROSS PARTS OF THE REGION. THE WIND ADVISORY THEREFORE REMAINS IN EFFECT FOR THE ENTIRE CWA. A PUBLIC INFORMATION STATEMENT /PNS/ IS BEING UPDATED WITH SOME SNOWFALL AMOUNTS FROM THIS MORNING AND WIND GUSTS SO FAR. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/... THE PRESSURE GRADIENT WILL BEGIN TO RELAX A BIT TONIGHT AS THE HIGH PRESSURE SYSTEM TO OUR WEST MOVES CLOSER TO OUR AREA. WINDS WILL DIMINISH SLOWLY OVERNIGHT WITH MOST OF THE GUSTS DROPPING OFF BY OR SHORTLY AFTER MIDNIGHT. SKIES WILL BECOME MOSTLY CLEAR AND TEMPERATURES WILL BOTTOM OUT IN THE UPPER TEENS AND 20S. && .LONG TERM /SUNDAY THROUGH FRIDAY/... NORTHERN TIER OF USA SHOWS A SUCCESSION OF THREE STRENGTHENING SHORT WAVES IN THE UPPER MIDWEST TENDING TO GETTING SQUASHED AS THEY MOVE INTO CONFLUENCE ZONE OVER SOUTHEAST CANADA. THIS MAY EVENTUALLY BODE WELL FOR MUCH NE PA AND NW NJ SNOW/ICE ENTHUSIASTS MIDDLE OF THE WEEK AND NEXT WEEKEND. THE FIRST SHORT WAVE ASSOCIATED SFC LOW VICINITY OF LSUPR SUNDAY EVENING WEAKENS TO A NOVA SCOTIA PASSAGE TUESDAY MORNING. THE SECOND SHORT WAVE STRONGER LOW PRESSURE SYSTEM IN THE MIDWEST WEDNESDAY BECOMES A POTENTIALLY BIGGER PLAYER HERE AS IT EVENTUALLY MOVES OFF THE NJ OR DE COAST THURSDAY. PLS SEE THE 150 PM PMDEPD FROM HPC ON THIS. WHILE THE 12Z/25 GEFS CONTS TO INSIST ON A NORTH TRACK...AM WARY OF WARM SOLNS E OF THE APPALACHIANS WITH A MID LVL /500MB/ CONFLUENCE ZONE THAT IS IN SE CANADA/NORTHERN NEW ENGLAND. AS AN EXAMPLE OF BUST POTENTIAL...THE 12Z/23 NCEP MOS GUIDANCE FCST FOR PHL ON 12/24 WAS 68-71F. THE EC SCORCHED THE GUIDANCE WITH HIGHS NEAR 50. THE DAYTIME HIGH WAS 49. THINK THE BUST POTENTIAL MAY AGAIN BE PRETTY LARGE FOR WED/THU HERE IN OUR FA. AM APPROACHING WARM SOLNS WITH CAUTION AND COMPLETELY ADOPTING THE MUCH COLDER THAN NCEP GUIDANCE SOLN FOR WED-FRI. THE THIRD SHORT WAVE THAT WILL BECOME A PLAYER IS DEPARTING THE UPPER MIDWEST FRIDAY NIGHT. COULD SEE ICE OR SNOW TO START ON THAT ONE IN THE POCS AND FAR NW NJ. NOT CONCENTRATING ON THAT LATTER EVENT. TEMPS IN THIS PATTERN WILL CONTINUE ABOVE NORMAL. NCEP MODEL GUIDANCE APPEARS MUCH TOO WARM ON DAYTIME MAX`S IN NJ/PA IF PCPN IS OCCURRING ON WED-THU. USED HPC GUIDANCE TEMPS. THE DAILIES... SUNDAY NIGHT AND MONDAY...FAIR IN DRY SW FLOW WAA BEHIND THE DEPARTING MID ATLC COAST SFC HIGH. A CHILLY RADIATIONAL COOLING START TO MONDAY MORNING WARMS QUICKLY TO ABOVE NORMAL TEMPS IN THE AFTN WITH GUSTY SW WINDS 20-25 MPH. BLENDED MOS GUIDANCE. WILL THIS BE A FWX CONCERN FOR AN SPS AFTN? MONDAY NIGHT...DRY CFP. BLENDED MOS GUIDANCE. TUESDAY...DRY HIGH PRES ARRIVES... WITH A TENDENCY OF MORE HIGH PRES OVER SE CANADA...IE A COLDER WET BULB LYING IN WAIT FOR THE NORTHERN ZONES. TUESDAY NIGHT-WEDNESDAY...COMPLEX BUT A WARM FRONT WILL PRODUCE A PERIOD OF PRECIPITATION WEDNESDAY..SOME OF IT EXPECTED TO BE SNOW FROM KABE-KSMQ REGION NORTH AND MAYBE RIVALING ONE OF THE MORE SIGNIFICANT SNOW EVENTS OF THE WINTER SO FAR. THAT SOUTHERN EDGE OF WINTER WX IS NOT SET IN STONE BUT THATS THE BEST ESTIMATE I CAN OFFER AT THIS JUNCTURE FROM MODEL ENSEMBLING AND REALIZING WE ARE STILL IN MET WINTER. 12Z/25 HPC GUIDANCE TEMPS/WINDS. WEDNESDAY NIGHT-THURSDAY...THE CLOSED LOW ALOFT IN THE MIDWEST HAS NO WHERE TO GO BUT E OR ESE FORCED BY THE CONFLUENCE ZONE IN MAINE. THAT MEANS PLENTY OF VORT RIDING OVER WHATEVER THE AXIS OF LEFTOVER DEEPER MOISTURE. IF THAT MOIST AXIS IS NORTH OF OUR FA...THEN VERY LITTLE PCPN. BUT IF THE WARM FRONTAL WAVE DEVELOPS EWD FROM NJ OR DE AS PER THE ECMWF ON WED NIGHT...IT WILL HAVE THE BAROCLINIC ZONE AXIS SET UP FOR A NEW SFC LOW TO FORM OFF NJ/DE THURSDAY MORNING RAISING THE POTENTIAL FOR MORE SNOW IN NE PA AND NW NJ AND SOME COLD DRIZZLE OR A FEW SHOWERS ELSEWHERE S OF KSMQ- KABE. THERE IS A LOW PROB FOR HAZARDOUS WX ALL THE WAY DOWN TO PHIL. 12Z/25 HPC GUIDANCE TEMPS/WINDS. FRIDAY...DRY CANADIAN HIGH PRES REASSERTS CONTROL HERE...BRIEFLY. HOWEVER THE NEXT LOW PRESSURE SYSTEM WILL BE APPROACHING...POSSIBLY SPREADING COLD PRECIPITATION INTO OUR AREA FRIDAY NIGHT. 12Z/25 HPC GUIDANCE AND NOT MUCH ENERGY INTO MODIFYING DATA FOR THIS DATE. && .AVIATION /19Z SATURDAY THROUGH THURSDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. AN INTENSE STORM IN THE CANADIAN MARITIMES WILL CONTINUE TO TRACK NORTHEASTWARD AND AWAY FROM OUR AREA. HIGH PRESSURE WILL THEN BUILD INTO OUR AREA DURING SUNDAY. A TIGHT PRESSURE GRADIENT BETWEEN THIS HIGH AND LOW PRESSURE TO OUR NORTHEAST WILL CONTINUE TO DRIVE GUSTY WEST TO NORTHWEST WINDS THROUGH ABOUT THE FIRST HALF OF TONIGHT. THE PEAK GUSTS WILL GENERALLY BE AROUND 40 KNOTS, HOWEVER THESE ARE EXPECTED TO DIMINISH THROUGH THE NIGHT AS THE VERTICAL MIXING SHRINKS AND HIGH PRESSURE EDGES CLOSER FROM THE WEST. A DECENT AMOUNT OF STRATOCUMULUS AROUND THE REGION THIS AFTERNOON WILL THIN OUT FROM SOUTHEAST TO NORTHWEST AS SOME DRYING WORKS IN AND HIGH PRESSURE GETS A BIT CLOSER. ANY SNOW SHOWERS ARE EXPECTED TO RETREAT BACK NORTHWESTWARD THROUGH THE EVENING, AND GENERALLY BE NORTH OF KABE. HOWEVER UNTIL THEN, SOME BRIEF REDUCTIONS IN THE LOCAL VISIBILITIES AND CEILINGS MAY OCCUR. THE OVERALL IMPACT OF THESE CARRIES SOME UNCERTAINTY, THEREFORE SOME SHORT-FUSED AMENDMENTS MAY BE NEEDED TO ACCOUNT FOR ANY SNOW SHOWERS THAT LOOK TO IMPACT ANY LOCAL TERMINALS. FOR SUNDAY, A CALMER DAY IS EXPECTED AS HIGH PRESSURE SETTLES RIGHT OVER THE AREA. THIS WILL ALLOW FOR MUCH LESS WIND, THEREFORE A WESTERLY WIND SHOULD BE ON THE ORDER OF 10 TO 15 KNOTS BEFORE WEAKENING MORE BY LATE IN THE DAY. THERE APPEARS TO BE ENOUGH DRYING IN THE LOWER AND MIDDLE LEVELS OF THE ATMOSPHERE TO LIMIT ANY STRATOCUMULUS DEVELOPMENT. THEREFORE, VFR IS EXPECTED. OUTLOOK... SUNDAY NIGHT-TUESDAY...VFR. SW GUSTS TO 20 KT POSSIBLE MON AFTN. WEDNESDAY/THURSDAY...MVFR CONDS IN SHOWERS EXCEPT MIXED WINTRY PCPN POSSIBLE KABE-KSMQ NORTHWARD WHERE CONDS SHOULD DETERIORATE TO OCNL IFR. && .MARINE... THE PRESSURE GRADIENT BETWEEN THE DEPARTING STORM AND HIGH PRESSURE PUSHING IN FROM THE WEST IS AND WILL CONTINUE TO PRODUCE STRONG WESTERLY WINDS TODAY. A GALE WARNING REMAINS IN EFFECT ON ALL OF OUR WATERS UNTIL 1 AM SUNDAY. THE WINDS HAVE KICKED UP THE SEAS TO 6 TO 8 FEET ON THE OCEAN WATERS AND 2 TO 5 FEET ON DELAWARE BAY. THIS WILL CONTINUE THROUGH THE DAY. WINDS AND SEAS WILL BEGIN TO LOWER TONIGHT AS HIGH PRESSURE TO OUR WEST APPROACHES. ONCE THE GALE WARNING COMES DOWN, A SMALL CRAFT ADVISORY WILL BE NEEDED LATER TONIGHT. THE GRADIENT COULD SUPPORT SMALL CRAFT WIND GUSTS SUNDAY MORNING... BUT AS HIGH PRESSURE APPROACHES IN THE AFTERNOON...WINDS AND SEAS SHOULD DROP BELOW SMALL CRAFT LEVELS. OUTLOOK... SUNDAY NIGHT...QUIET WITH LIGHT WIND. MONDAY...SCA SW GUSTS POSSIBLE IN THE AFTN. MONDAY NIGHT....NW SCA GUSTS POSSIBLE. TUESDAY...NO HEADLINE. WEDNESDAY/THURSDAY...SCA POSSIBLE...COMPLEX. UNCERTAINTY WHETHER A WFRONTAL WAVE DEVELOPS OFF NJ .. SIMILAR TO YESTERDAY THE 24TH. WIND COULD RANGE FROM E TO SW WITH A TENDENCY FOR E IN THE NNJ WATERS AND SW IN THE SRN WATERS BUT UNCERTAINTY EXISTS. UNCERTAINTY BUT ODDS SEEM TO FAVOR A MOSTLY NE FLOW WITH GUSTS 20-30 KTS AT TIMES BY WED NIGHT AND THU. && .TIDES/COASTAL FLOODING... WITH THE STRONG WESTERLY WINDS TODAY, TIDAL DEPARTURES WILL BECOME INCREASINGLY NEGATIVE. IT NOW APPEARS THAT BLOWOUT CONDITIONS WILL LIKELY OCCUR AROUND THE TIME OF LOW TIDE THIS AFTERNOON AND EVENING. FOR THIS REASON, A LOW WATER ADVISORY HAS BEEN ISSUED ALONG OUR NEW JERSEY AND DELAWARE OCEAN FRONTS FROM 2 PM TO 6 PM AND ON DELAWARE BAY FROM 4 PM TO 9 PM. WATER LEVELS WILL REMAIN VERY LOW WELL INTO TONIGHT AND IT REMAINS A POSSIBILITY THAT THE SUNDAY MORNING LOW TIDE CYCLE COULD ALSO SEE BLOWOUT OR NEAR BLOWOUT CONDITIONS. WE WILL CONTINUE TO MONITOR THE SITUATION AND ISSUE APPROPRIATE STATEMENTS OR ADVISORIES. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ054-055- 060>062-067>071. NJ...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NJZ001-007>010- 012>027. DE...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR DEZ001>004. MD...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR MDZ008-012-015- 019-020. MARINE...LOW WATER ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ450>455. GALE WARNING UNTIL 1 AM EST SUNDAY FOR ANZ430-431-450>455. LOW WATER ADVISORY UNTIL 9 PM EST THIS EVENING FOR ANZ430-431. && $$ SYNOPSIS...HAYES/DRAG 213P NEAR TERM...GORSE SHORT TERM...RPW LONG TERM...DRAG 213P AVIATION...DRAG/GORSE 213P MARINE...DRAG/GORSE 213P TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1202 PM EST SAT FEB 25 2012 .SYNOPSIS... AN INTENSE AREA OF LOW PRESSURE WILL MOVE NORTHEASTWARD AND ACROSS THE CANADIAN MARITIMES THIS AFTERNOON. HIGH PRESSURE OVER THE LOWER MISSISSIPPI VALLEY WILL BUILD EAST, REACHING THE MID ATLANTIC COAST MONDAY. A WEAK COLD FRONT WILL CROSS THE REGION MONDAY NIGHT, FOLLOWED BY HIGH PRESSURE TUESDAY. A STRONG COLD FRONT WILL APPROACH THE AREA WEDNESDAY, THEN CROSS THE REGION WEDNESDAY NIGHT. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FOR THE END OF THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE EARLIER NARROW BUT BRIEFLY INTENSE SNOW BAND HAS WEAKENED AS IT MOVED INTO PORTIONS OF SOUTHERN NEW JERSEY EARLIER. THIS PRODUCED LOCALLY UP TO 1.5 INCHES OF SNOW IN A SHORT PERIOD OF TIME IN PORTIONS OF SOUTHEASTERN PENNSYLVANIA. THE COMBINATION OF STEEPENING LOW-LEVEL LAPSE RATES, CAA AND A DEEP CYCLONIC FLOW IS ALLOWING ADDITIONAL SNOW SHOWERS TO DEVELOP. THESE TO MAY DEVELOP INTO EAST TO WEST TYPE BANDS. BASED ON THE SOUNDINGS AND OBSERVING VISIBLE SATELLITE IMAGERY, THE ACTIVITY DOES HAVE A CONVECTIVE LOOK. THEREFORE, SOME LOCAL BUT BRIEF BURSTS OF SNOW ARE POSSIBLE THROUGH THE AFTERNOON. THE CLOUDS HAVE EVEN CLEARED OUT BEHIND SOME OF THE HEAVIER SNOW SHOWERS AS THE AIRMASS STABILIZES FOR A TIME. WE WILL MAINLY CARRY CHC POPS ACROSS MOSTLY THE NORTHERN HALF OF THE CWA TO ACCOUNT FOR THIS ACTIVITY. THE HRRR APPEARS TO BE THE ONLY HIGH RESOLUTION GUIDANCE THAT HAS CAPTURED THE SNOW BANDS DECENTLY SO FAR. BASED ON THE FORECAST SOUNDINGS, THE STRONGER WINDS MAY ACTUALLY OCCUR LATER THIS AFTERNOON AS THE LAPSE RATES MAX OUT AND WE GET EVEN DEEPER MIXING ALONG WITH SOME STRONGER WINDS ALOFT. THE WINDS HAVE BEEN SHOWING SIGNS OF INCREASING SO FAR WITH SOME GUSTS TO AROUND 45 MPH ACROSS PARTS OF THE REGION. THE WIND ADVISORY THEREFORE REMAINS IN EFFECT FOR THE ENTIRE CWA. A PUBLIC INFORMATION STATEMENT /PNS/ IS BEING UPDATED WITH SOME SNOWFALL AMOUNTS FROM THIS MORNING AND WIND GUSTS SO FAR. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/... THE PRESSURE GRADIENT WILL BEGIN TO RELAX A BIT TONIGHT AS THE HIGH PRESSURE SYSTEM TO OUR WEST MOVES CLOSER TO OUR AREA. WINDS WILL DIMINISH SLOWLY OVERNIGHT WITH MOST OF THE GUSTS DROPPING OFF BY OR SHORTLY AFTER MIDNIGHT. SKIES WILL BECOME MOSTLY CLEAR AND TEMPERATURES WILL BOTTOM OUT IN THE UPPER TEENS AND 20S. && .LONG TERM /SUNDAY THROUGH FRIDAY/... A FAIRLY QUIET PERIOD FOR THE MOST PART...WITH THE MOST ACTIVE PERIOD BEING WEDNESDAY INTO WEDNESDAY NIGHT. THE GRADIENT COULD SUPPORT 25 MPH WIND GUSTS SUNDAY MORNING...BUT AS HIGH PRESSURE BUILDS TO THE EAST SOUTH OF THE AREA...THE GRADIENT SHOULD RELAX IN THE AFTERNOON. CONVECTIVE TEMPERATURES SEEM TO BE OUT OF REACH BY SOMETIME IN THE AFTERNOON...SO MOSTLY SUNNY SHOULD DO IT. THE COOLEST DAY OF THE LONG TERM SHOULD BE SUNDAY. 850 MB TEMPERATURES SUPPORT HIGHS FROM THE MID 30S NORTH TO THE UPPER 40S SOUTH. THE MOS BLEND SHOULD SUFFICE FOR HIGHS...SINCE IT APPEARS TO BE IN LINE WITH THE ABOVE THINKING. DIMINISHING WINDS AND MAINLY CLEAR SKIES SHOULD RESULT IN GOOD RADIATIONAL COOLING CONDITIONS IN PROTECTED LOCATIONS (SUCH AS THE PINE BARRENS IN NEW JERSEY). FOR THE MOST PART...THE MOS BLEND SHOULD BE OK FOR MOST PLACES...BUT FOR PROTECTED LOCATIONS THESE NUMBERS WERE DROPPED BY 3 TO 8 DEGREES. MID LEVEL MOISTURE STARTS TO INCREASE MONDAY IN THE WARM AIR ADVECTION AHEAD OF A NORTHERN STREAM SHORT WAVE. SINCE THE AIRMASS IS DRY TO START...SO MOST OF THE MOISTURE SHOULD GO INTO HIGH AND MID LEVEL CLOUDS...MAINLY ACROSS THE NORTH. AS WINDS SHIFT MONDAY AFTERNOON...THE LOWER LEVELS WARM...AND OUTSIDE OF THE INFLUENCE OF THE TERRAIN AND THE WATER...GFS MOS NUMBERS LOOK BETTER FOR HIGHS. THE NORTHERN STREAM SHORT WAVE SHOULD PASS THROUGH NEW ENGLAND MONDAY NIGHT. THE WARM AIR ADVECTION MAXIMIZES NORTH OF THE AREA...SO FOR NOW THE FRONTAL PASSAGE APPEARS TO BE DRY. THERE IS SOME COLD AIR ADVECTION BEHIND THE FRONT...AND THIS COULD TRANSLATE IN TO GUSTY NORTHWEST WINDS IN THE HIGHER TERRAIN. IN ADDITION...THE UPSLOPE FLOW COULD RESULT IN CLOUDS IN THE TERRAIN...AND PERHAPS SOME SNOW SHOWERS NEAR KMPO. THE MID LEVEL FLOW QUICKLY BECOMES QUASI ZONAL IN THE MID LEVELS TUESDAY...WITH RISING HEIGHTS. THE COLD AIR ADVECTION BEHIND THE FRONT AND SHORT WAVE ENDS TUESDAY MORNING...AND ANY GUSTINESS TO THE WIND SHOULD END AS WELL. 850 MB TEMPERATURES SUGGEST HIGHS ABOVE NORMAL ONCE AGAIN. WARM AIR ADVECTION SHOULD MOISTEN THE COLUMN TUESDAY NIGHT...BUT AT THIS POINT ANY LIGHT PRECIPITATION SHOULD OCCUR AFTER MIDNIGHT. DRY IS COLD THIS TIME OF YEAR...AND EVAPORATIVE COOLING COULD PRESENT SOME PRECIPITATION TYPE PROBLEMS ACROSS THE TERRAIN. THE WARM AIR ADVECTION APPEARS TO BE IMPRESSIVE...BUT NO SIGNATURES THIS FAR OUT OF ANY ORGANIZATION TO THE PRECIPITATION. STILL...ACCUMULATING SNOW IS POSSIBLE IN THE HIGHER TERRAIN...AND SNOW AND SLEET WHERE ADDED TO THE FORECAST FOR TUESDAY NIGHT. WEDNESDAY SHOULD BE THE MOST ACTIVE DAY OF THE WEEK. THE OVERRUNNING PRECIPITATION PROBABLY PEAKS DURING THE MORNING HOURS NORTH OF A WARM FRONT THAT LOOKS TO BISECT THE AREA. MID RANGE MODELS ARE SUGGESTING A STABLE SURFACE WAVE COULD DEVELOP ON THE FRONT... HALTING ITS MOVE NORTH. IF THIS OCCURS...HIGHS FOR WEDNESDAY COULD BE TOO HIGH...AND THE POTENTIAL FOR WINTRY WEATHER IN THE TERRAIN COULD EXTEND INTO WEDNESDAY MORNING. MODELS ARE ALL SHOWING SOME VERSION OF A LOW LEVEL JET LATE IN THE DAY OR WEDNESDAY EVENING ACROSS SOUTHERN ZONES. THE LOW LEVEL JET WILL PROBABLY BE THE FOCAL POINT FOR CONVECTIVE TYPE PRECIPITATION AHEAD OF A STRONG COLD FRONT WEDNESDAY EVENING. AT THIS DISTANCE... BULK SHEAR APPEARS TO BE GOOD...BUT INSTABILITY MARGINAL (WHICH IS TYPICAL FOR THE END OF THE COOL SEASON). TOO EARLY TO MENTION THUNDER YET...BUT AS PRECIPITABLE WATER VALUES PEAK NEAR 1.50 INCHES (WHICH IS 2 TO 3 STANDARD DEVIATIONS ABOVE NORMAL)...THERE IS A HEAVY RAIN THREAT. IN ADDITION...THERE COULD BE SOME WIND ISSUES...BUT THIS WILL BE PREDICATED ON THE POSITION OF THE WARM FRONT...WHICH CAN BE PROBLEMATIC (TO SAY THE LEAST) THIS TIME OF YEAR. THE SHORT WAVE EXITS THURSDAY MORNING...AS THE MID LEVEL FLOW BECOMES QUASI ZONAL ONCE AGAIN. THURSDAY LOOKS A BIT COOLER WITH THE POTENTIAL FOR WEST TO NORTHWEST GUSTINESS DURING THE DAY. FRIDAY LOOKS WARMER AND DRY...BEFORE ANOTHER SYSTEM APPROACHES NEXT WEEKEND. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. AN INTENSE STORM IN THE CANADIAN MARITIMES WILL CONTINUE TO TRACK NORTHEASTWARD AND AWAY FROM OUR AREA. HIGH PRESSURE WILL THEN BUILD INTO OUR AREA DURING SUNDAY. A TIGHT PRESSURE GRADIENT BETWEEN THIS HIGH AND LOW PRESSURE TO OUR NORTHEAST WILL CONTINUE TO DRIVE GUSTY WEST TO NORTHWEST WINDS THROUGH ABOUT THE FIRST HALF OF TONIGHT. THE PEAK GUSTS WILL GENERALLY BE AROUND 40 KNOTS, HOWEVER THESE ARE EXPECTED TO DIMINISH THROUGH THE NIGHT AS THE VERTICAL MIXING SHRINKS AND HIGH PRESSURE EDGES CLOSER FROM THE WEST. A DECENT AMOUNT OF STRATOCUMULUS AROUND THE REGION THIS AFTERNOON WILL THIN OUT FROM SOUTHEAST TO NORTHWEST AS SOME DRYING WORKS IN AND HIGH PRESSURE GETS A BIT CLOSER. ANY SNOW SHOWERS ARE EXPECTED TO RETREAT BACK NORTHWESTWARD THROUGH THE EVENING, AND GENERALLY BE NORTH OF KABE. HOWEVER UNTIL THEN, SOME BRIEF REDUCTIONS IN THE LOCAL VISIBILITIES AND CEILINGS MAY OCCUR. THE OVERALL IMPACT OF THESE CARRIES SOME UNCERTAINTY, THEREFORE SOME SHORT-FUSED AMENDMENTS MAY BE NEEDED TO ACCOUNT FOR ANY SNOW SHOWERS THAT LOOK TO IMPACT ANY LOCAL TERMINALS. FOR SUNDAY, A CALMER DAY IS EXPECTED AS HIGH PRESSURE SETTLES RIGHT OVER THE AREA. THIS WILL ALLOW FOR MUCH LESS WIND, THEREFORE A WESTERLY WIND SHOULD BE ON THE ORDER OF 10 TO 15 KNOTS BEFORE WEAKENING MORE BY LATE IN THE DAY. THERE APPEARS TO BE ENOUGH DRYING IN THE LOWER AND MIDDLE LEVELS OF THE ATMOSPHERE TO LIMIT ANY STRATOCUMULUS DEVELOPMENT. THEREFORE, VFR IS EXPECTED. OUTLOOK... WITH HIGH PRESSURE IN CONTROL...VFR CONDITIONS ARE EXPECTED SUNDAY NIGHT AND MONDAY. A WEAK COLD FRONT WILL CROSS THE AREA MONDAY NIGHT...BUT AT THIS POINT IT APPEARS AS THOUGH THERE WILL BE LITTLE IN THE WAY OF SENSIBLE WEATHER...SO VFR CONDITIONS ARE EXPECTED. WEST TO NORTHWEST WINDS COULD GUST TO 25 KNOTS FOR A TIME BEHIND THE FRONT LATE MONDAY NIGHT AND TUESDAY MORNING. A WARM FRONT WILL APPROACH THE AREA TUESDAY NIGHT...BUT AT THIS DISTANCE TUESDAY NIGHT APPEARS AS THOUGH IT WILL BE VFR. OVERRUNNING PRECIPITATION IS POSSIBLE WEDNESDAY...AND IN THE VICINITY OF THE FRONT MVFR CONDITIONS ARE EXPECTED...WITH IFR CONDITIONS POSSIBLE. WHILE IT IS A DISTANCE AWAY...A LOW LEVEL JET COULD RESULT IN LOW LEVEL WIND SHEAR...AND THE JET COULD HELP FUEL SOME THUNDERSTORMS. && .MARINE... THE PRESSURE GRADIENT BETWEEN THE DEPARTING STORM AND HIGH PRESSURE PUSHING IN FROM THE WEST IS AND WILL CONTINUE TO PRODUCE STRONG WESTERLY WINDS TODAY. A GALE WARNING REMAINS IN EFFECT ON ALL OF OUR WATERS UNTIL 1 AM SUNDAY. THE WINDS HAVE KICKED UP THE SEAS TO 6 TO 8 FEET ON THE OCEAN WATERS AND 2 TO 5 FEET ON DELAWARE BAY. THIS WILL CONTINUE THROUGH THE DAY. WINDS AND SEAS WILL BEGIN TO LOWER TONIGHT AS HIGH PRESSURE TO OUR WEST APPROACHES. ONCE THE GALE WARNING COMES DOWN, A SMALL CRAFT ADVISORY WILL BE NEEDED LATER TONIGHT. THE GRADIENT COULD SUPPORT SMALL CRAFT WIND GUSTS SUNDAY MORNING... BUT AS HIGH PRESSURE APPROACHES IN THE AFTERNOON...WINDS AND SEAS SHOULD DROP BELOW SMALL CRAFT LEVELS. THE HIGH WILL CREST SOUTH OF THE AREA SUNDAY NIGHT AND MONDAY...WITH WINDS AND SEAS REMAINING BELOW SMALL CRAFT LEVELS DURING THAT TIME. A WEAK COLD FRONT WILL CROSS THE WATERS LATE MONDAY NIGHT. AHEAD OF THE FRONT...THE SOUTHWEST FLOW PROBABLY STAYS BELOW SMALL CRAFT LEVELS BUT IT COULD GET CLOSE ON THE OCEAN. SEAS COULD GET CLOSE TO 5 FEET ACROSS THE NORTHERN OCEAN WATERS IN THE SOUTHWEST FETCH FOR A TIME LATE MONDAY NIGHT. BEHIND THE FRONT...THE LOW LEVEL PUSH COULD RESULT IN A PERIOD OF SMALL CRAFT WEST NORTHWEST WINDS LATE MONDAY NIGHT AND TUESDAY MORNING. HOWEVER...THE GRADIENT DROPS OFF IN THE AFTERNOON...AND WINDS AND SEAS SHOULD REMAIN BELOW SMALL CRAFT LEVELS TUESDAY NIGHT AND EARLY WEDNESDAY. THE WIND FORECAST FOR WEDNESDAY WILL BE PROBLEMATIC. MID RANGE MODELS ARE SHOWING A WARM FRONT APPROACHING FROM THE SOUTHWEST. THERE IS SOME MODEL SPREAD WITH RESPECT TO JUST HOW FAR NORTH THE FRONT GETS. IF IT REMAINS MOSTLY SOUTH OF THE WATERS WEDNESDAY... WINDS AND SEAS COULD GET CLOSE TO SMALL CRAFT LEVELS IN THE EAST TO SOUTHEAST FLOW. MODELS ARE ALSO SHOWING A FAIRLY STRONG LOW LEVEL JET CROSSING THE SOUTHERN WATERS WEDNESDAY AFTERNOON. AGAIN...DEPENDING ON THE POSITION OF THE WARM FRONT...SOUTHERN OCEAN WATERS COULD SEE NEAR GALE FORCE GUSTS FROM THE SOUTH AND SOUTHWEST WEDNESDAY AFTERNOON AND EVENING AHEAD OF A STRONG COLD FRONT. CONFIDENCE IN THIS IS LOW RIGHT NOW...GIVEN MODEL SPREAD ON THE WARM FRO && .TIDES/COASTAL FLOODING... WITH THE STRONG WESTERLY WINDS TODAY, TIDAL DEPARTURES WILL BECOME INCREASINGLY NEGATIVE. IT NOW APPEARS THAT BLOWOUT CONDITIONS WILL LIKELY OCCUR AROUND THE TIME OF LOW TIDE THIS AFTERNOON AND EVENING. FOR THIS REASON, A LOW WATER ADVISORY HAS BEEN ISSUED ALONG OUR NEW JERSEY AND DELAWARE OCEAN FRONTS FROM 2 PM TO 6 PM AND ON DELAWARE BAY FROM 4 PM TO 9 PM. WATER LEVELS WILL REMAIN VERY LOW WELL INTO TONIGHT AND IT REMAINS A POSSIBILITY THAT THE SUNDAY MORNING LOW TIDE CYCLE COULD ALSO SEE BLOWOUT OR NEAR BLOWOUT CONDITIONS. WE WILL CONTINUE TO MONITOR THE SITUATION AND ISSUE APPROPRIATE STATEMENTS OR ADVISORIES. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ054-055- 060>062-067>071. NJ...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NJZ001-007>010- 012>027. DE...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR DEZ001>004. MD...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR MDZ008-012-015- 019-020. MARINE...LOW WATER ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ450>455. GALE WARNING UNTIL 1 AM EST SUNDAY FOR ANZ430-431-450>455. LOW WATER ADVISORY FROM 4 PM THIS AFTERNOON TO 9 PM EST THIS EVENING FOR ANZ430-431. && $$ SYNOPSIS...HAYES NEAR TERM...GORSE SHORT TERM...RPW LONG TERM...HAYES AVIATION...GORSE/HAYES MARINE...GORSE/HAYES/RPW TIDES/COASTAL FLOODING...RPW
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
934 AM EST SAT FEB 25 2012 .SYNOPSIS... LOW PRESSURE DEEPENING OFF THE NEW ENGLAND COAST THIS MORNING WILL TRACK IN THE CANADIAN MARITIMES THIS AFTERNOON. HIGH PRESSURE OVER THE LOWER MISSISSIPPI VALLEY WILL BUILD EAST...REACHING THE MID ATLANTIC COAST MONDAY. A WEAK COLD FRONT WILL CROSS THE REGION MONDAY NIGHT...FOLLOWED BY HIGH PRESSURE TUESDAY. A STRONG COLD FRONT WILL APPROACH THE AREA WEDNESDAY...THEN CROSS THE REGION WEDNESDAY NIGHT. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FOR THE END OF THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A RATHER IMPRESSIVE BUT LOCALIZED EVENT THIS MORNING AS A FAIRLY NARROW BAND OF MODERATE TO HEAVY SNOW HAS BEEN SETTLING SOUTHEASTWARD ACROSS PORTIONS OF EASTERN PENNSYLVANIA. THIS BAND IS GENERALLY ON THE NORTH SIDE OF A STRONG AREA OF CHANNELIZED VORTICITY AND AHEAD OF AN UPPER-LEVEL TROUGH AXIS. THE NEARBY 12Z RAOBS INDICATE STEEPER LOW-LEVEL LAPSE RATES WITH EVEN SOME WEAK INSTABILITY PRESENT. THIS COMBINED WITH A DEEP CYCLONIC FLOW AND CAA IS HELPING TO FOCUS THE NARROW BAND OF SNOW. THIS BAND HAS PRODUCED UP TO 1.5 INCHES OF SNOW IN PORTIONS OF BERKS COUNTY. SOME PENNDOT CAMERAS INDICATE THE VISIBILITY IS GREATLY REDUCED WITHIN THIS BAND WITH THE SNOW QUICKLY ACCUMULATING. IT APPEARS MOST OF THE ACCUMULATION IS ON NON ROADWAY SURFACES. AN EARLIER UPDATE REFINED THE POPS BASED ON THE MOVEMENT OF THE BAND. THE HRRR HAS THIS BAND BUT IT WAS A BIT TO FAR NORTH INITIALLY. THIS BAND MAY TEND TO BREAK UP AS WE GET MORE OF A DIURNAL INFLUENCE TO DISRUPT IT, HOWEVER STEEP LOW-LEVEL LAPSE RATES AND ENOUGH MOISTURE MAY RESULT IN ADDITIONAL SNOW SHOWERS DEVELOPING THROUGH THE AFTERNOON. THE HRRR IS SHOWING THIS POTENTIAL, THEREFORE WE EXPANDED THE CHC POPS SOME THIS AFTERNOON. WE HAVE LOWER CONFIDENCE WITH A SOUTHEASTERN EXTENT THOUGH, BUT FOR NOW ADDED IN A SPRINKLE/FLURRY MENTION FOR SOME. THE STRATOCUMULUS SHOULD DEVELOP AND EXPAND EASTWARD THROUGH THE AFTERNOON DUE TO LOW-LEVEL HEATING AND ALSO STEEPENING LOW-LEVEL LAPSE RATES. THE NEXT CONCERN TO TACKLE IS THE WINDS. SO FAR THE WINDS HAVE BEEN A BIT LOWER AND THIS MAY BE A RESULT OF THE MIXING NOT QUITE BEING ALL THAT DEEP JUST YET. BASED ON THE FORECAST SOUNDINGS, THE PEAK WIND GUSTS /40 TO 50 MPH/ MAY ACTUALLY OCCUR LATER THIS AFTERNOON AS THE LAPSE RATES MAX OUT AND WE GET EVEN DEEPER MIXING ALONG WITH SOME STRONGER WINDS ALOFT. THE WIND ADVISORY THEREFORE REMAINS IN EFFECT FOR THE ENTIRE CWA. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/... THE PRESSURE GRADIENT WILL BEGIN TO RELAX A BIT TONIGHT AS THE HIGH PRESSURE SYSTEM TO OUR WEST MOVES CLOSER TO OUR AREA. WINDS WILL DIMINISH SLOWLY OVERNIGHT WITH MOST OF THE GUSTS DROPPING OFF BY OR SHORTLY AFTER MIDNIGHT. SKIES WILL BECOME MOSTLY CLEAR AND TEMPERATURES WILL BOTTOM OUT IN THE UPPER TEENS AND 20S. && .LONG TERM /SUNDAY THROUGH FRIDAY/... A FAIRLY QUIET PERIOD FOR THE MOST PART...WITH THE MOST ACTIVE PERIOD BEING WEDNESDAY INTO WEDNESDAY NIGHT. THE GRADIENT COULD SUPPORT 25 MPH WIND GUSTS SUNDAY MORNING...BUT AS HIGH PRESSURE BUILDS TO THE EAST SOUTH OF THE AREA...THE GRADIENT SHOULD RELAX IN THE AFTERNOON. CONVECTIVE TEMPERATURES SEEM TO BE OUT OF REACH BY SOMETIME IN THE AFTERNOON...SO MOSTLY SUNNY SHOULD DO IT. THE COOLEST DAY OF THE LONG TERM SHOULD BE SUNDAY. 850 MB TEMPERATURES SUPPORT HIGHS FROM THE MID 30S NORTH TO THE UPPER 40S SOUTH. THE MOS BLEND SHOULD SUFFICE FOR HIGHS...SINCE IT APPEARS TO BE IN LINE WITH THE ABOVE THINKING. DIMINISHING WINDS AND MAINLY CLEAR SKIES SHOULD RESULT IN GOOD RADIATIONAL COOLING CONDITIONS IN PROTECTED LOCATIONS (SUCH AS THE PINE BARRENS IN NEW JERSEY). FOR THE MOST PART...THE MOS BLEND SHOULD BE OK FOR MOST PLACES...BUT FOR PROTECTED LOCATIONS THESE NUMBERS WERE DROPPED BY 3 TO 8 DEGREES. MID LEVEL MOISTURE STARTS TO INCREASE MONDAY IN THE WARM AIR ADVECTION AHEAD OF A NORTHERN STREAM SHORT WAVE. SINCE THE AIRMASS IS DRY TO START...SO MOST OF THE MOISTURE SHOULD GO INTO HIGH AND MID LEVEL CLOUDS...MAINLY ACROSS THE NORTH. AS WINDS SHIFT MONDAY AFTERNOON...THE LOWER LEVELS WARM...AND OUTSIDE OF THE INFLUENCE OF THE TERRAIN AND THE WATER...GFS MOS NUMBERS LOOK BETTER FOR HIGHS. THE NORTHERN STREAM SHORT WAVE SHOULD PASS THROUGH NEW ENGLAND MONDAY NIGHT. THE WARM AIR ADVECTION MAXIMIZES NORTH OF THE AREA...SO FOR NOW THE FRONTAL PASSAGE APPEARS TO BE DRY. THERE IS SOME COLD AIR ADVECTION BEHIND THE FRONT...AND THIS COULD TRANSLATE IN TO GUSTY NORTHWEST WINDS IN THE HIGHER TERRAIN. IN ADDITION...THE UPSLOPE FLOW COULD RESULT IN CLOUDS IN THE TERRAIN...AND PERHAPS SOME SNOW SHOWERS NEAR KMPO. THE MID LEVEL FLOW QUICKLY BECOMES QUASI ZONAL IN THE MID LEVELS TUESDAY...WITH RISING HEIGHTS. THE COLD AIR ADVECTION BEHIND THE FRONT AND SHORT WAVE ENDS TUESDAY MORNING...AND ANY GUSTINESS TO THE WIND SHOULD END AS WELL. 850 MB TEMPERATURES SUGGEST HIGHS ABOVE NORMAL ONCE AGAIN. WARM AIR ADVECTION SHOULD MOISTEN THE COLUMN TUESDAY NIGHT...BUT AT THIS POINT ANY LIGHT PRECIPITATION SHOULD OCCUR AFTER MIDNIGHT. DRY IS COLD THIS TIME OF YEAR...AND EVAPORATIVE COOLING COULD PRESENT SOME PRECIPITATION TYPE PROBLEMS ACROSS THE TERRAIN. THE WARM AIR ADVECTION APPEARS TO BE IMPRESSIVE...BUT NO SIGNATURES THIS FAR OUT OF ANY ORGANIZATION TO THE PRECIPITATION. STILL...ACCUMULATING SNOW IS POSSIBLE IN THE HIGHER TERRAIN...AND SNOW AND SLEET WHERE ADDED TO THE FORECAST FOR TUESDAY NIGHT. WEDNESDAY SHOULD BE THE MOST ACTIVE DAY OF THE WEEK. THE OVERRUNNING PRECIPITATION PROBABLY PEAKS DURING THE MORNING HOURS NORTH OF A WARM FRONT THAT LOOKS TO BISECT THE AREA. MID RANGE MODELS ARE SUGGESTING A STABLE SURFACE WAVE COULD DEVELOP ON THE FRONT... HALTING ITS MOVE NORTH. IF THIS OCCURS...HIGHS FOR WEDNESDAY COULD BE TOO HIGH...AND THE POTENTIAL FOR WINTRY WEATHER IN THE TERRAIN COULD EXTEND INTO WEDNESDAY MORNING. MODELS ARE ALL SHOWING SOME VERSION OF A LOW LEVEL JET LATE IN THE DAY OR WEDNESDAY EVENING ACROSS SOUTHERN ZONES. THE LOW LEVEL JET WILL PROBABLY BE THE FOCAL POINT FOR CONVECTIVE TYPE PRECIPITATION AHEAD OF A STRONG COLD FRONT WEDNESDAY EVENING. AT THIS DISTANCE... BULK SHEAR APPEARS TO BE GOOD...BUT INSTABILITY MARGINAL (WHICH IS TYPICAL FOR THE END OF THE COOL SEASON). TOO EARLY TO MENTION THUNDER YET...BUT AS PRECIPITABLE WATER VALUES PEAK NEAR 1.50 INCHES (WHICH IS 2 TO 3 STANDARD DEVIATIONS ABOVE NORMAL)...THERE IS A HEAVY RAIN THREAT. IN ADDITION...THERE COULD BE SOME WIND ISSUES...BUT THIS WILL BE PREDICATED ON THE POSITION OF THE WARM FRONT...WHICH CAN BE PROBLEMATIC (TO SAY THE LEAST) THIS TIME OF YEAR. THE SHORT WAVE EXITS THURSDAY MORNING...AS THE MID LEVEL FLOW BECOMES QUASI ZONAL ONCE AGAIN. THURSDAY LOOKS A BIT COOLER WITH THE POTENTIAL FOR WEST TO NORTHWEST GUSTINESS DURING THE DAY. FRIDAY LOOKS WARMER AND DRY...BEFORE ANOTHER SYSTEM APPROACHES NEXT WEEKEND. && .AVIATION /14Z SATURDAY THROUGH WEDNESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. THE MAIN AREA OF CLOUDS ACROSS THE AREA HAS BEEN CONFINED TO PORTIONS OF EASTERN PENNSYLVANIA WITH A HEAVIER SNOW BAND SO FAR. THIS IS SETTLING SOUTHEASTWARD AND NEAR THE KRDG AREA. THIS MAY NOT EXTEND FAR ENOUGH SOUTHEASTWARD TO IMPACT KPHL, KPNE AND KILG THEREFORE NO MENTION WAS INCLUDED AT THIS TIME. ELSEWHERE, STRATOCUMULUS SHOULD FILL IN THROUGH THE DAY WITH PERHAPS THE LEAST AMOUNT OF COVERAGE NEAR KMIV AND KACY. OVERALL, VFR IS EXPECTED WITH THE EXCEPTION IF A SNOW SHOWER MOVES THROUGH. THIS WOULD REDUCE THE LOCAL VISIBILITIES QUITE A BIT FOR A TIME WITH SOME LOWER CEILINGS. AS THE VERTICAL MIXING DEEPENS THROUGH THE DAY, THE WINDS ARE EXPECTED TO INCREASE SOME MORE WITH PEAK GUSTS NEAR 40 KNOTS BY LATER THIS AFTERNOON. THE WINDS WILL REMAIN GUSTY FOR AWHILE THIS EVENING, ALTHOUGH THE MIXING SHOULD SHRINK WITH TIME ALLOWING THE WIND SPEEDS OVERALL TO COME DOWN THROUGH THE NIGHT. MOST OF THE WINDS GUSTS SHOULD BE GONE AROUND MIDNIGHT. OUTLOOK... VFR CONDITIONS ARE EXPECTED SUNDAY...AS HIGH PRESSURE BUILDS EAST SOUTH OF THE AREA. WEST TO NORTHWEST WINDS COULD GUST TO 25 KNOTS DURING THE MORNING AND EARLY AFTERNOON...THEN DIMINISH BY LATE IN THE DAY. WITH HIGH PRESSURE IN CONTROL...VFR CONDITIONS ARE EXPECTED SUNDAY NIGHT AND MONDAY. A WEAK COLD FRONT WILL CROSS THE AREA MONDAY NIGHT...BUT AT THIS POINT IT APPEARS AS THOUGH THERE WILL BE LITTLE IN THE WAY OF SENSIBLE WEATHER...SO VFR CONDITIONS ARE EXPECTED. WEST TO NORTHWEST WINDS COULD GUST TO 25 KNOTS FOR A TIME BEHIND THE FRONT LATE MONDAY NIGHT AND TUESDAY MORNING. A WARM FRONT WILL APPROACH THE AREA TUESDAY NIGHT...BUT AT THIS DISTANCE TUESDAY NIGHT APPEARS AS THOUGH IT WILL BE VFR. OVERRUNNING PRECIPITATION IS POSSIBLE WEDNESDAY...AND IN THE VICINITY OF THE FRONT MVFR CONDITIONS ARE EXPECTED...WITH IFR CONDITIONS POSSIBLE. WHILE IT IS A DISTANCE AWAY...A LOW LEVEL JET COULD RESULT IN LOW LEVEL WIND SHEAR...AND THE JET COULD HELP FUEL SOME THUNDERSTORMS. && .MARINE... THE PRESSURE GRADIENT BETWEEN THE DEPARTING STORM AND HIGH PRESSURE PUSHING IN FROM THE WEST IS AND WILL CONTINUE TO PRODUCE STRONG WESTERLY WINDS TODAY. A GALE WARNING REMAINS IN EFFECT ON ALL OF OUR WATERS UNTIL 1 AM SUNDAY. THE WINDS HAVE KICKED UP THE SEAS TO 6 TO 8 FEET ON THE OCEAN WATERS AND 2 TO 5 FEET ON DELAWARE BAY. THIS WILL CONTINUE THROUGH THE DAY. WINDS AND SEAS WILL BEGIN TO LOWER TONIGHT AS HIGH PRESSURE TO OUR WEST APPROACHES. ONCE THE GALE WARNING COMES DOWN, A SMALL CRAFT ADVISORY WILL BE NEEDED LATER TONIGHT. THE GRADIENT COULD SUPPORT SMALL CRAFT WIND GUSTS SUNDAY MORNING... BUT AS HIGH PRESSURE APPROACHES IN THE AFTERNOON...WINDS AND SEAS SHOULD DROP BELOW SMALL CRAFT LEVELS. THE HIGH WILL CREST SOUTH OF THE AREA SUNDAY NIGHT AND MONDAY...WITH WINDS AND SEAS REMAINING BELOW SMALL CRAFT LEVELS DURING THAT TIME. A WEAK COLD FRONT WILL CROSS THE WATERS LATE MONDAY NIGHT. AHEAD OF THE FRONT...THE SOUTHWEST FLOW PROBABLY STAYS BELOW SMALL CRAFT LEVELS BUT IT COULD GET CLOSE ON THE OCEAN. SEAS COULD GET CLOSE TO 5 FEET ACROSS THE NORTHERN OCEAN WATERS IN THE SOUTHWEST FETCH FOR A TIME LATE MONDAY NIGHT. BEHIND THE FRONT...THE LOW LEVEL PUSH COULD RESULT IN A PERIOD OF SMALL CRAFT WEST NORTHWEST WINDS LATE MONDAY NIGHT AND TUESDAY MORNING. HOWEVER...THE GRADIENT DROPS OFF IN THE AFTERNOON...AND WINDS AND SEAS SHOULD REMAIN BELOW SMALL CRAFT LEVELS TUESDAY NIGHT AND EARLY WEDNESDAY. THE WIND FORECAST FOR WEDNESDAY WILL BE PROBLEMATIC. MID RANGE MODELS ARE SHOWING A WARM FRONT APPROACHING FROM THE SOUTHWEST. THERE IS SOME MODEL SPREAD WITH RESPECT TO JUST HOW FAR NORTH THE FRONT GETS. IF IT REMAINS MOSTLY SOUTH OF THE WATERS WEDNESDAY... WINDS AND SEAS COULD GET CLOSE TO SMALL CRAFT LEVELS IN THE EAST TO SOUTHEAST FLOW. MODELS ARE ALSO SHOWING A FAIRLY STRONG LOW LEVEL JET CROSSING THE SOUTHERN WATERS WEDNESDAY AFTERNOON. AGAIN...DEPENDING ON THE POSITION OF THE WARM FRONT...SOUTHERN OCEAN WATERS COULD SEE NEAR GALE FORCE GUSTS FROM THE SOUTH AND SOUTHWEST WEDNESDAY AFTERNOON AND EVENING AHEAD OF A STRONG COLD FRONT. CONFIDENCE IN THIS IS LOW RIGHT NOW...GIVEN MODEL SPREAD ON THE WARM FRO && .TIDES/COASTAL FLOODING... WITH THE STRONG WESTERLY WINDS TODAY, TIDAL DEPARTURES WILL BECOME INCREASINGLY NEGATIVE. IT NOW APPEARS THAT BLOWOUT CONDITIONS WILL LIKELY OCCUR AROUND THE TIME OF LOW TIDE THIS AFTERNOON AND EVENING. FOR THIS REASON, A LOW WATER ADVISORY HAS BEEN ISSUED ALONG OUR NEW JERSEY AND DELAWARE OCEAN FRONTS FROM 2 PM TO 6 PM AND ON DELAWARE BAY FROM 4 PM TO 9 PM. WATER LEVELS WILL REMAIN VERY LOW WELL INTO TONIGHT AND IT REMAINS A POSSIBILITY THAT THE SUNDAY MORNING LOW TIDE CYCLE COULD ALSO SEE BLOWOUT OR NEAR BLOWOUT CONDITIONS. WE WILL CONTINUE TO MONITOR THE SITUATION AND ISSUE APPROPRIATE STATEMENTS OR ADVISORIES. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ054-055- 060>062-067>071. NJ...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NJZ001-007>010- 012>027. DE...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR DEZ001>004. MD...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR MDZ008-012-015- 019-020. MARINE...LOW WATER ADVISORY FROM 2 PM THIS AFTERNOON TO 6 PM EST THIS EVENING FOR ANZ450>455. GALE WARNING UNTIL 1 AM EST SUNDAY FOR ANZ430-431-450>455. LOW WATER ADVISORY FROM 4 PM THIS AFTERNOON TO 9 PM EST THIS EVENING FOR ANZ430-431. && $$ SYNOPSIS...HAYES NEAR TERM...GORSE SHORT TERM...RPW LONG TERM...HAYES AVIATION...GORSE/HAYES MARINE...GORSE/HAYES/RPW TIDES/COASTAL FLOODING...RPW
AREA FORECAST DISCUSSION...CORRECTED
NWS MOUNT HOLLY NJ
803 AM EST SAT FEB 25 2012 .SYNOPSIS... LOW PRESSURE DEEPENING OFF THE NEW ENGLAND COAST THIS MORNING WILL TRACK IN THE CANADIAN MARITIMES THIS AFTERNOON. HIGH PRESSURE OVER THE LOWER MISSISSIPPI VALLEY WILL BUILD EAST...REACHING THE MID ATLANTIC COAST MONDAY. A WEAK COLD FRONT WILL CROSS THE REGION MONDAY NIGHT...FOLLOWED BY HIGH PRESSURE TUESDAY. A STRONG COLD FRONT WILL APPROACH THE AREA WEDNESDAY...THEN CROSS THE REGION WEDNESDAY NIGHT. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FOR THE END OF THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE DEEP CYCLONIC FLOW IN CONJUNCTION WITH A STRONG AREA OF CHANNELIZED VORTICITY AND CAA IS HELPING TO FOCUS A NARROW BAND OF SNOW FROM NEAR WESTERN PENNSYLVANIA ALL THE WAY TO PORTIONS OF EASTERN PENNSYLVANIA. A CHECK OF SOME PENNDOT CAMERAS INDICATED THIS BAND IS PUTTING DOWN A QUICK COATING OF SNOW ACROSS A NARROW AREA IN SCHUYLKILL COUNTY AND THIS HAS MOVED INTO NORTHERN BERKS AND PORTIONS OF LEHIGH COUNTY TO EVEN UPPER BUCKS. IT APPEARS THE GREATER THE PRECIPITATION INTENSITY IS IT FALLS AS SNOW, WHILE SOME WEAKER RADAR RETURNS ESPECIALLY SOUTH OF THE BAND IS MAINLY SPRINKLES. THE FORECAST HAS BEEN UPDATED TO ADD A NARROW RIBBON OF LIKELY POPS FOR A TIME THIS MORNING. THE HRRR HAS THIS BAND BUT IT IS A BIT TO FAR NORTH INITIALLY. THE HOURLY GRIDS WERE ALSO TWEAKED A BIT. OTHERWISE, OUR WEATHER EVENT TODAY WILL BE THE WIND. AS LOW PRESSURE CONTINUES TO MOVE OFF TO THE NORTHEAST AWAY FROM OUR AREA, HIGH PRESSURE WILL MOVE IN FROM THE WEST. THE PRESSURE GRADIENT BETWEEN THESE TWO SYSTEMS WILL PRODUCE GUSTY WEST WINDS TODAY. WIND GUSTS ARE EXPECTED TO REACH TO AROUND 45 MPH ESPECIALLY FROM LATER THIS MORNING INTO THE EVENING HOURS. A WIND ADVISORY REMAINS IN EFFECT UNTIL 7 PM TODAY FOR THE ENTIRE CWA. THE WIND WILL MAKE IT FEEL LIKE ITS IN THE 20S NORTH AND MAINLY 30S ELSEWHERE. SKIES WILL BE PARTLY TO MOSTLY SUNNY SOUTH AND PARTLY CLOUDY TO CLOUDY NORTH. OUTSIDE OF THE BAND THIS MORNING, THERE WILL BE SCATTERED SNOW SHOWERS OR FLURRIES ESPECIALLY IN THE NORTHERN MOUNTAINS. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/... THE PRESSURE GRADIENT WILL BEGIN TO RELAX A BIT TONIGHT AS THE HIGH PRESSURE SYSTEM TO OUR WEST MOVES CLOSER TO OUR AREA. WINDS WILL DIMINISH SLOWLY OVERNIGHT WITH MOST OF THE GUSTS DROPPING OFF BY OR SHORTLY AFTER MIDNIGHT. SKIES WILL BECOME MOSTLY CLEAR AND TEMPERATURES WILL BOTTOM OUT IN THE UPPER TEENS AND 20S. && .LONG TERM /SUNDAY THROUGH FRIDAY/... A FAIRLY QUIET PERIOD FOR THE MOST PART...WITH THE MOST ACTIVE PERIOD BEING WEDNESDAY INTO WEDNESDAY NIGHT. THE GRADIENT COULD SUPPORT 25 MPH WIND GUSTS SUNDAY MORNING...BUT AS HIGH PRESSURE BUILDS TO THE EAST SOUTH OF THE AREA...THE GRADIENT SHOULD RELAX IN THE AFTERNOON. CONVECTIVE TEMPERATURES SEEM TO BE OUT OF REACH BY SOMETIME IN THE AFTERNOON...SO MOSTLY SUNNY SHOULD DO IT. THE COOLEST DAY OF THE LONG TERM SHOULD BE SUNDAY. 850 MB TEMPERATURES SUPPORT HIGHS FROM THE MID 30S NORTH TO THE UPPER 40S SOUTH. THE MOS BLEND SHOULD SUFFICE FOR HIGHS...SINCE IT APPEARS TO BE IN LINE WITH THE ABOVE THINKING. DIMINISHING WINDS AND MAINLY CLEAR SKIES SHOULD RESULT IN GOOD RADIATIONAL COOLING CONDITIONS IN PROTECTED LOCATIONS (SUCH AS THE PINE BARRENS IN NEW JERSEY). FOR THE MOST PART...THE MOS BLEND SHOULD BE OK FOR MOST PLACES...BUT FOR PROTECTED LOCATIONS THESE NUMBERS WERE DROPPED BY 3 TO 8 DEGREES. MID LEVEL MOISTURE STARTS TO INCREASE MONDAY IN THE WARM AIR ADVECTION AHEAD OF A NORTHERN STREAM SHORT WAVE. SINCE THE AIRMASS IS DRY TO START...SO MOST OF THE MOISTURE SHOULD GO INTO HIGH AND MID LEVEL CLOUDS...MAINLY ACROSS THE NORTH. AS WINDS SHIFT MONDAY AFTERNOON...THE LOWER LEVELS WARM...AND OUTSIDE OF THE INFLUENCE OF THE TERRAIN AND THE WATER...GFS MOS NUMBERS LOOK BETTER FOR HIGHS. THE NORTHERN STREAM SHORT WAVE SHOULD PASS THROUGH NEW ENGLAND MONDAY NIGHT. THE WARM AIR ADVECTION MAXIMIZES NORTH OF THE AREA...SO FOR NOW THE FRONTAL PASSAGE APPEARS TO BE DRY. THERE IS SOME COLD AIR ADVECTION BEHIND THE FRONT...AND THIS COULD TRANSLATE IN TO GUSTY NORTHWEST WINDS IN THE HIGHER TERRAIN. IN ADDITION...THE UPSLOPE FLOW COULD RESULT IN CLOUDS IN THE TERRAIN...AND PERHAPS SOME SNOW SHOWERS NEAR KMPO. THE MID LEVEL FLOW QUICKLY BECOMES QUASI ZONAL IN THE MID LEVELS TUESDAY...WITH RISING HEIGHTS. THE COLD AIR ADVECTION BEHIND THE FRONT AND SHORT WAVE ENDS TUESDAY MORNING...AND ANY GUSTINESS TO THE WIND SHOULD END AS WELL. 850 MB TEMPERATURES SUGGEST HIGHS ABOVE NORMAL ONCE AGAIN. WARM AIR ADVECTION SHOULD MOISTEN THE COLUMN TUESDAY NIGHT...BUT AT THIS POINT ANY LIGHT PRECIPITATION SHOULD OCCUR AFTER MIDNIGHT. DRY IS COLD THIS TIME OF YEAR...AND EVAPORATIVE COOLING COULD PRESENT SOME PRECIPITATION TYPE PROBLEMS ACROSS THE TERRAIN. THE WARM AIR ADVECTION APPEARS TO BE IMPRESSIVE...BUT NO SIGNATURES THIS FAR OUT OF ANY ORGANIZATION TO THE PRECIPITATION. STILL...ACCUMULATING SNOW IS POSSIBLE IN THE HIGHER TERRAIN...AND SNOW AND SLEET WHERE ADDED TO THE FORECAST FOR TUESDAY NIGHT. WEDNESDAY SHOULD BE THE MOST ACTIVE DAY OF THE WEEK. THE OVERRUNNING PRECIPITATION PROBABLY PEAKS DURING THE MORNING HOURS NORTH OF A WARM FRONT THAT LOOKS TO BISECT THE AREA. MID RANGE MODELS ARE SUGGESTING A STABLE SURFACE WAVE COULD DEVELOP ON THE FRONT... HALTING ITS MOVE NORTH. IF THIS OCCURS...HIGHS FOR WEDNESDAY COULD BE TOO HIGH...AND THE POTENTIAL FOR WINTRY WEATHER IN THE TERRAIN COULD EXTEND INTO WEDNESDAY MORNING. MODELS ARE ALL SHOWING SOME VERSION OF A LOW LEVEL JET LATE IN THE DAY OR WEDNESDAY EVENING ACROSS SOUTHERN ZONES. THE LOW LEVEL JET WILL PROBABLY BE THE FOCAL POINT FOR CONVECTIVE TYPE PRECIPITATION AHEAD OF A STRONG COLD FRONT WEDNESDAY EVENING. AT THIS DISTANCE... BULK SHEAR APPEARS TO BE GOOD...BUT INSTABILITY MARGINAL (WHICH IS TYPICAL FOR THE END OF THE COOL SEASON). TOO EARLY TO MENTION THUNDER YET...BUT AS PRECIPITABLE WATER VALUES PEAK NEAR 1.50 INCHES (WHICH IS 2 TO 3 STANDARD DEVIATIONS ABOVE NORMAL)...THERE IS A HEAVY RAIN THREAT. IN ADDITION...THERE COULD BE SOME WIND ISSUES...BUT THIS WILL BE PREDICATED ON THE POSITION OF THE WARM FRONT...WHICH CAN BE PROBLEMATIC (TO SAY THE LEAST) THIS TIME OF YEAR. THE SHORT WAVE EXITS THURSDAY MORNING...AS THE MID LEVEL FLOW BECOMES QUASI ZONAL ONCE AGAIN. THURSDAY LOOKS A BIT COOLER WITH THE POTENTIAL FOR WEST TO NORTHWEST GUSTINESS DURING THE DAY. FRIDAY LOOKS WARMER AND DRY...BEFORE ANOTHER SYSTEM APPROACHES NEXT WEEKEND. && .AVIATION /13Z SATURDAY THROUGH WEDNESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. SCT TO BKN SC ARE OCCURRING IN SOME OF OUR NORTHERN AND WESTERN AREAS. THE WIND WILL CONTINUE TO BE THE MAIN WEATHER FACTOR TODAY. WHILE SPEEDS HAVE DROPPED OFF SOME EARLY THIS MORNING, THEY WILL INCREASE AGAIN BY MID OR LATE MORNING. SUSTAINED W WINDS WILL RUN IN THE LOWER TO MID 20S WITH GUSTS APPROACHING 40 KT. THE STRONG WINDS AND COLD AIR ADVECTION WILL CAUSE THE SC TO OVERSPREAD MUCH OF THE AREA TODAY. SNOW SHOWERS OR FLURRIES SHOULD BE LIMITED TO OUR NORTHWESTERN AREAS WITH THESE GETTING CLOSE TO KRDG AND KABE. THESE MAY REDUCE THE LOCAL CEILINGS AND VISIBILITIES FOR A TIME BUT SO FAR THIS MORNING A MAIN BAND IS BETWEEN KRDG AND KABE. ONCE THE SUN SETS, WINDS WILL BEGIN TO DIMINISH AND SKIES WILL CLEAR. MOST OF THE WINDS GUSTS SHOULD BE GONE BY OR SHORTLY AFTER MIDNIGHT. OUTLOOK... VFR CONDITIONS ARE EXPECTED SUNDAY...AS HIGH PRESSURE BUILDS EAST SOUTH OF THE AREA. WEST TO NORTHWEST WINDS COULD GUST TO 25 KNOTS DURING THE MORNING AND EARLY AFTERNOON...THEN DIMINISH BY LATE IN THE DAY. WITH HIGH PRESSURE IN CONTROL...VFR CONDITIONS ARE EXPECTED SUNDAY NIGHT AND MONDAY. A WEAK COLD FRONT WILL CROSS THE AREA MONDAY NIGHT...BUT AT THIS POINT IT APPEARS AS THOUGH THERE WILL BE LITTLE IN THE WAY OF SENSIBLE WEATHER...SO VFR CONDITIONS ARE EXPECTED. WEST TO NORTHWEST WINDS COULD GUST TO 25 KNOTS FOR A TIME BEHIND THE FRONT LATE MONDAY NIGHT AND TUESDAY MORNING. A WARM FRONT WILL APPROACH THE AREA TUESDAY NIGHT...BUT AT THIS DISTANCE TUESDAY NIGHT APPEARS AS THOUGH IT WILL BE VFR. OVERRUNNING PRECIPITATION IS POSSIBLE WEDNESDAY...AND IN THE VICINITY OF THE FRONT MVFR CONDITIONS ARE EXPECTED...WITH IFR CONDITIONS POSSIBLE. WHILE IT IS A DISTANCE AWAY...A LOW LEVEL JET COULD RESULT IN LOW LEVEL WIND SHEAR...AND THE JET COULD HELP FUEL SOME THUNDERSTORMS. && .MARINE... THE PRESSURE GRADIENT BETWEEN THE DEPARTING STORM AND HIGH PRESSURE PUSHING IN FROM THE WEST IS AND WILL CONTINUE TO PRODUCE STRONG W WINDS TODAY. A GALE WARNING IS IN EFFECT ON ALL OF OUR WATERS UNTIL 1 AM SUNDAY. THE WINDS HAVE KICKED UP THE SEAS TO 6 TO 8 FEET ON THE OCEAN WATERS AND 2 TO 5 FEET ON DELAWARE BAY. THIS WILL CONTINUE THROUGH THE DAY. WINDS AND SEAS WILL BEGIN TO LOWER TONIGHT AS THE HIGH PRESSURE SYSTEM TO OUR WEST APPROACHES. ONCE THE GALE WARNING COMES DOWN, A SMALL CRAFT ADVISORY WILL BE NEEDED LATER TONIGHT. THE GRADIENT COULD SUPPORT SMALL CRAFT WIND GUSTS SUNDAY MORNING... BUT AS HIGH PRESSURE APPROACHES IN THE AFTERNOON...WINDS AND SEAS SHOULD DROP BELOW SMALL CRAFT LEVELS. THE HIGH WILL CREST SOUTH OF THE AREA SUNDAY NIGHT AND MONDAY...WITH WINDS AND SEAS REMAINING BELOW SMALL CRAFT LEVELS DURING THAT TIME. A WEAK COLD FRONT WILL CROSS THE WATERS LATE MONDAY NIGHT. AHEAD OF THE FRONT...THE SOUTHWEST FLOW PROBABLY STAYS BELOW SMALL CRAFT LEVELS BUT IT COULD GET CLOSE ON THE OCEAN. SEAS COULD GET CLOSE TO 5 FEET ACROSS THE NORTHERN OCEAN WATERS IN THE SOUTHWEST FETCH FOR A TIME LATE MONDAY NIGHT. BEHIND THE FRONT...THE LOW LEVEL PUSH COULD RESULT IN A PERIOD OF SMALL CRAFT WEST NORTHWEST WINDS LATE MONDAY NIGHT AND TUESDAY MORNING. HOWEVER...THE GRADIENT DROPS OFF IN THE AFTERNOON...AND WINDS AND SEAS SHOULD REMAIN BELOW SMALL CRAFT LEVELS TUESDAY NIGHT AND EARLY WEDNESDAY. THE WIND FORECAST FOR WEDNESDAY WILL BE PROBLEMATIC. MID RANGE MODELS ARE SHOWING A WARM FRONT APPROACHING FROM THE SOUTHWEST. THERE IS SOME MODEL SPREAD WITH RESPECT TO JUST HOW FAR NORTH THE FRONT GETS. IF IT REMAINS MOSTLY SOUTH OF THE WATERS WEDNESDAY... WINDS AND SEAS COULD GET CLOSE TO SMALL CRAFT LEVELS IN THE EAST TO SOUTHEAST FLOW. MODELS ARE ALSO SHOWING A FAIRLY STRONG LOW LEVEL JET CROSSING THE SOUTHERN WATERS WEDNESDAY AFTERNOON. AGAIN...DEPENDING ON THE POSITION OF THE WARM FRONT...SOUTHERN OCEAN WATERS COULD SEE NEAR GALE FORCE GUSTS FROM THE SOUTH AND SOUTHWEST WEDNESDAY AFTERNOON AND EVENING AHEAD OF A STRONG COLD FRONT. CONFIDENCE IN THIS IS LOW RIGHT NOW...GIVEN MODEL SPREAD ON THE WARM FRO && .TIDES/COASTAL FLOODING... WITH THE STRONG WESTERLY WINDS TODAY, TIDAL DEPARTURES WILL BECOME INCREASINGLY NEGATIVE. IT NOW APPEARS THAT BLOWOUT CONDITIONS WILL LIKELY OCCUR AROUND THE TIME OF LOW TIDE THIS AFTERNOON AND EVENING. FOR THIS REASON, A LOW WATER ADVISORY HAS BEEN ISSUED ALONG OUR NEW JERSEY AND DELAWARE OCEAN FRONTS FROM 2 PM TO 6 PM AND ON DELAWARE BAY FROM 4 PM TO 9 PM. WATER LEVELS WILL REMAIN VERY LOW WELL INTO TONIGHT AND IT REMAINS A POSSIBILITY THAT THE SUNDAY MORNING LOW TIDE CYCLE COULD ALSO SEE BLOWOUT OR NEAR BLOWOUT CONDITIONS. WE WILL CONTINUE TO MONITOR THE SITUATION AND ISSUE APPROPRIATE STATEMENTS OR ADVISORIES. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ054-055- 060>062-067>071. NJ...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NJZ001-007>010- 012>027. DE...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR DEZ001>004. MD...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR MDZ008-012-015- 019-020. MARINE...LOW WATER ADVISORY FROM 2 PM THIS AFTERNOON TO 6 PM EST THIS EVENING FOR ANZ450>455. GALE WARNING UNTIL 1 AM EST SUNDAY FOR ANZ430-431-450>455. LOW WATER ADVISORY FROM 4 PM THIS AFTERNOON TO 9 PM EST THIS EVENING FOR ANZ430-431. && $$ SYNOPSIS...HAYES NEAR TERM...GORSE/RPW SHORT TERM...RPW LONG TERM...HAYES AVIATION...GORSE/HAYES/RPW MARINE...HAYES/RPW TIDES/COASTAL FLOODING...RPW CORRECTED SOME WORDING IN THE NEAR TERM.
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
753 AM EST SAT FEB 25 2012 .SYNOPSIS... LOW PRESSURE DEEPENING OFF THE NEW ENGLAND COAST THIS MORNING WILL TRACK IN THE CANADIAN MARITIMES THIS AFTERNOON. HIGH PRESSURE OVER THE LOWER MISSISSIPPI VALLEY WILL BUILD EAST...REACHING THE MID ATLANTIC COAST MONDAY. A WEAK COLD FRONT WILL CROSS THE REGION MONDAY NIGHT...FOLLOWED BY HIGH PRESSURE TUESDAY. A STRONG COLD FRONT WILL APPROACH THE AREA WEDNESDAY...THEN CROSS THE REGION WEDNESDAY NIGHT. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FOR THE END OF THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE DEEP CYCLONIC FLOW IN CONJUNCTION WITH A STRONG AREA OF CHANNELIZED VORTICITY AND CAA IS HELPING TO FOCUS A NARROW BAND OF SNOW FROM NEAR WESTERN PENNSYLVANIA ALL THE WAY TO PORTIONS OF EASTERN PENNSYLVANIA. A CHECK OF SOME PENNDOT CAMERAS INDICATED THIS BAND IS PUTTING DOWN A QUICK COATING SNOW IN A NARROW AREA IN SCHUYLKILL COUNTY AND THIS HAS MOVED INTO NORTHERN BERKS AND PORTIONS OF LEHIGH COUNTY. IT APPEARS THE GREATER THE PRECIPITATION INTENSITY IS IT FALLS AS SNOW, WHILE SOME WEAKER RADAR RETURNS ESPECIALLY SOUTH OF THE BAND IS MAINLY SPRINKLES. THE FORECAST HAS BEEN UPDATED TO ADD A NARROW RIBBON OF LIKELY POPS FOR A TIME THIS MORNING. THE HRRR HAS THIS BAND BUT IT IS A BIT TO FAR NORTH INITIALLY. THE HOURLY GRIDS WERE ALSO TWEAKED A BIT. OTHERWISE, OUR WEATHER EVENT TODAY WILL BE THE WIND. AS LOW PRESSURE CONTINUES TO MOVE OFF TO THE NORTHEAST AWAY FROM OUR AREA, HIGH PRESSURE WILL MOVE IN FROM THE WEST. THE PRESSURE GRADIENT BETWEEN THESE TWO SYSTEMS WILL PRODUCE GUSTY WEST WINDS TODAY. WIND GUSTS ARE EXPECTED TO REACH TO AROUND 45 MPH ESPECIALLY FROM LATER THIS MORNING INTO THE EVENING HOURS. A WIND ADVISORY REMAINS IN EFFECT UNTIL 7 PM TODAY FOR THE ENTIRE CWA. THE WIND WILL MAKE IT FEEL LIKE ITS IN THE 20S NORTH AND MAINLY 30S ELSEWHERE. SKIES WILL BE PARTLY TO MOSTLY SUNNY SOUTH AND PARTLY CLOUDY TO CLOUDY NORTH. OUTSIDE OF THE BAND THIS MORNING, THERE WILL BE SCATTERED SNOW SHOWERS OR FLURRIES ESPECIALLY IN THE NORTHERN MOUNTAINS. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/... THE PRESSURE GRADIENT WILL BEGIN TO RELAX A BIT TONIGHT AS THE HIGH PRESSURE SYSTEM TO OUR WEST MOVES CLOSER TO OUR AREA. WINDS WILL DIMINISH SLOWLY OVERNIGHT WITH MOST OF THE GUSTS DROPPING OFF BY OR SHORTLY AFTER MIDNIGHT. SKIES WILL BECOME MOSTLY CLEAR AND TEMPERATURES WILL BOTTOM OUT IN THE UPPER TEENS AND 20S. && .LONG TERM /SUNDAY THROUGH FRIDAY/... A FAIRLY QUIET PERIOD FOR THE MOST PART...WITH THE MOST ACTIVE PERIOD BEING WEDNESDAY INTO WEDNESDAY NIGHT. THE GRADIENT COULD SUPPORT 25 MPH WIND GUSTS SUNDAY MORNING...BUT AS HIGH PRESSURE BUILDS TO THE EAST SOUTH OF THE AREA...THE GRADIENT SHOULD RELAX IN THE AFTERNOON. CONVECTIVE TEMPERATURES SEEM TO BE OUT OF REACH BY SOMETIME IN THE AFTERNOON...SO MOSTLY SUNNY SHOULD DO IT. THE COOLEST DAY OF THE LONG TERM SHOULD BE SUNDAY. 850 MB TEMPERATURES SUPPORT HIGHS FROM THE MID 30S NORTH TO THE UPPER 40S SOUTH. THE MOS BLEND SHOULD SUFFICE FOR HIGHS...SINCE IT APPEARS TO BE IN LINE WITH THE ABOVE THINKING. DIMINISHING WINDS AND MAINLY CLEAR SKIES SHOULD RESULT IN GOOD RADIATIONAL COOLING CONDITIONS IN PROTECTED LOCATIONS (SUCH AS THE PINE BARRENS IN NEW JERSEY). FOR THE MOST PART...THE MOS BLEND SHOULD BE OK FOR MOST PLACES...BUT FOR PROTECTED LOCATIONS THESE NUMBERS WERE DROPPED BY 3 TO 8 DEGREES. MID LEVEL MOISTURE STARTS TO INCREASE MONDAY IN THE WARM AIR ADVECTION AHEAD OF A NORTHERN STREAM SHORT WAVE. SINCE THE AIRMASS IS DRY TO START...SO MOST OF THE MOISTURE SHOULD GO INTO HIGH AND MID LEVEL CLOUDS...MAINLY ACROSS THE NORTH. AS WINDS SHIFT MONDAY AFTERNOON...THE LOWER LEVELS WARM...AND OUTSIDE OF THE INFLUENCE OF THE TERRAIN AND THE WATER...GFS MOS NUMBERS LOOK BETTER FOR HIGHS. THE NORTHERN STREAM SHORT WAVE SHOULD PASS THROUGH NEW ENGLAND MONDAY NIGHT. THE WARM AIR ADVECTION MAXIMIZES NORTH OF THE AREA...SO FOR NOW THE FRONTAL PASSAGE APPEARS TO BE DRY. THERE IS SOME COLD AIR ADVECTION BEHIND THE FRONT...AND THIS COULD TRANSLATE IN TO GUSTY NORTHWEST WINDS IN THE HIGHER TERRAIN. IN ADDITION...THE UPSLOPE FLOW COULD RESULT IN CLOUDS IN THE TERRAIN...AND PERHAPS SOME SNOW SHOWERS NEAR KMPO. THE MID LEVEL FLOW QUICKLY BECOMES QUASI ZONAL IN THE MID LEVELS TUESDAY...WITH RISING HEIGHTS. THE COLD AIR ADVECTION BEHIND THE FRONT AND SHORT WAVE ENDS TUESDAY MORNING...AND ANY GUSTINESS TO THE WIND SHOULD END AS WELL. 850 MB TEMPERATURES SUGGEST HIGHS ABOVE NORMAL ONCE AGAIN. WARM AIR ADVECTION SHOULD MOISTEN THE COLUMN TUESDAY NIGHT...BUT AT THIS POINT ANY LIGHT PRECIPITATION SHOULD OCCUR AFTER MIDNIGHT. DRY IS COLD THIS TIME OF YEAR...AND EVAPORATIVE COOLING COULD PRESENT SOME PRECIPITATION TYPE PROBLEMS ACROSS THE TERRAIN. THE WARM AIR ADVECTION APPEARS TO BE IMPRESSIVE...BUT NO SIGNATURES THIS FAR OUT OF ANY ORGANIZATION TO THE PRECIPITATION. STILL...ACCUMULATING SNOW IS POSSIBLE IN THE HIGHER TERRAIN...AND SNOW AND SLEET WHERE ADDED TO THE FORECAST FOR TUESDAY NIGHT. WEDNESDAY SHOULD BE THE MOST ACTIVE DAY OF THE WEEK. THE OVERRUNNING PRECIPITATION PROBABLY PEAKS DURING THE MORNING HOURS NORTH OF A WARM FRONT THAT LOOKS TO BISECT THE AREA. MID RANGE MODELS ARE SUGGESTING A STABLE SURFACE WAVE COULD DEVELOP ON THE FRONT... HALTING ITS MOVE NORTH. IF THIS OCCURS...HIGHS FOR WEDNESDAY COULD BE TOO HIGH...AND THE POTENTIAL FOR WINTRY WEATHER IN THE TERRAIN COULD EXTEND INTO WEDNESDAY MORNING. MODELS ARE ALL SHOWING SOME VERSION OF A LOW LEVEL JET LATE IN THE DAY OR WEDNESDAY EVENING ACROSS SOUTHERN ZONES. THE LOW LEVEL JET WILL PROBABLY BE THE FOCAL POINT FOR CONVECTIVE TYPE PRECIPITATION AHEAD OF A STRONG COLD FRONT WEDNESDAY EVENING. AT THIS DISTANCE... BULK SHEAR APPEARS TO BE GOOD...BUT INSTABILITY MARGINAL (WHICH IS TYPICAL FOR THE END OF THE COOL SEASON). TOO EARLY TO MENTION THUNDER YET...BUT AS PRECIPITABLE WATER VALUES PEAK NEAR 1.50 INCHES (WHICH IS 2 TO 3 STANDARD DEVIATIONS ABOVE NORMAL)...THERE IS A HEAVY RAIN THREAT. IN ADDITION...THERE COULD BE SOME WIND ISSUES...BUT THIS WILL BE PREDICATED ON THE POSITION OF THE WARM FRONT...WHICH CAN BE PROBLEMATIC (TO SAY THE LEAST) THIS TIME OF YEAR. THE SHORT WAVE EXITS THURSDAY MORNING...AS THE MID LEVEL FLOW BECOMES QUASI ZONAL ONCE AGAIN. THURSDAY LOOKS A BIT COOLER WITH THE POTENTIAL FOR WEST TO NORTHWEST GUSTINESS DURING THE DAY. FRIDAY LOOKS WARMER AND DRY...BEFORE ANOTHER SYSTEM APPROACHES NEXT WEEKEND. && .AVIATION /13Z SATURDAY THROUGH WEDNESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. SCT TO BKN SC ARE OCCURRING IN SOME OF OUR NORTHERN AND WESTERN AREAS. THE WIND WILL CONTINUE TO BE THE MAIN WEATHER FACTOR TODAY. WHILE SPEEDS HAVE DROPPED OFF SOME EARLY THIS MORNING, THEY WILL INCREASE AGAIN BY MID OR LATE MORNING. SUSTAINED W WINDS WILL RUN IN THE LOWER TO MID 20S WITH GUSTS APPROACHING 40 KT. THE STRONG WINDS AND COLD AIR ADVECTION WILL CAUSE THE SC TO OVERSPREAD MUCH OF THE AREA TODAY. SNOW SHOWERS OR FLURRIES SHOULD BE LIMITED TO OUR NORTHWESTERN AREAS WITH THESE GETTING CLOSE TO KRDG AND KABE. THESE MAY REDUCE THE LOCAL CEILINGS AND VISIBILITIES FOR A TIME BUT SO FAR THIS MORNING A MAIN BAND IS BETWEEN KRDG AND KABE. ONCE THE SUN SETS, WINDS WILL BEGIN TO DIMINISH AND SKIES WILL CLEAR. MOST OF THE WINDS GUSTS SHOULD BE GONE BY OR SHORTLY AFTER MIDNIGHT. OUTLOOK... VFR CONDITIONS ARE EXPECTED SUNDAY...AS HIGH PRESSURE BUILDS EAST SOUTH OF THE AREA. WEST TO NORTHWEST WINDS COULD GUST TO 25 KNOTS DURING THE MORNING AND EARLY AFTERNOON...THEN DIMINISH BY LATE IN THE DAY. WITH HIGH PRESSURE IN CONTROL...VFR CONDITIONS ARE EXPECTED SUNDAY NIGHT AND MONDAY. A WEAK COLD FRONT WILL CROSS THE AREA MONDAY NIGHT...BUT AT THIS POINT IT APPEARS AS THOUGH THERE WILL BE LITTLE IN THE WAY OF SENSIBLE WEATHER...SO VFR CONDITIONS ARE EXPECTED. WEST TO NORTHWEST WINDS COULD GUST TO 25 KNOTS FOR A TIME BEHIND THE FRONT LATE MONDAY NIGHT AND TUESDAY MORNING. A WARM FRONT WILL APPROACH THE AREA TUESDAY NIGHT...BUT AT THIS DISTANCE TUESDAY NIGHT APPEARS AS THOUGH IT WILL BE VFR. OVERRUNNING PRECIPITATION IS POSSIBLE WEDNESDAY...AND IN THE VICINITY OF THE FRONT MVFR CONDITIONS ARE EXPECTED...WITH IFR CONDITIONS POSSIBLE. WHILE IT IS A DISTANCE AWAY...A LOW LEVEL JET COULD RESULT IN LOW LEVEL WIND SHEAR...AND THE JET COULD HELP FUEL SOME THUNDERSTORMS. && .MARINE... THE PRESSURE GRADIENT BETWEEN THE DEPARTING STORM AND HIGH PRESSURE PUSHING IN FROM THE WEST IS AND WILL CONTINUE TO PRODUCE STRONG W WINDS TODAY. A GALE WARNING IS IN EFFECT ON ALL OF OUR WATERS UNTIL 1 AM SUNDAY. THE WINDS HAVE KICKED UP THE SEAS TO 6 TO 8 FEET ON THE OCEAN WATERS AND 2 TO 5 FEET ON DELAWARE BAY. THIS WILL CONTINUE THROUGH THE DAY. WINDS AND SEAS WILL BEGIN TO LOWER TONIGHT AS THE HIGH PRESSURE SYSTEM TO OUR WEST APPROACHES. ONCE THE GALE WARNING COMES DOWN, A SMALL CRAFT ADVISORY WILL BE NEEDED LATER TONIGHT. THE GRADIENT COULD SUPPORT SMALL CRAFT WIND GUSTS SUNDAY MORNING... BUT AS HIGH PRESSURE APPROACHES IN THE AFTERNOON...WINDS AND SEAS SHOULD DROP BELOW SMALL CRAFT LEVELS. THE HIGH WILL CREST SOUTH OF THE AREA SUNDAY NIGHT AND MONDAY...WITH WINDS AND SEAS REMAINING BELOW SMALL CRAFT LEVELS DURING THAT TIME. A WEAK COLD FRONT WILL CROSS THE WATERS LATE MONDAY NIGHT. AHEAD OF THE FRONT...THE SOUTHWEST FLOW PROBABLY STAYS BELOW SMALL CRAFT LEVELS BUT IT COULD GET CLOSE ON THE OCEAN. SEAS COULD GET CLOSE TO 5 FEET ACROSS THE NORTHERN OCEAN WATERS IN THE SOUTHWEST FETCH FOR A TIME LATE MONDAY NIGHT. BEHIND THE FRONT...THE LOW LEVEL PUSH COULD RESULT IN A PERIOD OF SMALL CRAFT WEST NORTHWEST WINDS LATE MONDAY NIGHT AND TUESDAY MORNING. HOWEVER...THE GRADIENT DROPS OFF IN THE AFTERNOON...AND WINDS AND SEAS SHOULD REMAIN BELOW SMALL CRAFT LEVELS TUESDAY NIGHT AND EARLY WEDNESDAY. THE WIND FORECAST FOR WEDNESDAY WILL BE PROBLEMATIC. MID RANGE MODELS ARE SHOWING A WARM FRONT APPROACHING FROM THE SOUTHWEST. THERE IS SOME MODEL SPREAD WITH RESPECT TO JUST HOW FAR NORTH THE FRONT GETS. IF IT REMAINS MOSTLY SOUTH OF THE WATERS WEDNESDAY... WINDS AND SEAS COULD GET CLOSE TO SMALL CRAFT LEVELS IN THE EAST TO SOUTHEAST FLOW. MODELS ARE ALSO SHOWING A FAIRLY STRONG LOW LEVEL JET CROSSING THE SOUTHERN WATERS WEDNESDAY AFTERNOON. AGAIN...DEPENDING ON THE POSITION OF THE WARM FRONT...SOUTHERN OCEAN WATERS COULD SEE NEAR GALE FORCE GUSTS FROM THE SOUTH AND SOUTHWEST WEDNESDAY AFTERNOON AND EVENING AHEAD OF A STRONG COLD FRONT. CONFIDENCE IN THIS IS LOW RIGHT NOW...GIVEN MODEL SPREAD ON THE WARM FRO && .TIDES/COASTAL FLOODING... WITH THE STRONG WESTERLY WINDS TODAY, TIDAL DEPARTURES WILL BECOME INCREASINGLY NEGATIVE. IT NOW APPEARS THAT BLOWOUT CONDITIONS WILL LIKELY OCCUR AROUND THE TIME OF LOW TIDE THIS AFTERNOON AND EVENING. FOR THIS REASON, A LOW WATER ADVISORY HAS BEEN ISSUED ALONG OUR NEW JERSEY AND DELAWARE OCEAN FRONTS FROM 2 PM TO 6 PM AND ON DELAWARE BAY FROM 4 PM TO 9 PM. WATER LEVELS WILL REMAIN VERY LOW WELL INTO TONIGHT AND IT REMAINS A POSSIBILITY THAT THE SUNDAY MORNING LOW TIDE CYCLE COULD ALSO SEE BLOWOUT OR NEAR BLOWOUT CONDITIONS. WE WILL CONTINUE TO MONITOR THE SITUATION AND ISSUE APPROPRIATE STATEMENTS OR ADVISORIES. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ054-055- 060>062-067>071. NJ...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NJZ001-007>010- 012>027. DE...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR DEZ001>004. MD...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR MDZ008-012-015- 019-020. MARINE...LOW WATER ADVISORY FROM 2 PM THIS AFTERNOON TO 6 PM EST THIS EVENING FOR ANZ450>455. GALE WARNING UNTIL 1 AM EST SUNDAY FOR ANZ430-431-450>455. LOW WATER ADVISORY FROM 4 PM THIS AFTERNOON TO 9 PM EST THIS EVENING FOR ANZ430-431. && $$ SYNOPSIS...HAYES NEAR TERM...GORSE/RPW SHORT TERM...RPW LONG TERM...HAYES AVIATION...GORSE/HAYES/RPW MARINE...HAYES/RPW TIDES/COASTAL FLOODING...RPW
AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
916 PM CST SUN FEB 26 2012 .DISCUSSION... 916 PM CST SLIGHT ADJUSTMENTS MADE TO THE GOING FORECAST WITH A SOMEWHAT DIFFUSE YET MARKED COLD FRONT NOW MOVING EAST ACROSS THE FORECAST AREA. WINDS HAD DIMINISHED AHEAD OF THE FRONT WITH LESS MIXING AFTER SUNDOWN...BUT BEHIND THE FRONT THE WEST NORTHWEST WINDS ARE AGAIN GUSTING UPSTREAM...INCLUDING EVEN A FEW 25 TO 30 KT GUSTS IN NORTHEAST IA AND SOUTHWEST WI. NAM AND RUC SOUNDINGS BOTH DO NOT ADVERTISE THERMAL PROFILES TO HAVE THESE BROUGHT DOWN IN THE FORECAST AREA BUT BELIEVE BOTH MODELS MAY NOT BE ADEQUATELY ANALYZING THE COLD AIR ADVECTION PROFILES WITH THE FRONTAL PASSAGE. SO OCCASIONAL GUSTS BEING QUITE A WAYS HIGHER THAN GUIDANCE ADVERTISES ARE POSSIBLE THROUGH THE REST OF TONIGHT AFTER THE FRONT. A STRONG 130 KT JET SEEN ON WATER VAPOR AND UPPER AIR ANALYSIS IS DIRECTLY NORTH OF THE AREA OFFERING SOME FAVORABLE BROAD QG FOR WEAK ASCENT OVER THE AREA. THE MID TO UPPER LEVELS APPEAR TO BE MOISTENING ON SATELLITE CHANNELS AND STARTING TO SEE THE FIRST CLOUD OBSERVATIONS AROUND 8K TO 12K FT. THE RUC SEEMS TO HAVE A GOOD HANDLE ON THE EVOLUTION GIVEN THE PATTERN...AND EXPECT CLOUDS TO DEVELOP OVER THE SOUTHEAST FORECAST AREA THROUGH EARLY OVERNIGHT AND SLOWLY SHIFT EAST. THE CLOUDS AND WIND FIELD AND ASSOCIATED ADVECTION ARE OF COURSE DIRECTLY IMPACTING THE TEMPERATURES WHICH HAVE BEEN SOMEWHAT ERRATICALLY DROPPING...EVEN CLIMBING SLIGHTLY AS MIXING RE-ENSUES BEFORE DROPPING WITHIN THE APPARENT COLD AIR ADVECTION. HAVE DONE BEST AS ABLE TO ADJUST HOURLY TRENDS...BUT ALL IN ALL GOING MINIMUM TEMPERATURE FORECAST STILL LOOKS VERY REASONABLE. && .PREV DISCUSSION... 320 PM CST FOR THE REMAINDER OF THE AFTERNOON AND EVENING...THE MAIN CONCERN WILL CONTINUE TO FOCUS ON WINDS. WILL LET THE WIND ADVISORY RIDE UNTIL EXPIRATION. THE ONLY SITE TO REMAIN NEAR ADVISORY CRITERIA IS PONTIAC WITH GUSTS TO 35KT/40MPH AT 20Z WITH HIGHER GUSTS OBSERVED FARTHER SOUTH. SINCE THERE WILL STILL BE A COUPLE MORE HOURS WITH STRONG GUST POTENTIAL...WILL LET THE ADVISORY RIDE RATHER THAN CANCEL EARLY. OTHERWISE...THE FORECAST IS GENERALLY ON TRACK WITH MILD CONDITIONS OVER THE REGION. TEMPERATURES OVER THE NORTHWESTERN PORTIONS OF THE CWA...INCLUDING THE ROCKFORD AREA...REMAIN A BIT COOLER THAT THE REST OF THE AREA DUE TO THE RESIDUAL SNOW COVER. HOWEVER...STRONG WARM ADVECTION AHEAD OF THE STRONG LOW PRESSURE SYSTEM APPROACHING THE UPPER MISSISSIPPI VALLEY HAS ALLOWED TEMPERATURES TO REACH WELL INTO THE 50S ELSEWHERE. EXPECT WINDS TO BEGIN TO DROP OFF EARLY THIS EVENING AS THE FRONTAL TROUGH CROSSES THE MISSISSIPPI RIVER...RELAXING THE PRESSURE GRADIENT. STILL EXPECT A WEAK COLD FRONT TO PUSH SEWD THROUGH THE CWA OVERNIGHT TONIGHT. GIVEN GENERALLY DRY CONDITIONS IN PLACE...DO NOT EXPECT ANY PCPN WITH THE FROPA...AND ACTUALLY ONLY SOME INCREASING CLOUD COVER OVER NWRN IL WITH SOME BACKWASH CLOUD WRAPPING AROUND THE SWRN PERIPHERY OF THE LOW. COOLER AIR AND HIGH PRESSURE WILL BUILD IN BEHIND THE EXITING LOW AND TEMPS OVERNIGHT TONIGHT SHOULD DROP INTO THE MIDDLE 20S ALG AND WEST OF THE I-39 CORRIDOR AND THE THE UPPER 20S TO LOWER 30S ELSEWHERE. FOR THE SHORT TERM FORECAST PERIOD...FROM MONDAY THROUGH WEDNESDAY...THE PERIOD WILL START OUT QUIET ON MONDAY AS HIGH PRESSURE PASSES THROUGH THE UPPER MIDWEST AND GREAT LAKES REGIONS. SKIES WILL GENERALLY BE MOSTLY SUNNY...THOUGH TEMPERATURES WILL BE NEAR OR SLIGHTLY BELOW NORMAL...RANGING FROM THE UPPER 30S NORTH OF I-80 AND THE LOWER 40S TO THE SOUTH AND LOWS TUESDAY MORNING WILL DROP INTO THE 20S. THE NEXT CHANCE FOR PCPN WILL COME ON TUESDAY AS THE STRONG PACIFIC SYSTEM LIFTS OUT OF THE CENTRAL ROCKIES AND ACROSS THE UPPER MISSISSIPPI VALLEY. THE LATEST MODEL TRENDS CONTINUE TO SLOW DOWN THE PROGRESS OF THE SYSTEM SLIGHTLY...WITH THE MODELS IN GENERALLY GOOD AGREEMENT ON NOT INTRODUCING PCPN INTO THE WRN PORTIONS OF THE CWA UNTIL LATE TUESDAY MORNING...AND THEN SPREADING EWD ACROSS THE CWA THROUGH THE DAY. THE STRONGEST SFC AND UPPER LEVEL FORCING WILL NOT BE IN PLACE UNTIL TUESDAY NIGHT. WHILE THERE WILL AN INCREASE IN LOW LEVEL MOISTURE AS THE GULF OF MEXICO OPENS UP IN ADVANCE OF THE SFC LOW...HAVE SOME CONCERN ABOUT THE THUNDER POTENTIAL WITH THE SYSTEM. FOR ONE THING...THE BEST FORCING WILL NOT BE IN PLACE UNTIL THE EVENING HOURS AND THE CWA WILL BE NORTH OF THE ASSOCIATED WARM FRONT. SOME MODEST ISENTROPIC LIFT AND MODEST ELEVATED INSTABILITY SHOULD BE IN PLACE...BUT GIVEN THE EXPECTED TRACK OF THE SFC LOW THROUGH THE UPPER MISSISSIPPI VALLEY AND WISCONSIN...AT THIS POINT...IT DOES NOT LOOK LIKE THE CWA WILL EVER BE IN A WARM SECTOR ENVIRONMENT. SO...WILL KEEP THE CHANCE THUNDER IN THE FORECAST FOR TUESDAY EVENING...BUT HAVE TRIMMED BACK THE TS POTENTIAL FOR THE OVERNIGHT HOURS AS THE COLD FRONT CROSSES THE AREA AT AN UNFAVORABLE TIME AND THEN A MID LEVEL DRY SLOT PUSHES IN VERY QUICKLY FOLLOWING THE FROPA. THERE SHOULD BE A BREAK IN THE PCPN BY WEDNESDAY MORNING AS THE DRY SLOT MOVES OVERHEAD...BUT AS THE SFC LOW MOVES OFF TO THE EAST...THERE WILL BE A CHANCE OF SOME LIGHT SNOW OR A RAIN/SNOW MIX ON THE BACKSIDE OF THE EXITING SYSTEM FOR WEDNESDAY AFTERNOON AND EVENING. FOR THE LONGER TERM FORECAST PERIOD...FROM THURSDAY THROUGH SUNDAY...THE MEDIUM RANGE GUIDANCE IS RELATIVELY CONSISTENT IN INDICATING A FAIRLY PROGRESSIVE PATTERN WITH INCREASING AMPLITUDE. THE STORM TRACK SHOULD BE A SERIES OF PACIFIC ORIGIN SYSTEMS WITH NO SIGNIFICANT ARCTIC INFLUENCE. THE TREND THROUGH THE LONGER TERM WILL BE FOR ABOVE NORMAL TEMPERATURES THROUGH FRIDAY WITH PERIODIC LOW PCPN CHANCES. THE STRONGEST UPPER LEVEL LOW IS ADVERTISED TO CROSS THE UPPER MIDWEST BY NEXT WEEKEND...WHICH SHOULD BRING COOLER CONDITIONS AND PERHAPS A CHANCE FOR SOME LIGHT SNOW...ESPECIALLY FOR THE NORTHERN PORTIONS OF THE CWA. KREIN && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 03Z... * COLD FRONT MOVING THROUGH WITH SHIFT TO WEST WINDS. * WEST WINDS GUSTING 20-25 KTS FOR A TIME MONDAY MORNING BEFORE DECREASING AGAIN DURING THE AFTERNOON. * VERY LOW PROBABILITY FOR A BRIEF PERIOD OF 2000-3000 FT BKN CEILING MID MORNING MONDAY. RATZER //DISCUSSION...UPDATED 03Z... FRONT MAKING A LITTLE FASTER PROGRESS ACROSS NORTHERN IL THAN PREVIOUSLY ANTICIPATED...WITH BOUNDARY NOW MOVING INTO CHI TERMINALS. WILL LIKELY SEE A BRIEF PERIOD OF 280-ISH WITH GUSTS NEAR 20 KTS WITH FROPA...THEN EXPECT WINDS TO SETTLE BACK TO A 260-ISH DIRECTION AFTER A COUPLE OF HOURS. ALSO...IR SATELLITE IMAGERY AND METARS AROUND KVYS INDICATES SOME CLOUD DEVELOPMENT AROUND 8000 FT AGL. 01Z RUC MODEL RUN SUGGESTS THIS MAY BECOME MORE WIDESPREAD PERHAPS OVER OR JUST EAST OF THE CHICAGO AREA OVER THE NEXT SEVERAL HOURS. HAVE INCLUDED A PERIOD OF VFR CEILING AT GYY FOR THIS...WHICH BEING FARTHER EAST HAS THE GREATER POTENTIAL FOR DEVELOPING A VFR CIG. RATZER PREVIOUS DISCUSSION FROM 00Z... LOW PRESSURE OVER NORTHWEST WISCONSIN THIS EVENING WILL CONTINUE TO WEAKEN AS IT TRACKS EAST ACROSS THE NORTHERN LAKES TONIGHT... AND WILL TRAIL A COLD FRONT FROM WEST TO EAST ACROSS THE TERMINALS OVERNIGHT. GUSTY SOUTH WINDS ALREADY QUICKLY DIMINISHING AS PRESSURE GRADIENT WEAKENS IN ADVANCE OF THE COLD FRONTAL TROUGH... AND EXPECT WINDS TO CONTINUE TO DIMINISH AND GRADUALLY VEER SOUTHWEST THIS EVENING. ACTUAL FRONTAL PASSAGE ANTICIPATED OVERNIGHT WITH A WIND SHIFT TO THE WEST...AND GUSTS PICKING BACK UP INTO THE 20-25 KT RANGE FOR A TIME MONDAY MORNING AS LOW LEVEL MIXING DEEPENS WITH COLD ADVECTION BEHIND THE FRONT AND A RETURN OF TIGHTER SURFACE PRESSURE GRADIENT. HIGH PRESSURE WILL BUILD EAST FAIRLY QUICKLY HOWEVER...ALLOWING PRESSURE GRADIENT TO WEAKEN AGAIN FROM THE WEST DURING THE AFTERNOON HOURS. WINDS WILL THEN SHIFT NORTHWEST AND DECREASE BELOW 10 KTS EARLY MONDAY EVENING AS SURFACE HIGH MOVES IN FROM THE WEST. CLOUD WISE...ONLY A LITTLE PATCHY CIRRUS ACROSS REGION IN OTHERWISE DRY ATMOSPHERE. POTENTIAL DOES EXIST FOR SOME FLAT STRATOCU TO DEVELOP MONDAY MORNING AS LOW LEVEL LAPSE RATES STEEPEN AND MIXED LAYER DEEPENS A BIT BEHIND THE COLD FRONT. CLOUD BASES IN THE 2000-3000 FT AGL RANGE POSSIBLE AND COULD PERHAPS EVEN FORM A BRIEF BROKEN DECK FOR A TIME MID-LATE MORNING...THOUGH THIS APPEARS A LOW PROBABILITY AS AIR SPREADING IN FROM THE WEST/NORTHWEST IS ALSO VERY DRY. RATZER //ORD AND MDW CONFIDENCE...UPDATED 03Z... * HIGH CONFIDENCE IN WIND TRENDS. * HIGH CONFIDENCE IN VFR CONDITIONS. * LOW CONFIDENCE IN SCT020-030 BECOMING A BRIEF BROKEN CEILING MONDAY MORNING. RATZER //OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z... TUESDAY...CHANCE OF RAIN/SNOW CHANGING TO RAIN BY AFTERNOON. MVFR POSSIBLE. MORE RAIN AND POSSIBLY A THUNDERSTORM TUESDAY NIGHT. WEDNESDAY...CHANCE OF RAIN/SNOW WEDNESDAY AFTERNOON THEN A CHANCE OF SNOW SHOWERS WEDNESDAY NIGHT. MVFR POSSIBLE. THURSDAY...VFR. FRIDAY...CHANCE OF RAIN/SNOW...MVFR POSSIBLE. SATURDAY...CHANCE OF LIGHT SNOW...MVFR POSSIBLE. RATZER && .MARINE... 320 PM CST WINDS HAVE STRUGGLED TO STRENGTHEN TO GALES TODAY...WITH ONLY A FEW GALES REPORTED ALONG THE SOUTHERN END OF LAKE MICHIGAN. WILL CONTINUE THE GALE WARNING AS PLANNED...AND EVEN EXTEND IT BY AN HOUR. WINDS WILL STAY STRONG AS THE LOW PASSES OVER THE UPPER PENINSULA OF MICHIGAN TONIGHT...AND THEN DIMINISH BEHIND THE LOW. WINDS WILL ALSO SHIFT FROM SOUTH TO WEST BEHIND THE COLD FRONT THAT PASSES OVER THE LAKE AROUND MIDNIGHT. HIGH PRESSURE MOVES INTO THE NORTHERN GREAT PLAINS MONDAY AFTERNOON AND MOVES OVER LAKE MICHIGAN MONDAY NIGHT. WINDS VEER FROM NORTHWEST TO SOUTHEAST AS THE LOW PASSES OVER THE LAKE AND REMAIN LIGHT THROUGH EARLY TUESDAY MORNING. THE NEXT CHANCE OF GALES ARRIVES AHEAD OF THE NEXT LOW PRESSURE SYSTEM LATE TUESDAY EVENING. WINDS BECOME SOUTHWEST AND WEAKEN AS THE LOW PASSES OVER LAKE MICHIGAN ON WEDNESDAY. MODELS INDICATE EITHER THE LOW WILL STRENGTHEN SLIGHTLY AS IS MOVES OVERHEAD OR IT WILL ACT LIKE THE SYSTEM TODAY AND WEAKEN. ALSO KEPT WINDS LOWER THAN GUIDANCE BECAUSE WARM AIR ADVECTION AHEAD OF THE LOW MAY CREATE A STABLE LAYER OVER THE LAKE. HOWEVER DUE TO THE INCONSISTENCIES IN MODEL SOLUTIONS...KEPT WINDS AT LOW GALES. IN EXTENDED LAND...ANOTHER LOW PRESSURE SYSTEM ARRIVES FROM THE SOUTHWEST LATE ON FRIDAY. MODELS ARE INCONSISTENT WITH THIS SYSTEM...THEREFORE WHILE GALES ARE POSSIBLE WITH THIS LOW...KEPT WINDS AT SUB GALES FOR NOW. && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL 10 PM SUNDAY. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
911 PM CST SUN FEB 26 2012 .DISCUSSION... 320 PM CST FOR THE REMAINDER OF THE AFTERNOON AND EVENING...THE MAIN CONCERN WILL CONTINUE TO FOCUS ON WINDS. WILL LET THE WIND ADVISORY RIDE UNTIL EXPIRATION. THE ONLY SITE TO REMAIN NEAR ADVISORY CRITERIA IS PONTIAC WITH GUSTS TO 35KT/40MPH AT 20Z WITH HIGHER GUSTS OBSERVED FARTHER SOUTH. SINCE THERE WILL STILL BE A COUPLE MORE HOURS WITH STRONG GUST POTENTIAL...WILL LET THE ADVISORY RIDE RATHER THAN CANCEL EARLY. OTHERWISE...THE FORECAST IS GENERALLY ON TRACK WITH MILD CONDITIONS OVER THE REGION. TEMPERATURES OVER THE NORTHWESTERN PORTIONS OF THE CWA...INCLUDING THE ROCKFORD AREA...REMAIN A BIT COOLER THAT THE REST OF THE AREA DUE TO THE RESIDUAL SNOW COVER. HOWEVER...STRONG WARM ADVECTION AHEAD OF THE STRONG LOW PRESSURE SYSTEM APPROACHING THE UPPER MISSISSIPPI VALLEY HAS ALLOWED TEMPERATURES TO REACH WELL INTO THE 50S ELSEWHERE. EXPECT WINDS TO BEGIN TO DROP OFF EARLY THIS EVENING AS THE FRONTAL TROUGH CROSSES THE MISSISSIPPI RIVER...RELAXING THE PRESSURE GRADIENT. STILL EXPECT A WEAK COLD FRONT TO PUSH SEWD THROUGH THE CWA OVERNIGHT TONIGHT. GIVEN GENERALLY DRY CONDITIONS IN PLACE...DO NOT EXPECT ANY PCPN WITH THE FROPA...AND ACTUALLY ONLY SOME INCREASING CLOUD COVER OVER NWRN IL WITH SOME BACKWASH CLOUD WRAPPING AROUND THE SWRN PERIPHERY OF THE LOW. COOLER AIR AND HIGH PRESSURE WILL BUILD IN BEHIND THE EXITING LOW AND TEMPS OVERNIGHT TONIGHT SHOULD DROP INTO THE MIDDLE 20S ALG AND WEST OF THE I-39 CORRIDOR AND THE THE UPPER 20S TO LOWER 30S ELSEWHERE. FOR THE SHORT TERM FORECAST PERIOD...FROM MONDAY THROUGH WEDNESDAY...THE PERIOD WILL START OUT QUIET ON MONDAY AS HIGH PRESSURE PASSES THROUGH THE UPPER MIDWEST AND GREAT LAKES REGIONS. SKIES WILL GENERALLY BE MOSTLY SUNNY...THOUGH TEMPERATURES WILL BE NEAR OR SLIGHTLY BELOW NORMAL...RANGING FROM THE UPPER 30S NORTH OF I-80 AND THE LOWER 40S TO THE SOUTH AND LOWS TUESDAY MORNING WILL DROP INTO THE 20S. THE NEXT CHANCE FOR PCPN WILL COME ON TUESDAY AS THE STRONG PACIFIC SYSTEM LIFTS OUT OF THE CENTRAL ROCKIES AND ACROSS THE UPPER MISSISSIPPI VALLEY. THE LATEST MODEL TRENDS CONTINUE TO SLOW DOWN THE PROGRESS OF THE SYSTEM SLIGHTLY...WITH THE MODELS IN GENERALLY GOOD AGREEMENT ON NOT INTRODUCING PCPN INTO THE WRN PORTIONS OF THE CWA UNTIL LATE TUESDAY MORNING...AND THEN SPREADING EWD ACROSS THE CWA THROUGH THE DAY. THE STRONGEST SFC AND UPPER LEVEL FORCING WILL NOT BE IN PLACE UNTIL TUESDAY NIGHT. WHILE THERE WILL AN INCREASE IN LOW LEVEL MOISTURE AS THE GULF OF MEXICO OPENS UP IN ADVANCE OF THE SFC LOW...HAVE SOME CONCERN ABOUT THE THUNDER POTENTIAL WITH THE SYSTEM. FOR ONE THING...THE BEST FORCING WILL NOT BE IN PLACE UNTIL THE EVENING HOURS AND THE CWA WILL BE NORTH OF THE ASSOCIATED WARM FRONT. SOME MODEST ISENTROPIC LIFT AND MODEST ELEVATED INSTABILITY SHOULD BE IN PLACE...BUT GIVEN THE EXPECTED TRACK OF THE SFC LOW THROUGH THE UPPER MISSISSIPPI VALLEY AND WISCONSIN...AT THIS POINT...IT DOES NOT LOOK LIKE THE CWA WILL EVER BE IN A WARM SECTOR ENVIRONMENT. SO...WILL KEEP THE CHANCE THUNDER IN THE FORECAST FOR TUESDAY EVENING...BUT HAVE TRIMMED BACK THE TS POTENTIAL FOR THE OVERNIGHT HOURS AS THE COLD FRONT CROSSES THE AREA AT AN UNFAVORABLE TIME AND THEN A MID LEVEL DRY SLOT PUSHES IN VERY QUICKLY FOLLOWING THE FROPA. THERE SHOULD BE A BREAK IN THE PCPN BY WEDNESDAY MORNING AS THE DRY SLOT MOVES OVERHEAD...BUT AS THE SFC LOW MOVES OFF TO THE EAST...THERE WILL BE A CHANCE OF SOME LIGHT SNOW OR A RAIN/SNOW MIX ON THE BACKSIDE OF THE EXITING SYSTEM FOR WEDNESDAY AFTERNOON AND EVENING. FOR THE LONGER TERM FORECAST PERIOD...FROM THURSDAY THROUGH SUNDAY...THE MEDIUM RANGE GUIDANCE IS RELATIVELY CONSISTENT IN INDICATING A FAIRLY PROGRESSIVE PATTERN WITH INCREASING AMPLITUDE. THE STORM TRACK SHOULD BE A SERIES OF PACIFIC ORIGIN SYSTEMS WITH NO SIGNIFICANT ARCTIC INFLUENCE. THE TREND THROUGH THE LONGER TERM WILL BE FOR ABOVE NORMAL TEMPERATURES THROUGH FRIDAY WITH PERIODIC LOW PCPN CHANCES. THE STRONGEST UPPER LEVEL LOW IS ADVERTISED TO CROSS THE UPPER MIDWEST BY NEXT WEEKEND...WHICH SHOULD BRING COOLER CONDITIONS AND PERHAPS A CHANCE FOR SOME LIGHT SNOW...ESPECIALLY FOR THE NORTHERN PORTIONS OF THE CWA. KREIN && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 03Z... * COLD FRONT MOVING THROUGH WITH SHIFT TO WEST WINDS. * WEST WINDS GUSTING 20-25 KTS FOR A TIME MONDAY MORNING BEFORE DECREASING AGAIN DURING THE AFTERNOON. * VERY LOW PROBABILITY FOR A BRIEF PERIOD OF 2000-3000 FT BKN CEILING MID MORNING MONDAY. RATZER //DISCUSSION...UPDATED 03Z... FRONT MAKING A LITTLE FASTER PROGRESS ACROSS NORTHERN IL THAN PREVIOUSLY ANTICIPATED...WITH BOUNDARY NOW MOVING INTO CHI TERMINALS. WILL LIKELY SEE A BRIEF PERIOD OF 280-ISH WITH GUSTS NEAR 20 KTS WITH FROPA...THEN EXPECT WINDS TO SETTLE BACK TO A 260-ISH DIRECTION AFTER A COUPLE OF HOURS. ALSO...IR SATELLITE IMAGERY AND METARS AROUND KVYS INDICATES SOME CLOUD DEVELOPMENT AROUND 8000 FT AGL. 01Z RUC MODEL RUN SUGGESTS THIS MAY BECOME MORE WIDESPREAD PERHAPS OVER OR JUST EAST OF THE CHICAGO AREA OVER THE NEXT SEVERAL HOURS. HAVE INCLUDED A PERIOD OF VFR CEILING AT GYY FOR THIS...WHICH BEING FARTHER EAST HAS THE GREATER POTENTIAL FOR DEVELOPING A VFR CIG. RATZER PREVIOUS DISCUSSION FROM 00Z... LOW PRESSURE OVER NORTHWEST WISCONSIN THIS EVENING WILL CONTINUE TO WEAKEN AS IT TRACKS EAST ACROSS THE NORTHERN LAKES TONIGHT... AND WILL TRAIL A COLD FRONT FROM WEST TO EAST ACROSS THE TERMINALS OVERNIGHT. GUSTY SOUTH WINDS ALREADY QUICKLY DIMINISHING AS PRESSURE GRADIENT WEAKENS IN ADVANCE OF THE COLD FRONTAL TROUGH... AND EXPECT WINDS TO CONTINUE TO DIMINISH AND GRADUALLY VEER SOUTHWEST THIS EVENING. ACTUAL FRONTAL PASSAGE ANTICIPATED OVERNIGHT WITH A WIND SHIFT TO THE WEST...AND GUSTS PICKING BACK UP INTO THE 20-25 KT RANGE FOR A TIME MONDAY MORNING AS LOW LEVEL MIXING DEEPENS WITH COLD ADVECTION BEHIND THE FRONT AND A RETURN OF TIGHTER SURFACE PRESSURE GRADIENT. HIGH PRESSURE WILL BUILD EAST FAIRLY QUICKLY HOWEVER...ALLOWING PRESSURE GRADIENT TO WEAKEN AGAIN FROM THE WEST DURING THE AFTERNOON HOURS. WINDS WILL THEN SHIFT NORTHWEST AND DECREASE BELOW 10 KTS EARLY MONDAY EVENING AS SURFACE HIGH MOVES IN FROM THE WEST. CLOUD WISE...ONLY A LITTLE PATCHY CIRRUS ACROSS REGION IN OTHERWISE DRY ATMOSPHERE. POTENTIAL DOES EXIST FOR SOME FLAT STRATOCU TO DEVELOP MONDAY MORNING AS LOW LEVEL LAPSE RATES STEEPEN AND MIXED LAYER DEEPENS A BIT BEHIND THE COLD FRONT. CLOUD BASES IN THE 2000-3000 FT AGL RANGE POSSIBLE AND COULD PERHAPS EVEN FORM A BRIEF BROKEN DECK FOR A TIME MID-LATE MORNING...THOUGH THIS APPEARS A LOW PROBABILITY AS AIR SPREADING IN FROM THE WEST/NORTHWEST IS ALSO VERY DRY. RATZER //ORD AND MDW CONFIDENCE...UPDATED 03Z... * HIGH CONFIDENCE IN WIND TRENDS. * HIGH CONFIDENCE IN VFR CONDITIONS. * LOW CONFIDENCE IN SCT020-030 BECOMING A BRIEF BROKEN CEILING MONDAY MORNING. RATZER //OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z... TUESDAY...CHANCE OF RAIN/SNOW CHANGING TO RAIN BY AFTERNOON. MVFR POSSIBLE. MORE RAIN AND POSSIBLY A THUNDERSTORM TUESDAY NIGHT. WEDNESDAY...CHANCE OF RAIN/SNOW WEDNESDAY AFTERNOON THEN A CHANCE OF SNOW SHOWERS WEDNESDAY NIGHT. MVFR POSSIBLE. THURSDAY...VFR. FRIDAY...CHANCE OF RAIN/SNOW...MVFR POSSIBLE. SATURDAY...CHANCE OF LIGHT SNOW...MVFR POSSIBLE. RATZER && .MARINE... 320 PM CST WINDS HAVE STRUGGLED TO STRENGTHEN TO GALES TODAY...WITH ONLY A FEW GALES REPORTED ALONG THE SOUTHERN END OF LAKE MICHIGAN. WILL CONTINUE THE GALE WARNING AS PLANNED...AND EVEN EXTEND IT BY AN HOUR. WINDS WILL STAY STRONG AS THE LOW PASSES OVER THE UPPER PENINSULA OF MICHIGAN TONIGHT...AND THEN DIMINISH BEHIND THE LOW. WINDS WILL ALSO SHIFT FROM SOUTH TO WEST BEHIND THE COLD FRONT THAT PASSES OVER THE LAKE AROUND MIDNIGHT. HIGH PRESSURE MOVES INTO THE NORTHERN GREAT PLAINS MONDAY AFTERNOON AND MOVES OVER LAKE MICHIGAN MONDAY NIGHT. WINDS VEER FROM NORTHWEST TO SOUTHEAST AS THE LOW PASSES OVER THE LAKE AND REMAIN LIGHT THROUGH EARLY TUESDAY MORNING. THE NEXT CHANCE OF GALES ARRIVES AHEAD OF THE NEXT LOW PRESSURE SYSTEM LATE TUESDAY EVENING. WINDS BECOME SOUTHWEST AND WEAKEN AS THE LOW PASSES OVER LAKE MICHIGAN ON WEDNESDAY. MODELS INDICATE EITHER THE LOW WILL STRENGTHEN SLIGHTLY AS IS MOVES OVERHEAD OR IT WILL ACT LIKE THE SYSTEM TODAY AND WEAKEN. ALSO KEPT WINDS LOWER THAN GUIDANCE BECAUSE WARM AIR ADVECTION AHEAD OF THE LOW MAY CREATE A STABLE LAYER OVER THE LAKE. HOWEVER DUE TO THE INCONSISTENCIES IN MODEL SOLUTIONS...KEPT WINDS AT LOW GALES. IN EXTENDED LAND...ANOTHER LOW PRESSURE SYSTEM ARRIVES FROM THE SOUTHWEST LATE ON FRIDAY. MODELS ARE INCONSISTENT WITH THIS SYSTEM...THEREFORE WHILE GALES ARE POSSIBLE WITH THIS LOW...KEPT WINDS AT SUB GALES FOR NOW. && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL 10 PM SUNDAY. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1120 AM CST SAT FEB 25 2012 .DISCUSSION... ISSUED 958 AM CST SAT FEB 25 2012 STILL SEEING SOME LINGERING CLOUD COVER...MAINLY IN BANDS FROM MACOMB SOUTHEAST INTO LAWRENCEVILLE...AND PEORIA TO DANVILLE. JUST SOME LINGERING FLURRIES LINGERING...MAINLY IN THE SOUTHEAST... ALTHOUGH LAWRENCEVILLE VISIBILITY HAD DROPPED TO 4 MILES IN LIGHT SNOW LAST HOUR. STILL AM EXPECTING TO SEE THESE FEATURES DIMINISHING OVER THE NEXT FEW HOURS...ALTHOUGH RUC CU-RULE SUGGEST THE CLOUDS OVER THE SOUTHEAST LINGERING TO NEARLY MID-AFTERNOON. HAVE SEEN WINDS GUSTING FROM 30-35 MPH THIS MORNING. HOWEVER...THESE WILL STEADILY DIMINISH THE NEXT SEVERAL HOURS... AS SURFACE RIDGING OVER WESTERN MISSOURI BUILDS EASTWARD. HAVE SENT SOME UPDATED GRIDS TO ADJUST THE SKY COVER AND WIND TRENDS. ZONE UPDATE THAT WAS ISSUED AROUND 5 AM IS STILL OK...BUT WILL BE UPDATED CLOSER TO NOON TO REMOVE MORNING WORDING. GEELHART && .AVIATION... ISSUED 1120 AM CST SAT FEB 25 2012 STILL SEEING A BIT OF MVFR CEILINGS LINGERING LATE THIS MORNING... HOWEVER THESE SHOULD BE LIFTING THROUGH 20Z AS CLOUDS AND WINDS DIMINISH FROM THE WEST. SURFACE HIGH PRESSURE WILL MOVE EAST ACROSS THE TAF SITES THIS EVENING...WITH SOUTHEAST WINDS INCREASING OVERNIGHT. HAVE INTRODUCED LLWS MENTION AT KPIA/KSPI LATE IN THE NIGHT...AS A 50-60 KNOT LOW LEVEL JET APPROACHES FROM THE WEST AHEAD OF A COLD FRONT IN THE PLAINS. BY THE TIME THE CORE OF THIS JET MOVES OVER THE REMAINDER OF THE TAF SITES...DAYTIME MIXING WILL BRING SOME OF THESE WINDS DOWN TO THE SURFACE...SO HAVE GONE WITH 30-35 KNOT SURFACE GUSTS LATE IN THE PERIOD. GEELHART && .PREV DISCUSSION... ISSUED 330 AM CST SAT FEB 25 2012 ASIDE FROM A CHANCE OF FLURRIES INTO MID MORNING...DRY WEATHER EXPECTED OVER CENTRAL IL THROUGH MONDAY NIGHT. MORE ACTIVE WEATHER PATTERN EXPECTED DURING THE MIDDLE AND LATER PART OF NEXT WEEK WITH TWO DEEPENING LOW PRESSURE SYSTEMS EJECTING NE ACROSS THE MIDWEST. WINTER LIKE TEMPERATURES EXPECTED TODAY THEN WARM UP SUNDAY WITH STRONG SOUTHERLY WINDS AND ABOVE NORMAL TEMPERATURES OVERALL NEXT WEEK...WHICH HAS BEEN THE NORM THIS PAST WINTER. SHORT TERM...TODAY THROUGH MONDAY NIGHT VERY STRONG AND STILL DEEPENING 977 MB LOW PRESSURE OFF THE MAINE COAST AND STRONG 512 DM 500 MB LOW ALONG THE SOUTHERN QUEBEC/ONTARIO PROVINCE LINE AND FAIRLY STRONG UPPER LEVEL TROF OVER THE GREAT LAKES AND OHIO VALLEY STILL INFLUENCING CENTRAL IL WEATHER THIS MORNING. HAVE PATCHES OF CLOUDS AND FLURRIES PIVOTING THROUGH WITH BRISK WNW WINDS GUSTING 15 TO 30 MPH. TEMPS MOSTLY IN THE UPPER 20S AND LOWER 30S...BUT COOLER MID 20S FROM I-74 NE. DEWPOINTS GENERALLY IN THE UPPER TEENS AND LOWER 20S. FAIRLY STRONG SHORT WAVES STILL AFFECTING IL THIS MORNING AND TO GIVE PARTLY TO MOSTLY CLOUDY SKIES WITH A CHANCE OF FLURRIES INTO MID MORNING ESPECIALLY EAST CENTRAL IL ALONG WITH BRISK WNW WINDS. 1030 MB HIGH PRESSURE OVER EAST TX AND RIDGING NORTHWARD ACROSS THE GREAT PLAINS WILL SHIFT EAST INTO THE MS VALLEY THIS AFTERNOON DECREASING CLOUDS AND WINDS. COOL HIGHS FROM 32-38F WITH MILDEST READINGS IN SE IL AND SW OF SPRINGFIELD. HIGH PRESSURE DRIFTS EAST INTO THE CENTRAL APPALACHIANS OVERNIGHT WHILE LOW PRESSURE EMERGES INTO THE NORTHERN PLAINS BY DAWN SUNDAY. LOWS TONIGHT IN THE LOW TO MID 20S AND LIKELY REACHED BY MIDNIGHT WITH NEARLY STEADY OVERNIGHT WITH SSE WINDS INCREASING TO 10-20 MPH BY SUNRISE SUNDAY. LOW PRESSURE TRACKS EAST TOWARD UPPER MI BY MIDNIGHT SUNDAY NIGHT WITH STRONG PRESSURE GRADIENT SETTING UP OVER IL AND STRONG SOUTH WINDS WITH GUSTS 30 TO 40 MPH. HIGHS IN THE 30S TODAY JUMP UP INTO THE 50S SUNDAY AFTERNOON WITH MOSTLY SUNNY SKIES. FRONTAL BOUNDARY TO PRESS SE ACROSS CENTRAL IL BY OVERNIGHT SUNDAY NIGHT AND PASSES THROUGH DRY WITH UPPER LEVEL DYNAMICS PASSING NORTH OVER THE GREAT LAKES REGION AND DEEPER MOISTURE FROM THE GULF OF MEXICO CUT OFF BY HIGH PRESSURE RIDGE FROM THE MID ATLANTIC STATES AND RIDGING WSW ACROSS DIXIE. MOSTLY SUNNY SKIES AGAIN MONDAY AND A BIT COOLER OVER CENTRAL IL BEHIND THE FRONT WITH HIGHS RANGING FROM THE MID 40S NORTH OF PEORIA AND MID 50S IN SE IL. LONG TERM...TUESDAY THROUGH FRIDAY NIGHT NOT TOO MANY CHANGES MADE TO THE EXTENDED FORECAST AND MOST MODELS CONTINUE DRY CONDITIONS MONDAY NIGHT AND THEN SPREAD RAIN SHOWERS ACROSS IL DURING TUE AND ESPECIALLY TUE NIGHT. IL GETTING ESTABLISHED IN A MORE SW UPPER LEVEL FLOW WITH TWO LOW PRESSURE SYSTEMS DEEPENING NE INTO THE MIDWEST AND KEEPING IL ON THE MILDER SIDE OF THE STORM TRACK. BEST CHANCES OF SHOWERS AND POSSIBLE THUNDERSTORMS WILL BE TUE AFTERNOON AND TUE NIGHT. CENTRAL AND SE IL GETS DRY SLOTTED DURING WED WITH BEST CHANCES OF PRECIPITATION NORTH AND EAST OF CENTRAL IL. ANOTHER STRONG LOW PRESSURE QUICKLY ON ITS HEALS AND DEEPENS INTO THE MIDWEST FRI AND FRI NIGHT WITH NEXT CHANCE OF PRECIPITATION WHICH APPEARS TO BE MAINLY RAIN AGAIN WITH LOW PRESSURE TRACK NORTH OF CENTRAL IL. KEEPING TEMPS ABOVE NORMAL DURING NEXT WEEK AS WE HEAD INTO EARLY MARCH. KH && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
958 AM CST SAT FEB 25 2012 .DISCUSSION... ISSUED 958 AM CST SAT FEB 25 2012 STILL SEEING SOME LINGERING CLOUD COVER...MAINLY IN BANDS FROM MACOMB SOUTHEAST INTO LAWRENCEVILLE...AND PEORIA TO DANVILLE. JUST SOME LINGERING FLURRIES LINGERING...MAINLY IN THE SOUTHEAST... ALTHOUGH LAWRENCEVILLE VISIBILITY HAD DROPPED TO 4 MILES IN LIGHT SNOW LAST HOUR. STILL AM EXPECTING TO SEE THESE FEATURES DIMINISHING OVER THE NEXT FEW HOURS...ALTHOUGH RUC CU-RULE SUGGEST THE CLOUDS OVER THE SOUTHEAST LINGERING TO NEARLY MID-AFTERNOON. HAVE SEEN WINDS GUSTING FROM 30-35 MPH THIS MORNING. HOWEVER...THESE WILL STEADILY DIMINISH THE NEXT SEVERAL HOURS... AS SURFACE RIDGING OVER WESTERN MISSOURI BUILDS EASTWARD. HAVE SENT SOME UPDATED GRIDS TO ADJUST THE SKY COVER AND WIND TRENDS. ZONE UPDATE THAT WAS ISSUED AROUND 5 AM IS STILL OK...BUT WILL BE UPDATED CLOSER TO NOON TO REMOVE MORNING WORDING. GEELHART && .AVIATION... ISSUED 541 AM CST SAT FEB 25 2012...FOR THE 12Z TAFS A WEAK SURFACE IMPULSE COMBINED WITH THE UPPER TROUGH AXIS WILL KEEP MVFR CLOUDS WITH FLURRIES AND LIGHT SNOW SHOWERS AROUND THIS MORNING. A FEW PERIODS OF MVFR VIS MAY RESULT FROM ANY HEAVIER SNOW BURSTS. A DUSTING OF SNOW COULD ACCUMULATE FROM THE HEAVIER SNOWS...BUT OVERALL LITTLE ACCUMULATION IS EXPECTED. WINDS JUST OFF THE SURFACE ARE STILL RATHER BRISK, AND WIND GUSTS ARE EXPECTED TO RETURN AS MIXING HEIGHTS INCREASE. WE SHOULD SEE NORTHWEST WINDS GUSTING AROUND 20 KT AT TIMES...ESPECIALLY THIS MORNING. THAT SHOULD HELP TO BLOW SNOW OFF OF MANY TRAVEL SURFACES. HOWEVER...SOME SLIPPERY CONDITIONS COULD LINGER TODAY AS TEMPS CLIMB ONLY SLIGHTLY ABOVE FREEZING. WINDS WILL DIMINISH LATER THIS AFTERNOON...AND BECOME VARIABLE TONIGHT AS THE HIGH PRESSURE PULLS OFF TO THE EAST. A SOUTHEAST WIND IS EVENTUALLY EXPECTED TO DEVELOP BY LATE TONIGHT...UNDER MOSTLY CLEAR SKIES. SHIMON && .PREV DISCUSSION... ISSUED 330 AM CST SAT FEB 25 2012 ASIDE FROM A CHANCE OF FLURRIES INTO MID MORNING...DRY WEATHER EXPECTED OVER CENTRAL IL THROUGH MONDAY NIGHT. MORE ACTIVE WEATHER PATTERN EXPECTED DURING THE MIDDLE AND LATER PART OF NEXT WEEK WITH TWO DEEPENING LOW PRESSURE SYSTEMS EJECTING NE ACROSS THE MIDWEST. WINTER LIKE TEMPERATURES EXPECTED TODAY THEN WARM UP SUNDAY WITH STRONG SOUTHERLY WINDS AND ABOVE NORMAL TEMPERATURES OVERALL NEXT WEEK...WHICH HAS BEEN THE NORM THIS PAST WINTER. SHORT TERM...TODAY THROUGH MONDAY NIGHT VERY STRONG AND STILL DEEPENING 977 MB LOW PRESSURE OFF THE MAINE COAST AND STRONG 512 DM 500 MB LOW ALONG THE SOUTHERN QUEBEC/ONTARIO PROVINCE LINE AND FAIRLY STRONG UPPER LEVEL TROF OVER THE GREAT LAKES AND OHIO VALLEY STILL INFLUENCING CENTRAL IL WEATHER THIS MORNING. HAVE PATCHES OF CLOUDS AND FLURRIES PIVOTING THROUGH WITH BRISK WNW WINDS GUSTING 15 TO 30 MPH. TEMPS MOSTLY IN THE UPPER 20S AND LOWER 30S...BUT COOLER MID 20S FROM I-74 NE. DEWPOINTS GENERALLY IN THE UPPER TEENS AND LOWER 20S. FAIRLY STRONG SHORT WAVES STILL AFFECTING IL THIS MORNING AND TO GIVE PARTLY TO MOSTLY CLOUDY SKIES WITH A CHANCE OF FLURRIES INTO MID MORNING ESPECIALLY EAST CENTRAL IL ALONG WITH BRISK WNW WINDS. 1030 MB HIGH PRESSURE OVER EAST TX AND RIDGING NORTHWARD ACROSS THE GREAT PLAINS WILL SHIFT EAST INTO THE MS VALLEY THIS AFTERNOON DECREASING CLOUDS AND WINDS. COOL HIGHS FROM 32-38F WITH MILDEST READINGS IN SE IL AND SW OF SPRINGFIELD. HIGH PRESSURE DRIFTS EAST INTO THE CENTRAL APPALACHIANS OVERNIGHT WHILE LOW PRESSURE EMERGES INTO THE NORTHERN PLAINS BY DAWN SUNDAY. LOWS TONIGHT IN THE LOW TO MID 20S AND LIKELY REACHED BY MIDNIGHT WITH NEARLY STEADY OVERNIGHT WITH SSE WINDS INCREASING TO 10-20 MPH BY SUNRISE SUNDAY. LOW PRESSURE TRACKS EAST TOWARD UPPER MI BY MIDNIGHT SUNDAY NIGHT WITH STRONG PRESSURE GRADIENT SETTING UP OVER IL AND STRONG SOUTH WINDS WITH GUSTS 30 TO 40 MPH. HIGHS IN THE 30S TODAY JUMP UP INTO THE 50S SUNDAY AFTERNOON WITH MOSTLY SUNNY SKIES. FRONTAL BOUNDARY TO PRESS SE ACROSS CENTRAL IL BY OVERNIGHT SUNDAY NIGHT AND PASSES THROUGH DRY WITH UPPER LEVEL DYNAMICS PASSING NORTH OVER THE GREAT LAKES REGION AND DEEPER MOISTURE FROM THE GULF OF MEXICO CUT OFF BY HIGH PRESSURE RIDGE FROM THE MID ATLANTIC STATES AND RIDGING WSW ACROSS DIXIE. MOSTLY SUNNY SKIES AGAIN MONDAY AND A BIT COOLER OVER CENTRAL IL BEHIND THE FRONT WITH HIGHS RANGING FROM THE MID 40S NORTH OF PEORIA AND MID 50S IN SE IL. LONG TERM...TUESDAY THROUGH FRIDAY NIGHT NOT TOO MANY CHANGES MADE TO THE EXTENDED FORECAST AND MOST MODELS CONTINUE DRY CONDITIONS MONDAY NIGHT AND THEN SPREAD RAIN SHOWERS ACROSS IL DURING TUE AND ESPECIALLY TUE NIGHT. IL GETTING ESTABLISHED IN A MORE SW UPPER LEVEL FLOW WITH TWO LOW PRESSURE SYSTEMS DEEPENING NE INTO THE MIDWEST AND KEEPING IL ON THE MILDER SIDE OF THE STORM TRACK. BEST CHANCES OF SHOWERS AND POSSIBLE THUNDERSTORMS WILL BE TUE AFTERNOON AND TUE NIGHT. CENTRAL AND SE IL GETS DRY SLOTTED DURING WED WITH BEST CHANCES OF PRECIPITATION NORTH AND EAST OF CENTRAL IL. ANOTHER STRONG LOW PRESSURE QUICKLY ON ITS HEALS AND DEEPENS INTO THE MIDWEST FRI AND FRI NIGHT WITH NEXT CHANCE OF PRECIPITATION WHICH APPEARS TO BE MAINLY RAIN AGAIN WITH LOW PRESSURE TRACK NORTH OF CENTRAL IL. KEEPING TEMPS ABOVE NORMAL DURING NEXT WEEK AS WE HEAD INTO EARLY MARCH. KH && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1141 AM CST SAT FEB 25 2012 .AVIATION... VFR CONDITIONS TO PREVAIL THROUGH 18Z/26TH. FEW-SCT STRATOCU WITH MVFR BASES (2000-2500 FT AGL) WILL BE FOUND THROUGH MID AFTN BEFORE DIMINISHING WITH LOSS OF HEATING. SFC RIDGE WILL PASS THIS EVE WITH W/NW WINDS AROUND 10 KTS BECOMING NEAR CALM TO LIGHT S/SW EARLY EVE BEFORE BACKING TO E/SE AND INCREASING 10-15 KTS WITH GUSTS OVRNGT AS PRESSURE GRADIENT STRENGTHENS BETWEEN DEPARTING SFC RIDGE AND LOW EMERGING INTO THE NORTHERN PLAINS. ADDED MENTION OF LLWS AFT 06Z AS STRONG S/SW LOW LEVEL JET DEVELOPS... WITH NAM AND GFS SOUNDINGS SHOWING 45-55 KTS DEVELOPING IN 1500-2000 FT AGL. && .PREV DISCUSSION... /ISSUED 538 AM CST SAT FEB 25 2012/ UPDATE... SATELLITE AND RADAR TRENDS SHOW FLURRIES CONTINUE BACK INTO CENTRAL IOWA WITH A SOUTHEAST MOVEMENT. RUC TRENDS USING PRESSURE ADVECTION ON THE 1.5PV SFC AND 500MB VORT MAX SHOW AN AREA OF LIFT WHERE THE FLURRIES ARE CURRENTLY DEPICTED IN OBS/RADAR. THE RUC DECREASES THE LIFT THROUGH THE MORNING AS THE VORT MAX MOVES EAST ACROSS THE CWFA. THUS ISOLATED FLURRIES WILL BE SEEN THROUGH MID MORNING OVER ROUGHLY THE WESTERN HALF WHILE FLURRIES CONTINUE OVER THE EASTERN THIRD. STRONG SUBSIDENCE BEHIND THE VORT MAX WILL ALLOW RAPID CLEARING OF CLOUDS FROM WEST TO EAST DURING THE MORNING HOURS WITH A MAJORITY OF THE CWFA BECOMING MOSTLY SUNNY BY MID DAY. DIURNAL CU/SC MAY STILL FIRE AS THE COLD POCKET ALOFT MOVES INTO THE AREA. AND UPDATE TO THE FCST WILL BE AVAILABLE SHORTLY. ..08.. PREV DISCUSSION... /ISSUED 308 AM CST SAT FEB 25 2012/ SYNOPSIS... 06Z SFC ANALYSIS HAS A HIGH PRESSURE RIDGE OVER THE PLAINS. SEVERAL WEAK TROFS RAN FROM THE OHIO VALLEY BACK INTO THE UPPER MIDWEST. DEW POINTS WERE IN THE 20S AND 30S ACROSS MUCH OF THE MIDWEST WITH TEENS AND SINGLE DIGITS OVER THE NORTHERN PLAINS. RADAR AND SATELLITE DATA SHOWS SNOW SHOWERS AND FLURRIES ASSOCIATED WITH A DISTURBANCE ALOFT MOVING THROUGH THE REGION. SHORT TERM...TODAY AND TONIGHT... RADAR AND OBS TRENDS THE PAST FEW HOURS INDICATE THAT MOST OF THE AREA WILL BE PRECIPITATION FREE AT SUNRISE. THE EXCEPTION APPEARS TO BE THE NORTHEAST PART OF THE CWFA WHERE SOME FLURRIES MAY BE SEEN WITH THE PASSAGE OF A RESPECTABLE VORT MAX AND SHORTWAVE SHORTLY AFTER SUNRISE. WINDS HAVE INCREASED CONSIDERABLY WITH THE PASSAGE OF A WEAK SFC TROF. LOW LEVEL LAPSE RATES WERE STILL FAIRLY STEEP SO HIGHER MOMENTUM AIR WAS ABLE TO MIX DOWN TO THE SFC. RUC TRENDS SHOW LOW LEVEL LAPSE RATES STABILIZING THROUGH SUNRISE SO WINDS SHOULD DIMINISH. HOWEVER...THE STRONGER WINDS IN NORTHERN AND SOUTH CENTRAL IOWA CANNOT BE EXPLAINED BY LAPSE RATES. A POSSIBLE EXPLANATION IS ONE OF THE TWO PV ANOMALIES THAT ARE ROTATING THROUGH THE REGION. PER THE RUC THESE ANOMALIES SHOULD EXIT THE CWFA THIS MORNING SO THE STRONG WINDS MAY PERSIST PAST SUNRISE FOR PARTS OF THE AREA. SUBSIDENCE BEHIND THE SHORTWAVES ALOFT SHOULD ALLOW CLOUDS TO BREAK UP DURING THE MORNING AND AFTERNOON AND ALLOW MORE SUN TO BE SEEN. A COLD POCKET ALOFT MOVING INTO THE AREA THIS AFTERNOON MAY ALLOW DIURNAL CU/SC TO DEVELOP ACROSS PARTS OF THE AREA. THE SOUTHERN EDGE OF THE SNOW FIELD SHOULD MELT DURING THE DAY BUT THE DEEPER SNOW PACK ACROSS THE NORTHERN CWFA WILL PERSIST. THUS TEMPERATURES SHOULD HOLD JUST BELOW FREEZING ACROSS THE NORTHERN CWFA WHILE BEING AT OR ABOVE FREEZING FROM I-80 ON SOUTH. TONIGHT...THE SFC RIDGE IS RIGHT OVER THE AREA AT SUNSET. THUS TEMPERATURES SHOULD DROP QUICKLY THIS EVENING. AS RETURN FLOW BECOMES ESTABLISHED BY LATE EVENING TEMPERATURES SHOULD LEVEL OFF AND THEN SLOWLY RISE AFTER MIDNIGHT AS CLOUDS SLOWLY INCREASE. 08.. LONG TERM...SUNDAY THROUGH FRIDAY... MODELS CONTINUE TO SHOW AN ACTIVE WEEK AS A SERIES OF UPPER TROFS MOVE THROUGH THE REGION. THE FIRST SYSTEM WILL TRAVERSE THE NORTHERN TIER OF STATES MOVING FROM THE EASTERN DAKOTAS THROUGH NORTHERN MN INTO THE WESTERN GREAT LAKES REGION SUNDAY AND SUNDAY NIGHT. THE MAIN FEATURES FOR THIS SYSTEM WILL BE GUSTY WINDS AHEAD OF AND JUST BEHIND A WEAK COLD FRONT MOVING THROUGH SUNDAY AFTERNOON. SHALLOW MIXING DURING THE DAY SHOULD BE ABLE TO TAP 25-35KT WINDS JUST OFF THE SURFACE RESULTING IN SOUTHWEST TO WEST WINDS GUSTING TO AROUND 30KTS. THE LOW LEVEL THERMAL RIDGE WILL PASS THROUGH THE CWFA DURING DAY...WHICH SHOULD HELP TEMPERATURES CLIMB INTO THE MID 50S SOUTH. MORE CLOUDS AND LINGERING SNOW COVER IN THE NORTH WILL HELP KEEP HIGHS IN THE MID 40S. THE BULK OF THE FORCING WILL REMAIN WELL NORTH OF THE AREA AND THE AIR FEEDING INTO IT WILL BE DRY...SO A DRY FORECAST WAS CONTINUED. ANOTHER...MORE SUBSTANTIAL TROF...WILL MOVE INTO THE WESTERN U.S. MONDAY AND LIFT NORTHEAST INTO THE CENTRAL PLAINS TUESDAY WHERE IT CLOSES OFF AND OCCLUDES. MOST OF THE 00Z MODELS CONTINUE TO AGREE THAT THE OCCLUDED SURFACE LOW WILL TRACK TO OUR WEST AND NORTH THROUGH MN. THE EXCEPTION WAS THE 00Z ECMWF WHICH WAS FURTHER SOUTH...TRACKING THE SURFACE LOW ACROSS NORTHERN IA. DESPITE THE DIFFERENCES IN THE TRACK...THE SYSTEM SHOULD BRING SOME WIDESPREAD PRECIP TO THE REGION TUESDAY AND TUESDAY NIGHT WHEN THE BEST FORCING WILL MOVE THROUGH AND GULF MOISTURE IS PULLED NORTH INTO THE REGION. FOR THE MOST PART THE PRECIP WILL BE IN THE FORM OF RAIN WITH LOW LEVEL TEMPS WARMING CONSIDERABLY DUE TO STRONG WAA AHEAD OF THE SYSTEM. AS THE PRECIP MOVES INTO THE REGION TUESDAY MORNING THERE COULD BE SOME FREEZING RAIN WEST OF THE MS RIVER...BEFORE THE LOW LEVEL COLD AIR IS SCOURED OUT. A MENTION OF THUNDER WAS MAINTAINED...MAINLY SOUTH...FOR TUESDAY AFTERNOON AND EVENING WITH MODELS SHOWING SOME WEAK ELEVATED CAPE WITH THE SURFACE OCCLUSION. A DRY SLOT NOSES INTO THE MID MISSISSIPPI VALLEY TUESDAY EVENING...WHICH SHOULD SHUT DOWN THE PRECIP BEFORE THE COLD AIR WRAPS INTO THE FORECAST AREA FROM THE SOUTHWEST. WEDNESDAY LOOKS LIKE ANOTHER WINDY DAY IN THE STRONG PRESSURE GRADIENT BEHIND SYSTEM. CURRENT SOLUTIONS SUGGEST SUSTAINED WEST WINDS OF 20 TO 30 MPH. YET ANOTHER TROF IS FORECAST TO MOVE INTO THE PACIFIC NORTHWEST WEDNESDAY NIGHT AND MOVE INTO THE CENTRAL U.S. FRIDAY. THE GFS/ECMWF WERE IN GOOD AGREEMENT LIFTING A SURFACE LOW NORTHEAST AHEAD OF THE UPPER TROF. BOTH MODELS MOVE THE LOW THROUGH OR NEAR EASTERN IOWA...SO THE CHANCE POPS FOR FRIDAY WERE MAINTAINED. BASED ON THE TRACK OF THE SYSTEM THERE SHOULD BE A MIX OF PRECIP WITH THIS SYSTEM. ..DLF.. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
538 AM CST SAT FEB 25 2012 .UPDATE... SATELLITE AND RADAR TRENDS SHOW FLURRIES CONTINUE BACK INTO CENTRAL IOWA WITH A SOUTHEAST MOVEMENT. RUC TRENDS USING PRESSURE ADVECTION ON THE 1.5PV SFC AND 500MB VORT MAX SHOW AN AREA OF LIFT WHERE THE FLURRIES ARE CURRENTLY DEPICTED IN OBS/RADAR. THE RUC DECREASES THE LIFT THROUGH THE MORNING AS THE VORT MAX MOVES EAST ACROSS THE CWFA. THUS ISOLATED FLURRIES WILL BE SEEN THROUGH MID MORNING OVER ROUGHLY THE WESTERN HALF WHILE FLURRIES CONTINUE OVER THE EASTERN THIRD. STRONG SUBSIDENCE BEHIND THE VORT MAX WILL ALLOW RAPID CLEARING OF CLOUDS FROM WEST TO EAST DURING THE MORNING HOURS WITH A MAJORITY OF THE CWFA BECOMING MOSTLY SUNNY BY MID DAY. DIURNAL CU/SC MAY STILL FIRE AS THE COLD POCKET ALOFT MOVES INTO THE AREA. AND UPDATE TO THE FCST WILL BE AVAILABLE SHORTLY. ..08.. && .AVIATION... MVFR TO VFR CONDITIONS WITH FLURRIES WILL IMPROVE TO VFR BY 18Z/25. HIGH PRESSURE WILL MOVE ACRS THE AREA ALLOWING WINDS TO DROP AND BECOMING SOUTHERLY BY 00Z/26. VFR CONDITIONS WILL CONTINUE AFT 00Z/26 WITH HIGH LEVEL CLOUDS MOVING INTO THE AREA AS SOUTHERLY RETURN FLOW STRENGTHENS. ..08.. && .PREV DISCUSSION... /ISSUED 308 AM CST SAT FEB 25 2012/ SYNOPSIS... 06Z SFC ANALYSIS HAS A HIGH PRESSURE RIDGE OVER THE PLAINS. SEVERAL WEAK TROFS RAN FROM THE OHIO VALLEY BACK INTO THE UPPER MIDWEST. DEW POINTS WERE IN THE 20S AND 30S ACROSS MUCH OF THE MIDWEST WITH TEENS AND SINGLE DIGITS OVER THE NORTHERN PLAINS. RADAR AND SATELLITE DATA SHOWS SNOW SHOWERS AND FLURRIES ASSOCIATED WITH A DISTURBANCE ALOFT MOVING THROUGH THE REGION. SHORT TERM...TODAY AND TONIGHT... RADAR AND OBS TRENDS THE PAST FEW HOURS INDICATE THAT MOST OF THE AREA WILL BE PRECIPITATION FREE AT SUNRISE. THE EXCEPTION APPEARS TO BE THE NORTHEAST PART OF THE CWFA WHERE SOME FLURRIES MAY BE SEEN WITH THE PASSAGE OF A RESPECTABLE VORT MAX AND SHORTWAVE SHORTLY AFTER SUNRISE. WINDS HAVE INCREASED CONSIDERABLY WITH THE PASSAGE OF A WEAK SFC TROF. LOW LEVEL LAPSE RATES WERE STILL FAIRLY STEEP SO HIGHER MOMENTUM AIR WAS ABLE TO MIX DOWN TO THE SFC. RUC TRENDS SHOW LOW LEVEL LAPSE RATES STABILIZING THROUGH SUNRISE SO WINDS SHOULD DIMINISH. HOWEVER...THE STRONGER WINDS IN NORTHERN AND SOUTH CENTRAL IOWA CANNOT BE EXPLAINED BY LAPSE RATES. A POSSIBLE EXPLANATION IS ONE OF THE TWO PV ANOMALIES THAT ARE ROTATING THROUGH THE REGION. PER THE RUC THESE ANOMALIES SHOULD EXIT THE CWFA THIS MORNING SO THE STRONG WINDS MAY PERSIST PAST SUNRISE FOR PARTS OF THE AREA. SUBSIDENCE BEHIND THE SHORTWAVES ALOFT SHOULD ALLOW CLOUDS TO BREAK UP DURING THE MORNING AND AFTERNOON AND ALLOW MORE SUN TO BE SEEN. A COLD POCKET ALOFT MOVING INTO THE AREA THIS AFTERNOON MAY ALLOW DIURNAL CU/SC TO DEVELOP ACROSS PARTS OF THE AREA. THE SOUTHERN EDGE OF THE SNOW FIELD SHOULD MELT DURING THE DAY BUT THE DEEPER SNOW PACK ACROSS THE NORTHERN CWFA WILL PERSIST. THUS TEMPERATURES SHOULD HOLD JUST BELOW FREEZING ACROSS THE NORTHERN CWFA WHILE BEING AT OR ABOVE FREEZING FROM I-80 ON SOUTH. TONIGHT...THE SFC RIDGE IS RIGHT OVER THE AREA AT SUNSET. THUS TEMPERATURES SHOULD DROP QUICKLY THIS EVENING. AS RETURN FLOW BECOMES ESTABLISHED BY LATE EVENING TEMPERATURES SHOULD LEVEL OFF AND THEN SLOWLY RISE AFTER MIDNIGHT AS CLOUDS SLOWLY INCREASE. .08.. LONG TERM...SUNDAY THROUGH FRIDAY... MODELS CONTINUE TO SHOW AN ACTIVE WEEK AS A SERIES OF UPPER TROFS MOVE THROUGH THE REGION. THE FIRST SYSTEM WILL TRAVERSE THE NORTHERN TIER OF STATES MOVING FROM THE EASTERN DAKOTAS THROUGH NORTHERN MN INTO THE WESTERN GREAT LAKES REGION SUNDAY AND SUNDAY NIGHT. THE MAIN FEATURES FOR THIS SYSTEM WILL BE GUSTY WINDS AHEAD OF AND JUST BEHIND A WEAK COLD FRONT MOVING THROUGH SUNDAY AFTERNOON. SHALLOW MIXING DURING THE DAY SHOULD BE ABLE TO TAP 25-35KT WINDS JUST OFF THE SURFACE RESULTING IN SOUTHWEST TO WEST WINDS GUSTING TO AROUND 30KTS. THE LOW LEVEL THERMAL RIDGE WILL PASS THROUGH THE CWFA DURING DAY...WHICH SHOULD HELP TEMPERATURES CLIMB INTO THE MID 50S SOUTH. MORE CLOUDS AND LINGERING SNOW COVER IN THE NORTH WILL HELP KEEP HIGHS IN THE MID 40S. THE BULK OF THE FORCING WILL REMAIN WELL NORTH OF THE AREA AND THE AIR FEEDING INTO IT WILL BE DRY...SO A DRY FORECAST WAS CONTINUED. ANOTHER...MORE SUBSTANTIAL TROF...WILL MOVE INTO THE WESTERN U.S. MONDAY AND LIFT NORTHEAST INTO THE CENTRAL PLAINS TUESDAY WHERE IT CLOSES OFF AND OCCLUDES. MOST OF THE 00Z MODELS CONTINUE TO AGREE THAT THE OCCLUDED SURFACE LOW WILL TRACK TO OUR WEST AND NORTH THROUGH MN. THE EXCEPTION WAS THE 00Z ECMWF WHICH WAS FURTHER SOUTH...TRACKING THE SURFACE LOW ACROSS NORTHERN IA. DESPITE THE DIFFERENCES IN THE TRACK...THE SYSTEM SHOULD BRING SOME WIDESPREAD PRECIP TO THE REGION TUESDAY AND TUESDAY NIGHT WHEN THE BEST FORCING WILL MOVE THROUGH AND GULF MOISTURE IS PULLED NORTH INTO THE REGION. FOR THE MOST PART THE PRECIP WILL BE IN THE FORM OF RAIN WITH LOW LEVEL TEMPS WARMING CONSIDERABLY DUE TO STRONG WAA AHEAD OF THE SYSTEM. AS THE PRECIP MOVES INTO THE REGION TUESDAY MORNING THERE COULD BE SOME FREEZING RAIN WEST OF THE MS RIVER...BEFORE THE LOW LEVEL COLD AIR IS SCOURED OUT. A MENTION OF THUNDER WAS MAINTAINED...MAINLY SOUTH...FOR TUESDAY AFTERNOON AND EVENING WITH MODELS SHOWING SOME WEAK ELEVATED CAPE WITH THE SURFACE OCCLUSION. A DRY SLOT NOSES INTO THE MID MISSISSIPPI VALLEY TUESDAY EVENING...WHICH SHOULD SHUT DOWN THE PRECIP BEFORE THE COLD AIR WRAPS INTO THE FORECAST AREA FROM THE SOUTHWEST. WEDNESDAY LOOKS LIKE ANOTHER WINDY DAY IN THE STRONG PRESSURE GRADIENT BEHIND SYSTEM. CURRENT SOLUTIONS SUGGEST SUSTAINED WEST WINDS OF 20 TO 30 MPH. YET ANOTHER TROF IS FORECAST TO MOVE INTO THE PACIFIC NORTHWEST WEDNESDAY NIGHT AND MOVE INTO THE CENTRAL U.S. FRIDAY. THE GFS/ECMWF WERE IN GOOD AGREEMENT LIFTING A SURFACE LOW NORTHEAST AHEAD OF THE UPPER TROF. BOTH MODELS MOVE THE LOW THROUGH OR NEAR EASTERN IOWA...SO THE CHANCE POPS FOR FRIDAY WERE MAINTAINED. BASED ON THE TRACK OF THE SYSTEM THERE SHOULD BE A MIX OF PRECIP WITH THIS SYSTEM. ..DLF.. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
308 AM CST SAT FEB 25 2012 .SYNOPSIS... 06Z SFC ANALYSIS HAS A HIGH PRESSURE RIDGE OVER THE PLAINS. SEVERAL WEAK TROFS RAN FROM THE OHIO VALLEY BACK INTO THE UPPER MIDWEST. DEW POINTS WERE IN THE 20S AND 30S ACROSS MUCH OF THE MIDWEST WITH TEENS AND SINGLE DIGITS OVER THE NORTHERN PLAINS. RADAR AND SATELLITE DATA SHOWS SNOW SHOWERS AND FLURRIES ASSOCIATED WITH A DISTURBANCE ALOFT MOVING THROUGH THE REGION. && .SHORT TERM...TODAY AND TONIGHT... RADAR AND OBS TRENDS THE PAST FEW HOURS INDICATE THAT MOST OF THE AREA WILL BE PRECIPITATION FREE AT SUNRISE. THE EXCEPTION APPEARS TO BE THE NORTHEAST PART OF THE CWFA WHERE SOME FLURRIES MAY BE SEEN WITH THE PASSAGE OF A RESPECTABLE VORT MAX AND SHORTWAVE SHORTLY AFTER SUNRISE. WINDS HAVE INCREASED CONSIDERABLY WITH THE PASSAGE OF A WEAK SFC TROF. LOW LEVEL LAPSE RATES WERE STILL FAIRLY STEEP SO HIGHER MOMENTUM AIR WAS ABLE TO MIX DOWN TO THE SFC. RUC TRENDS SHOW LOW LEVEL LAPSE RATES STABILIZING THROUGH SUNRISE SO WINDS SHOULD DIMINISH. HOWEVER...THE STRONGER WINDS IN NORTHERN AND SOUTH CENTRAL IOWA CANNOT BE EXPLAINED BY LAPSE RATES. A POSSIBLE EXPLANATION IS ONE OF THE TWO PV ANOMALIES THAT ARE ROTATING THROUGH THE REGION. PER THE RUC THESE ANOMALIES SHOULD EXIT THE CWFA THIS MORNING SO THE STRONG WINDS MAY PERSIST PAST SUNRISE FOR PARTS OF THE AREA. SUBSIDENCE BEHIND THE SHORTWAVES ALOFT SHOULD ALLOW CLOUDS TO BREAK UP DURING THE MORNING AND AFTERNOON AND ALLOW MORE SUN TO BE SEEN. A COLD POCKET ALOFT MOVING INTO THE AREA THIS AFTERNOON MAY ALLOW DIURNAL CU/SC TO DEVELOP ACROSS PARTS OF THE AREA. THE SOUTHERN EDGE OF THE SNOW FIELD SHOULD MELT DURING THE DAY BUT THE DEEPER SNOW PACK ACROSS THE NORTHERN CWFA WILL PERSIST. THUS TEMPERATURES SHOULD HOLD JUST BELOW FREEZING ACROSS THE NORTHERN CWFA WHILE BEING AT OR ABOVE FREEZING FROM I-80 ON SOUTH. TONIGHT...THE SFC RIDGE IS RIGHT OVER THE AREA AT SUNSET. THUS TEMPERATURES SHOULD DROP QUICKLY THIS EVENING. AS RETURN FLOW BECOMES ESTABLISHED BY LATE EVENING TEMPERATURES SHOULD LEVEL OFF AND THEN SLOWLY RISE AFTER MIDNIGHT AS CLOUDS SLOWLY INCREASE. ..08.. .LONG TERM...SUNDAY THROUGH FRIDAY... MODELS CONTINUE TO SHOW AN ACTIVE WEEK AS A SERIES OF UPPER TROFS MOVE THROUGH THE REGION. THE FIRST SYSTEM WILL TRAVERSE THE NORTHERN TIER OF STATES MOVING FROM THE EASTERN DAKOTAS THROUGH NORTHERN MN INTO THE WESTERN GREAT LAKES REGION SUNDAY AND SUNDAY NIGHT. THE MAIN FEATURES FOR THIS SYSTEM WILL BE GUSTY WINDS AHEAD OF AND JUST BEHIND A WEAK COLD FRONT MOVING THROUGH SUNDAY AFTERNOON. SHALLOW MIXING DURING THE DAY SHOULD BE ABLE TO TAP 25-35KT WINDS JUST OFF THE SURFACE RESULTING IN SOUTHWEST TO WEST WINDS GUSTING TO AROUND 30KTS. THE LOW LEVEL THERMAL RIDGE WILL PASS THROUGH THE CWFA DURING DAY...WHICH SHOULD HELP TEMPERATURES CLIMB INTO THE MID 50S SOUTH. MORE CLOUDS AND LINGERING SNOW COVER IN THE NORTH WILL HELP KEEP HIGHS IN THE MID 40S. THE BULK OF THE FORCING WILL REMAIN WELL NORTH OF THE AREA AND THE AIR FEEDING INTO IT WILL BE DRY...SO A DRY FORECAST WAS CONTINUED. ANOTHER...MORE SUBSTANTIAL TROF...WILL MOVE INTO THE WESTERN U.S. MONDAY AND LIFT NORTHEAST INTO THE CENTRAL PLAINS TUESDAY WHERE IT CLOSES OFF AND OCCLUDES. MOST OF THE 00Z MODELS CONTINUE TO AGREE THAT THE OCCLUDED SURFACE LOW WILL TRACK TO OUR WEST AND NORTH THROUGH MN. THE EXCEPTION WAS THE 00Z ECMWF WHICH WAS FURTHER SOUTH...TRACKING THE SURFACE LOW ACROSS NORTHERN IA. DESPITE THE DIFFERENCES IN THE TRACK...THE SYSTEM SHOULD BRING SOME WIDESPREAD PRECIP TO THE REGION TUESDAY AND TUESDAY NIGHT WHEN THE BEST FORCING WILL MOVE THROUGH AND GULF MOISTURE IS PULLED NORTH INTO THE REGION. FOR THE MOST PART THE PRECIP WILL BE IN THE FORM OF RAIN WITH LOW LEVEL TEMPS WARMING CONSIDERABLY DUE TO STRONG WAA AHEAD OF THE SYSTEM. AS THE PRECIP MOVES INTO THE REGION TUESDAY MORNING THERE COULD BE SOME FREEZING RAIN WEST OF THE MS RIVER...BEFORE THE LOW LEVEL COLD AIR IS SCOURED OUT. A MENTION OF THUNDER WAS MAINTAINED...MAINLY SOUTH...FOR TUESDAY AFTERNOON AND EVENING WITH MODELS SHOWING SOME WEAK ELEVATED CAPE WITH THE SURFACE OCCLUSION. A DRY SLOT NOSES INTO THE MID MISSISSIPPI VALLEY TUESDAY EVENING...WHICH SHOULD SHUT DOWN THE PRECIP BEFORE THE COLD AIR WRAPS INTO THE FORECAST AREA FROM THE SOUTHWEST. WEDNESDAY LOOKS LIKE ANOTHER WINDY DAY IN THE STRONG PRESSURE GRADIENT BEHIND SYSTEM. CURRENT SOLUTIONS SUGGEST SUSTAINED WEST WINDS OF 20 TO 30 MPH. YET ANOTHER TROF IS FORECAST TO MOVE INTO THE PACIFIC NORTHWEST WEDNESDAY NIGHT AND MOVE INTO THE CENTRAL U.S. FRIDAY. THE GFS/ECMWF WERE IN GOOD AGREEMENT LIFTING A SURFACE LOW NORTHEAST AHEAD OF THE UPPER TROF. BOTH MODELS MOVE THE LOW THROUGH OR NEAR EASTERN IOWA...SO THE CHANCE POPS FOR FRIDAY WERE MAINTAINED. BASED ON THE TRACK OF THE SYSTEM THERE SHOULD BE A MIX OF PRECIP WITH THIS SYSTEM. ..DLF.. && .AVIATION... /ISSUED 1129 PM CST FRI FEB 24 2012/ STRONG NORTHWEST FLOW OVER THE AREA BEHIND THE EXITING STORM SYSTEM FROM LAST NIGHT. TERMINALS ARE CURRENTLY AFFECTED BY A FIELD OF MID LEVEL VFR STRATOCUMULUS WITH FLURRIES...GENERALLY BETWEEN 3500 AND 5000 FT...WHICH IS EXPECTED TO REMAIN OVER THE AREA MOST OF THE NIGHT. A WEAK DISTURBANCE IN THE FLOW NOW AFFECTING CENTRAL IOWA SHOULD DROP SOUTHEAST AND MAY BRING SOME MVFR SNOW SHOWERS TO KCID...KMLI AND KBRL...GENERALLY THROUGH 09Z. THIS WAVE PASSES EAST OF THE TERMINALS AND ALLOW CLEARING TO OCCUR 12Z-18Z. NORTHWEST WINDS TO REMAIN IN THE 10 TO 15 KTS RANGE OVERNIGHT...NOT DIMINISHING TO LESS THAN 10KTS UNTIL ABOUT 17Z SATURDAY MORNING. SATURDAY AFTERNOON WINDS TO TURN FROM NORTHWEST TO WEST...AND THEN SOUTHWEST OR EVEN SOUTH BY 00Z...DEPENDING ON LOCATION. LIGHT SOUTH TO SOUTHEAST WINDS TO LINGER 00-06Z/26TH. ..LE.. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
659 PM MST SUN FEB 26 2012 .UPDATE... ISSUED AT 651 PM MST SUN FEB 26 2012 SFC HIGH NOW SETTLING OVER THE AREA AS WINDS HAVE RAPIDLY DECREASED. 00Z SOUNDINGS INDICATE DRY AIR MASS IN PLACE AT DNR AND TO A LESSER EXTENT DDC...WITH LOW LEVEL MIXING RATIOS NOTICEABLY HIGHER AT KLBF. WITH THESE OBSERVATIONS AND EXPECTED WIND FIELD...STILL EXPECT A FAIRLY SHARP NORTHEAST TO SOUTHWEST TD GRADIENT THROUGH THE EVENING...ALTHOUGH THERE WILL BE SOME RECOVERY WITH LOSS OF DEEP MIXING. WHILE THINGS WILL BE SLIGHTLY MORE HUMID...MOISTURE PROFILES DO NOT LOOK DEEP ENOUGH TO PREVENT TEMPS FROM DROPPING SHARPLY GIVEN LIGHT WINDS...DRY AIR AND MINIMAL HIGH CLOUD COVER. HAVE LOWERED TEMPS 4-5 DEGREES AT SEVERAL LOCATIONS...ESPECIALLY NORMAL COLD SPOTS LIKE WESTERN CHEYENNE COUNTY. && .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 236 PM MST SUN FEB 26 2012 LATEST VISIBLE SATELLITE IMAGERY AND RUC UPPER AIR ANALYSIS SHOW AN UPPER LEVEL TROUGH OVER THE NORTHERN CONUS WITH AN UPPER LEVEL JET OVER NORTHWEST KANSAS AND SOUTHERN NEBRASKA. SURFACE OBSERVATIONS REPORT NORTHWEST WINDS GUSTING 35 TO 45 MPH AS THE STRONGER WINDS ABOVE THE SURFACE MIX DOWN. THE STRONG WINDS THAT PLAGUED THE NORTHERN PORTIONS OF THE TRI-STATE AREA WILL COME TO AN END AROUND SUNSET AS TEMPERATURES COOL. DURING THE NIGHT A SURFACE HIGH PRESSURE WILL MOVE EAST THROUGH NEBRASKA...CAUSING THE WINDS TO SWING TO THE NORTH. DURING THE OVERNIGHT HOURS ISENTROPIC ANALYSIS AND RELATIVE HUMIDITY PLOTS SHOW SOME LIFT AND SATURATED AIR MOVING INTO THE AREA FROM THE SOUTH...WHICH WILL LEAD INCREASED CLOUD COVER FROM NORTH TO SOUTH. WITH DRIER AIR IN PLACE AND LIGHT WINDS...TEMPERATURES WILL BE COOLER THAN LAST NIGHT...RANGING FROM THE UPPER TEENS IN SOUTHWEST NEBRASKA TO THE LOWER 20S IN WEST CENTRAL KANSAS. MONDAY THROUGH MONDAY NIGHT...UPPER LOW WILL BE OVER PACIFIC COAST EARLY MONDAY MORNING...AND WILL STILL BE OVER GREAT BASIN EARLY MONDAY EVENING. OVERALL TREND WITH GUIDANCE HAS BEEN TO SLOW DOWN THIS FEATURE. WHILE THERE IS DECENT H7-H5 MOISTURE IN PLACE BY 18Z MONDAY...WITH LIMITED LIFT AND DRY LAYER BELOW H7...I DECIDED AGAINST MENTION OF SPRINKLES MONDAY AFTERNOON. I ADJUSTED TIMING TO KEEP FORECAST DRY THROUGH 03Z...AND TO LIMIT BEST CHANCES IN THE FAR EASTERN PART OF THE CWA...TRIMMING POPS IN THE WEST. WAA OVERNIGHT MONDAY WILL RESULT IN TEMPS INCREASING AFTER MIDNIGHT...WITH LOWS LIKELY LATE MONDAY EVENING. AS A RESULT PRECIP SHOULD MAINLY FALL AS RAIN...THOUGH A BRIEF RAIN/SNOW MIX COULDNT BE RULED OUT IN EASTERN COLORADO. WHILE WINDY CONDITIONS ARE EXPECTED MONDAY...LIMITED MIXING DUE TO CLOUD COVER SHOULD KEEP CONDITIONS BELOW ADVISORY LEVELS. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 236 PM MST SUN FEB 26 2012 TUESDAY...THE UPPER LOW WILL DEEPEN AS IT MOVES OUT OF THE INTER-MOUNTAIN WEST TOWARDS THE NEBRASKA PANHANDLE BY MIDDAY TUESDAY. GUIDANCE HAS COME IN GOOD AGREEMENT WITH A NORTHERN TRACK...SPEEDING UP THE EASTWARD THE UPPER LOW. THIS RESULTS IN A DRY SLOT QUICKLY PROGRESSING NORTH OVER THE CWA BY 18Z. I ADJUSTED POPS ACCORDINGLY WITH HIGHEST POPS TUESDAY MORNING...AND THEN DECREASING IN COVERAGE TUESDAY AFTERNOON. I LEFT ISOLATED THUNDERSTORMS IN FORECAST WITH GUIDANCE STILL SHOWING INSTABILITY AXIS ACROSS EASTERN HALF OF CWA. STRONG WINDS ALOFT WILL ALSO LEAD TO STRONG WINDS TUESDAY AS THE SYSTEM MOVES THROUGH THE REGION...WHICH COULD RESULT IN WARNING CRITERIA WINDS (GUSTS 60MPH OR GREATER). WEDNESDAY THROUGH SUNDAY...SHORTWAVE RIDGE WILL BUILD IN THE REGION WEDNESDAY AND THURSDAY...WITH DRY CONDITIONS AND MILD TEMPS CONTINUING. A SHORTWAVE TROUGH IS STILL EXPECTED TO PASS OVER THE REGION THURSDAY NIGHT. MEASURABLE PRECIP CANT BE RULED OUT...SO SLIGHT CHANCE POPS WERE LEFT IN PLACE. THE REMAINDER OF THE FORECAST PERIOD IS EXPECTED TO REMAIN DRY. SEASONAL HIGH TEMPERATURES (MID/UPPER 40S) WILL RETURN FRIDAY AND SATURDAY...WITH NW FLOW OVER THE CENTRAL HIGH PLAINS. RIDGE WILL BEGIN TO DEEPEN SUNDAY ACROSS THE WESTERN US...WITH MILD TEMPERATURES RETURNING TO THE CWA. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 406 PM MST SUN FEB 26 2012 VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. WINDS WILL SUBSIDE EARLY IN THE PERIOD AS DAYTIME MIXING ENDS...AND WINDS WILL BE LESS THAN 10 KNOTS FOR MOST OF THE NIGHT. THESE LIGHT WINDS SHOULD REMAIN FROM THE NORTHWEST DURING THE EVENING...BUT THEY WILL BECOME MORE VARIABLE DURING THE EARLY MORNING HOURS BEFORE BECOMING SOUTHEASTERLY. THESE SOUTHEASTERLY WINDS WILL INCREASE AND BEGIN GUSTING AGAIN AS MIXING INCREASES AFTER SUNRISE...AND WINDS WILL TAKE ON MORE OF A SOUTHERLY COMPONENT BY 18Z. && .GLD WATCHES/WARNINGS/ADVISORIES... CO...NONE. KS...NONE. NE...NONE. && $$ UPDATE...JRM SHORT TERM...JTL/DR LONG TERM....DR AVIATION...CJS
AREA FORECAST DISCUSSION...UPDATED
NWS TOPEKA KS
527 PM CST SUN FEB 26 2012 ...UPDATE TO AVIATION... .DISCUSSION... SHORT RANGE FORECAST - TONIGHT AND MONDAY... CLEAR SKIES AND W-NW DOWNSLOPE WINDS HAVE ALLOWED SURFACE TEMPERATURES TO RISE INTO THE UPPER 50S TO MID 60S ACROSS MOST OF NORTHEAST KANSAS. EXPECT THE WARM AND DRY CONDITIONS TO PERSIST FOR THE REST OF THE AFTERNOON. SURFACE HIGH PRESSURE WILL BUILD INTO THE NORTHERN PLAINS AND NOSE INTO THE FORECAST AREA BRINGING CLEAR SKIES OVERNIGHT WITH CALM WINDS. DO NOT EXPECT MUCH IN THE WAY OF COLD AIR ADVECTION...BUT RADIATIONAL COOLING WILL ALLOW THE BOUNDARY LAYER TO COOL TO BELOW FREEZING. EXPECT SOME COLD AIR ADVECTION TO TRICKLE INTO THE AREA BEHIND THE VERY LIGHT NORTHERLY FLOW FOR MONDAY. MIXING NOT QUITE AS DEEP ON MONDAY AS SUNDAY...SO THAT FACTOR IN COMBINATION WITH THE WEAK COLD AIR ADVECTION WILL KEEP TEMPS ON MONDAY MORE SEASONAL. CLOUDS WILL BE ON THE INCREASE BY MONDAY AFTERNOON/EVENING AS WARM/MOIST AIR GETS ADVECTED NORTHWARD. CONDENSATION AS A RESULT OF THE ISENTROPIC LIFT ASSOCIATED WITH THE WARM AIR ADVECTION WILL LIKELY BEGIN SHORTLY AFTER NOON...WHICH WILL ALSO AID IN KEEPING TEMPERATURES FROM RISING MUCH HIGHER THAN THE LOWER 50S. JL LEIGHTON LONG TERM - MONDAY NIGHT THROUGH SUNDAY... MONDAY NIGHT THROUGH TUESDAY NIGHT... MODEL AGREEMENT IS NOW FAIRLY GOOD IN THE TRACK OF A POTENT NEGATIVELY TILTED UPPER LEVEL TROUGH. THE SURFACE LOW WILL TRACK WELL NORTH OF THE LOCAL FORECAST AREA WITH A SHARP FAST MOVING DRY LINE CROSSING THE AREA BETWEEN 21Z TUESDAY AND 03Z WEDNESDAY. WARM MOIST ADVECTION WILL TAKE PLACE ON MONDAY NIGHT AND TUESDAY MORNING AHEAD OF THE SYSTEM WITH SHOWERS AND A FEW ELEVATED THUNDERSTORMS EXPECTED TO DEVELOP AND MOVE INTO THE AREA MONDAY NIGHT. THIS ACTIVITY SHOULD ALL REMAIN BELOW SEVERE LIMITS WITH SOME LOW END POTENTIAL FOR SMALL HAIL THROUGH NOON ON TUESDAY. WHILE CLOUD COVER WILL BE ABUNDANT THROUGH THE DAY ON TUESDAY... TEMPERATURES WILL WARM NICELY WITH AMPLE WARM ADVECTION. THE CLOUD LAYER WILL ALSO BE RELATIVELY SHALLOW AND LOW BY TUESDAY AFTERNOON...AND A FEW BREAKS WILL BE POSSIBLE AHEAD OF THE DRY LINE BY LATE AFTERNOON. SURFACE DEWPOINTS WILL CLIMB INTO THE MID 50S BY LATE TUESDAY ACROSS MUCH OF THE FORECAST AREA WITH TEMPS IN THE UPPER 50S AND LOW 60S. EXPECT THE DRY LINE TO ENTER THE FORECAST AREA SOMETIME BETWEEN 21Z AND 00Z...AND PUSH EAST INTO MISSOURI ONLY 3 TO 4 HOURS LATER. CONVECTION IS EXPECTED TO DEVELOP IMMEDIATELY ALONG THE DRY LINE BOUNDARY BY LATE AFTERNOON AND CROSS THE FORECAST AREA...BUT SUBSTANTIAL UNCERTAINTY EXISTS REGARDING THE POTENTIAL FOR STRONG TO SEVERE STORMS. CURRENT INDICATIONS ARE THAT 200-500 J/KG OF SURFACE BASED CAPE WILL BE PRESENT IN A NARROW BAND NEAR THE BOUNDARY. THOSE ARE MEAGER VALUES BUT THE MAJORITY OF THIS INSTABILITY WILL BE IN THE LOWEST 15000 FEET OF THE ATMOSPHERE WITH MAX LIFTED INDEX VALUES IN THAT LAYER APPROACHING -5. THIS WOULD SUGGEST THE POTENTIAL FOR SOME STRONGER SHALLOW UPDRAFTS. SHEAR THROUGH THE DEPTH OF THE CONVECTIVE LAYER...ABOUT 0-4 KM...IS 50-60 KTS WHILE 0-1 KM SHEAR IS 30-40 KTS. THESE VALUES ARE MORE THAN SUFFICIENT TO PRODUCE ORGANIZED STORMS WITH SOME POTENTIAL FOR LOW TOPPED SUPERCELL DEVELOPMENT. HOWEVER...THE UNIDIRECTIONAL NATURE OF THE SHEAR MAY SUGGEST MORE OF A QUASI-LINEAR DEVELOPMENT WITH A BIT MORE POTENTIAL FOR DAMAGING WINDS AT THE SURFACE. IT WILL BE DIFFICULT TO GET LARGE HAIL WITH SUCH SHALLOW UPDRAFTS PERHAPS HAVING TROUBLE CLIMBING ABOVE THE -20C LEVEL...BUT AT LEAST SMALL HAIL WOULD REMAIN POSSIBLE. TORNADO POTENTIAL IS NON-ZERO...BUT HIGHLY DEPENDENT UPON DEVELOPMENT OF MORE ROBUST UPDRAFTS...AND STRONG UPDRAFT POTENTIAL IS THE MOST SIGNIFICANT UNCERTAINTY WITH THIS FORECAST. WEDNESDAY THROUGH SUNDAY... WILL DRY OUT QUICKLY BEHIND THIS SYSTEM AND REMAIN DRY WITH A SLIGHT COOL DOWN FOR WEDNESDAY AND A QUICK RECOVERY WITH WARM TEMPS AGAIN ON THURSDAY. A WEAKER STORM SYSTEM WILL THEN CROSS THE PLAINS THURSDAY NIGHT INTO FRIDAY. THIS SYSTEM DOES NOT HAVE A PARTICULARLY STRONG PRECIP SIGNAL BUT APPEARS WORTHY OF AT LEAST A SLIGHT CHANCE OF LIGHT RAIN WITH PERHAPS A MIX TO LIGHT SNOW THURSDAY NIGHT. IT DOES NOT APPEAR TO BE A HIGH IMPACT EVENT AT THIS TIME. EXPECT DRY CONDITIONS AND NEAR NORMAL TEMPERATURES FOR SATURDAY AND SUNDAY. BARJENBRUCH && .AVIATION... VFR CONDITIONS WILL CONTINUE THROUGH THE TERMINAL FCST PERIOD WITH ONLY SCT HIGH CLOUDS EXPECTED. LIGHT NORTHWEST WINDS THIS EVENING WILL BECOME NORTHEAST 6-10KTS BY 09Z AND THEN CONTINUE THE REMAINDER OF THE FORECAST. && .FIRE WEATHER... DEEP MIXING HAS COMMENCED ACROSS ALL OF NORTHEAST KANSAS BRINGING VERY DRY LOW LEVEL AIR TO THE SURFACE. RUC SOUNDINGS INDICATE THAT THE ATMOSPHERE HAS MIXED TO APPROXIMATELY 800 MB OR 5600 FEET. W-NW WINDS AT THE SURFACE CONTAIN QUITE A BIT OF A DOWNSLOPE TRAJECTORY WHICH HAS AIDED IN WARMING AND DRYING THE AIR. AS A RESULT RELATIVE HUMIDITY VALUES HAVE DROPPED INTO THE MID TEENS THIS AFTERNOON...AND WILL LIKELY REMAIN IN THE MIDDLE TEENS THROUGH AT LEAST SUNSET. WINDS THROUGHOUT THE DAY HAVE BEEN RELATIVELY LIGHT AS OBSERVATIONS HAVE INDICATED 10 TO 15 MPH W-NW WINDS. DUE TO THE DEEP MIXING SOME WIND GUSTS OF UP TO 20-25 MPH ARE POSSIBLE...BUT THOSE GUSTS WILL BE RATHER INFREQUENT. RH VALUES WILL START TO RISE ONCE SURFACE TEMPERATURES BEGIN TO COOL RIGHT AROUND SUNSET. JL && .TOP WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR KSZ008>012- 020>024-026-034>040. && $$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
406 PM MST SUN FEB 26 2012 .UPDATE... ISSUED AT 335 PM MST SUN FEB 26 2012 OBSERVATIONS ALONG AND NORTH OF HIGHWAY 24 SHOW THAT THE WIND GUSTS HAVE BEEN BELOW CRITERIA FOR A COUPLE OF HOURS...WITH SPEEDS OF 30 TO 35 MPH COMMON. AM EXPECTING THE WINDS TO CONTINUE TO DECLINE SO WILL GO AHEAD AND CANCEL THE WIND ADVISORY. RED FLAG CONDITIONS ARE STILL BEING REPORTED ACROSS THE TRI-STATE AREA SO WILL LET THE RED FLAG WARNING CONTINUE. && .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 236 PM MST SUN FEB 26 2012 LATEST VISIBLE SATELLITE IMAGERY AND RUC UPPER AIR ANALYSIS SHOW AN UPPER LEVEL TROUGH OVER THE NORTHERN CONUS WITH AN UPPER LEVEL JET OVER NORTHWEST KANSAS AND SOUTHERN NEBRASKA. SURFACE OBSERVATIONS REPORT NORTHWEST WINDS GUSTING 35 TO 45 MPH AS THE STRONGER WINDS ABOVE THE SURFACE MIX DOWN. THE STRONG WINDS THAT PLAGUED THE NORTHERN PORTIONS OF THE TRI-STATE AREA WILL COME TO AN END AROUND SUNSET AS TEMPERATURES COOL. DURING THE NIGHT A SURFACE HIGH PRESSURE WILL MOVE EAST THROUGH NEBRASKA...CAUSING THE WINDS TO SWING TO THE NORTH. DURING THE OVERNIGHT HOURS ISENTROPIC ANALYSIS AND RELATIVE HUMIDITY PLOTS SHOW SOME LIFT AND SATURATED AIR MOVING INTO THE AREA FROM THE SOUTH...WHICH WILL LEAD INCREASED CLOUD COVER FROM NORTH TO SOUTH. WITH DRIER AIR IN PLACE AND LIGHT WINDS...TEMPERATURES WILL BE COOLER THAN LAST NIGHT...RANGING FROM THE UPPER TEENS IN SOUTHWEST NEBRASKA TO THE LOWER 20S IN WEST CENTRAL KANSAS. MONDAY THROUGH MONDAY NIGHT...UPPER LOW WILL BE OVER PACIFIC COAST EARLY MONDAY MORNING...AND WILL STILL BE OVER GREAT BASIN EARLY MONDAY EVENING. OVERALL TREND WITH GUIDANCE HAS BEEN TO SLOW DOWN THIS FEATURE. WHILE THERE IS DECENT H7-H5 MOISTURE IN PLACE BY 18Z MONDAY...WITH LIMITED LIFT AND DRY LAYER BELOW H7...I DECIDED AGAINST MENTION OF SPRINKLES MONDAY AFTERNOON. I ADJUSTED TIMING TO KEEP FORECAST DRY THROUGH 03Z...AND TO LIMIT BEST CHANCES IN THE FAR EASTERN PART OF THE CWA...TRIMMING POPS IN THE WEST. WAA OVERNIGHT MONDAY WILL RESULT IN TEMPS INCREASING AFTER MIDNIGHT...WITH LOWS LIKELY LATE MONDAY EVENING. AS A RESULT PRECIP SHOULD MAINLY FALL AS RAIN...THOUGH A BRIEF RAIN/SNOW MIX COULDNT BE RULED OUT IN EASTERN COLORADO. WHILE WINDY CONDITIONS ARE EXPECTED MONDAY...LIMITED MIXING DUE TO CLOUD COVER SHOULD KEEP CONDITIONS BELOW ADVISORY LEVELS. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 236 PM MST SUN FEB 26 2012 TUESDAY...THE UPPER LOW WILL DEEPEN AS IT MOVES OUT OF THE INTER-MOUNTAIN WEST TOWARDS THE NEBRASKA PANHANDLE BY MIDDAY TUESDAY. GUIDANCE HAS COME IN GOOD AGREEMENT WITH A NORTHERN TRACK...SPEEDING UP THE EASTWARD THE UPPER LOW. THIS RESULTS IN A DRY SLOT QUICKLY PROGRESSING NORTH OVER THE CWA BY 18Z. I ADJUSTED POPS ACCORDINGLY WITH HIGHEST POPS TUESDAY MORNING...AND THEN DECREASING IN COVERAGE TUESDAY AFTERNOON. I LEFT ISOLATED THUNDERSTORMS IN FORECAST WITH GUIDANCE STILL SHOWING INSTABILITY AXIS ACROSS EASTERN HALF OF CWA. STRONG WINDS ALOFT WILL ALSO LEAD TO STRONG WINDS TUESDAY AS THE SYSTEM MOVES THROUGH THE REGION...WHICH COULD RESULT IN WARNING CRITERIA WINDS (GUSTS 60MPH OR GREATER). WEDNESDAY THROUGH SUNDAY...SHORTWAVE RIDGE WILL BUILD IN THE REGION WEDNESDAY AND THURSDAY...WITH DRY CONDITIONS AND MILD TEMPS CONTINUING. A SHORTWAVE TROUGH IS STILL EXPECTED TO PASS OVER THE REGION THURSDAY NIGHT. MEASURABLE PRECIP CANT BE RULED OUT...SO SLIGHT CHANCE POPS WERE LEFT IN PLACE. THE REMAINDER OF THE FORECAST PERIOD IS EXPECTED TO REMAIN DRY. SEASONAL HIGH TEMPERATURES (MID/UPPER 40S) WILL RETURN FRIDAY AND SATURDAY...WITH NW FLOW OVER THE CENTRAL HIGH PLAINS. RIDGE WILL BEGIN TO DEEPEN SUNDAY ACROSS THE WESTERN US...WITH MILD TEMPERATURES RETURNING TO THE CWA. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 406 PM MST SUN FEB 26 2012 VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. WINDS WILL SUBSIDE EARLY IN THE PERIOD AS DAYTIME MIXING ENDS...AND WINDS WILL BE LESS THAN 10 KNOTS FOR MOST OF THE NIGHT. THESE LIGHT WINDS SHOULD REMAIN FROM THE NORTHWEST DURING THE EVENING...BUT THEY WILL BECOME MORE VARIABLE DURING THE EARLY MORNING HOURS BEFORE BECOMING SOUTHEASTERLY. THESE SOUTHEASTERLY WINDS WILL INCREASE AND BEGIN GUSTING AGAIN AS MIXING INCREASES AFTER SUNRISE...AND WINDS WILL TAKE ON MORE OF A SOUTHERLY COMPONENT BY 18Z. && .GLD WATCHES/WARNINGS/ADVISORIES... CO...RED FLAG WARNING UNTIL 6 PM MST THIS EVENING FOR COZ252>254. KS...RED FLAG WARNING UNTIL 6 PM MST /7 PM CST/ THIS EVENING FOR KSZ001>004-013>016-027>029-041-042. NE...RED FLAG WARNING UNTIL 6 PM MST /7 PM CST/ THIS EVENING FOR NEZ079>081. && $$ UPDATE...JTL SHORT TERM...JTL/DR LONG TERM....DR AVIATION...CJS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1248 AM EST SAT FEB 25 2012 .SYNOPSIS... LOW PRESSURE WILL INTENSIFY AS IT TRACKS THROUGH THE GULF OF MAINE LATE TONIGHT. THIS STRONG LOW PRESSURE WILL CONTINUE NORTHEAST THROUGH THE MARITIMES SATURDAY INTO SATURDAY NIGHT. HIGH PRESSURE WILL BUILD IN LATER SUNDAY INTO SUNDAY NIGHT. && .NEAR TERM /THROUGH TODAY/... UPDATE 3: ONLY CHG WAS TO INCLUDE LATEST OBSVD SFC TEMPS FOR 05-06Z TM FRAME. OTHERWISE...STORM IS UNDERWAY WITH INCREASING SN ECHOES SPREADING OVR THE FA ATTM OF THIS UPDATE. NO CHGS TO BE MADE TO THE CURRENT FCST ATTM...AS WE MONITORED RADAR ESTIMATES OF SNFL ACROSS THE FA OVR THE NEXT SEVERAL HRS. UPDATE 2: HRRR MODEL AND THIS EVENINGS RUN OF THE NAM STILL INDICATING SNOW AMOUNTS OF 10 TO 14 INCHES ACROSS MOST OF NORTHERN AND CENTRAL SECTIONS. HAVE ADDED HEAVY SNOW TO THE FORECAST FOR ALL OF CENTRAL AND NORTHERN ZONES WITH SNOW RATES BETWEEN 1 AND 2 INCHES FROM MIDNIGHT TO DAYBREAK SATURDAY. MODELS INDICATING SNOW TO END EARLY SATURDAY MORNING AS LOW MOVES RAPIDLY EAST OF THE REGION. UPDATE 1: HRRR AND OTHER MODEL WINDS INDICATING SOUTHEAST WINDS TO INCREASE ACROSS COASTAL SECTIONS AROUND MIDNIGHT AS LOW LEVEL JET DEVELOPS IN ADVANCE OF LOW MOVING THROUGH THE GULF OF MAINE. WILL MOVE WIND ADVISORY UP TO MIDNIGHT OTHERWISE NO OTHER CHANGES NEEDED AT THIS TIME. ORGNL DISC: AN INTERESTING STORM SETTING UP FOR THE CWA. LOW PRES IS MOVING ACROSS THE EASTERN GREAT LAKES ATTM AND THEN IS FCST TO REDEVELOP ALONG THE NEW ENGLAND COAST AND THEN RAPIDLY MOVE NE ACROSS EASTERN MAINE BY SATURDAY MORNING. TREMENDOUS MID LEVEL FORCING SETTING UP FROM 00-06Z ACROSS THE SOUTHERN AREAS AND THEN THIS FORCING LIFT NE OVERNIGHT INTO NORTHERN AND EASTERN AREAS. 1000-700MB FRONTOGENETICAL FORCING IS THE STRONGEST WE HAVE SEEN THIS SEASON SO FAR AND GIVEN STRONG THERMAL GRADIENT IN THE LLVLS, WE ARE EXPECTING A PERIOD OF HEAVY PRECIP. TEMPERATURES WILL BE WARM ENOUGH INITIALLY ACROSS THE SOUTHERN AREAS SUCH AS BANGOR AND EVEN DOVER-FOXCROFT FOR RAIN BUT AS DYNAMIC COOLING TAKES HOLD, THE PRECIP WILL CHANGE TO SNOW WHICH WILL BE HEAVY AT TIMES LATER THIS EVENING INTO THE OVERNIGHT PERIOD. WE COULD VERY WELL SEE UP TO 2 INCHES/HR WHICH WILL LEAD TO HEFTY SNOWFALL AMOUNTS UP THROUGH 06Z. THE BANGOR REGION SHOULD SEE TEMPERATURES TO REMAIN ABOVE 32F OVERNIGHT AND AS THE FORCING LETS UP OVERNIGHT, SNOWFALL WILL BE MORE OF A LIGHT TO MODERATE NATURE. THIS COMBINED W/THE MILD SFC TEMPERATURES WILL ALLOW FOR SETTLING AND EVEN SOME MELTING. RAIN AND EVEN SLEET WILL MIX IN FOR A TIME IF NOT EVEN GO OVER TO RAIN BEFORE GOING BACK TO SNOW BY SATURDAY MORNING. THEREFORE, STAYED W/A WINTER WEATHER ADVISORY BUT BEEFED UP SNOWFALL TOTALS FOR THE BANGOR AND CALAIS REGIONS TO 5 TO 8 INCHES OVER A 12-18 HR PERIOD. THIS WILL NEED TO MONITORED BY THE EVENING CREW ESPECIALLY IF THE LOW TRACKS FURTHER S OVER THE WATERS ALLOWING FOR COLDER AIR TO SETTLE IN LEADING TO HIGHER SNOWFALL TOTALS. ON THE COAST, THINKING HERE IS THAT ENOUGH WARMER AIR COMING IN FROM THE GULF OF MAINE WATERS WILL ALLOW FOR ANY FROZEN PRECIP TO GO TO RAIN, WHICH COULD BE HEAVY AT TIMES. ATTM, WE KEPT SNOWFALL AMOUNTS DOWN TO NO MORE THAN AN INCH OR 2. WINDS APPEAR TO BE MORE OF A CONCERN AS A LLVL JET OF 55 KTS MOVES ALONG THE COAST FROM ABOUT 09-18Z SATURDAY. WINDS WILL BE SSW WHICH HISTORICALLY TENDS TO STAY ALOFT AS THE WARMER AIR OVERRIDES THE COOLER SFC. A WIND ADVISORY IS UP AS GUSTS OF 50 MPH ARE POSSIBLE. THIS IS SUPPORTED BY THE BUFKIT PROFILES SHOWING A GOOD ALIGNMENT FROM THE SFC UP THROUGH ABOUT 3K FT OF 45-50KT. ACROSS THE NORTHERN AND CENTRAL AREAS, MORE SNOWFALL LOOKS TO BE IN ORDER AS THE COLUMN WILL BE COLD ENOUGH TO SUPPORT ALL SNOW AND W/A GOOD PERIOD OF SNOWFALL RATES OF UP TO 2 INCHES/HR FROM 06-12Z, AMOUNTS OF UP TO 10+ INCHES ARE POSSIBLE BY 12Z SATURDAY ESPECIALLY ACROSS AROOSTOOK COUNTY AND PORTIONS OF PISCATAQUIS AND NORTHERN PENOBSCOT COUNTIES. WINTER STORM WARNINGS REMAIN IN PLACE IN THESE AREAS. THINGS WILL WIND DOWN BY MIDDAY SATURDAY AS THE LOW EXITS INTO NEW BRUNSWICK W/A STEADY LIGHT SNOWFALL MAINLY ACROSS NORTHERN AREAS. WNW WINDS WILL INCREASE BEHIND THE SYSTEM LEADING TO BLOWING AND DRIFTING SNOW. THIS WILL NEED TO BE ADDRESSED BY THE LATER CREWS. A POSSIBLE SURGE IS POSSIBLE COMING UP THE PENOBSCOT OVERNIGHT INTO THE BANGOR REGION W/A SSE WIND OF 25+MPH. ATTM, IT APPEARS THAT THE TIME FRAME IS TOO SHORT OF DURATION AND QPF NOT HIGH ENOUGH TO CAUSE SIGNIFICANT PROBLEMS. THE EVENING AND MIDNIGHT CREW NEED TO KEEP AN EYE ON THIS AS HIGH TIDE IS LATER TONIGHT AT 05-06Z TIME FRAME. && .SHORT TERM /TONIGHT THROUGH MONDAY/... STRONG LOW PRESSURE WILL BE MOVING AWAY TO THE NORTHEAST SATURDAY AFTERNOON. SNOW SHOWERS WILL CONTINUE OVER THE NORTH AND STRONG GUSTY WINDS FOLLOWING THE SYSTEM WILL BUFFET THE REGION WITH GUSTY WINDS. BLOWING AND DRIFTING SNOW WILL AFFECT CENTRAL AND NORTHERN AREAS. COLD ADVECTION SATURDAY NIGHT INTO SUNDAY COMBINED WITH THE TIGHT GRADIENT WILL CAUSE SOME BLOWING AND DRIFTING TO CONTINUE...MAINLY ACROSS ROADWAYS WITH OPEN EXPOSURE TO THE WEST. WINDS WILL THEN SUBSIDE SUNDAY NIGHT AS HIGH PRESSURE BUILDS OVER AND TEMPS DROP BELOW ZERO NORTH AND INTO THE SINGLE DIGITS DOWNEAST. A WEAK SHORTWAVE APPROACHING ON MONDAY WILL THEN BRING CLOUDS AND THE CHANCE FOR SOME SNOW SHOWERS OR PATCHY LIGHT SNOW ACROSS THE AREA. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... AT THE START OF THE LONG TERM BOTH MODELS ARE SHOWING A HIGH PRESSURE RIDGE EXTENDED ACROSS THE REGION...A WEAK LOW OVER SRN QUEBEC. BY TUESDAY MORNING THE LOW WILL MOVE EAST OF THE AREA TO SRN NOVA SCOTIA. HIGHER PRESSURE WILL BUILD BACK INTO THE AREA. BY TUESDAY EVENING THE HIGH PRESSURE RIDGE IS BUILT BACK ACROSS THE REGION. A NEW LOW IS MOVING INTO THE CENTRAL PLAINS. BY WEDNESDAY MORNING THE NEW LOW IS INTO THE WRN GREAT LAKES. WITH AN OCCLUDED SYSTEM WRAPPED AROUND IT. BY WEDNESDAY EVENING THE LOW WILL MOVE INTO THE CENTRAL GREAT LAKES REGION. THE OCCLUDED SYSTEM WILL MOVE INTO NH/ME. BY THURSDAY MORNING THE MODELS ARE SHOWING 2NDRY DEVELOPMENT ALONG THE GULF OF MAINE. THE GFS HAS THE 2NDRY LOW OVER SRN NOVA SCOTIA...A NEW LOW OVER NRN NE...THE ECMWF HAS IT OVER CAPE COD. THE GFS HAS THE PARENT LOW SOUTH OF JAMES BAY. THE ECMWF HAS IT OVER LAKE HURON. BY THURSDAY EVENING THE GFS MOVES THE PARENT LOW THROUGH MAINE INTO ERN NEW BRUNSWICK...THE NEW LOW TO NRN IL...THE ECMWF MOVES THE PARENT LOW TO SRN QUEBEC...MAINTAINS THE LOW S OF NOVA SCOTIA...AND SHOWS A NEW LOW OVER NRN MO. BY FRIDAY MORNING THE GFS SHOWS A WEAK HIGH PRESSURE RIDGE BUILT ACROSS ME...WITH THE NEW LOW MOVING EAST TO LAKE HURON. THE ECMWF MOVES THE PARENT LOW TO ERN NOVA SCOTIA...MOVES THE NEW LOW TO NRN IL/IN. BY FRIDAY EVENING THE GFS MOVES THE NEW LOW TO SRN QUEBEC...THE ECMWF FILLS THE NEW LOW AND MAINTAINS THE HIGH RIDGE ACROSS ME. BOTH MODELS ARE SHOWING DEVELOPMENT ALONG THE GULF OF MEXICO. AND BY THE END OF THE PERIOD. THE GFS MOVE A NEW LOW OFF THE EAST COAST EAST OF DELMARVA DEVELOPS A FRONTAL SYSTEM FROM THIS LOW THROUGH NEW BRUNSWICK WRAPPED INTO THE LOW OVER SRN QUEBEC. THE ECMWF DEVELOPS THE LOW ALONG THE GULF COAST AND MOVES IT NORTH INTO WV...MAINTAINS THE HIGH PRESSURE RIDGE ACROSS ME. SO THE GFS AND ECMWF WERE IN GOOD GENERAL AGREEMENT THROUGH WEDNESDAY. LOADED GMOS...ADJUSTED THE SKY AND POP GRIDS TO BETTER SUPPORT ONE ANOTHER. LOADED NAWAVE 4 FOR SEAS IN THE COASTAL WATERS. PLUS 15 PERCENT FOR WIND GUSTS OVER LAND...20 PERCENT OVER WATER. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... NEAR TERM: VFR DROPPING TO MVFR THIS EVENING AND THEN RIGHT DOWN TO IFR/LIFR THROUGH EARLY SATURDAY. LLWS COULD BE A CONCERN FOR KBHB OVERNIGHT W/WINDS OF 45 KTS JUST ABOVE 800 FT. SHORT TERM: STRONG GUSTY WINDS ARE EXPECTED ACROSS THE AREA THIS WEEKEND. IFR TO MVFR CONDITIONS ARE EXPECTED OVER THE NORTH ON SATURDAY WITH MVFR TO VFR CONDITIONS DOWNEAST. MVFR CONDITIONS ARE EXPECTED OVER THE NORTH SATURDAY NIGHT WITH VFR CONDITIONS DOWNEAST. VFR CONDITIONS ARE EXPECTED SUNDAY INTO MONDAY. && .MARINE... NEAR TERM: UPDATE:HRRR AND OTHER MODEL WINDS INDICATING SOUTHEAST WINDS TO INCREASE ACROSS THE WATERS AROUND MIDNIGHT AS LOW LEVEL JET DEVELOPS IN ADVANCE OF LOW MOVING THROUGH THE GULF OF MAINE. WILL MOVE GALE UP TO MIDNIGHT OTHERWISE NO OTHER CHANGES NEEDED AT THIS TIME. THE GALE WARNING REMAINS UP. WINDS WERE INCREASED TO SUSTAINED 35 KTS W/GUSTS HITTING 45 KTS. A FEW GUSTS TO STORM FORCE(47KT) ARE POSSIBLE EARLY SATURDAY ESPECIALLY ACROSS THE OUTER WATERS BUT THE TIME FRAME LOOKS TO BE SHORT LIVED. WAVE HEIGHTS WERE RAISED IN REGARDS TO THE INCREASING WINDS GOING W/SEAS OF 10 -14 FT BY SATURDAY. SHORT TERM: A GALE WARNING IS EXPECTED FOR STRONG GUSTY WEST WINDS SATURDAY INTO SUNDAY. WINDS WILL DIMINISH SUNDAY NIGHT AS HIGH PRESSURE BUILDS OVER. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...WINTER STORM WARNING UNTIL NOON EST TODAY FOR MEZ001>004. WINTER STORM WARNING UNTIL 10 AM EST THIS MORNING FOR MEZ005- 006-010-011-031-032. WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR MEZ015>017. WIND ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR MEZ029-030. MARINE...GALE WARNING UNTIL 5 PM EST SUNDAY FOR ANZ050>052. && $$ NEAR TERM...VJN SHORT TERM...BLOOMER LONG TERM...NORTON AVIATION...VJN MARINE...VJN/BLOOMER
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1011 AM EST SAT FEB 25 2012 .SYNOPSIS... HIGH PRESSURE BUILDS INTO THE AREA FOR THE WEEKEND. THE HIGH WILL MOVE OFF THE COAST SUNDAY NIGHT. A COLD FRONT WILL MOVE THROUGH THE MID-ATLANTIC MONDAY...FOLLOWED BY HIGH PRESSURE TUESDAY. A STORM SYSTEM MAY IMPACT THE AREA DURING THE MIDDLE OF NEXT WEEK. && .NEAR TERM /THROUGH THIS AFTERNOON/... 15Z SFC ANALYSIS SHOWS A STRONG 969 LOW NEAR THE BAY OF FUNDY. A TIGHT PRESSURE GRADIENT BETWEEN THE LOW AND A 1028 HIGH OVER THE MIDWEST EXISTS OVER THE MID-ATLANTIC REGION TDA. LOOKING AT THE 12Z IAD SOUNDING AND FCST RUC SOUNDINGS...STEEP LAPSE RATES IN THE LOWEST 9 KFT SHOULD STEEPEN FURTHER WITH SFC HEATING...WHICH WILL RESULT IN EFFICIENT MIXING OF HIGHER WIND GUSTS DOWN TO THE SFC. LATEST RUC/NAM MOMENTUM TRANSFER IN BUKFIT SHOWS LLVL WINDS WILL ONLY BE MARGINAL TO SUPPORT WIND ADVISORY CRITERIA OF 45-50 MPH GUSTS. ADVISORY-LVL WIND GUSTS WILL LIKELY BE MORE ISOLATED IN NATURE...BUT CLOSE ENOUGH TO CONTINUE THE ADVISORY. BANDS OF SNOW SHOWERS STREAMING IN FROM THE GREAT LAKES WILL CONTINUE TO IMPACT THE WEST-FACING SLOPES OF THE ALLEGHENY AND POTOMAC HIGHLANDS THRUOUT THE DAY. HAVE ADDED WRN ALLEGANY AND WRN HIGHLAND COUNTY IN THE WINTER WX ADVISORY. WE HAVE ALREADY HAD REPORTS OF 1-2 INCHES OF SNOW IN THESE AREAS...WITH AN ADDITIONAL 2-3 INCHES LIKELY DURING THE DAY TDA. SNOW SHOWER ACTIVIYY WAS ABLE TO BRIEFLY REACH AREAS AS FAR EAST AS DC EARLIER THIS MRNG. WITH THE APPROACH OF A THE UPPER-LEVEL TROUGH AND SUCH STEEP LAPSE RATES SUPPORTING WEAK INSTABILITY...DO NOT SEE A REASON WHY ISO TO SCT RA/SN SHOWER ACTIVITY CANT CONTINUE ACROSS THE AREA. SNOW ACCUMULATION IS NOT EXPECTED DUE TO THE SHORT DURATION OF ANY SHOWER AND ABOVE FREEZING SFC TEMPS. SHOWER ACTIVITY WILL ALSO MAKE CLOUD AND TEMPS FCST TRICKY. WHILE MOST OF THE REGION EAST OF THE HIGHLANDS WILL BE MSTLY SUNNY TDA...SKIES WILL BECOME CLOUDY WITH THE PASSAGE OF A BRIEF SHOWER. ALSO...EVAPORATIVE COOLING WILL CAUSE TEMPS TO DROP SEVERAL DEGREES IN SHOWERS. CURRENT FCST REFLECTS MAX TEMPS RANGING FROM AROUND 30F ALONG THE ALLEGHENY FRONT TO NEAR 50F IN THE NRN PIEDMONT AND LWR SRN MD. && .SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/... SNOW OVER THE POTOMAC HIGHLANDS WILL TAPER OFF THIS EVENING AS HIGH PRESSURE APPROACHES THE APPALACHIANS. WINDS ARE EXPECTED TO DIMINISH THIS EVENING AND OVERNIGHT. GUSTS ARE POSSIBLE WELL INTO THE EVENING IF A LOW LEVEL INVERSION IS SLOW TO DEVELOP. AS LONG AS DECOUPLING TAKES PLACE OVERNIGHT...GOOD RADIATIONAL COOLING CONDITIONS WILL HELP LOWS DROP INTO THE 20S OVER MOST OF THE CWA...EXCEPT OVER URBAN BALTIMORE/WASHINGTON DC WHICH SHOULD MANAGE TO STAY AROUND 30. && .LONG TERM /MONDAY THROUGH FRIDAY/... THE FIRST HALF OF THIS COMING WEEK WILL BE FAIRLY QUIET. A WEAK LOW PRESSURE SYSTEM WILL SWING BY TO THE NORTH IN THE MIDDLE OF THE 3-DAY STRETCH. SUNDAY WILL BE THE FIRST OF THESE DAYS INFLUENCED BY A LARGE SFC HIGH. A COMPACT LOW PRESSURE SYSTEM WILL SLIDE EWD ACROSS THE GREAT LAKES/NEW ENGLAND ON MONDAY...BOUNCING THE HIGH TEMPORARILY AWAY FROM THE AREA BUT STILL KEEPING MID-ATLC WX RELATIVELY WARM AND QUIET. ANOTHER SEASONAL DAY ON TUE. SUNDAY WILL BE RELATIVELY COOL...AS TEMPS STRUGGLE TO REACH THE U40S BY MID AFTN. HIGHS MON-WED WILL PEAK IN THE L60S ACROSS THE SRN HALF OF THE AREA...W/ U50S ACROSS THE NRN HALF. CHANGES WILL ARRIVE BY THE MIDDLE OF THE WEEK HOWEVER...AS A STABLE PATTERN OF WAVE AFTER WAVE OF LOW PRESSURE SYSTEMS MOVE ACROSS THE CONUS. EACH OF THE NEXT COUPLE OF SYSTEMS WILL MOVE DUE EAST ALONG THE JET STREAM WHICH IS ROUGHLY PARKED OVER SRN CANADA. THE MONDAY LOW PRESSURE SYSTEM WILL BE A WEAK CLIPPER PASSING JUST NORTH OF THE AREA...BUT THE SUBSEQUENT SYSTEMS TOWARD THE MIDDLE AND LATTER PARTS OF THE WEEK WILL BE MUCH MORE POTENT. THE NEXT FEATURE WILL BE CUT-OFF UPPER LOW THAT DIGS INTO THE WRN HALF OF THE US...EVENTUALLY MOVING INTO THE PLAINS AND GAINING STRENGTH. TUE INTO WED...THIS INTENSE AND LARGE SCALE SYSTEM WILL TRUDGE ACROSS THE PLAINS AND INTO THE GREAT LAKES/OHIO VLY. BY EARLY WED...PERIODS OF RAIN WILL MOVE ACROSS THE MID-ATLC. CONVECTIVE CHANCES LOOK BEST JUST SOUTH OF THE AREA ATTM...THOUGH TODAY/S ACTIVITY WAS EVIDENCE THAT THE CONVECTIVE REGION COULD CERTAINLY AFFECT A PORTION OF THE CWA /ESPECIALLY THE SRN TIER/ IF THE SYSTEM WERE TO MOVE A BIT FURTHER NORTH THAN THE LATEST GUIDANCE SUGGESTS. THIS ACTIVITY IS EXPECTED TO END BY EARLY THU. A BRIEF BREAK THU/FRI BEFORE ANOTHER UPPER WAVE DIGS DOWN INTO THE PLAINS AND DEVELOPS ANOTHER POTENT AND FAR-REACHING LOW PRESSURE SYSTEM /FROM THE GULF TO THE GREAT LAKES/...MOVING OVER OUR AREA FRI NIGHT INTO THE WEEKEND. && .AVIATION /15Z SATURDAY THROUGH WEDNESDAY/... MAINLY VFR CONDITIONS TDA. HOWEVER...A BRIEF RA/SN SHOWER COULD IMPACT THE TERMINALS LATE THIS MRNG AND ERY AFTN. COVERAGE WILL BE TOO LOW TO INCLUDE IN 15Z TAFS. MAIN IMPACT TDA WILL BE GUSTY WLY WINDS SUSTAINED BETWEEN 15-25 KT...GUSTING 35-40 KT THRU THE AFTN. WINDS DIMINISH GRADUALLY TONIGHT...BUT GUSTS 20-30 KT MAY CONTINUE THROUGH THE EVENING HOURS. HIGH PRESSURE WILL LARGELY HOLD FAIR CONDITIONS OVER THE REGION SUN-TUE NIGHT. A COLD FRONT W/ PERIODS OF RAIN WILL MOVE THRU THE AREA ON WED...MOVING OFF THE COAST WED NIGHT. ANOTHER QUIET COUPLE OF DAYS...THEN ANOTHER COLD FRONT FOR THE WEEKEND. && .MARINE... GALE WARNING IN EFFECT AGAIN TODAY AS GUSTY W WINDS WILL PERSIST OVER THE WATERS. WINDS WILL DIMINISH THIS EVENING...BUT A SCA WILL BE NEEDED OVERNIGHT. BREEZY NWLY WINDS WILL SUBSIDE BY SUNRISE SUN MRNG...THEN REMAIN FAIRLY LIGHT UNTIL MON AFTN. A DRY COLD FRONT WILL SWING ACROSS THE REGION DURING THE DAY...PICKING UP MARGINAL SCA GUSTS INTO THE EVE HRS. LIGHTER WINDS FOR TUE...THEN PICKING UP OUT OF THE SOUTH ON WED...AHEAD OF A STRONGER COLD FRONT THAT WILL ALSO BRING RAIN TO THE REGION DURING THE MIDDLE PART OF THE WEEK. BY WED NIGHT...THIS FEATURE WILL SLIDE OFF THE MID ATLC COAST...AS HIGH PRESSURE BUILDS IN FOR THE REST OF THE WORK WEEK. && .FIRE WEATHER... DESPITE THE STRONG WNW WINDS OF 20-30 MPH WITH GUSTS NEAR 45 MPH AND MIN RH VALUES BETWEEN 25-35 PERCENT TDA...FUEL MOISTURE WILL BE TOO HIGH WARRANT ANY FIRE WEATHER HEADLINES. && .EQUIPMENT... KLWX WSR-88D RADAR IS STILL IN THE PROCESS OF BEING TESTED W/ DUAL POL TECHNOLOGY. SEE PRODUCT /WBCPNSLWX/ FOR DETAILS...OR REFER TO WWW.WEATHER.GOV/LWX/DUALPOL_UPGRADE.PHP FOR ADDITIONAL INFORMATION. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...WIND ADVISORY UNTIL 6 PM EST THIS EVENING FOR DCZ001. MD...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR MDZ501. WIND ADVISORY UNTIL 6 PM EST THIS EVENING FOR MDZ003>007- 009>011-013-014-018-501-502. VA...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR VAZ503. WIND ADVISORY UNTIL 6 PM EST THIS EVENING FOR VAZ025>031- 036>040-042-053-054-501-503-504. WV...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR WVZ501- 503-505. WIND ADVISORY UNTIL 6 PM EST THIS EVENING FOR WVZ050>053-055- 501>506. MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST SUNDAY FOR ANZ530>534-537-539>543. GALE WARNING UNTIL 6 PM EST THIS EVENING FOR ANZ530>543. SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 2 AM EST SUNDAY FOR ANZ535-536-538. && $$ UPDATE...KLEIN PREV DISC...KS/GMS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
422 AM EST SAT FEB 25 2012 .SYNOPSIS... A COLD NORTHWESTERLY FLOW WILL ALLOW FOR SCATTERED SNOW SHOWERS WITH GUSTY WINDS TO CONTINUE ACROSS THE AREA TODAY. HIGH PRESSURE WILL BRING AN END TO SNOW SHOWERS TONIGHT AND ALLOW FOR DRY WEATHER THROUGH TUESDAY. && .NEAR TERM /THROUGH TODAY/... THE LATEST RUC MID-LEVEL ANALYSIS INDICATES CYCLONIC FLOW ACROSS THE EASTERN GREAT LAKES AND UPPER OHIO VALLEY. A WEST- NORTHWESTERLY 850MB FLOW WITH COLD AIR ADVECTION IS ONGOING. AT THE SURFACE, A 982MB SURFACE LOW ACROSS MAINE WITH A TIGHTENED PRESSURE GRADIENT CONTINUE TO ALLOW FOR WINDS GUSTING AT 25 TO 35 MPH AT TIMES ACROSS THE UPPER OHIO VALLEY. COLD AIR ADVECTION CONTINUE TO FUEL SCATTERED SNOW SHOWERS ALONG WITH SNOW SQUALLS MOVING ACROSS THE AREA. TODAY...THE COLD NORTHWESTERLY FLOW OFF OF AN UNFROZEN LAKE ERIE WILL CONTINUE TO ALLOW FOR SCATTERED SNOW SHOWERS ACROSS THE AREA. ALTHOUGH THERE IS NO HURON CONNECTION IN PLACE, FETCH ACROSS ERIE ALONG WITH INVERSION LEVELS UP TO 9KFT INTO THE EARLY AFTERNOON WILL ALLOW FOR SOME HEAVIER SNOW SHOWERS AND SQUALLS AT TIMES. IN ADDITION, WIND GUSTS UP TO 35 MPH ACROSS THE LOWLANDS AND 45 MPH ACROSS THE HIGHER ELEVATIONS WILL CONTINUE. COVERAGE OF SNOW SHOWERS WILL DECREASE SOUTH OF THE LAKE EFFECT ZONES THIS MORNING AND THUS THE ADVISORY THERE EXPIRES AT 15Z. ADVISORY MAY NEED TO BE EXTENDED FOR CLARION/JEFFERSON COUTIES. ADDITIONAL ACCUMULATION GENERALLY OF 1 TO 2 INCHES WILL BE POSSIBLE IN THE ADVISORY AREAS, ALTHOUGH NOT OUT OF THE QUESTION LOCALIZED AREAS IN THE LAKE EFFECT ZONES AND RIDGES COULD SEE 2 TO 4 ADDITIONAL INCHES. FORECAST TEMPS ARE CLOSER TO THE COOLER MET FOR HIGHS, RANGING FROM NEAR 30 ALONG THE I-80 CORRIDOR AND EASTERN RIDGES TO THE MID 30S ELSEWHERE. && .SHORT TERM /TONIGHT THROUGH MONDAY/... THERE IS STRONG OPERATIONAL MODEL AGREEMENT THAT A HIGH PRESSURE RIDGE WILL APPROACH FROM THE WEST TONIGHT AND MOVE ACROSS THE AREA ON SUNDAY. A SURFACE LOW WILL PASS NORTH OF THE AREA ON MONDAY. ALL DEEPER MOISTURE WILL REMAIN NORTH OF THIS SYSTEM AS THE NEXT HIGH APPROACHES FROM THE NORTHWEST. WITH A DEEP LAYER OF DRY AIR MOVING INTO THE AREA AND SUBSIDENCE ALOFT, ABUNDANT SUNSHINE CAN BE EXPECTED SUNDAY AND MONDAY. THIS WILL ALLOW FOR TEMPERATURES TO MODERATE EACH DAY. HIGHS SUNDAY WILL BE NEAR NORMAL SEASONAL VALUES, WARMING TO 10 DEGREES ABOVE NORMAL ON MONDAY. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... HARD TO ARGUE WITH SUCH STRIKING SIMILARITIES BETWEEN THE ECMWF/GFS AND ENSEMBLE MEANS FOR THE LONG TERM PERIOD. MODELS HAVE BEEN RELATIVELY CONSISTENT WITH THE PASSAGE OF AN UPPER LEVEL WAVE AND IT`S ATTENDANT SURFACE LOW NORTH OF THE GREAT LAKES KEEPING THE REGION DRY ON TUESDAY. THEN...A STRONGER SYSTEM DEVELOPS OVER THE PLAINS BRINGING A WARM FRONT/COLD FRONT ACROSS THE REGION WEDNESDAY. AT THIS POINT...WE LOOK TO BE IN THE WARMER AIR KEEPING THE PRECIPITATION MAINLY RAIN THROUGH WEDNESDAY NIGHT. WITH ONLY SLIGHT AMPLIFICATION AND TIMING DIFFERENCES IN THE OVERALL PATTERN THROUGH THE LONG TERM PERIOD...MAINTAINED POPS/TEMPS ETC CLOSE TO HPC GUIDANCE THROUGHOUT THE PERIOD. THIS KEPT TEMPERATURES 5-10 DEGREES ABOVE NORMAL. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... TWO PRIMARY AVIATION HAZARDS THROUGH THE TAF PERIOD ARE GUSTY WINDS AND ISOLATED IFR/LIFR CONDITIONS IN HEAVY SNOW BANDS. WIND GUSTS HAVE LIGHTENED SOMEWHAT THROUGH THE EVENING HOURS...BUT MOST SITES CAN STILL EXPECT TO SEE WESTERLY 25 KT GUSTS OVERNIGHT. GUSTS COULD PICK BACK UP TO 30-35 KTS THIS AFTERNOON. MVFR CONDITIONS ARE EXPECTED IN OCCASIONAL SNOW SHOWERS IN ALL LOCATIONS...WITH PREVAILING IFR CONDITIONS EXPECTED AT FKL AND DUJ WITH MORE SNOW EXPECTED AT THOSE SITES. HEAVIER SNOW BANDS TONIGHT HAVE DROPPED VISIBILITIES IN SOME LOCATIONS ALL THE WAY TO ONE- HALF MILE...BUT THESE BANDS WILL NEED TO BE COVERED WITH TEMPO GROUPS AS NEEDED THROUGH MUCH OF THE PERIOD. SNOW SHOULD COME TO AN END THIS EVENING...WITH GUSTS ALSO DIMINISHING AT THAT TIME. OUTLOOK...SATURDAY NIGHT THROUGH WEDNESDAY... INCOMING HIGH PRESSURE RESTORING VFR LATE SATURDAY NIGHT, AND MAINTAINING VFR SUNDAY INTO TUESDAY. RAIN SHOWERS AND RESTRICTIONS POSSIBLE LATE TUESDAY NIGHT AND WEDNESDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR MDZ001. OH...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR OHZ041. PA...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR PAZ013>016-020>023-073. LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR PAZ007>009. WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR PAZ074- 076. WV...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR WVZ023- 041. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
136 AM EST SAT FEB 25 2012 .SYNOPSIS... COLD BLUSTERY WESTERLY WINDS IN THE WAKE OF FRIDAY`S STRONG LOW PRESSURE SYSTEM WILL CAUSE SNOW SHOWERS OVERNIGHT AND SATURDAY. HIGH PRESSURE YIELDS DRY WEATHER AND A SLOW MODERATING TREND FROM SUNDAY INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH TODAY/... A QUICK UPDATE HAS BEEN ISSUED TO ADD COUNTIES ALONG AND NORTH OF THE PITTSBURGH METRO TO A WINTER WEATHER ADVISORY. TWO CORRIDORS OF SNOW SQUALLS CONTINUE TO TRAIN OVER THE SAME AREAS. WITH UP TO 2 INCHES MEASURED IN THESE AREAS, ADDITIONAL SNOWFALL AMOUNTS LED TO SHORT-FUSED WINTER WEATHER ADVISORY THROUGH THE MID-MORNING. THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A 500MB CLOSED LOW ACROSS EASTERN CANADA WITH THE UPPER OHIO VALLEY IN A ZONAL FLOW AT THE BASE OF THE LOW. 850MB STILL INDICATES A WEST-NORTHWESTERLY FLOW WITH COLD AIR ADVECTION ONGOING. AT THE SURFACE, A 988MB SURFACE LOW IS LOCATED ACROSS ONTARIO WITH A TIGHTENED PRESSURE GRADIENT SOUTH OF THIS FEATURE AND ACROSS THE UPPER OHIO VALLEY. WEAK INSTABILITY ALONG WITH COLD AIR ADVECTION HAS ALLOW FOR SCATTERED SNOW SHOWERS ALONG WITH SNOW SQUALLS TO MOVE ACROSS AREAS MOSTLY NORTH OF I-70 CORRIDOR THIS EVENING. THERE HAVE BEEN NUMEROUS REPORTS OF THUNDERSNOW ACROSS THE PITTSBURGH METRO AND IN MERCER COUNTY. OVERNIGHT...LOW-LEVEL FLOW WILL VEER SLIGHTLY, SHIFTING TO MORE NORTHWESTERLY BY DAWN. COLD AIR ADVECTION WILL CONTINUE WITH WEAK INSTABILITY AND WILL ALLOW FOR SCATTERED SNOW SHOWERS AND SQUALLS WITH REDUCED VISIBILITIES AND A QUICK INCH POSSIBLE. GENERALLY 1 TO 3 INCHES POSSIBLE FOR THE LAKE EFFECT ZONES AND EASTERN RIDGES WITH A CORRIDOR ACROSS THE PITTSBURGH METRO EXPECTING 1 TO 3 TOTAL. OVERNIGHT LOWS ARE FAIRLY CLOSE TO LAMP GUIDANCE WITH TEMPS DROPPING INTO THE UPPER 20S TO LOWER 30S ACROSS THE LOWLANDS AND THE MID 20S ACROSS THE EASTERN RIDGES. THIS WILL ALLOW FOR SOME SLICK ROADS TO DEVELOP AS TEMPS DROP BELOW FREEZING. IN ADDITION, WITH TIGHTENED PRESSURE GRADIENT, WIND GUSTS UP TO 35 MPH WILL STILL BE POSSIBLE. THIS MAY LEAD TO BLOWING SNOW ACROSS THE HIGHER ELEVATIONS. SATURDAY...COLD NORTHWEST FLOW OFF OF AN UNFROZEN LAKE ERIE WILL CONTINUE TO ALLOW FOR SCATTERED SNOW SHOWERS ACROSS THE AREA. ACCUMULATIONS WILL MOSTLY BE FOCUSED AGAIN IN THE LAKE EFFECT AND UPSLOPE AREAS WHICH HAVE ADVISORIES OUT FOR SNOW. SNOW SHOWERS WILL BEGIN TO DECREASE IN COVERAGE LATE IN THE DAY. FORECAST TEMPS ARE CLOSER TO THE COOLER MET, RANGING FROM NEAR 30 ALONG THE I-80 CORRIDOR AND EASTERN RIDGES TO THE MID 30S ELSEWHERE. && .SHORT TERM /TONIGHT THROUGH MONDAY/... SURFACE LOW WILL EXIT OFF THE CANADIAN COAST WITH SURFACE RIDGE BUILDING INTO REGION LATER SATURDAY NIGHT AND SUNDAY. SNOW SHOWERS WILL QUICKLY DIMINISH SATURDAY EVENING WITH SKIES CLEARING SUNDAY. TEMPERATURES WILL MODERATE TO NEAR NORMAL SUNDAY AFTERNOON. WEAK AND MOISTURE STARVED FRONT WILL BRING A FEW CLOUDS MONDAY OTHERWISE DRY WITH WARMING TEMPERATURES. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... HARD TO ARGUE WITH SUCH STRIKING SIMILARITIES BETWEEN THE ECMWF/GFS AND ENSEMBLE MEANS FOR THE LONG TERM PERIOD. MODELS HAVE BEEN RELATIVELY CONSISTENT WITH THE PASSAGE OF AN UPPER LEVEL WAVE AND IT`S ATTENDANT SURFACE LOW NORTH OF THE GREAT LAKES KEEPING THE REGION DRY ON TUESDAY. THEN...A STRONGER SYSTEM DEVELOPS OVER THE PLAINS BRINGING A WARM FRONT/COLD FRONT ACROSS THE REGION WEDNESDAY. AT THIS POINT...WE LOOK TO BE IN THE WARMER AIR KEEPING THE PRECIPITATION MAINLY RAIN THROUGH WEDNESDAY NIGHT. WITH ONLY SLIGHT AMPLIFICATION AND TIMING DIFFERENCES IN THE OVERALL PATTERN THROUGH THE LONG TERM PERIOD...MAINTAINED POPS/TEMPS ETC CLOSE TO HPC GUIDANCE THROUGHOUT THE PERIOD. THIS KEPT TEMPERATURES 5-10 DEGREES ABOVE NORMAL. && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... TWO PRIMARY AVIATION HAZARDS THROUGH THE TAF PERIOD ARE GUSTY WINDS AND ISOLATED IFR/LIFR CONDITIONS IN HEAVY SNOW BANDS. WIND GUSTS HAVE LIGHTENED SOMEWHAT THROUGH THE EVENING HOURS...BUT MOST SITES CAN STILL EXPECT TO SEE WESTERLY 25 KT GUSTS OVERNIGHT. GUSTS COULD PICK BACK UP TO 30-35 KTS THIS AFTERNOON. MVFR CONDITIONS ARE EXPECTED IN OCCASIONAL SNOW SHOWERS IN ALL LOCATIONS...WITH PREVAILING IFR CONDITIONS EXPECTED AT FKL AND DUJ WITH MORE SNOW EXPECTED AT THOSE SITES. HEAVIER SNOW BANDS TONIGHT HAVE DROPPED VISIBILITIES IN SOME LOCATIONS ALL THE WAY TO ONE- HALF MILE...BUT THESE BANDS WILL NEED TO BE COVERED WITH TEMPO GROUPS AS NEEDED THROUGH MUCH OF THE PERIOD. SNOW SHOULD COME TO AN END THIS EVENING...WITH GUSTS ALSO DIMINISHING AT THAT TIME. OUTLOOK...SATURDAY NIGHT THROUGH WEDNESDAY... INCOMING HIGH PRESSURE RESTORING VFR LATE SATURDAY NIGHT, AND MAINTAINING VFR SUNDAY INTO TUESDAY. RAIN SHOWERS AND RESTRICTIONS POSSIBLE LATE TUESDAY NIGHT AND WEDNESDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR MDZ001. OH...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR OHZ041. PA...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR PAZ013>016-020>023-073. LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR PAZ007>009. WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR PAZ074- 076. WV...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR WVZ023- 041. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1252 AM EST SAT FEB 25 2012 .SYNOPSIS... COLD BLUSTERY WESTERLY WINDS IN THE WAKE OF FRIDAY`S STRONG LOW PRESSURE SYSTEM WILL CAUSE SNOW SHOWERS OVERNIGHT AND SATURDAY. HIGH PRESSURE YIELDS DRY WEATHER AND A SLOW MODERATING TREND FROM SUNDAY INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH TODAY/... A QUICK UPDATE HAS BEEN ISSUED TO ADD COUNTIES ALONG AND NORTH OF THE PITTSBURGH METRO TO A WINTER WEATHER ADVISORY. TWO CORRIDORS OF SNOW SQUALLS CONTINUE TO TRAIN OVER THE SAME AREAS. WITH UP TO 2 INCHES MEASURED IN THESE AREAS, ADDITIONAL SNOWFALL AMOUNTS LED TO SHORT-FUSED WINTER WEATHER ADVISORY THROUGH THE MID-MORNING. THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A 500MB CLOSED LOW ACROSS EASTERN CANADA WITH THE UPPER OHIO VALLEY IN A ZONAL FLOW AT THE BASE OF THE LOW. 850MB STILL INDICATES A WEST-NORTHWESTERLY FLOW WITH COLD AIR ADVECTION ONGOING. AT THE SURFACE, A 988MB SURFACE LOW IS LOCATED ACROSS ONTARIO WITH A TIGHTENED PRESSURE GRADIENT SOUTH OF THIS FEATURE AND ACROSS THE UPPER OHIO VALLEY. WEAK INSTABILITY ALONG WITH COLD AIR ADVECTION HAS ALLOW FOR SCATTERED SNOW SHOWERS ALONG WITH SNOW SQUALLS TO MOVE ACROSS AREAS MOSTLY NORTH OF I-70 CORRIDOR THIS EVENING. THERE HAVE BEEN NUMEROUS REPORTS OF THUNDERSNOW ACROSS THE PITTSBURGH METRO AND IN MERCER COUNTY. OVERNIGHT...LOW-LEVEL FLOW WILL VEER SLIGHTLY, SHIFTING TO MORE NORTHWESTERLY BY DAWN. COLD AIR ADVECTION WILL CONTINUE WITH WEAK INSTABILITY ALLOW FOR SCATTERED SNOW SHOWERS AND SQUALLS WITH REDUCED VISIBILITIES AND A QUICK INCH POSSIBLE. GENERALLY 1 TO 3 INCHES POSSIBLE FOR THE LAKE EFFECT ZONES AND EASTERN RIDGES WITH A CORRIDOR ACROSS THE PITTSBURGH METRO EXPECTING 1 TO 3 TOTAL. OVERNIGHT LOWS ARE FAIRLY CLOSE TO LAMP GUIDANCE WITH TEMPS DROPPING INTO THE UPPER 20S TO LOWER 30S ACROSS THE LOWLANDS AND THE MID 20S ACROSS THE EASTERN RIDGES. THIS WILL ALLOW FOR SOME SLICK ROADS TO DEVELOP AS TEMPS DROP BELOW FREEZING. IN ADDITION, WITH TIGHTENED PRESSURE GRADIENT, WIND GUSTS UP TO 35 MPH WILL STILL BE POSSIBLE. THIS MAY LEAD TO BLOWING SNOW ACROSS THE HIGHER ELEVATIONS. SATURDAY...COLD NORTHWEST FLOW OFF OF AN UNFROZEN LAKE ERIE WILL CONTINUE TO ALLOW FOR SCATTERED SNOW SHOWERS ACROSS THE AREA. ACCUMULATIONS WILL MOSTLY BE FOCUSED AGAIN IN THE LAKE EFFECT AND UPSLOPE AREAS WHICH HAVE ADVISORIES OUT FOR SNOW. SNOW SHOWERS WILL BEGIN TO DECREASE IN COVERAGE LATE IN THE DAY. FORECAST TEMPS ARE CLOSER TO THE COOLER MET, RANGING FROM NEAR 30 ALONG THE I-80 CORRIDOR AND EASTERN RIDGES TO THE MID 30S ELSEWHERE. && .SHORT TERM /TONIGHT THROUGH MONDAY/... SURFACE LOW WILL EXIT OFF THE CANADIAN COAST WITH SURFACE RIDGE BUILDING INTO REGION LATER SATURDAY NIGHT AND SUNDAY. SNOW SHOWERS WILL QUICKLY DIMINISH SATURDAY EVENING WITH SKIES CLEARING SUNDAY. TEMPERATURES WILL MODERATE TO NEAR NORMAL SUNDAY AFTERNOON. WEAK AND MOISTURE STARVED FRONT WILL BRING A FEW CLOUDS MONDAY OTHERWISE DRY WITH WARMING TEMPERATURES. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... HARD TO ARGUE WITH SUCH STRIKING SIMILARITIES BETWEEN THE ECMWF/GFS AND ENSEMBLE MEANS FOR THE LONG TERM PERIOD. MODELS HAVE BEEN RELATIVELY CONSISTENT WITH THE PASSAGE OF AN UPPER LEVEL WAVE AN IT`S ATTENDANT SURFACE LOW NORTH OF THE GREAT LAKES KEEPING THE REGION DRY ON TUESDAY. THEN...A STRONGER SYSTEM DEVELOPS OVER THE PLAINS BRINGING A WARM FRONT/COLD FRONT ACROSS THE REGION WEDNESDAY. AT THIS POINT...WE LOOK TO BE IN THE WARMER AIR KEEPING THE PRECIPITATION MAINLY RAIN THROUGH WEDNESDAY NIGHT. WITH ONLY SLIGHT AMPLIFICATION AND TIMING DIFFERENCES IN THE OVERALL PATTERN THROUGH THE LONG TERM PERIOD...MAINTAINED POPS/TEMPS ETC CLOSE TO HPC GUIDANCE THROUGHOUT THE PERIOD. THIS KEPT TEMPERATURES 5-10 DEGREES ABOVE NORMAL && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... WIND CONTINUES TO BE MAIN AVIATION HAZARD TONIGHT. BASED ON RECENT NAM MODEL OUTPUT, WESTERLY WINDS CAN STILL GUST TO 35-40 KTS TIL 02Z, THEN SUBSIDE TO GUSTS OF 30 KTS, THAT CAN CONTINUE INTO SATURDAY AFTERNOON. REGARDING FLIGHT CONDITIONS, POST SYSTEM COOL DOWN COUPLED WITH GREAT LAKES MOISTURE WILL RESULT IN A PROLONGED PERIOD OF STRATOCUMULUS WITH CEILINGS MAINLY IN THE MVFR RANGE. EMBEDDED BANDS OF LAKE EFFECT SNOW SHOWERS MAY YIELD BRIEF IFR EPISODES, BUT ONLY CONFIDENT ENOUGH TO MENTION TEMPO IFR FOR KFKL AND KDUJ DUE TO MORE PREVALENCE OF LAKE EFFECT SNOW SHOWERS. OUTLOOK...SATURDAY NIGHT THROUGH WEDNESDAY... INCOMING HIGH PRESSURE RESTORING VFR LATE SATURDAY NIGHT, AND MAINTAINING VFR SUNDAY INTO TUESDAY. RAIN SHOWERS AND RESTRICTIONS POSSIBLE LATE TUESDAY NIGHT AND WEDNESDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR MDZ001. OH...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR OHZ041. PA...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR PAZ013>016-020>023-073. LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR PAZ007>009. WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR PAZ074- 076. WV...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR WVZ023- 041. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1149 PM EST FRI FEB 24 2012 .SYNOPSIS... COLD BLUSTERY WESTERLY WINDS IN THE WAKE OF FRIDAY`S STRONG LOW PRESSURE SYSTEM WILL CAUSE SNOW SHOWERS OVERNIGHT AND SATURDAY. HIGH PRESSURE YIELDS DRY WEATHER AND A SLOW MODERATING TREND FROM SUNDAY INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH SATURDAY/... AN ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED THIS EVENING TO INCREASE SNOW AMOUNTS IN AREAS WHERE SNOW SQUALLS ARE MOVING ACROSS THE AREA. THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A 500MB CLOSED LOW ACROSS EASTERN CANADA WITH THE UPPER OHIO VALLEY IN A ZONAL FLOW AT THE BASE OF THE LOW. 850MB STILL INDICATES A WEST-NORTHWESTERLY FLOW WITH COLD AIR ADVECTION ONGOING. AT THE SURFACE, A 988MB SURFACE LOW IS LOCATED ACROSS ONTARIO WITH A TIGHTENED PRESSURE GRADIENT SOUTH OF THIS FEATURE AND ACROSS THE UPPER OHIO VALLEY. WEAK INSTABILITY ALONG WITH COLD AIR ADVECTION HAS ALLOW FOR SCATTERED SNOW SHOWERS ALONG WITH SNOW SQUALLS TO MOVE ACROSS AREAS MOSTLY NORTH OF I-70 CORRIDOR THIS EVENING. THERE HAVE BEEN NUMEROUS REPORTS OF THUNDERSNOW ACROSS THE PITTSBURGH METRO AND IN MERCER COUNTY. OVERNIGHT...LOW-LEVEL FLOW WILL VEER SLIGHTLY, SHIFTING TO MORE NORTHWESTERLY BY DAWN. COLD AIR ADVECTION WILL CONTINUE WITH WEAK INSTABILITY ALLOW FOR SCATTERED SNOW SHOWERS AND SQUALLS WITH REDUCED VISIBILITIES AND A QUICK INCH POSSIBLE. GENERALLY 1 TO 3 INCHES POSSIBLE FOR THE LAKE EFFECT ZONES AND EASTERN RIDGES WITH A CORRIDOR ACROSS THE PITTSBURGH METRO EXPECTING 1 TO 2 TOTAL. OVERNIGHT LOWS ARE FAIRLY CLOSE TO LAMP GUIDANCE WITH TEMPS DROPPING INTO THE UPPER 20S TO LOWER 30S ACROSS THE LOWLANDS AND THE MID 20S ACROSS THE EASTERN RIDGES. THIS WILL ALLOW FOR SOME SLICK ROADS TO DEVELOP AS TEMPS DROP BELOW FREEZING. IN ADDITION, WITH TIGHTENED PRESSURE GRADIENT, WIND GUSTS UP TO 35 MPH WILL STILL BE POSSIBLE. THIS MAY LEAD TO BLOWING SNOW ACROSS THE HIGHER ELEVATIONS. SATURDAY...COLD NORTHWEST FLOW OFF OF AN UNFROZEN LAKE ERIE WILL CONTINUE TO ALLOW FOR SCATTERED SNOW SHOWERS ACROSS THE AREA. ACCUMULATIONS WILL MOSTLY BE FOCUSED AGAIN IN THE LAKE EFFECT AND UPSLOPE AREAS WHICH HAVE ADVISORIES OUT FOR SNOW. SNOW SHOWERS WILL BEGIN TO DECREASE IN COVERAGE LATE IN THE DAY. FORECAST TEMPS ARE CLOSER TO THE COOLER MET, RANGING FROM NEAR 30 ALONG THE I-80 CORRIDOR AND EASTERN RIDGES TO THE MID 30S ELSEWHERE. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... SURFACE LOW WILL EXIT OFF THE CANADIAN COAST WITH SURFACE RIDGE BUILDING INTO REGION LATER SATURDAY NIGHT AND SUNDAY. SNOW SHOWERS WILL QUICKLY DIMINISH SATURDAY EVENING WITH SKIES CLEARING SUNDAY. TEMPERATURES WILL MODERATE TO NEAR NORMAL SUNDAY AFTERNOON. WEAK AND MOISTURE STARVED FRONT WILL BRING A FEW CLOUDS MONDAY OTHERWISE DRY WITH WARMING TEMPERATURES. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... HARD TO ARGUE WITH SUCH STRIKING SIMILARITIES BETWEEN THE ECMWF/GFS AND ENSEMBLE MEANS FOR THE LONG TERM PERIOD. MODELS HAVE BEEN RELATIVELY CONSISTENT WITH THE PASSAGE OF AN UPPER LEVEL WAVE AN IT`S ATTENDANT SURFACE LOW NORTH OF THE GREAT LAKES KEEPING THE REGION DRY ON TUESDAY. THEN...A STRONGER SYSTEM DEVELOPS OVER THE PLAINS BRINGING A WARM FRONT/COLD FRONT ACROSS THE REGION WEDNESDAY. AT THIS POINT...WE LOOK TO BE IN THE WARMER AIR KEEPING THE PRECIPITATION MAINLY RAIN THROUGH WEDNESDAY NIGHT. WITH ONLY SLIGHT AMPLIFICATION AND TIMING DIFFERENCES IN THE OVERALL PATTERN THROUGH THE LONG TERM PERIOD...MAINTAINED POPS/TEMPS ETC CLOSE TO HPC GUIDANCE THROUGHOUT THE PERIOD. THIS KEPT TEMPERATURES 5-10 DEGREES ABOVE NORMAL && .AVIATION /04Z SATURDAY THROUGH WEDNESDAY/... WIND CONTINUES TO BE MAIN AVIATION HAZARD TONIGHT. BASED ON RECENT NAM MODEL OUTPUT, WESTERLY WINDS CAN STILL GUST TO 35-40 KTS TIL 02Z, THEN SUBSIDE TO GUSTS OF 30 KTS, THAT CAN CONTINUE INTO SATURDAY AFTERNOON. REGARDING FLIGHT CONDITIONS, POST SYSTEM COOL DOWN COUPLED WITH GREAT LAKES MOISTURE WILL RESULT IN A PROLONGED PERIOD OF STRATOCUMULUS WITH CEILINGS MAINLY IN THE MVFR RANGE. EMBEDDED BANDS OF LAKE EFFECT SNOW SHOWERS MAY YIELD BRIEF IFR EPISODES, BUT ONLY CONFIDENT ENOUGH TO MENTION TEMPO IFR FOR KFKL AND KDUJ DUE TO MORE PREVALENCE OF LAKE EFFECT SNOW SHOWERS. OUTLOOK...SATURDAY NIGHT THROUGH WEDNESDAY... INCOMING HIGH PRESSURE RESTORING VFR LATE SATURDAY NIGHT, AND MAINTAINING VFR SUNDAY INTO TUESDAY. RAIN SHOWERS AND RESTRICTIONS POSSIBLE LATE TUESDAY NIGHT AND WEDNESDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...WINTER WEATHER ADVISORY UNTIL 6 PM EST SATURDAY FOR MDZ001. OH...NONE. PA...LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST SATURDAY FOR PAZ007>009. WINTER WEATHER ADVISORY UNTIL 6 PM EST SATURDAY FOR PAZ074-076. WV...WINTER WEATHER ADVISORY UNTIL 6 PM EST SATURDAY FOR WVZ023-041. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
117 PM EST SAT FEB 25 2012 .UPDATE... ISSUED AT 116 PM EST SAT FEB 25 2012 NO MAJOR CHANGES TO THE GOING FORECAST THIS MORNING AND INTO THE AFTN. LES BANDS OVER WRN LK SUPERIOR HAVE BECOME MORE DISORGANIZED LATE THIS MORNING AND INTO EARLY AFTN AS SFC TROUGH HAS WEAKENED AND HIGH PRESSURE RIDGE MOVES IN. THUS...HAVE LET THE LES WARNING END AS EXPECTED AT 18Z. THAT BEING SAID...06-12Z MODEL RUNS HAVE HELD UP MOISTURE AND HIGHER INVERSION HEIGHTS...SO HAVE DELAYED THE ENDING OF THE -SHSN LATER THIS AFTN WHEN WINDS REALLY LIGHTEN UP. ELSEWHERE...LIGHT LES CONTINUES IN NCNTRL UPPER MI. THE STRONGEST BANDS IN WRN ALGER COUNTY ARE FAIRLY LIGHT AND KMQT RADAR ESTIMATING ONLY ABOUT 0.25IN/HR. EXPECT THIS LIGHT LES TO GRADUALLY SHIFT E THROUGH THE AFTN AND EARLY EVENING HOURS...AS LLVL FLOW BACKS MORE TO THE WNW. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 514 AM EST SAT FEB 25 2012 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW AN ACTIVE PATTERN EVOLVING WITH A FAIRLY PROGRESSIVE STORM TRACK ACROSS THE CONUS TO THE S OF A BROAD POLAR VORTEX COVERING FAR NRN CANADA. ONE SHORTWAVE TROF IS HEADING INTO NEW ENGLAND. UPSTREAM...TROF NOW OVER THE PACIFIC NW WILL ALREADY BE IN THE UPPER LAKES BY LATE SUN. FOLLOWING THAT TROF ARE 2 MORE...ONE HEADING TOWARD THE GULF OF ALASKA AND THE SECOND W OF THE ALEUTIANS. MEDIUM RANGE GUIDANCE INDICATES THAT THE ONE APPROACHING THE GULF OF ALASKA COULD PRODUCE A SIGNIFICANT CNTRL CONUS TO GREAT LAKES STORM SYSTEM MIDWEEK. THE FOLLOWING SYSTEM W OF THE ALEUTIANS MAY PRODUCE A SIMILAR SYSTEM LATE WEEK...THOUGH GUIDANCE IS MUCH MORE VARIED AS WOULD BE EXPECTED AT THAT TIME RANGE. SO...AFTER A QUIET WINTER...THERE WILL BE 3 OPPORTUNITIES FOR WIDESPREAD PCPN OVER THE NEXT 7 DAYS OR SO WITH AT LEAST ONE SYSTEM BRINGING THE POTENTIAL FOR SIGNIFICANT PCPN. IN THE SHORT TERM...ONGOING LAKE EFFECT/LAKE ENHANCED SNOW IS THE CONCERN TODAY AND THEN ATTENTION TURNS TO THE TROF NOW OVER THE PACIFIC NW THAT WILL REACH THE AREA SUN. DEEP MOISTURE PER 00Z KINL/CWPL/KGRB SOUNDINGS ALONG WITH 850MB TEMPS AROUND -13C WAS SUPPORTING DECENT LES INTO NCNTRL UPPER MI EARLIER IN THE NIGHT WITH NNW FLOW FAVORING THE AREA FROM AROUND MARQUETTE E TO PICTURED ROCKS. OUT W...THERE HAS BEEN ADDITIONAL SUPPORT FROM SHORTWAVE THAT HAS DROPPED SSE THRU MN. WAVE HAD ENHANCED SFC TROFFING OVER WRN LAKE SUPERIOR PER SFC OBS. THIS LED TO MDT/HVY SNOW FOCUSING OVER WRN GOGEBIC/ONTONAGON COUNTIES. AS SHORTWAVE OVER MN CONTINUES SE AND FLOW BECOMES MUCH MORE PROGRESSIVE TODAY...MIDLEVEL RIDGE WILL SHIFT E TO MN BY EVENING...BRINGING 500MB HEIGHT RISES OF 80-120M ACROSS UPPER MI BTWN 12Z AND 00Z. END RESULT IS A BREAKDOWN OF THE SFC TROF OVER LAKE SUPERIOR DURING THE MORNING WITH FLOW BECOMING ANTICYCLONIC DURING THE AFTN. WITH APPROACHING MIDLEVEL RIDGE/HEIGHT RISES AND RESULTING LARGE SCALE SUBSIDENCE...NAM/GFS ARE VERY AGGRESSIVE IN QUICKLY LOWERING INVERSION TO AROUND 3KFT AND SHARPLY DRYING THE COLUMN. GIVEN RECENT RADAR TRENDS SHOWING RAPIDLY DIMINISHING LES AND SATELLITE IMAGERY SHOWING CLOUDS CLEARING OVER LAKE SUPERIOR...THE MODEL FCST OF DRYING AIR MASS AND LOWERING INVERSION LOOKS RIGHT ON TRACK. SO...FCST FOR TODAY WILL SHOW A STEADY DECREASE IN LES NEAR LAKE SUPERIOR WITH BULK OF ADDITIONAL ACCUMULATIONS FALLING FROM NOW TO MID MORNING. BY LATE AFTN... NOTHING MORE THAN ISOLD -SHSN/FLURRIES WILL LINGER IN THE AREAS FAVORED BY NW FLOW. AS FOR THE HEADLINE OVER THE FAR W...THERE ARE STILL SOME HINTS OF HEAVIER LES INTO PORTIONS OF GOGEBIC/ONTONAGON COUNTIES ON KDLH RADAR AND WEBCAM FROM BERGLAND AREA SHOWED FAIRLY HVY SNOW AN HR OR TWO AGO...SO A FEW MORE INCHES OF SNOW ARE POSSIBLE YET EARLY THIS MORNING BEFORE LES COLLAPSES. ELSEWHERE... THERE WON`T BE MUCH MORE THAN A DUSTING. ANY LINGERING -SHSN/FLURRIES WILL END THIS EVENING AS SFC HIGH PRES RIDGE SHIFTS ACROSS THE AREA. LOOKS LIKE THERE WILL BE A SHORT WINDOW FOR TEMPS TO PLUMMET BEFORE HIGH CLOUDS INCREASE/THICKEN FROM W TO E DURING THE NIGHT. BEST OPPORTUNITY WOULD PROBABLY BE OVER THE CNTRL DUE TO LONGER PERIOD BTWN DEPARTURE OF LAKE STRATOCU AND INCREASE OF HIGH CLOUDS. INHERITED FCST OF MINS BLO OR ON THE LOW SIDE OF AVBL GUIDANCE LOOKS ON TRACK. TEMPS SHOULD BECOME STEADY OR BEGIN TO RISE OVERNIGHT AS HIGH CLOUDS THICKEN UNDER DEVELOPING WAA/ISENTROPIC ASCENT REGIME. ON SUN...FOCUS WILL BE ON SHORTWAVE TROF MOVING FROM THE DAKOTAS EARLY IN THE MORNING TO THE UPPER LAKES SUN EVENING. ALTHOUGH SYSTEM WILL BE WEAKENING AS IT MOVES INTO INCREASINGLY CONFLUENT FLOW... MODELS STILL INDICATE FAIRLY IMPRESSIVE DEEP LAYER FORCING AS SUGGESTED BY QVECTOR CONVERGENCE. ALSO...THERE IS A STRONG PUSH OF ISENTROPIC ASCENT FOR ABOUT 6-9HRS. WITH MIXING RATIOS OF 2-2.5G/KG ON THE 285K SFC (ROUGHLY 720-760MB)...THERE IS THE POTENTIAL FOR MAX SNOW ACCUMULATIONS UPWARDS OF 3-4INCHES. GREATEST ACCUMULATIONS SHOULD BE OVER THE NW WHERE STRONGER ISENTROPIC ASCENT IS BETTER CO-LOCATED WITH LEFT EXIT OF 135KT UPPER JET STREAK. ALL AREAS SHOULD SEE AT LEAST A PERIOD OF SNOW SUN...AND ACCUMULATIONS OF GENERALLY 1-3 INCHES LOOK REASONABLE AT THIS POINT. HOWEVER...OF NOTE IS THE REGIONAL GEM WHICH HAS THE MOST PCPN WITH AMOUNTS GENERALLY 0.25 TO 0.45 INCHES SUN. THIS WOULD RESULT IN SNOW AMOUNTS 1-2 INCHES HIGHER THAN CURRENTLY EXPECTED. WITH 850MB TEMPS AROUND THE THRESHOLD FOR LAKE ENHANCEMENT OVER NRN LAKE MICHIGAN...SRLY FLOW COULD GIVE A BOOST TO SNOW TOTALS OVER THE ERN FCST AREA. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 514 AM EST SAT FEB 25 2012 THE 500MB TROUGH CURRENTLY SET UP ALONG THE WEST COAST WILL RESIDE SOMEWHERE OVER NORTHERN MN BY 00Z MONDAY. WHILE THE 25/00Z GEM AND 24/21Z SREF KEEP IT AS AN OPEN WAVE AT THIS TIME...THE 25/00Z GFS/NAM AND 24/12Z DEEPEN THE SYSTEM A BIT MORE INTO A CLOSED LOW. AS HAS BEEN THE TREND...THE GFS IS ON THE QUICKER WESTERN SIDE...WHILE THE 24/12Z AND 25/00Z ECMWF RUNS WERE ON A SLIGHTLY SLOWER TRACK /6 TO 9 HOURS SLOWER THAN THE GFS/. ALL SOLUTIONS RETURN TO MORE OF AN OPEN WAVE FEATURE AT 500MB AS IT CROSSES SUNDAY NIGHT...WITH THE SFC LOW TRACKING ALONG THE LAKE SUPERIOR/UPPER MI BORDER BEFORE EXITING EAST OF LAKE SUPERIOR MONDAY MORNING. 850MB TEMPS OF -4 TO -10C /WARMEST SE/. WHILE IT MAY BE TOO WARM FOR PURE LAKE EFFECT...LAKE ENHANCEMENT WILL NOT BE OUT OF THE QUESTION. SLIGHTLY COLDER AIR WILL SLIDE IN ON THE BACK SIDE OF THE EXITING SFC LOW...WITH 850MB TEMPS RANGING FROM -10 TO -13C BY 00Z TUESDAY ON NW FLOW. THIS WILL KEEP TEMPS ACROSS THE KEWEENAW PENINSULA IN CHECK...REMAINING STEADY THROUGH THE DAY. HIGH PRESSURE WILL BE OVER THE REGION MONDAY NIGHT WITH TEMPS ABLE TO COOL INTO THE TEENS UNDER LIGHT WIND AND MAINLY DRY WEATHER. THE NEXT SYSTEM OF INTEREST LOOKS TO BE TRACKING A LITTLE TOO FAR TO OUR SE TO PRODUCE ANYTHING BUT SNOW FOR MOST OF THE AREA. A MIX WAS KEPT ONLY ALONG LAKE MI TUESDAY NIGHT...BUT MAY NEED TO BE REMOVED IF THIS MORE SE TREND REMAINS AS COLD ENOUGH AIR WOULD KEEP ONLY SNOW OVER THE REGION. THE MAIN CONCERN IS HEAVY SNOW...WHICH IF THE GFS WOULD BE CORRECT...WOULD RESULT IN WINTER WEATHER HEADLINES ACROSS MOST OF UPPER MICHIGAN. WILL WAIT TO SEE HOW IT PANS OUT...AS THE SE TREND LOOKS TO DOMINATE. THE CONSENSUS IS THE HAVE THE NEARLY STACKED 500MB TO SFC LOW BETWEEN S MN AND IA AT 12Z WEDNESDAY. AS HAS BEEN THE TREND...THE ECMWF IS AGAIN ON THE SLOW SIDE. LOOKING AT THE SFC PATTERN...THE GFS LOOKS TO BE A COMPROMISE BETWEEN THE FARTHER NE CANADIAN AND THE SW ECMWF. WILL NOT JUMP ON ANY PARTICULAR SOLUTION AT THIS POINT...BUT WILL CONTINUE TO HIGHLIGHT THE POTENTIAL FOR HEAVY SNOW AMOUNTS IN THE HWO/EHWO AND ELSEWHERE. STRONG ESE WINDS WILL ALSO NEED TO BE MONITORED FOR MARINE CONCERNS AND BLOWING SNOW WEDNESDAY...BEFORE TURNING MORE NORTHEASTERLY WEDNESDAY NIGHT WITH GUSTY WINDS CONTINUING. 850MB TEMPS OF -6 TO -10C WILL ONCE AGAIN LIMIT STRAIGHT LAKE EFFECT...BUT WITH A GOOD MOISTURE FEED FROM THE GULF WITH THIS SYSTEM DEEP MOISTURE WILL BE AVAILABLE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1245 PM EST SAT FEB 25 2012 EXPECT LES TO DIMINISH AT ALL THREE SITES THROUGH THE AFTERNOON HOURS...WHICH SHOULD EVENTUALLY TRANSITION ALL SITES TO VFR CONDITIONS BY THIS EVENING. ATTENTION THEN TURNS TO LOW CURRENTLY OVER THE NORTHERN ROCKIES THAT WILL APPROACH THE AREA DURING THE DAY ON SUN. THIS WILL BRING INCREASING MID/HIGH CLOUDS TO THE AREA TONIGHT...WITH SNOW DEVELOPING FROM WEST TO EAST DURING THE MORNING HOURS. HAVE BROUGHT CONDITIONS DOWN TO MVFR/IFR AS A STARTING POINT...WITH THE LOWEST VSBYS NEAR THE END OF THE TAF PERIOD. ACTUALLY HEAVIES SNOW LOOKS TO FALL JUST AFTER THE CURRENT TAF PERIOD AND WILL LIKELY NEED VSBYS BELOW ALT LANDING MINS HEADING INTO SUN AFTN. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 514 AM EST SAT FEB 25 2012 ACTIVE WEATHER EXPECTED THRU THE MIDDLE OF NEXT WEEK WITH A PROGRESSIVE REGIME BRINGING A SERIES OF LOW PRES AND HIGH PRES SYSTEMS ACROSS THE GREAT LAKES REGION. HIGH PRES RIDGE ARRIVING TONIGHT WILL BRING DECREASING WINDS TODAY THRU THIS EVENING. ALREADY BY LATE TONIGHT...WINDS WILL BE ON THE INCREASE AGAIN OVER WRN LAKE SUPERIOR IN RESPONSE TO THE NEXT LOW PRES SYSTEM MOVING OUT OVER THE NRN PLAINS. SOUTHEASTERLY WINDS SHOULD INCREASE UP TO 30KT SUN AS THE LOW APPROACHES. WITH TIGHT PRES GRADIENT ON FRONT SIDE OF LOW PRES SYSTEM AND LINGERING OVERWATER INSTABILITY...GALES ARE A POSSIBILITY. LATER FCSTS MAY NEED TO INCLUDE A GALE WATCH. WITH LOW WEAKENING AS IT PASSES...WINDS ON THE BACKSIDE OF THE SYSTEM MON WON`T BE AS STRONG. WINDS WILL CONTINUE TO DIMINISH INTO TUE AS HIGH PRES ARRIVES. WINDS WILL THEN INCREASE AGAIN TO 15-30KT TUE NIGHT/WED AS THE NEXT LOW PRES SYSTEM APPROACHES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... GALE WATCH FROM SUNDAY MORNING THROUGH SUNDAY EVENING FOR LMZ248- 250. && $$ UPDATE...SRF SHORT TERM...ROLFSON LONG TERM...KF AVIATION...SRF MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1246 PM EST SAT FEB 25 2012 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 514 AM EST SAT FEB 25 2012 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW AN ACTIVE PATTERN EVOLVING WITH A FAIRLY PROGRESSIVE STORM TRACK ACROSS THE CONUS TO THE S OF A BROAD POLAR VORTEX COVERING FAR NRN CANADA. ONE SHORTWAVE TROF IS HEADING INTO NEW ENGLAND. UPSTREAM...TROF NOW OVER THE PACIFIC NW WILL ALREADY BE IN THE UPPER LAKES BY LATE SUN. FOLLOWING THAT TROF ARE 2 MORE...ONE HEADING TOWARD THE GULF OF ALASKA AND THE SECOND W OF THE ALEUTIANS. MEDIUM RANGE GUIDANCE INDICATES THAT THE ONE APPROACHING THE GULF OF ALASKA COULD PRODUCE A SIGNIFICANT CNTRL CONUS TO GREAT LAKES STORM SYSTEM MIDWEEK. THE FOLLOWING SYSTEM W OF THE ALEUTIANS MAY PRODUCE A SIMILAR SYSTEM LATE WEEK...THOUGH GUIDANCE IS MUCH MORE VARIED AS WOULD BE EXPECTED AT THAT TIME RANGE. SO...AFTER A QUIET WINTER...THERE WILL BE 3 OPPORTUNITIES FOR WIDESPREAD PCPN OVER THE NEXT 7 DAYS OR SO WITH AT LEAST ONE SYSTEM BRINGING THE POTENTIAL FOR SIGNIFICANT PCPN. IN THE SHORT TERM...ONGOING LAKE EFFECT/LAKE ENHANCED SNOW IS THE CONCERN TODAY AND THEN ATTENTION TURNS TO THE TROF NOW OVER THE PACIFIC NW THAT WILL REACH THE AREA SUN. DEEP MOISTURE PER 00Z KINL/CWPL/KGRB SOUNDINGS ALONG WITH 850MB TEMPS AROUND -13C WAS SUPPORTING DECENT LES INTO NCNTRL UPPER MI EARLIER IN THE NIGHT WITH NNW FLOW FAVORING THE AREA FROM AROUND MARQUETTE E TO PICTURED ROCKS. OUT W...THERE HAS BEEN ADDITIONAL SUPPORT FROM SHORTWAVE THAT HAS DROPPED SSE THRU MN. WAVE HAD ENHANCED SFC TROFFING OVER WRN LAKE SUPERIOR PER SFC OBS. THIS LED TO MDT/HVY SNOW FOCUSING OVER WRN GOGEBIC/ONTONAGON COUNTIES. AS SHORTWAVE OVER MN CONTINUES SE AND FLOW BECOMES MUCH MORE PROGRESSIVE TODAY...MIDLEVEL RIDGE WILL SHIFT E TO MN BY EVENING...BRINGING 500MB HEIGHT RISES OF 80-120M ACROSS UPPER MI BTWN 12Z AND 00Z. END RESULT IS A BREAKDOWN OF THE SFC TROF OVER LAKE SUPERIOR DURING THE MORNING WITH FLOW BECOMING ANTICYCLONIC DURING THE AFTN. WITH APPROACHING MIDLEVEL RIDGE/HEIGHT RISES AND RESULTING LARGE SCALE SUBSIDENCE...NAM/GFS ARE VERY AGGRESSIVE IN QUICKLY LOWERING INVERSION TO AROUND 3KFT AND SHARPLY DRYING THE COLUMN. GIVEN RECENT RADAR TRENDS SHOWING RAPIDLY DIMINISHING LES AND SATELLITE IMAGERY SHOWING CLOUDS CLEARING OVER LAKE SUPERIOR...THE MODEL FCST OF DRYING AIR MASS AND LOWERING INVERSION LOOKS RIGHT ON TRACK. SO...FCST FOR TODAY WILL SHOW A STEADY DECREASE IN LES NEAR LAKE SUPERIOR WITH BULK OF ADDITIONAL ACCUMULATIONS FALLING FROM NOW TO MID MORNING. BY LATE AFTN... NOTHING MORE THAN ISOLD -SHSN/FLURRIES WILL LINGER IN THE AREAS FAVORED BY NW FLOW. AS FOR THE HEADLINE OVER THE FAR W...THERE ARE STILL SOME HINTS OF HEAVIER LES INTO PORTIONS OF GOGEBIC/ONTONAGON COUNTIES ON KDLH RADAR AND WEBCAM FROM BERGLAND AREA SHOWED FAIRLY HVY SNOW AN HR OR TWO AGO...SO A FEW MORE INCHES OF SNOW ARE POSSIBLE YET EARLY THIS MORNING BEFORE LES COLLAPSES. ELSEWHERE... THERE WON`T BE MUCH MORE THAN A DUSTING. ANY LINGERING -SHSN/FLURRIES WILL END THIS EVENING AS SFC HIGH PRES RIDGE SHIFTS ACROSS THE AREA. LOOKS LIKE THERE WILL BE A SHORT WINDOW FOR TEMPS TO PLUMMET BEFORE HIGH CLOUDS INCREASE/THICKEN FROM W TO E DURING THE NIGHT. BEST OPPORTUNITY WOULD PROBABLY BE OVER THE CNTRL DUE TO LONGER PERIOD BTWN DEPARTURE OF LAKE STRATOCU AND INCREASE OF HIGH CLOUDS. INHERITED FCST OF MINS BLO OR ON THE LOW SIDE OF AVBL GUIDANCE LOOKS ON TRACK. TEMPS SHOULD BECOME STEADY OR BEGIN TO RISE OVERNIGHT AS HIGH CLOUDS THICKEN UNDER DEVELOPING WAA/ISENTROPIC ASCENT REGIME. ON SUN...FOCUS WILL BE ON SHORTWAVE TROF MOVING FROM THE DAKOTAS EARLY IN THE MORNING TO THE UPPER LAKES SUN EVENING. ALTHOUGH SYSTEM WILL BE WEAKENING AS IT MOVES INTO INCREASINGLY CONFLUENT FLOW... MODELS STILL INDICATE FAIRLY IMPRESSIVE DEEP LAYER FORCING AS SUGGESTED BY QVECTOR CONVERGENCE. ALSO...THERE IS A STRONG PUSH OF ISENTROPIC ASCENT FOR ABOUT 6-9HRS. WITH MIXING RATIOS OF 2-2.5G/KG ON THE 285K SFC (ROUGHLY 720-760MB)...THERE IS THE POTENTIAL FOR MAX SNOW ACCUMULATIONS UPWARDS OF 3-4INCHES. GREATEST ACCUMULATIONS SHOULD BE OVER THE NW WHERE STRONGER ISENTROPIC ASCENT IS BETTER CO-LOCATED WITH LEFT EXIT OF 135KT UPPER JET STREAK. ALL AREAS SHOULD SEE AT LEAST A PERIOD OF SNOW SUN...AND ACCUMULATIONS OF GENERALLY 1-3 INCHES LOOK REASONABLE AT THIS POINT. HOWEVER...OF NOTE IS THE REGIONAL GEM WHICH HAS THE MOST PCPN WITH AMOUNTS GENERALLY 0.25 TO 0.45 INCHES SUN. THIS WOULD RESULT IN SNOW AMOUNTS 1-2 INCHES HIGHER THAN CURRENTLY EXPECTED. WITH 850MB TEMPS AROUND THE THRESHOLD FOR LAKE ENHANCEMENT OVER NRN LAKE MICHIGAN...SRLY FLOW COULD GIVE A BOOST TO SNOW TOTALS OVER THE ERN FCST AREA. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 514 AM EST SAT FEB 25 2012 THE 500MB TROUGH CURRENTLY SET UP ALONG THE WEST COAST WILL RESIDE SOMEWHERE OVER NORTHERN MN BY 00Z MONDAY. WHILE THE 25/00Z GEM AND 24/21Z SREF KEEP IT AS AN OPEN WAVE AT THIS TIME...THE 25/00Z GFS/NAM AND 24/12Z DEEPEN THE SYSTEM A BIT MORE INTO A CLOSED LOW. AS HAS BEEN THE TREND...THE GFS IS ON THE QUICKER WESTERN SIDE...WHILE THE 24/12Z AND 25/00Z ECMWF RUNS WERE ON A SLIGHTLY SLOWER TRACK /6 TO 9 HOURS SLOWER THAN THE GFS/. ALL SOLUTIONS RETURN TO MORE OF AN OPEN WAVE FEATURE AT 500MB AS IT CROSSES SUNDAY NIGHT...WITH THE SFC LOW TRACKING ALONG THE LAKE SUPERIOR/UPPER MI BORDER BEFORE EXITING EAST OF LAKE SUPERIOR MONDAY MORNING. 850MB TEMPS OF -4 TO -10C /WARMEST SE/. WHILE IT MAY BE TOO WARM FOR PURE LAKE EFFECT...LAKE ENHANCEMENT WILL NOT BE OUT OF THE QUESTION. SLIGHTLY COLDER AIR WILL SLIDE IN ON THE BACK SIDE OF THE EXITING SFC LOW...WITH 850MB TEMPS RANGING FROM -10 TO -13C BY 00Z TUESDAY ON NW FLOW. THIS WILL KEEP TEMPS ACROSS THE KEWEENAW PENINSULA IN CHECK...REMAINING STEADY THROUGH THE DAY. HIGH PRESSURE WILL BE OVER THE REGION MONDAY NIGHT WITH TEMPS ABLE TO COOL INTO THE TEENS UNDER LIGHT WIND AND MAINLY DRY WEATHER. THE NEXT SYSTEM OF INTEREST LOOKS TO BE TRACKING A LITTLE TOO FAR TO OUR SE TO PRODUCE ANYTHING BUT SNOW FOR MOST OF THE AREA. A MIX WAS KEPT ONLY ALONG LAKE MI TUESDAY NIGHT...BUT MAY NEED TO BE REMOVED IF THIS MORE SE TREND REMAINS AS COLD ENOUGH AIR WOULD KEEP ONLY SNOW OVER THE REGION. THE MAIN CONCERN IS HEAVY SNOW...WHICH IF THE GFS WOULD BE CORRECT...WOULD RESULT IN WINTER WEATHER HEADLINES ACROSS MOST OF UPPER MICHIGAN. WILL WAIT TO SEE HOW IT PANS OUT...AS THE SE TREND LOOKS TO DOMINATE. THE CONSENSUS IS THE HAVE THE NEARLY STACKED 500MB TO SFC LOW BETWEEN S MN AND IA AT 12Z WEDNESDAY. AS HAS BEEN THE TREND...THE ECMWF IS AGAIN ON THE SLOW SIDE. LOOKING AT THE SFC PATTERN...THE GFS LOOKS TO BE A COMPROMISE BETWEEN THE FARTHER NE CANADIAN AND THE SW ECMWF. WILL NOT JUMP ON ANY PARTICULAR SOLUTION AT THIS POINT...BUT WILL CONTINUE TO HIGHLIGHT THE POTENTIAL FOR HEAVY SNOW AMOUNTS IN THE HWO/EHWO AND ELSEWHERE. STRONG ESE WINDS WILL ALSO NEED TO BE MONITORED FOR MARINE CONCERNS AND BLOWING SNOW WEDNESDAY...BEFORE TURNING MORE NORTHEASTERLY WEDNESDAY NIGHT WITH GUSTY WINDS CONTINUING. 850MB TEMPS OF -6 TO -10C WILL ONCE AGAIN LIMIT STRAIGHT LAKE EFFECT...BUT WITH A GOOD MOISTURE FEED FROM THE GULF WITH THIS SYSTEM DEEP MOISTURE WILL BE AVAILABLE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1245 PM EST SAT FEB 25 2012 EXPECT LES TO DIMINISH AT ALL THREE SITES THROUGH THE AFTERNOON HOURS...WHICH SHOULD EVENTUALLY TRANSITION ALL SITES TO VFR CONDITIONS BY THIS EVENING. ATTENTION THEN TURNS TO LOW CURRENTLY OVER THE NORTHERN ROCKIES THAT WILL APPROACH THE AREA DURING THE DAY ON SUN. THIS WILL BRING INCREASING MID/HIGH CLOUDS TO THE AREA TONIGHT...WITH SNOW DEVELOPING FROM WEST TO EAST DURING THE MORNING HOURS. HAVE BROUGHT CONDITIONS DOWN TO MVFR/IFR AS A STARTING POINT...WITH THE LOWEST VSBYS NEAR THE END OF THE TAF PERIOD. ACTUALLY HEAVIES SNOW LOOKS TO FALL JUST AFTER THE CURRENT TAF PERIOD AND WILL LIKELY NEED VSBYS BELOW ALT LANDING MINS HEADING INTO SUN AFTN. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 514 AM EST SAT FEB 25 2012 ACTIVE WEATHER EXPECTED THRU THE MIDDLE OF NEXT WEEK WITH A PROGRESSIVE REGIME BRINGING A SERIES OF LOW PRES AND HIGH PRES SYSTEMS ACROSS THE GREAT LAKES REGION. HIGH PRES RIDGE ARRIVING TONIGHT WILL BRING DECREASING WINDS TODAY THRU THIS EVENING. ALREADY BY LATE TONIGHT...WINDS WILL BE ON THE INCREASE AGAIN OVER WRN LAKE SUPERIOR IN RESPONSE TO THE NEXT LOW PRES SYSTEM MOVING OUT OVER THE NRN PLAINS. SOUTHEASTERLY WINDS SHOULD INCREASE UP TO 30KT SUN AS THE LOW APPROACHES. WITH TIGHT PRES GRADIENT ON FRONT SIDE OF LOW PRES SYSTEM AND LINGERING OVERWATER INSTABILITY...GALES ARE A POSSIBILITY. LATER FCSTS MAY NEED TO INCLUDE A GALE WATCH. WITH LOW WEAKENING AS IT PASSES...WINDS ON THE BACKSIDE OF THE SYSTEM MON WON`T BE AS STRONG. WINDS WILL CONTINUE TO DIMINISH INTO TUE AS HIGH PRES ARRIVES. WINDS WILL THEN INCREASE AGAIN TO 15-30KT TUE NIGHT/WED AS THE NEXT LOW PRES SYSTEM APPROACHES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW WARNING UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON FOR MIZ002-009. LAKE SUPERIOR... NONE. LAKE MICHIGAN... GALE WATCH FROM SUNDAY MORNING THROUGH SUNDAY EVENING FOR LMZ248- 250. && $$ SHORT TERM...ROLFSON LONG TERM...KF AVIATION...SRF MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
601 AM EST SAT FEB 25 2012 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 514 AM EST SAT FEB 25 2012 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW AN ACTIVE PATTERN EVOLVING WITH A FAIRLY PROGRESSIVE STORM TRACK ACROSS THE CONUS TO THE S OF A BROAD POLAR VORTEX COVERING FAR NRN CANADA. ONE SHORTWAVE TROF IS HEADING INTO NEW ENGLAND. UPSTREAM...TROF NOW OVER THE PACIFIC NW WILL ALREADY BE IN THE UPPER LAKES BY LATE SUN. FOLLOWING THAT TROF ARE 2 MORE...ONE HEADING TOWARD THE GULF OF ALASKA AND THE SECOND W OF THE ALEUTIANS. MEDIUM RANGE GUIDANCE INDICATES THAT THE ONE APPROACHING THE GULF OF ALASKA COULD PRODUCE A SIGNIFICANT CNTRL CONUS TO GREAT LAKES STORM SYSTEM MIDWEEK. THE FOLLOWING SYSTEM W OF THE ALEUTIANS MAY PRODUCE A SIMILAR SYSTEM LATE WEEK...THOUGH GUIDANCE IS MUCH MORE VARIED AS WOULD BE EXPECTED AT THAT TIME RANGE. SO...AFTER A QUIET WINTER...THERE WILL BE 3 OPPORTUNITIES FOR WIDESPREAD PCPN OVER THE NEXT 7 DAYS OR SO WITH AT LEAST ONE SYSTEM BRINGING THE POTENTIAL FOR SIGNIFICANT PCPN. IN THE SHORT TERM...ONGOING LAKE EFFECT/LAKE ENHANCED SNOW IS THE CONCERN TODAY AND THEN ATTENTION TURNS TO THE TROF NOW OVER THE PACIFIC NW THAT WILL REACH THE AREA SUN. DEEP MOISTURE PER 00Z KINL/CWPL/KGRB SOUNDINGS ALONG WITH 850MB TEMPS AROUND -13C WAS SUPPORTING DECENT LES INTO NCNTRL UPPER MI EARLIER IN THE NIGHT WITH NNW FLOW FAVORING THE AREA FROM AROUND MARQUETTE E TO PICTURED ROCKS. OUT W...THERE HAS BEEN ADDITIONAL SUPPORT FROM SHORTWAVE THAT HAS DROPPED SSE THRU MN. WAVE HAD ENHANCED SFC TROFFING OVER WRN LAKE SUPERIOR PER SFC OBS. THIS LED TO MDT/HVY SNOW FOCUSING OVER WRN GOGEBIC/ONTONAGON COUNTIES. AS SHORTWAVE OVER MN CONTINUES SE AND FLOW BECOMES MUCH MORE PROGRESSIVE TODAY...MIDLEVEL RIDGE WILL SHIFT E TO MN BY EVENING...BRINGING 500MB HEIGHT RISES OF 80-120M ACROSS UPPER MI BTWN 12Z AND 00Z. END RESULT IS A BREAKDOWN OF THE SFC TROF OVER LAKE SUPERIOR DURING THE MORNING WITH FLOW BECOMING ANTICYCLONIC DURING THE AFTN. WITH APPROACHING MIDLEVEL RIDGE/HEIGHT RISES AND RESULTING LARGE SCALE SUBSIDENCE...NAM/GFS ARE VERY AGGRESSIVE IN QUICKLY LOWERING INVERSION TO AROUND 3KFT AND SHARPLY DRYING THE COLUMN. GIVEN RECENT RADAR TRENDS SHOWING RAPIDLY DIMINISHING LES AND SATELLITE IMAGERY SHOWING CLOUDS CLEARING OVER LAKE SUPERIOR...THE MODEL FCST OF DRYING AIR MASS AND LOWERING INVERSION LOOKS RIGHT ON TRACK. SO...FCST FOR TODAY WILL SHOW A STEADY DECREASE IN LES NEAR LAKE SUPERIOR WITH BULK OF ADDITIONAL ACCUMULATIONS FALLING FROM NOW TO MID MORNING. BY LATE AFTN... NOTHING MORE THAN ISOLD -SHSN/FLURRIES WILL LINGER IN THE AREAS FAVORED BY NW FLOW. AS FOR THE HEADLINE OVER THE FAR W...THERE ARE STILL SOME HINTS OF HEAVIER LES INTO PORTIONS OF GOGEBIC/ONTONAGON COUNTIES ON KDLH RADAR AND WEBCAM FROM BERGLAND AREA SHOWED FAIRLY HVY SNOW AN HR OR TWO AGO...SO A FEW MORE INCHES OF SNOW ARE POSSIBLE YET EARLY THIS MORNING BEFORE LES COLLAPSES. ELSEWHERE... THERE WON`T BE MUCH MORE THAN A DUSTING. ANY LINGERING -SHSN/FLURRIES WILL END THIS EVENING AS SFC HIGH PRES RIDGE SHIFTS ACROSS THE AREA. LOOKS LIKE THERE WILL BE A SHORT WINDOW FOR TEMPS TO PLUMMET BEFORE HIGH CLOUDS INCREASE/THICKEN FROM W TO E DURING THE NIGHT. BEST OPPORTUNITY WOULD PROBABLY BE OVER THE CNTRL DUE TO LONGER PERIOD BTWN DEPARTURE OF LAKE STRATOCU AND INCREASE OF HIGH CLOUDS. INHERITED FCST OF MINS BLO OR ON THE LOW SIDE OF AVBL GUIDANCE LOOKS ON TRACK. TEMPS SHOULD BECOME STEADY OR BEGIN TO RISE OVERNIGHT AS HIGH CLOUDS THICKEN UNDER DEVELOPING WAA/ISENTROPIC ASCENT REGIME. ON SUN...FOCUS WILL BE ON SHORTWAVE TROF MOVING FROM THE DAKOTAS EARLY IN THE MORNING TO THE UPPER LAKES SUN EVENING. ALTHOUGH SYSTEM WILL BE WEAKENING AS IT MOVES INTO INCREASINGLY CONFLUENT FLOW... MODELS STILL INDICATE FAIRLY IMPRESSIVE DEEP LAYER FORCING AS SUGGESTED BY QVECTOR CONVERGENCE. ALSO...THERE IS A STRONG PUSH OF ISENTROPIC ASCENT FOR ABOUT 6-9HRS. WITH MIXING RATIOS OF 2-2.5G/KG ON THE 285K SFC (ROUGHLY 720-760MB)...THERE IS THE POTENTIAL FOR MAX SNOW ACCUMULATIONS UPWARDS OF 3-4INCHES. GREATEST ACCUMULATIONS SHOULD BE OVER THE NW WHERE STRONGER ISENTROPIC ASCENT IS BETTER CO-LOCATED WITH LEFT EXIT OF 135KT UPPER JET STREAK. ALL AREAS SHOULD SEE AT LEAST A PERIOD OF SNOW SUN...AND ACCUMULATIONS OF GENERALLY 1-3 INCHES LOOK REASONABLE AT THIS POINT. HOWEVER...OF NOTE IS THE REGIONAL GEM WHICH HAS THE MOST PCPN WITH AMOUNTS GENERALLY 0.25 TO 0.45 INCHES SUN. THIS WOULD RESULT IN SNOW AMOUNTS 1-2 INCHES HIGHER THAN CURRENTLY EXPECTED. WITH 850MB TEMPS AROUND THE THRESHOLD FOR LAKE ENHANCEMENT OVER NRN LAKE MICHIGAN...SRLY FLOW COULD GIVE A BOOST TO SNOW TOTALS OVER THE ERN FCST AREA. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 514 AM EST SAT FEB 25 2012 THE 500MB TROUGH CURRENTLY SET UP ALONG THE WEST COAST WILL RESIDE SOMEWHERE OVER NORTHERN MN BY 00Z MONDAY. WHILE THE 25/00Z GEM AND 24/21Z SREF KEEP IT AS AN OPEN WAVE AT THIS TIME...THE 25/00Z GFS/NAM AND 24/12Z DEEPEN THE SYSTEM A BIT MORE INTO A CLOSED LOW. AS HAS BEEN THE TREND...THE GFS IS ON THE QUICKER WESTERN SIDE...WHILE THE 24/12Z AND 25/00Z ECMWF RUNS WERE ON A SLIGHTLY SLOWER TRACK /6 TO 9 HOURS SLOWER THAN THE GFS/. ALL SOLUTIONS RETURN TO MORE OF AN OPEN WAVE FEATURE AT 500MB AS IT CROSSES SUNDAY NIGHT...WITH THE SFC LOW TRACKING ALONG THE LAKE SUPERIOR/UPPER MI BORDER BEFORE EXITING EAST OF LAKE SUPERIOR MONDAY MORNING. 850MB TEMPS OF -4 TO -10C /WARMEST SE/. WHILE IT MAY BE TOO WARM FOR PURE LAKE EFFECT...LAKE ENHANCEMENT WILL NOT BE OUT OF THE QUESTION. SLIGHTLY COLDER AIR WILL SLIDE IN ON THE BACK SIDE OF THE EXITING SFC LOW...WITH 850MB TEMPS RANGING FROM -10 TO -13C BY 00Z TUESDAY ON NW FLOW. THIS WILL KEEP TEMPS ACROSS THE KEWEENAW PENINSULA IN CHECK...REMAINING STEADY THROUGH THE DAY. HIGH PRESSURE WILL BE OVER THE REGION MONDAY NIGHT WITH TEMPS ABLE TO COOL INTO THE TEENS UNDER LIGHT WIND AND MAINLY DRY WEATHER. THE NEXT SYSTEM OF INTEREST LOOKS TO BE TRACKING A LITTLE TOO FAR TO OUR SE TO PRODUCE ANYTHING BUT SNOW FOR MOST OF THE AREA. A MIX WAS KEPT ONLY ALONG LAKE MI TUESDAY NIGHT...BUT MAY NEED TO BE REMOVED IF THIS MORE SE TREND REMAINS AS COLD ENOUGH AIR WOULD KEEP ONLY SNOW OVER THE REGION. THE MAIN CONCERN IS HEAVY SNOW...WHICH IF THE GFS WOULD BE CORRECT...WOULD RESULT IN WINTER WEATHER HEADLINES ACROSS MOST OF UPPER MICHIGAN. WILL WAIT TO SEE HOW IT PANS OUT...AS THE SE TREND LOOKS TO DOMINATE. THE CONSENSUS IS THE HAVE THE NEARLY STACKED 500MB TO SFC LOW BETWEEN S MN AND IA AT 12Z WEDNESDAY. AS HAS BEEN THE TREND...THE ECMWF IS AGAIN ON THE SLOW SIDE. LOOKING AT THE SFC PATTERN...THE GFS LOOKS TO BE A COMPROMISE BETWEEN THE FARTHER NE CANADIAN AND THE SW ECMWF. WILL NOT JUMP ON ANY PARTICULAR SOLUTION AT THIS POINT...BUT WILL CONTINUE TO HIGHLIGHT THE POTENTIAL FOR HEAVY SNOW AMOUNTS IN THE HWO/EHWO AND ELSEWHERE. STRONG ESE WINDS WILL ALSO NEED TO BE MONITORED FOR MARINE CONCERNS AND BLOWING SNOW WEDNESDAY...BEFORE TURNING MORE NORTHEASTERLY WEDNESDAY NIGHT WITH GUSTY WINDS CONTINUING. 850MB TEMPS OF -6 TO -10C WILL ONCE AGAIN LIMIT STRAIGHT LAKE EFFECT...BUT WITH A GOOD MOISTURE FEED FROM THE GULF WITH THIS SYSTEM DEEP MOISTURE WILL BE AVAILABLE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 559 AM EST SAT FEB 25 2012 APPROACHING MIDLEVEL RIDGE/RISING HEIGHTS/SUBSIDENCE AND DRIER AIR WILL BRING AN END TO -SHSN/FLURRIES OFF LAKE SUPERIOR TODAY. BEFORE THAT HAPPENS...LINGERING...BUT WEAKENING CONVERGENCE ZONE OVER WRN LAKE SUPERIOR INTO FAR WRN UPPER MI MAY STILL YIELD HEAVIER SHSN AND IFR CONDITIONS AT KIWD FOR THE NEXT FEW HRS. OTHERWISE...MVFR CONDITIONS AT KIWD SHOULD TREND TO VFR BY EVENING IF NOT SOONER AS WINDS BACK AND CUTOFF OVERWATER TRAJECTORY. AT KCMX...MVFR CIGS AND MAYBE A FEW FLURRIES WILL PERSIST TODAY. MVFR CIGS SHOULD SCATTER OUT THIS EVENING AS SFC HIGH PRES RIDGE PASSES. AT KSAW...MVFR CIGS SHOULD SCATTER OUT MID TO LATE AFTN WITH FLURRIES ENDING AS WINDS BACK TO A NW DIRECTION. AFTER SFC HIGH PRES RIDGE PASSES TONIGHT... DEVELOPING UPSLOPE SSE FLOW OFF LAKE MICHIGAN MAY BRING A RETURN OF MVFR CIGS LATE. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 514 AM EST SAT FEB 25 2012 ACTIVE WEATHER EXPECTED THRU THE MIDDLE OF NEXT WEEK WITH A PROGRESSIVE REGIME BRINGING A SERIES OF LOW PRES AND HIGH PRES SYSTEMS ACROSS THE GREAT LAKES REGION. HIGH PRES RIDGE ARRIVING TONIGHT WILL BRING DECREASING WINDS TODAY THRU THIS EVENING. ALREADY BY LATE TONIGHT...WINDS WILL BE ON THE INCREASE AGAIN OVER WRN LAKE SUPERIOR IN RESPONSE TO THE NEXT LOW PRES SYSTEM MOVING OUT OVER THE NRN PLAINS. SOUTHEASTERLY WINDS SHOULD INCREASE UP TO 30KT SUN AS THE LOW APPROACHES. WITH TIGHT PRES GRADIENT ON FRONT SIDE OF LOW PRES SYSTEM AND LINGERING OVERWATER INSTABILITY...GALES ARE A POSSIBILITY. LATER FCSTS MAY NEED TO INCLUDE A GALE WATCH. WITH LOW WEAKENING AS IT PASSES...WINDS ON THE BACKSIDE OF THE SYSTEM MON WON`T BE AS STRONG. WINDS WILL CONTINUE TO DIMINISH INTO TUE AS HIGH PRES ARRIVES. WINDS WILL THEN INCREASE AGAIN TO 15-30KT TUE NIGHT/WED AS THE NEXT LOW PRES SYSTEM APPROACHES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW WARNING UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON FOR MIZ002-009. LAKE SUPERIOR...NONE. LAKE MICHIGAN... GALE WATCH FROM SUNDAY MORNING THROUGH SUNDAY EVENING FOR LMZ248- 250. && $$ SHORT TERM...ROLFSON LONG TERM...KF AVIATION...ROLFSON MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
514 AM EST SAT FEB 25 2012 .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 514 AM EST SAT FEB 25 2012 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW AN ACTIVE PATTERN EVOLVING WITH A FAIRLY PROGRESSIVE STORM TRACK ACROSS THE CONUS TO THE S OF A BROAD POLAR VORTEX COVERING FAR NRN CANADA. ONE SHORTWAVE TROF IS HEADING INTO NEW ENGLAND. UPSTREAM...TROF NOW OVER THE PACIFIC NW WILL ALREADY BE IN THE UPPER LAKES BY LATE SUN. FOLLOWING THAT TROF ARE 2 MORE...ONE HEADING TOWARD THE GULF OF ALASKA AND THE SECOND W OF THE ALEUTIANS. MEDIUM RANGE GUIDANCE INDICATES THAT THE ONE APPROACHING THE GULF OF ALASKA COULD PRODUCE A SIGNIFICANT CNTRL CONUS TO GREAT LAKES STORM SYSTEM MIDWEEK. THE FOLLOWING SYSTEM W OF THE ALEUTIANS MAY PRODUCE A SIMILAR SYSTEM LATE WEEK...THOUGH GUIDANCE IS MUCH MORE VARIED AS WOULD BE EXPECTED AT THAT TIME RANGE. SO...AFTER A QUIET WINTER...THERE WILL BE 3 OPPORTUNITIES FOR WIDESPREAD PCPN OVER THE NEXT 7 DAYS OR SO WITH AT LEAST ONE SYSTEM BRINGING THE POTENTIAL FOR SIGNIFICANT PCPN. IN THE SHORT TERM...ONGOING LAKE EFFECT/LAKE ENHANCED SNOW IS THE CONCERN TODAY AND THEN ATTENTION TURNS TO THE TROF NOW OVER THE PACIFIC NW THAT WILL REACH THE AREA SUN. DEEP MOISTURE PER 00Z KINL/CWPL/KGRB SOUNDINGS ALONG WITH 850MB TEMPS AROUND -13C WAS SUPPORTING DECENT LES INTO NCNTRL UPPER MI EARLIER IN THE NIGHT WITH NNW FLOW FAVORING THE AREA FROM AROUND MARQUETTE E TO PICTURED ROCKS. OUT W...THERE HAS BEEN ADDITIONAL SUPPORT FROM SHORTWAVE THAT HAS DROPPED SSE THRU MN. WAVE HAD ENHANCED SFC TROFFING OVER WRN LAKE SUPERIOR PER SFC OBS. THIS LED TO MDT/HVY SNOW FOCUSING OVER WRN GOGEBIC/ONTONAGON COUNTIES. AS SHORTWAVE OVER MN CONTINUES SE AND FLOW BECOMES MUCH MORE PROGRESSIVE TODAY...MIDLEVEL RIDGE WILL SHIFT E TO MN BY EVENING...BRINGING 500MB HEIGHT RISES OF 80-120M ACROSS UPPER MI BTWN 12Z AND 00Z. END RESULT IS A BREAKDOWN OF THE SFC TROF OVER LAKE SUPERIOR DURING THE MORNING WITH FLOW BECOMING ANTICYCLONIC DURING THE AFTN. WITH APPROACHING MIDLEVEL RIDGE/HEIGHT RISES AND RESULTING LARGE SCALE SUBSIDENCE...NAM/GFS ARE VERY AGGRESSIVE IN QUICKLY LOWERING INVERSION TO AROUND 3KFT AND SHARPLY DRYING THE COLUMN. GIVEN RECENT RADAR TRENDS SHOWING RAPIDLY DIMINISHING LES AND SATELLITE IMAGERY SHOWING CLOUDS CLEARING OVER LAKE SUPERIOR...THE MODEL FCST OF DRYING AIR MASS AND LOWERING INVERSION LOOKS RIGHT ON TRACK. SO...FCST FOR TODAY WILL SHOW A STEADY DECREASE IN LES NEAR LAKE SUPERIOR WITH BULK OF ADDITIONAL ACCUMULATIONS FALLING FROM NOW TO MID MORNING. BY LATE AFTN... NOTHING MORE THAN ISOLD -SHSN/FLURRIES WILL LINGER IN THE AREAS FAVORED BY NW FLOW. AS FOR THE HEADLINE OVER THE FAR W...THERE ARE STILL SOME HINTS OF HEAVIER LES INTO PORTIONS OF GOGEBIC/ONTONAGON COUNTIES ON KDLH RADAR AND WEBCAM FROM BERGLAND AREA SHOWED FAIRLY HVY SNOW AN HR OR TWO AGO...SO A FEW MORE INCHES OF SNOW ARE POSSIBLE YET EARLY THIS MORNING BEFORE LES COLLAPSES. ELSEWHERE... THERE WON`T BE MUCH MORE THAN A DUSTING. ANY LINGERING -SHSN/FLURRIES WILL END THIS EVENING AS SFC HIGH PRES RIDGE SHIFTS ACROSS THE AREA. LOOKS LIKE THERE WILL BE A SHORT WINDOW FOR TEMPS TO PLUMMET BEFORE HIGH CLOUDS INCREASE/THICKEN FROM W TO E DURING THE NIGHT. BEST OPPORTUNITY WOULD PROBABLY BE OVER THE CNTRL DUE TO LONGER PERIOD BTWN DEPARTURE OF LAKE STRATOCU AND INCREASE OF HIGH CLOUDS. INHERITED FCST OF MINS BLO OR ON THE LOW SIDE OF AVBL GUIDANCE LOOKS ON TRACK. TEMPS SHOULD BECOME STEADY OR BEGIN TO RISE OVERNIGHT AS HIGH CLOUDS THICKEN UNDER DEVELOPING WAA/ISENTROPIC ASCENT REGIME. ON SUN...FOCUS WILL BE ON SHORTWAVE TROF MOVING FROM THE DAKOTAS EARLY IN THE MORNING TO THE UPPER LAKES SUN EVENING. ALTHOUGH SYSTEM WILL BE WEAKENING AS IT MOVES INTO INCREASINGLY CONFLUENT FLOW... MODELS STILL INDICATE FAIRLY IMPRESSIVE DEEP LAYER FORCING AS SUGGESTED BY QVECTOR CONVERGENCE. ALSO...THERE IS A STRONG PUSH OF ISENTROPIC ASCENT FOR ABOUT 6-9HRS. WITH MIXING RATIOS OF 2-2.5G/KG ON THE 285K SFC (ROUGHLY 720-760MB)...THERE IS THE POTENTIAL FOR MAX SNOW ACCUMULATIONS UPWARDS OF 3-4INCHES. GREATEST ACCUMULATIONS SHOULD BE OVER THE NW WHERE STRONGER ISENTROPIC ASCENT IS BETTER CO-LOCATED WITH LEFT EXIT OF 135KT UPPER JET STREAK. ALL AREAS SHOULD SEE AT LEAST A PERIOD OF SNOW SUN...AND ACCUMULATIONS OF GENERALLY 1-3 INCHES LOOK REASONABLE AT THIS POINT. HOWEVER...OF NOTE IS THE REGIONAL GEM WHICH HAS THE MOST PCPN WITH AMOUNTS GENERALLY 0.25 TO 0.45 INCHES SUN. THIS WOULD RESULT IN SNOW AMOUNTS 1-2 INCHES HIGHER THAN CURRENTLY EXPECTED. WITH 850MB TEMPS AROUND THE THRESHOLD FOR LAKE ENHANCEMENT OVER NRN LAKE MICHIGAN...SRLY FLOW COULD GIVE A BOOST TO SNOW TOTALS OVER THE ERN FCST AREA. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY) ISSUED AT 514 AM EST SAT FEB 25 2012 THE 500MB TROUGH CURRENTLY SET UP ALONG THE WEST COAST WILL RESIDE SOMEWHERE OVER NORTHERN MN BY 00Z MONDAY. WHILE THE 25/00Z GEM AND 24/21Z SREF KEEP IT AS AN OPEN WAVE AT THIS TIME...THE 25/00Z GFS/NAM AND 24/12Z DEEPEN THE SYSTEM A BIT MORE INTO A CLOSED LOW. AS HAS BEEN THE TREND...THE GFS IS ON THE QUICKER WESTERN SIDE...WHILE THE 24/12Z AND 25/00Z ECMWF RUNS WERE ON A SLIGHTLY SLOWER TRACK /6 TO 9 HOURS SLOWER THAN THE GFS/. ALL SOLUTIONS RETURN TO MORE OF AN OPEN WAVE FEATURE AT 500MB AS IT CROSSES SUNDAY NIGHT...WITH THE SFC LOW TRACKING ALONG THE LAKE SUPERIOR/UPPER MI BORDER BEFORE EXITING EAST OF LAKE SUPERIOR MONDAY MORNING. 850MB TEMPS OF -4 TO -10C /WARMEST SE/. WHILE IT MAY BE TOO WARM FOR PURE LAKE EFFECT...LAKE ENHANCEMENT WILL NOT BE OUT OF THE QUESTION. SLIGHTLY COLDER AIR WILL SLIDE IN ON THE BACK SIDE OF THE EXITING SFC LOW...WITH 850MB TEMPS RANGING FROM -10 TO -13C BY 00Z TUESDAY ON NW FLOW. THIS WILL KEEP TEMPS ACROSS THE KEWEENAW PENINSULA IN CHECK...REMAINING STEADY THROUGH THE DAY. HIGH PRESSURE WILL BE OVER THE REGION MONDAY NIGHT WITH TEMPS ABLE TO COOL INTO THE TEENS UNDER LIGHT WIND AND MAINLY DRY WEATHER. THE NEXT SYSTEM OF INTEREST LOOKS TO BE TRACKING A LITTLE TOO FAR TO OUR SE TO PRODUCE ANYTHING BUT SNOW FOR MOST OF THE AREA. A MIX WAS KEPT ONLY ALONG LAKE MI TUESDAY NIGHT...BUT MAY NEED TO BE REMOVED IF THIS MORE SE TREND REMAINS AS COLD ENOUGH AIR WOULD KEEP ONLY SNOW OVER THE REGION. THE MAIN CONCERN IS HEAVY SNOW...WHICH IF THE GFS WOULD BE CORRECT...WOULD RESULT IN WINTER WEATHER HEADLINES ACROSS MOST OF UPPER MICHIGAN. WILL WAIT TO SEE HOW IT PANS OUT...AS THE SE TREND LOOKS TO DOMINATE. THE CONSENSUS IS THE HAVE THE NEARLY STACKED 500MB TO SFC LOW BETWEEN S MN AND IA AT 12Z WEDNESDAY. AS HAS BEEN THE TREND...THE ECMWF IS AGAIN ON THE SLOW SIDE. LOOKING AT THE SFC PATTERN...THE GFS LOOKS TO BE A COMPROMISE BETWEEN THE FARTHER NE CANADIAN AND THE SW ECMWF. WILL NOT JUMP ON ANY PARTICULAR SOLUTION AT THIS POINT...BUT WILL CONTINUE TO HIGHLIGHT THE POTENTIAL FOR HEAVY SNOW AMOUNTS IN THE HWO/EHWO AND ELSEWHERE. STRONG ESE WINDS WILL ALSO NEED TO BE MONITORED FOR MARINE CONCERNS AND BLOWING SNOW WEDNESDAY...BEFORE TURNING MORE NORTHEASTERLY WEDNESDAY NIGHT WITH GUSTY WINDS CONTINUING. 850MB TEMPS OF -6 TO -10C WILL ONCE AGAIN LIMIT STRAIGHT LAKE EFFECT...BUT WITH A GOOD MOISTURE FEED FROM THE GULF WITH THIS SYSTEM DEEP MOISTURE WILL BE AVAILABLE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1231 AM EST SAT FEB 25 2012 CONTINUED NRLY FLOW COMBINED WITH COOLER AIR MOVING ACROSS LAKE SUPERIOR WILL MAINTAIN LES AT TAF SITES INTO THE MORNING HRS. EXPECT MORE PERSISTENT AND HEAVIER LES LATE TONIGHT AT KIWD WHERE CONVERGENT NRLY WIND FIELD AND LONGER PERIOD OF DEEPER MOISTURE AND POTENTIAL ENHANCEMENT FROM NEARBY SHORTWAVE TO RESULT IN CONDITIONS LOWERING TO ALT LANDING MINS THERE. EXPECT CONDITIONS TO IMPROVE BY LATE MORNING AT KIWD AS DRIER AIR BEGINS TO MOVE IN. WINDS SHIFTING NORTH OVER LAKE SUPERIOR COULD PUSH SOME HEAVIER LES BANDS INTO KSAW THROUGH 08Z BUT EXPECT HEAVIER LES TO COLLASPE QUICKLY AS DRIER AIR MOVES IN NORTH OF THE LAKE. AS WINDS BACK GRADUALLY TO THE NW EXPECT CONDITIONS TO IMPROVE TO VFR AT KSAW BY MIDDAY. KCMX WILL SEE MVFR CIGS BUT ONLY VERY LIGHT LES WITH LESS FAVORABLE N/NNW WIND DIRECTION THERE. EXPECT KCMX TO ALSO IMPROVE TO VFR THIS AFTERNOON AS DRIER AIR WORKS IN FM NW OF THE LAKE. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 514 AM EST SAT FEB 25 2012 ACTIVE WEATHER EXPECTED THRU THE MIDDLE OF NEXT WEEK WITH A PROGRESSIVE REGIME BRINGING A SERIES OF LOW PRES AND HIGH PRES SYSTEMS ACROSS THE GREAT LAKES REGION. HIGH PRES RIDGE ARRIVING TONIGHT WILL BRING DECREASING WINDS TODAY THRU THIS EVENING. ALREADY BY LATE TONIGHT...WINDS WILL BE ON THE INCREASE AGAIN OVER WRN LAKE SUPERIOR IN RESPONSE TO THE NEXT LOW PRES SYSTEM MOVING OUT OVER THE NRN PLAINS. SOUTHEASTERLY WINDS SHOULD INCREASE UP TO 30KT SUN AS THE LOW APPROACHES. WITH TIGHT PRES GRADIENT ON FRONT SIDE OF LOW PRES SYSTEM AND LINGERING OVERWATER INSTABILITY...GALES ARE A POSSIBILITY. LATER FCSTS MAY NEED TO INCLUDE A GALE WATCH. WITH LOW WEAKENING AS IT PASSES...WINDS ON THE BACKSIDE OF THE SYSTEM MON WON`T BE AS STRONG. WINDS WILL CONTINUE TO DIMINISH INTO TUE AS HIGH PRES ARRIVES. WINDS WILL THEN INCREASE AGAIN TO 15-30KT TUE NIGHT/WED AS THE NEXT LOW PRES SYSTEM APPROACHES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW WARNING UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON FOR MIZ002-009. LAKE SUPERIOR... NONE. LAKE MICHIGAN... GALE WATCH FROM SUNDAY MORNING THROUGH SUNDAY EVENING FOR LMZ248- 250. && $$ SHORT TERM...ROLFSON LONG TERM...KF AVIATION...VOSS MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS DULUTH MN
701 PM CST SUN FEB 26 2012 .SHORT TERM... MODERATE TO HEAVY SNOW CONTINUED TO FALL OVER THE ARROWHEAD/IRON RANGE...WITH LIGHTER SNOW OVER THE REST OF THE NORTHLAND. THE SURFACE LOW IN NORTHWEST WISCONSIN WAS FILLING WITH NEAR 5 MB PRESSURE RISES OVER THE EASTERN DAKOTAS AND 2 MB FALLS OVER THE UP OF MICHIGAN. AREA RADARS AND OBSERVATIONS REVEAL SNOW INTENSITY DIMINISHING OVER THE WESTERN CWA WHERE VSBYS HAVE CLIMBED TO 5SM AT KPWC...3SM AT KXVG...8SM AT KGPZ AND 4SM AT KINL. WE WILL WAIT A BIT LONGER...BUT WE SHOULD BE ABLE TO CANCEL SOME OF THE HEADLINES IN THE WEST. SPOTTERS IN PINE COUNTY REPORTED SOME MIXED SLEET/SNOW/FREEZING DRIZZLE THIS EVENING. RUC13 SOUNDINGS REVEAL SEVERAL HOURS THIS EVENING WHERE DRIER AIR WILL BE PRESENT ABOVE A MOIST LAYER THAT REMAINS AT OR WARMER THAN -13C...SO A MIX WILL CONTINUE TO BE POSSIBLE. SATELLITE IMAGERY ALSO SHOWS WARMER CLOUD TOPS PRESENT OVER THAT AREA...INTO NORTHWEST WISCONSIN. SNOW SHOULD GRADUALLY DIMINISH FROM WEST TO EAST TONIGHT...REMAINING HEAVIEST IN THE ARROWHEAD. WE`LL ALSO HAVE TO KEEP AN EYE ON THE SOUTH SHORE AS WINDS BACK AROUND TO THE NORTH THEN NORTHWEST TONIGHT FOR SOME LAKE EFFECT SNOW SHOWERS. DELTA-T VALUES ARE NOT ALL THAT HIGH...BUT THE COMBINATION OF LIFT FROM THE SYSTEM AND THE LAKE WILL KEEP SNOW SHOWERS GOING LATER TONIGHT. A GRAVITY WAVE INDUCED AREA OF ENHANCED SNOWFALL WILL ALSO BE POSSIBLE SOUTH THROUGH PORTIONS OF DOUGLAS AND NORTHEAST PINE COUNTIES LATE THIS EVENING AND OVERNIGHT AS WINDS BECOME NORTHWEST. FLOW IS NOT ALL THAT STRONG...SO NOT SURE HOW STRONG A WAVE WILL RESULT. .PREV DISCUSSION... /ISSUED 537 PM CST SUN FEB 26 2012/ AVIATION.../0Z TAF ISSUANCE/ CURRENT LIFR CONDITIONS OVER THE NORTHERN AERODROMES WILL SLIGHTLY IMPROVE LATER THIS EVENING. SLIGHTLY BETTER CONDITIONS AT BRD AND HYR WILL PREVAIL THROUGH THE EVENING. EXPECT THE LIGHT SNOW TO SLOWLY DIMINISH OVERNIGHT WITH WINDS SHIFTING FROM THE NORTHWEST LATER THIS EVENING. SNOW WILL END MONDAY MORNING WITH CEILINGS IMPROVING TO LOW END VFR BY MONDAY AFTERNOON. PREV DISCUSSION... /ISSUED 347 PM CST SUN FEB 26 2012/ .WINTER WEATHER ADVISORIES MAY BE CANCELLED EARLY OVER SWRN CWA ..WINTER STORM WARNING MAY BE DOWNGRADED TO ADVISORY OVER SRN ST LOUIS/CARLTON COUNTIES... SHORT TERM...A GENERAL AREA OF 6 TO 10" HAS OCCURRED FROM NRN CASS COUNTY ACROSS ITASCA COUNTY AND SCTRL ST LOUIS CO TO TWO HARBORS. LESSER AMOUNTS ALONG BORDER IN NRN KOOCH CO AND NRN ST LOUIS COUNTY. MSAS SHOWS MAIN SFC LOW NEAR KJMR TRACKING ENE TOWARDS PRICE COUNTY AS OF MID AFTERNOON. MAIN FORCING HAS BEEN IN AREA OF MESOSCALE LIFT ALONG NSHORE AND EXTENDING WEST UNDERNEATH A DEFORMATION AXIS FROM THE IRON RANGE TO THE LEECH LAKE VICINITY. 85H LOW IS MOVING ACROSS BRD LAKES VICINITY TOWARDS DOUGLAS COUNTY. 88D RETURNS INCREASING SIGNIFICANTLY IN THE PAST HR OVER AITKIN COUNTY...AHEAD OF 85H LOW. PATCHY FREEZING DRIZZLE REPORTS FROM NEAR BRUNO NORTH TO MOOSE LAKE AND INTO ADJACENT WISCONSIN AS WARM ADVECTION LAYER HAS INCREASED ALOFT AHEAD OF MID LVL LOW. A SECONDARY MID LVL SHORTWAVE TROF OVER CTRL NDAK HAS KEPT AN EXTENSIVE AREA OF LIGHT SNOW WELL WEST OF REGION TODAY. TONIGHT/TOMORROW...85H LOW WILL PASS ACROSS APOSTLE ISLANDS BY MIDNIGHT. EXPECT BACKING OF BDRY LYR WIND TO AUGMENT SNOW ACROSS TWIN PORTS AND INTO SOUTH SHORE THROUGH THE EVENING. SECONDARY SHORTWAVE TROF WILL PASS ACROSS CWA LATE TONIGHT/EARLY TOMORROW. DEFORMATION AXIS WILL PIVOT SOUTHEAST WITH SNOW DECREASING ACROSS WRN AND NWRN CWA. SNOW SHOULD CONTINUE THROUGHOUT THE NIGHT OVER ERN HALF OF CWA. HIGHEST ACCUMULATIONS WILL OCCUR ALONG NSHORE AND INLAND TO IRON RANGE AND SHIFT MORE TOWARDS SOUTH SHORE BY EARLY MONDAY. PRECIP SHOULD DIMINISH QUICKLY BY MID MORNING MOST AREAS AS UPPER TROF MOVES EAST AND SUBSIDENT FLOW ALOFT DEVELOPS. TOMORROW NIGHT...SFC HIGH WILL MOVE INTO REGION TEMPORARILY UNDER BUILDING RIDGE ALOFT. MAY STILL HAVE SIGNIFICANT AMOUNT OF CLOUD COVER ACROSS CWA AS MID/HIGH CLOUDS SNEAK INTO RIDGE ALOFT. EXTENDED...TUESDAY THROUGH SUNDAY. THE MAJOR FOCUS FOR THE EXTENDED TIME PERIOD IS THE MAJOR WINTER STORM SHAPING UP FOR TUESDAY THROUGH WEDNESDAY NIGHT. THE MODELS ARE STARTING TO COME INTO BETTER AGREEMENT CONCERNING A VERY HEAVY SNOWFALL EVENT. THERE IS SOME DISAGREEMENT CONCERNING THE SPEED AT WHICH THE PRECIPITATION ARRIVES ON TUESDAY. THE GFS...UKMET AND NAM QUICKLY BRING QPF ACROSS THE CWA ON TUESDAY...WHILE THE ECMWF AND GEM ARE SLOWER IN BRINGING SNOW BACK INTO THE AREA. WILL ISSUE A WINTER STORM WATCH FOR THE ENTIRE SOUTHERN HALF OF THE CWA STARTING MIDDAY TUESDAY AND CONTINUING THROUGH WEDNESDAY. THINK THE HEAVIEST SNOW WILL MOVE INTO THE REGION TUESDAY NIGHT AND CONTINUE INTO WEDNESDAY. HAD A TOUGH TIME DECIDING ON THE LOCATION OF THE WATCH. THE MODELS ARE IN A BIT BETTER AGREEMENT CONCERNING HEAVY QPF VALUES IN THE SOUTHERN CWA...BUT THEY HAVE ALL SHIFTED NORTHWARD OVER THE PAST FEW RUNS. THINK AT SOME POINT WE MAY NEED TO EXTEND THE WATCH FURTHER NORTHWARD...AND INTO THE NORTH SHORE AS WELL...BUT THIS SHOULD BE A GOOD START. ALSO TRIED TO WATCH THE EXTENT OF THE DOUBLE HEADLINES IN THE AREA THAT WAS SEEING VERY HEAVY SNOWFALL TODAY...FROM THE IRON RANGE INTO THE ARROWHEAD/NORTH SHORE. THE STRENGTH OF THE SYSTEM...AND THE AVAILABLE MOISTURE COULD LEAD TO IMPRESSIVE SNOWFALL RATES...VERY STRONG WINDS AND A GREAT DEAL OF BLOWING AND DRIFTING SNOW. HAVE NOT RULED OUT THE POSSIBILITY OF BLIZZARD CONDITIONS IN AREAS BORDERING LAKE SUPERIOR...BUT WILL HOLD OFF FOR NOW ON ANY BLIZZARD WATCH. I WOULD NOT BE SURPRISED TO SEE AMOUNTS WELL IN EXCESS OF ONE FOOT SOMEWHERE IN THE NORTHLAND...BUT SPECIFIC AMOUNTS DEFINITELY TOO TOUGH TO PINPOINT FOR ANY ONE LOCATION AT THIS POINT. THE STORM SYSTEM MOVES OUT OF THE AREA WEDNESDAY NIGHT...AND SOME UNSETTLED WEATHER MOVES IN LATER IN THE WEEK AND INTO THE WEEKEND. THE MODELS ARE ALL OVER THE PLACE CONCERNING SPECIFIC PCPN CHANCES...BUT AT THIS POINT IT LOOKS LIKE THERE COULD BE SOME MIXED PCPN. AVIATION.../18Z TAF ISSUANCE/ A WINTER STORM WILL CONTINUE TO IMPACT THE NORTHLAND OVER MUCH OF THE TAF PERIOD. AT THIS POINT...IT APPEARS THAT THE MOST DRAMATIC VISIBILITY RESTRICTIONS WOULD BE ACROSS THE IRON RANGE AND THE ARROWHEAD...WHERE A DEFORMATION AXIS WILL SET UP AND ROTATE THROUGH THAT AREA. AREAS TO THE SOUTH AND FAR NORTH WILL SEE MORE EPISODIC PERIODS OF HEAVIER SNOW. KHIB LOOKS TO SEE THE MOST DRAMATIC VSBY RESTRICTIONS. OVERALL...FAIRLY WIDESPREAD MVFR TO EVEN LIFR CONDITIONS CAN BE EXPECTED. CONDITIONS WILL IMPROVE LATER TONIGHT AND ON MONDAY MORNING. && .POINT TEMPS/POPS... DLH 15 23 12 28 / 100 10 10 60 INL 9 19 4 28 / 90 20 10 10 BRD 15 22 16 30 / 70 10 10 70 HYR 18 26 10 32 / 70 10 10 60 ASX 21 26 11 31 / 90 30 10 60 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...WINTER STORM WARNING UNTIL 6 AM CST MONDAY FOR MNZ010>012- 018>021-025-026-035-037. WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY AFTERNOON FOR MNZ025-033>038. WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR MNZ033-034-036- 038. WI...WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY AFTERNOON FOR WIZ001>004-006>009. WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR WIZ001>004. && $$ SHORT TERM...MELDE/CANNON LONG TERM....DAP
AREA FORECAST DISCUSSION
NWS DULUTH MN
1208 PM CST SAT FEB 25 2012 .AVIATION.../18Z TAF ISSUANCE/ THE LOW CLOUDS IN PLACE ACROSS MUCH OF THE NORTHLAND THIS MORNING APPEAR TO BE BURNING OFF FAIRLY QUICKLY AS OF MIDDAY. HAVE KEPT SOME TEMPO BROKEN CONDITIONS AROUND FOR A TIME...BUT WE SHOULD SEE THE TREND CONTINUE FOR MUCH OF THE REGION. THE FOCUS WILL THEN SHIFT TO INCREASING AND THICKENING CLOUDS OVERNIGHT...AHEAD OF THE LOW PRESSURE SYSTEM MOVING INTO THE REGION ON SUNDAY. LIGHT SNOW SHOULD DEVELOP LATER IN THE NIGHT AND PROGRESSIVELY INCREASE IN INTENSITY THROUGHOUT SUNDAY MORNING. AS A RESULT...WILL GRADUALLY LOWER CIGS/VSBYS WITH TIME. && .PREV DISCUSSION... /ISSUED 1025 AM CST SAT FEB 25 2012/ UPDATE...PESKY LOW CLOUDS STILL BEING MAINTAINED ACROSS LARGE PART OF CWA. UPPER FLOW SHOWS UPPER JET AXIS IS TRANSLATING EAST ACROSS WRN CWA WITH AREA OF SHEAR VORTICITY BEING PRODUCED OVER ERN CWA. RUC13 85/70H RH STILL ABOVE 60 PERCENT EAST OF A INL TO BRD LINE HOWEVER STRATUS LAYER IS THIN WITH AREA LAKES SHOWING THROUGH VIS IMAGERY. SLOWED CLEARING PROCESS TODAY OVER ERN HALF OF CWA. ADDED POPS OVER WISC ZONES AS SHEAR VORTICITY WITHIN CYCLONIC MOIST FLOW PROMOTES ADDITIONAL SNOW SHOWER DEVELOPMENT. WILL LET WSY EXPIRE OVER ERN SNOW BELT AS PLANNED AT 11AM THIS MORNING. DEVELOPING SYSTEM WEST OF REGION IS STILL A BIT TRICKY AS UPPER TROF CARRYING SHORTWAVE SYSTEM IS SHOWING CONSIDERABLE BAGGINESS...ALLOWING POTENTIALLY SIGNIFICANT DIFFERENCE IN POSITION/EVOLUTION OF CLOSING OFF A MID LVL CENTER. DESPITE THAT...CURRENT NWP FCSTS STILL MAINTAIN CONSENSUS REGARDING TRACK OF LOW/MID LVL PRESSURE CENTERS. THIS WOULD KEEP HIGHEST PROBABILITY OF MAXIMUM SNOW ACCUMULATIONS ACROSS NRN 2/3 OF CWA. PREV DISCUSSION... /ISSUED 531 AM CST SAT FEB 25 2012/ AVIATION...12Z TAFS. MVFR CIGS WITH FLURRIES OR LIGHT SNOW WILL AFFECT ALL TAF SITES THROUGH THE 15Z TO 18Z TIME FRAME. THE EXCEPTION IS AT KINL WHERE VFR CIGS WILL PREVAIL. AS THE SFC RIDGE AXIS MOVES OVER THE FA TODAY...EXPECT ALL SITES TO REMAIN VFR. AFTER 26/03Z...CLOUDS WILL BE ON THE INCREASE AHEAD OF THE APPROACHING WINTER STORM. LIGHT SNOW WILL GRADUALLY OVERSPREAD THE AREA AFTER 06Z WITH CIGS/VSBYS DROPPING INTO THE MVFR RANGE. PREV DISCUSSION... /ISSUED 456 AM CST SAT FEB 25 2012/ SHORT TERM...LATEST SURFACE ANALYSIS SHOWS A DEPARTING LOW PRESSURE SYSTEM OVER THE NORTHEAST...AND A RIDGE OF HIGH PRESSURE OVER THE PLAINS...WITH THE NORTHLAND IN BETWEEN UNDER NWLY FLOW. THE NWLY WINDS COMBINED WITH COLD AIR HAVE RESULTED IN LAKE EFFECT SNOW ALONG THE SOUTH SHORE OF LAKE SUPERIOR...FROM THE BAYFIELD PENINSULA TO THE GOGEBIC RANGE WHERE 4.5 INCHES OF SNOW HAS FALLEN SO FAR AT GILE WI. THE SNOW SHOWERS WILL CONTINUE ACROSS THE SOUTH SHORE THIS MORNING...BUT THE SNOWFALL IS NOT EXPECTED TO BE HEAVY DUE TO UNFAVORABLE SURFACE WIND DIRECTION. AS A RESULT...ONLY AN ADDITIONAL 1 TO 2 INCHES ARE EXPECTED BY NOON TODAY. THE OTHER FORECAST CONCERN FOR THE SHORT TERM IS A VIGOROUS SHORTWAVE WHICH IS PROGGED TO TRACK EWD FROM NRN PLAINS ACROSS THE UPPER MIDWEST TONIGHT THROUGH SUNDAY NIGHT. THERE ARE STILL SOME DIFFERENCES BETWEEN THE VARIOUS MODELS...WITH THE GFS AND GEM SHOWING THE HEAVIEST PRECIP AMOUNTS. THE GFS AND GEM ALSO TAKE THE HEAVIER SNOW FURTHER SOUTH TO INCLUDE ALL OF NORTHEAST MINNESOTA INCLUDING THE BRAINERD AND DULUTH AREAS. THE ECMWF AND NAM FOCUS THE HEAVIEST SNOW ACROSS OUR NRN ZONES. BECAUSE OF THESE DIFFERING SOLUTIONS...WE HAVE DECIDED TO GO WITH AN AVERAGE OF THE MAIN NWP MODELS SIMILAR TO HPC`S SOLUTION. THIS WILL RESULT IN WARNING SNOWFALL AMOUNTS OF 5 TO 8 INCHES ACROSS OUR NRN ZONES...GENERALLY ALONG AND NORTH OF US HIGHWAY 2...WITH GRADUALLY LESSER AMOUNTS FARTHER SOUTH. ATTM WE OPTED TO GO WITH A WINTER WEATHER ADVISORY FOR THE BRAINERD AND DULUTH AREAS WITH SNOWFALL AMOUNTS GENERALLY RANGING FROM THE 3 TO 6 INCHES. HOWEVER IF THE GEM AND GFS SOLUTIONS TURN OUT TO BE CORRECT...THESE AREAS WILL NEED TO BE UPGRADED TO A WARNING. FINALLY ACROSS PINE COUNTY AND NWRN WI...WE HAVE DECIDED NOT TO ISSUE ANY HEADLINES ATTM SINCE WE EXPECT SNOWFALL AMOUNTS TO STAY BELOW ADVISORY LEVEL. HOWEVER THE DOUGLAS TO IRON COUNTY REGION WILL ALSO NEED TO BE MONITORED AS A COMBINATION OF SYNOPTIC AND LAKE EFFECT SNOW MAY RESULT IN HEAVIER THAN ANTICIPATED SNOWFALL AMOUNTS. THERE MAY BE SOME AREAS OF SHORT- LIVED BLOWING SNOW...ALTHOUGH WINDS ARE NOT EXPECTED TO BE STRONG. LONG TERM...SUNDAY NIGHT THROUGH FRIDAY. THE UPPER LEVEL TROF/SFC LOW EXIT THE AREA SUNDAY NIGHT. WITH HEADLINES IN PLACE...HAVE HIGHEST POPS ALIGNED WITH THE HEADLINES. SOME LES SHOWERS ARE POSSIBLE LATE SUNDAY NIGHT. HOWEVER...MODELS DISAGREE ON POTENTIAL WITH DIFFERENCES IN WIND FIELD/FETCH/CAA. POPS ALONG THE SOUTH SHORE ARE A MODEL COMPROMISE. ON MONDAY MORNING...SOME BACKWASH SNOW SHOWERS ARE POSSIBLE ALONG WITH SOME LES SHOWERS ALONG THE SOUTH SHORE. BY AFTERNOON...SFC/UPPER RIDGING ARRIVES TO END ALL SNOW CHANCES. MODEL DIFFERENCES BEGIN AGAIN ON MONDAY NIGHT AHEAD OF THE NEXT SYSTEM PROGGED TO AFFECT THE FA. USED THE 25/00Z ECMWF WHICH KEEPS THE RIDGING THROUGH 06Z TUESDAY AS MODELS TEND TO BE TOO FAST AT BREAKING DOWN RIDGING. USED A MODEL BLEND AFTER 06Z TUESDAY WITH THE ONSET OF THE NEXT ROUND OF SNOW. MODEL SOLUTIONS ARE ONCE AGAIN VARYING WIDELY AS A CUT OFF UPPER LOW CROSSES OUT OF THE ROCKIES AND INTO THE PLAINS. CONTINUED TO USE A CONSENSUS APPROACH WITH THIS SYSTEM AND HOW IT AFFECTS THE FA FROM TUESDAY THROUGH WEDNESDAY NIGHT. THIS SYSTEM WILL TAP INTO GULF OF MEXICO MOISTURE SO THE POSSIBILITY FOR SIGNIFICANT SNOW AMOUNTS CANNOT BE RULED OUT. HOWEVER...THE MODEL DIFFERENCES WITH THE SFC LOW TRACK PRECLUDE USING ANY HEADLINES ATTM. WILL KEEP THE BEEFY WORDING IN THE HWO. MODEL DIFFERENCES BECOME MORE PRONOUNCED FOR THURSDAY AND FRIDAY AND USED THE MODEL BLEND. && .POINT TEMPS/POPS... DLH 24 18 30 16 / 10 60 90 50 INL 20 12 26 7 / 10 80 100 60 BRD 25 19 30 13 / 10 60 80 60 HYR 27 18 35 19 / 40 20 80 40 ASX 28 19 34 21 / 60 20 90 50 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 6 AM CST MONDAY FOR MNZ010>012-018>021-025-026. WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM CST MONDAY FOR MNZ033>037. WI...NONE. && $$ SHORT TERM...CANNON LONG TERM....DAP AVIATION...DAP
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1025 AM CST SAT FEB 25 2012 .UPDATE...PESKY LOW CLOUDS STILL BEING MAINTAINED ACROSS LARGE PART OF CWA. UPPER FLOW SHOWS UPPER JET AXIS IS TRANSLATING EAST ACROSS WRN CWA WITH AREA OF SHEAR VORTICITY BEING PRODUCED OVER ERN CWA. RUC13 85/70H RH STILL ABOVE 60 PERCENT EAST OF A INL TO BRD LINE HOWEVER STRATUS LAYER IS THIN WITH AREA LAKES SHOWING THROUGH VIS IMAGERY. SLOWED CLEARING PROCESS TODAY OVER ERN HALF OF CWA. ADDED POPS OVER WISC ZONES AS SHEAR VORTICITY WITHIN CYCLONIC MOIST FLOW PROMOTES ADDITIONAL SNOW SHOWER DEVELOPMENT. WILL LET WSY EXPIRE OVER ERN SNOW BELT AS PLANNED AT 11AM THIS MORNING. DEVELOPING SYSTEM WEST OF REGION IS STILL A BIT TRICKY AS UPPER TROF CARRYING SHORTWAVE SYSTEM IS SHOWING CONSIDERABLE BAGGINESS...ALLOWING POTENTIALLY SIGNIFICANT DIFFERENCE IN POSITION/EVOLUTION OF CLOSING OFF A MID LVL CENTER. DESPITE THAT...CURRENT NWP FCSTS STILL MAINTAIN CONSENSUS REGARDING TRACK OF LOW/MID LVL PRESSURE CENTERS. THIS WOULD KEEP HIGHEST PROBABILITY OF MAXIMUM SNOW ACCUMULATIONS ACROSS NRN 2/3 OF CWA. && .PREV DISCUSSION... /ISSUED 531 AM CST SAT FEB 25 2012/ AVIATION...12Z TAFS. MVFR CIGS WITH FLURRIES OR LIGHT SNOW WILL AFFECT ALL TAF SITES THROUGH THE 15Z TO 18Z TIME FRAME. THE EXCEPTION IS AT KINL WHERE VFR CIGS WILL PREVAIL. AS THE SFC RIDGE AXIS MOVES OVER THE FA TODAY...EXPECT ALL SITES TO REMAIN VFR. AFTER 26/03Z...CLOUDS WILL BE ON THE INCREASE AHEAD OF THE APPROACHING WINTER STORM. LIGHT SNOW WILL GRADUALLY OVERSPREAD THE AREA AFTER 06Z WITH CIGS/VSBYS DROPPING INTO THE MVFR RANGE. PREV DISCUSSION... /ISSUED 456 AM CST SAT FEB 25 2012/ SHORT TERM...LATEST SURFACE ANALYSIS SHOWS A DEPARTING LOW PRESSURE SYSTEM OVER THE NORTHEAST...AND A RIDGE OF HIGH PRESSURE OVER THE PLAINS...WITH THE NORTHLAND IN BETWEEN UNDER NWLY FLOW. THE NWLY WINDS COMBINED WITH COLD AIR HAVE RESULTED IN LAKE EFFECT SNOW ALONG THE SOUTH SHORE OF LAKE SUPERIOR...FROM THE BAYFIELD PENINSULA TO THE GOGEBIC RANGE WHERE 4.5 INCHES OF SNOW HAS FALLEN SO FAR AT GILE WI. THE SNOW SHOWERS WILL CONTINUE ACROSS THE SOUTH SHORE THIS MORNING...BUT THE SNOWFALL IS NOT EXPECTED TO BE HEAVY DUE TO UNFAVORABLE SURFACE WIND DIRECTION. AS A RESULT...ONLY AN ADDITIONAL 1 TO 2 INCHES ARE EXPECTED BY NOON TODAY. THE OTHER FORECAST CONCERN FOR THE SHORT TERM IS A VIGOROUS SHORTWAVE WHICH IS PROGGED TO TRACK EWD FROM NRN PLAINS ACROSS THE UPPER MIDWEST TONIGHT THROUGH SUNDAY NIGHT. THERE ARE STILL SOME DIFFERENCES BETWEEN THE VARIOUS MODELS...WITH THE GFS AND GEM SHOWING THE HEAVIEST PRECIP AMOUNTS. THE GFS AND GEM ALSO TAKE THE HEAVIER SNOW FURTHER SOUTH TO INCLUDE ALL OF NORTHEAST MINNESOTA INCLUDING THE BRAINERD AND DULUTH AREAS. THE ECMWF AND NAM FOCUS THE HEAVIEST SNOW ACROSS OUR NRN ZONES. BECAUSE OF THESE DIFFERING SOLUTIONS...WE HAVE DECIDED TO GO WITH AN AVERAGE OF THE MAIN NWP MODELS SIMILAR TO HPC`S SOLUTION. THIS WILL RESULT IN WARNING SNOWFALL AMOUNTS OF 5 TO 8 INCHES ACROSS OUR NRN ZONES...GENERALLY ALONG AND NORTH OF US HIGHWAY 2...WITH GRADUALLY LESSER AMOUNTS FARTHER SOUTH. ATTM WE OPTED TO GO WITH A WINTER WEATHER ADVISORY FOR THE BRAINERD AND DULUTH AREAS WITH SNOWFALL AMOUNTS GENERALLY RANGING FROM THE 3 TO 6 INCHES. HOWEVER IF THE GEM AND GFS SOLUTIONS TURN OUT TO BE CORRECT...THESE AREAS WILL NEED TO BE UPGRADED TO A WARNING. FINALLY ACROSS PINE COUNTY AND NWRN WI...WE HAVE DECIDED NOT TO ISSUE ANY HEADLINES ATTM SINCE WE EXPECT SNOWFALL AMOUNTS TO STAY BELOW ADVISORY LEVEL. HOWEVER THE DOUGLAS TO IRON COUNTY REGION WILL ALSO NEED TO BE MONITORED AS A COMBINATION OF SYNOPTIC AND LAKE EFFECT SNOW MAY RESULT IN HEAVIER THAN ANTICIPATED SNOWFALL AMOUNTS. THERE MAY BE SOME AREAS OF SHORT- LIVED BLOWING SNOW...ALTHOUGH WINDS ARE NOT EXPECTED TO BE STRONG. LONG TERM...SUNDAY NIGHT THROUGH FRIDAY. THE UPPER LEVEL TROF/SFC LOW EXIT THE AREA SUNDAY NIGHT. WITH HEADLINES IN PLACE...HAVE HIGHEST POPS ALIGNED WITH THE HEADLINES. SOME LES SHOWERS ARE POSSIBLE LATE SUNDAY NIGHT. HOWEVER...MODELS DISAGREE ON POTENTIAL WITH DIFFERENCES IN WIND FIELD/FETCH/CAA. POPS ALONG THE SOUTH SHORE ARE A MODEL COMPROMISE. ON MONDAY MORNING...SOME BACKWASH SNOW SHOWERS ARE POSSIBLE ALONG WITH SOME LES SHOWERS ALONG THE SOUTH SHORE. BY AFTERNOON...SFC/UPPER RIDGING ARRIVES TO END ALL SNOW CHANCES. MODEL DIFFERENCES BEGIN AGAIN ON MONDAY NIGHT AHEAD OF THE NEXT SYSTEM PROGGED TO AFFECT THE FA. USED THE 25/00Z ECMWF WHICH KEEPS THE RIDGING THROUGH 06Z TUESDAY AS MODELS TEND TO BE TOO FAST AT BREAKING DOWN RIDGING. USED A MODEL BLEND AFTER 06Z TUESDAY WITH THE ONSET OF THE NEXT ROUND OF SNOW. MODEL SOLUTIONS ARE ONCE AGAIN VARYING WIDELY AS A CUT OFF UPPER LOW CROSSES OUT OF THE ROCKIES AND INTO THE PLAINS. CONTINUED TO USE A CONSENSUS APPROACH WITH THIS SYSTEM AND HOW IT AFFECTS THE FA FROM TUESDAY THROUGH WEDNESDAY NIGHT. THIS SYSTEM WILL TAP INTO GULF OF MEXICO MOISTURE SO THE POSSIBILITY FOR SIGNIFICANT SNOW AMOUNTS CANNOT BE RULED OUT. HOWEVER...THE MODEL DIFFERENCES WITH THE SFC LOW TRACK PRECLUDE USING ANY HEADLINES ATTM. WILL KEEP THE BEEFY WORDING IN THE HWO. MODEL DIFFERENCES BECOME MORE PRONOUNCED FOR THURSDAY AND FRIDAY AND USED THE MODEL BLEND. && .POINT TEMPS/POPS... DLH 24 18 30 16 / 10 60 90 50 INL 20 12 26 7 / 10 80 100 60 BRD 25 19 30 13 / 10 60 80 60 HYR 27 18 35 19 / 40 20 80 40 ASX 28 19 34 21 / 60 20 90 50 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 6 AM CST MONDAY FOR MNZ010>012-018>021-025-026. WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM CST MONDAY FOR MNZ033>037. WI...WINTER WEATHER ADVISORY UNTIL 11 AM CST THIS MORNING FOR WIZ002>004. && $$ SHORT TERM...CANNON
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1252 PM EST SAT FEB 25 2012 .SYNOPSIS... A NORTHWEST FLOW OF SEASONABLY COLD AIR ACROSS THE GREAT LAKES WILL BRING LAKE EFFECT SNOW AND SNOW SHOWERS TO MUCH OF THE AREA TODAY. WINDS WILL ALSO OCCASIONALLY GUST ABOVE 40 MPH. HIGH PRESSURE WILL BUILD INTO THE AREA ON SUNDAY BRINGING CLEARING SKIES. && .NEAR TERM /THROUGH TONIGHT/... 945 AM UPDATE...CHENANGO AND CORTLAND COUNTIES...ALONG WITH DELAWARE AND OTSEGO COUNTIES WITHIN THE PAST COUPLE HOURS...HAVE BEEN ADDED TO THE LAKE EFFECT SNOW ADVISORY. COMBINATION OF LAKE EFFECT AND UPSLOPE EFFECTS HAVE ANCHORED SNOW SHOWERS IN THE HIGHER TERRAIN FOR OTSEGO AND DELAWARE COUNTIES...WITH REPORTS OF BETWEEN 3 AND 4 INCHES ALREADY RECEIVED AS OF A LITTLE AFTER 8 AM. MEANWHILE...NARROW AND FAIRLY INTENSE SNOW BAND WITH UPSTREAM LAKE HURON CONNECTION...HOOKS UP TO NORTH OF BUFFALO...THROUGH ROCHESTER...INTO NORTHERN CORTLAND/CHENANGO COUNTIES. A SECOND BAND...WITH GEORGIAN BAY-LAKE ONTARIO CONNECTION...IS BEGINNING TO BREAK LAKE-TO-LAKE CONNECTION UPSTREAM...YET REMAINS FAIRLY STOUT IN ONONDAGA-MADISON COUNTIES. WITH PASSAGE OF SHORTWAVE THE NEXT SEVERAL HOURS...BOTH OF THESE BANDS WILL SHIFT SOUTH TO YIELD ADDITIONAL SNOWFALL FOR CHENANGO- CORTLAND COUNTIES ON TOP OF WHAT HAS ALREADY OCCURRED...AS WELL AS OTSEGO/DELAWARE WITH AID OF UPSLOPE ENHANCEMENT. SOUTH OF THE ADVISORY ZONES...SQUALLS WILL OCCUR YET WILL BE TRANSIENT...AND THUS WITH SNOW TOTALS BELOW ADVISORY CRITERIA. WE ARE EXPECTING 3 TO 6 INCHES TOTAL SNOW IN THE ADVISORY AREA...WITH HIGHER ELEVATIONS OF ONEIDA AND OTSEGO COUNTIES PUSHING INTO 5 TO 7 INCHES RANGE...BEFORE THE SNOW SHOWERS DIMINISH THIS EVENING. POPS AND SNOW AMOUNTS WERE ADJUSTED...TO REFLECT UPDATES AS DESCRIBED ABOVE...BASED ON EXPECTED EVOLUTION OF LAKE EFFECT BANDS THROUGH THE DAY. PREVIOUS DISCUSSION... MULTIPLE BAND LE SNOW EVENT UNDERWAY THIS MRNG. MAIN BAND RUNNING ALONG THE LAKE ONTARIO SHORE LINE INTO ONONDAGA AND ONEIDA COUNTIES. BAND SHOWS SOME SHEARING BUT APPEARS TO BE CONNECTED TO A BAND COMING OFF GEORGIAN BAY. TO THE SOUTH...SVRL STREAMERS COMING OFF HURON CROSSING ERN ERIE ARE CURVING CYCLONICALLY INTO THE FINGER ALKES AND SRN TIER...WITH INCRSD REFLECTIVETY OVER THE WRN CATS AS THE BANDS GET LFTD OVER THE MOUNTAINS. BOTH THE WRFARW AND HRRR SHOW CONTD MULTIPLE BANDS THRU THE DAY TODAY. ACTIVITY SHD BE ENHANCED BY A SCNDRY SHRT WV ROTATING THRU THE UPPER TROF DURING THE DAY. CRNTLY HAVE AN ADVISORY FOR THE NRN COUNTIES. BELIEVE THIS IS WELL PLACED AND SHD WRK AS AMTS SHD HOLD BLO WARNING DO TO THE STEADY SWRD MVMT OF THE BAND SHOWN BY THE SHRT RANGE MODELS. SOME CNCRN TO THE SOUTH ACROSS NRN CORTLAND AND CHENANGO FOR ADVISORY CRITERIA SNOWS THERE. NO PRBLMS THERE ATTM AS THE BANDS ARE GNRLY NORTH OF THERE. WHEN THE BAND DOES DROP THRU THE MRNG...DAYLIGHT AND BAND MVMT SHD KEEP AMTS DOWN. TO THE SOUTH...AN INCH OR TWO OF SNOW LOOKS LIKE A GOOD BET. && .SHORT TERM /SUNDAY THROUGH MONDAY/... DRIER AIR...RISING HGTS...AND A CUT OFF FROM THE UPSTREAM CONNECTION WILL QUICKLY HELP THE LE TO WIND DOWN THIS EVE. HIGH PRESSURE BLDS IN ON SUNDAY BRINGING YET ANOTHER QUICK END TO A COLD OUTBREAK. TEMPS WILL RCVR QUICKLY TO NEAR NORMS SUN AFTN...AND EVEN HIER MON. SYSTEM OVER THE WRN LAKES SWINGS A WRM FNT THRU EARLY MON BUT WITH DRY AIR IN PLACE AND UPR SUPPORT WELL WEST...LTL CHANCE FOR ANY REAL PCPN. MON LOOKS QUITE MILD WITH TEMPS ABV NRML AHD OF A WEAK AND DRY COLD FNT LATER MON OR EARLY TUE. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... 3 AM UPDATE... MAIN FEATURE TO MONITOR DURING THE MIDDLE OF NEXT WEEK WILL BE A STORM SYSTEM FORECAST BY ALL MODELS TO TRACK FROM THE ROCKIES TOWARD THE WESTERN GREAT LAKES TUESDAY INTO WEDNESDAY. MEANWHILE HIGH PRESSURE WILL BUILD FROM EASTERN CANADA TOWARD NORTHERN NEW ENGLAND. AFTER A DRY MILD DAY ON TUESDAY... PRECIPITATION APPEARS LIKELY DURING THE MIDDLE OF NEXT WEEK... POSSIBLY AS EARLY AS TUESDAY NIGHT... BUT MOST LIKELY ON WEDNESDAY. P-TYPE THROUGH WEDNESDAY WILL MOST LIKELY BE RAIN... ALTHOUGH STILL CAN`T RULE OUT A START AS SOME MIXED PRECIPITATION EARLY WEDNESDAY AS HIGH PRESSURE OVER EASTERN CANADA COULD SUPPLY A LITTLE LOW-LEVEL COLD AIR. THE EVOLUTION OF THIS SYSTEM AFTER WEDNESDAY COULD BE A LITTLE TRICKY... AS LATEST GFS/ECMWF INDICATE THAT THE UPPER FORCING WILL TRACK EAST- SOUTHEAST TOWARD THE MID-ATLANTIC COAST... WHICH COULD RESULT IN SOME RE- DEVELOPMENT ALONG THE EAST COAST. OBVIOUSLY DETAILS ARE VERY UNCERTAIN AT THIS POINT... BUT IT WOULD SEEM THAT THIS SYSTEM COULD END AS SOME SNOW SHOWERS ON THURSDAY. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... WDSPRD IFR/MVFR THIS AFTN DUE TO SHSN AND CIGS. BAND OF SQUALLS WILL PRODUCE LIFR ACRS THE SRN TIER BY MID AFTN. DRIER AIR WORKING INTO THE NORTH SXNS WILL GRADUALLY SPREAD S...BUT PATCHY LAKE CLDS/ISOLD MVFR MAY PERSIST WELL INTO THE OVRNGT HRS...BEST CHC WOULD BE SYR/ITH/BGM. VFR XPCTD ALL AREAS ON SUNDAY UNDER PC OR MOSTLY CLR SKIES. WINDS THIS AFTN NWLY 15-30 MPH...DIMINISHING LATER THIS EVNG TO 10-15 KTS AND NW WINDS ARND 10 KTS ON SUNDAY. .OUTLOOK... MON/TUE...MAINLY VFR. TUE NGT/WED/THU...IFR/MVFR MIXED PCPN OR RAIN. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ038>040-043- 044-047-048-072. NY...LAKE EFFECT SNOW ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR NYZ009-018-036-037-044>046-057. WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ009-015>018- 022>025-036-037-044>046-055>057-062. && $$ SYNOPSIS...DGM NEAR TERM...DGM/MDP SHORT TERM...DGM LONG TERM...HEDEN/MSE
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
951 AM EST SAT FEB 25 2012 .SYNOPSIS... A NORTHWEST FLOW OF SEASONABLY COLD AIR ACROSS THE GREAT LAKES WILL BRING LAKE EFFECT SNOW AND SNOW SHOWERS TO MUCH OF THE AREA TODAY. WINDS WILL ALSO OCCASIONALLY GUST ABOVE 40 MPH. HIGH PRESSURE WILL BUILD INTO THE AREA ON SUNDAY BRINGING CLEARING SKIES. && .NEAR TERM /THROUGH TONIGHT/... 945 AM UPDATE...CHENANGO AND CORTLAND COUNTIES...ALONG WITH DELAWARE AND OTSEGO COUNTIES WITHIN THE PAST COUPLE HOURS...HAVE BEEN ADDED TO THE LAKE EFFECT SNOW ADVISORY. COMBINATION OF LAKE EFFECT AND UPSLOPE EFFECTS HAVE ANCHORED SNOW SHOWERS IN THE HIGHER TERRAIN FOR OTSEGO AND DELAWARE COUNTIES...WITH REPORTS OF BETWEEN 3 AND 4 INCHES ALREADY RECEIVED AS OF A LITTLE AFTER 8 AM. MEANWHILE...NARROW AND FAIRLY INTENSE SNOW BAND WITH UPSTREAM LAKE HURON CONNECTION...HOOKS UP TO NORTH OF BUFFALO...THROUGH ROCHESTER...INTO NORTHERN CORTLAND/CHENANGO COUNTIES. A SECOND BAND...WITH GEORGIAN BAY-LAKE ONTARIO CONNECTION...IS BEGINNING TO BREAK LAKE-TO-LAKE CONNECTION UPSTREAM...YET REMAINS FAIRLY STOUT IN ONONDAGA-MADISON COUNTIES. WITH PASSAGE OF SHORTWAVE THE NEXT SEVERAL HOURS...BOTH OF THESE BANDS WILL SHIFT SOUTH TO YIELD ADDITIONAL SNOWFALL FOR CHENANGO- CORTLAND COUNTIES ON TOP OF WHAT HAS ALREADY OCCURRED...AS WELL AS OTSEGO/DELAWARE WITH AID OF UPSLOPE ENHANCEMENT. SOUTH OF THE ADVISORY ZONES...SQUALLS WILL OCCUR YET WILL BE TRANSIENT...AND THUS WITH SNOW TOTALS BELOW ADVISORY CRITERIA. WE ARE EXPECTING 3 TO 6 INCHES TOTAL SNOW IN THE ADVISORY AREA...WITH HIGHER ELEVATIONS OF ONEIDA AND OTSEGO COUNTIES PUSHING INTO 5 TO 7 INCHES RANGE...BEFORE THE SNOW SHOWERS DIMINISH THIS EVENING. POPS AND SNOW AMOUNTS WERE ADJUSTED...TO REFLECT UPDATES AS DESCRIBED ABOVE...BASED ON EXPECTED EVOLUTION OF LAKE EFFECT BANDS THROUGH THE DAY. PREVIOUS DISCUSSION... MULTIPLE BAND LE SNOW EVENT UNDERWAY THIS MRNG. MAIN BAND RUNNING ALONG THE LAKE ONTARIO SHORE LINE INTO ONONDAGA AND ONEIDA COUNTIES. BAND SHOWS SOME SHEARING BUT APPEARS TO BE CONNECTED TO A BAND COMING OFF GEORGIAN BAY. TO THE SOUTH...SVRL STREAMERS COMING OFF HURON CROSSING ERN ERIE ARE CURVING CYCLONICALLY INTO THE FINGER ALKES AND SRN TIER...WITH INCRSD REFLECTIVETY OVER THE WRN CATS AS THE BANDS GET LFTD OVER THE MOUNTAINS. BOTH THE WRFARW AND HRRR SHOW CONTD MULTIPLE BANDS THRU THE DAY TODAY. ACTIVITY SHD BE ENHANCED BY A SCNDRY SHRT WV ROTATING THRU THE UPPER TROF DURING THE DAY. CRNTLY HAVE AN ADVISORY FOR THE NRN COUNTIES. BELIEVE THIS IS WELL PLACED AND SHD WRK AS AMTS SHD HOLD BLO WARNING DO TO THE STEADY SWRD MVMT OF THE BAND SHOWN BY THE SHRT RANGE MODELS. SOME CNCRN TO THE SOUTH ACROSS NRN CORTLAND AND CHENANGO FOR ADVISORY CRITERIA SNOWS THERE. NO PRBLMS THERE ATTM AS THE BANDS ARE GNRLY NORTH OF THERE. WHEN THE BAND DOES DROP THRU THE MRNG...DAYLIGHT AND BAND MVMT SHD KEEP AMTS DOWN. TO THE SOUTH...AN INCH OR TWO OF SNOW LOOKS LIKE A GOOD BET. && .SHORT TERM /SUNDAY THROUGH MONDAY/... DRIER AIR...RISING HGTS...AND A CUT OFF FROM THE UPSTREAM CONNECTION WILL QUICKLY HELP THE LE TO WIND DOWN THIS EVE. HIGH PRESSURE BLDS IN ON SUNDAY BRINGING YET ANOTHER QUICK END TO A COLD OUTBREAK. TEMPS WILL RCVR QUICKLY TO NEAR NORMS SUN AFTN...AND EVEN HIER MON. SYSTEM OVER THE WRN LAKES SWINGS A WRM FNT THRU EARLY MON BUT WITH DRY AIR IN PLACE AND UPR SUPPORT WELL WEST...LTL CHANCE FOR ANY REAL PCPN. MON LOOKS QUITE MILD WITH TEMPS ABV NRML AHD OF A WEAK AND DRY COLD FNT LATER MON OR EARLY TUE. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... 3 AM UPDATE... MAIN FEATURE TO MONITOR DURING THE MIDDLE OF NEXT WEEK WILL BE A STORM SYSTEM FORECAST BY ALL MODELS TO TRACK FROM THE ROCKIES TOWARD THE WESTERN GREAT LAKES TUESDAY INTO WEDNESDAY. MEANWHILE HIGH PRESSURE WILL BUILD FROM EASTERN CANADA TOWARD NORTHERN NEW ENGLAND. AFTER A DRY MILD DAY ON TUESDAY... PRECIPITATION APPEARS LIKELY DURING THE MIDDLE OF NEXT WEEK... POSSIBLY AS EARLY AS TUESDAY NIGHT... BUT MOST LIKELY ON WEDNESDAY. P-TYPE THROUGH WEDNESDAY WILL MOST LIKELY BE RAIN... ALTHOUGH STILL CAN`T RULE OUT A START AS SOME MIXED PRECIPITATION EARLY WEDNESDAY AS HIGH PRESSURE OVER EASTERN CANADA COULD SUPPLY A LITTLE LOW-LEVEL COLD AIR. THE EVOLUTION OF THIS SYSTEM AFTER WEDNESDAY COULD BE A LITTLE TRICKY... AS LATEST GFS/ECMWF INDICATE THAT THE UPPER FORCING WILL TRACK EAST- SOUTHEAST TOWARD THE MID-ATLANTIC COAST... WHICH COULD RESULT IN SOME RE- DEVELOPMENT ALONG THE EAST COAST. OBVIOUSLY DETAILS ARE VERY UNCERTAIN AT THIS POINT... BUT IT WOULD SEEM THAT THIS SYSTEM COULD END AS SOME SNOW SHOWERS ON THURSDAY. && .AVIATION /15Z SATURDAY THROUGH WEDNESDAY/... STRONG WESTERLY WINDS AND AREAS OF LAKE EFFECT SNOW WILL EFFECT THE NY TAF SITES THROUGH TODAY. VSBYS AND CIGS WILL BE MAINLY MVFR... WITH PERIODS OF IFR LIKELY IN BRIEF... HEAVIER SQUALLS. BEST CHC FOR THESE HEAVIER SQUALLS WILL BE AT SYR AND RME... WITH A CHC FOR HEAVIER SQUALLS GETTING DOWN TO ITH AND BGM AFTER 14Z. WINDS WILL BE WESTERLY... SHIFTING TO WNW... WITH SPEEDS AVERAGING 15 TO 25 KTS WITH GUSTS 30 TO 40 KTS THROUGH THIS AFTERNOON. MEANWHILE EXPECT JUST SCT SNOW SHOWERS AT ELM AND GENERALLY JUST LIGHT FLURRIES AT AVP. NORTHWEST WINDS WILL BEGIN TO DIMINISH SATURDAY NIGHT... AND WITH MOISTURE DECREASING EXPECT LAKE EFFECT SNOW SHOWER COVERAGE AND INTENSITY TO DIMINISH THROUGH THE NIGHT. A FEW PERIODS OF MVFR VSBYS AND CICS CAN STILL BE EXPECTED THROUGH SATURDAY EVENING... ESPECIALLY AT SYR AND RME. NW WINDS WILL DIMINISH TO 10 TO 20 KTS WITH A FEW GUSTS TO 25 KTS. .OUTLOOK... SUN/MON/TUE...MAINLY VFR. WED...IFR/MVFR IN RAIN. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ038>040-043- 044-047-048-072. NY...LAKE EFFECT SNOW ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR NYZ009-018-036-037-044>046-057. WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ009-015>018- 022>025-036-037-044>046-055>057-062. && $$ SYNOPSIS...DGM NEAR TERM...DGM/MDP SHORT TERM...DGM LONG TERM...HEDEN/MSE AVIATION...MSE
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
849 AM EST SAT FEB 25 2012 .SYNOPSIS... A NORTHWEST FLOW OF SEASONABLY COLD AIR ACROSS THE GREAT LAKES WILL BRING LAKE EFFECT SNOW AND SNOW SHOWERS TO MUCH OF THE AREA TODAY. HIGH PRESSURE WILL BUILD INTO THE AREA ON SUNDAY BRINGING CLEARING SKIES. && .NEAR TERM /THROUGH TONIGHT/... 845 AM UPDATE...DELAWARE AND OTSEGO COUNTIES HAVE BEEN ADDED TO THE LAKE EFFECT SNOW ADVISORY. COMBINATION OF LAKE EFFECT AND UPSLOPE EFFECTS HAVE ANCHORED SNOW SHOWERS IN THE HIGHER TERRAIN...WITH REPORTS BETWEEN 3 AND 4 INCHES ALREADY RECEIVED. SO WE ARE EXPECTING 4 TO 6 INCHES TOTAL THERE TODAY BEFORE THE SNOW SHOWERS DIMINISH THIS EVENING. GENERAL IDEA OF FORECAST IS ON TRACK...THOUGH POPS AND SNOW AMOUNTS WERE ALSO ADJUSTED AS NEEDED BASED ON EXPECTED EVOLUTION OF LAKE EFFECT BANDS THROUGH THE DAY. PREVIOUS DISCUSSION... MULTIPLE BAND LE SNOW EVENT UNDERWAY THIS MRNG. MAIN BAND RUNNING ALONG THE LAKE ONTARIO SHORE LINE INTO ONONDAGA AND ONEIDA COUNTIES. BAND SHOWS SOME SHEARING BUT APPEARS TO BE CONNECTED TO A BAND COMING OFF GEORGIAN BAY. TO THE SOUTH...SVRL STREAMERS COMING OFF HURON CROSSING ERN ERIE ARE CURVING CYCLONICALLY INTO THE FINGER ALKES AND SRN TIER...WITH INCRSD REFLECTIVETY OVER THE WRN CATS AS THE BANDS GET LFTD OVER THE MOUNTAINS. BOTH THE WRFARW AND HRRR SHOW CONTD MULTIPLE BANDS THRU THE DAY TODAY. ACTIVITY SHD BE ENHANCED BY A SCNDRY SHRT WV ROTATING THRU THE UPPER TROF DURING THE DAY. CRNTLY HAVE AN ADVISORY FOR THE NRN COUNTIES. BELIEVE THIS IS WELL PLACED AND SHD WRK AS AMTS SHD HOLD BLO WARNING DO TO THE STEADY SWRD MVMT OF THE BAND SHOWN BY THE SHRT RANGE MODELS. SOME CNCRN TO THE SOUTH ACROSS NRN CORTLAND AND CHENANGO FOR ADVISORY CRITERIA SNOWS THERE. NO PRBLMS THERE ATTM AS THE BANDS ARE GNRLY NORTH OF THERE. WHEN THE BAND DOES DROP THRU THE MRNG...DAYLIGHT AND BAND MVMT SHD KEEP AMTS DOWN. TO THE SOUTH...AN INCH OR TWO OF SNOW LOOKS LIKE A GOOD BET. && .SHORT TERM /SUNDAY THROUGH MONDAY/... DRIER AIR...RISING HGTS...AND A CUT OFF FROM THE UPSTREAM CONNECTION WILL QUICKLY HELP THE LE TO WIND DOWN THIS EVE. HIGH PRESSURE BLDS IN ON SUNDAY BRINGING YET ANOTHER QUICK END TO A COLD OUTBREAK. TEMPS WILL RCVR QUICKLY TO NEAR NORMS SUN AFTN...AND EVEN HIER MON. SYSTEM OVER THE WRN LAKES SWINGS A WRM FNT THRU EARLY MON BUT WITH DRY AIR IN PLACE AND UPR SUPPORT WELL WEST...LTL CHANCE FOR ANY REAL PCPN. MON LOOKS QUITE MILD WITH TEMPS ABV NRML AHD OF A WEAK AND DRY COLD FNT LATER MON OR EARLY TUE. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... 3 AM UPDATE... MAIN FEATURE TO MONITOR DURING THE MIDDLE OF NEXT WEEK WILL BE A STORM SYSTEM FORECAST BY ALL MODELS TO TRACK FROM THE ROCKIES TOWARD THE WESTERN GREAT LAKES TUESDAY INTO WEDNESDAY. MEANWHILE HIGH PRESSURE WILL BUILD FROM EASTERN CANADA TOWARD NORTHERN NEW ENGLAND. AFTER A DRY MILD DAY ON TUESDAY... PRECIPITATION APPEARS LIKELY DURING THE MIDDLE OF NEXT WEEK... POSSIBLY AS EARLY AS TUESDAY NIGHT... BUT MOST LIKELY ON WEDNESDAY. P-TYPE THROUGH WEDNESDAY WILL MOST LIKELY BE RAIN... ALTHOUGH STILL CAN`T RULE OUT A START AS SOME MIXED PRECIPITATION EARLY WEDNESDAY AS HIGH PRESSURE OVER EASTERN CANADA COULD SUPPLY A LITTLE LOW-LEVEL COLD AIR. THE EVOLUTION OF THIS SYSTEM AFTER WEDNESDAY COULD BE A LITTLE TRICKY... AS LATEST GFS/ECMWF INDICATE THAT THE UPPER FORCING WILL TRACK EAST- SOUTHEAST TOWARD THE MID-ATLANTIC COAST... WHICH COULD RESULT IN SOME RE- DEVELOPMENT ALONG THE EAST COAST. OBVIOUSLY DETAILS ARE VERY UNCERTAIN AT THIS POINT... BUT IT WOULD SEEM THAT THIS SYSTEM COULD END AS SOME SNOW SHOWERS ON THURSDAY. && .AVIATION /14Z SATURDAY THROUGH WEDNESDAY/... STRONG WESTERLY WINDS AND AREAS OF LAKE EFFECT SNOW WILL EFFECT THE NY TAF SITES THROUGH TODAY. VSBYS AND CIGS WILL BE MAINLY MVFR... WITH PERIODS OF IFR LIKELY IN BRIEF... HEAVIER SQUALLS. BEST CHC FOR THESE HEAVIER SQUALLS WILL BE AT SYR AND RME... WITH A CHC FOR HEAVIER SQUALLS GETTING DOWN TO ITH AND BGM AFTER 14Z. WINDS WILL BE WESTERLY... SHIFTING TO WNW... WITH SPEEDS AVERAGING 15 TO 25 KTS WITH GUSTS 30 TO 40 KTS THROUGH THIS AFTERNOON. MEANWHILE EXPECT JUST SCT SNOW SHOWERS AT ELM AND GENERALLY JUST LIGHT FLURRIES AT AVP. NORTHWEST WINDS WILL BEGIN TO DIMINISH SATURDAY NIGHT... AND WITH MOISTURE DECREASING EXPECT LAKE EFFECT SNOW SHOWER COVERAGE AND INTENSITY TO DIMINISH THROUGH THE NIGHT. A FEW PERIODS OF MVFR VSBYS AND CICS CAN STILL BE EXPECTED THROUGH SATURDAY EVENING... ESPECIALLY AT SYR AND RME. NW WINDS WILL DIMINISH TO 10 TO 20 KTS WITH A FEW GUSTS TO 25 KTS. .OUTLOOK... SUN/MON/TUE...MAINLY VFR. WED...IFR/MVFR IN RAIN. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ038>040-043- 044-047-048-072. NY...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ009-015>018- 022>025-036-037-044>046-055>057-062. LAKE EFFECT SNOW ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR NYZ009-018-036-037-046-057. && $$ SYNOPSIS...DGM NEAR TERM...DGM/MDP SHORT TERM...DGM LONG TERM...HEDEN/MSE AVIATION...MSE
AREA FORECAST DISCUSSION
NWS BUFFALO NY
759 AM EST SAT FEB 25 2012 .SYNOPSIS... COLDER AIR BUILDING ACROSS THE EASTERN GREAT LAKES WILL CONTINUE TO GENERATE LAKE EFFECT SNOW TODAY. HIGH PRESSURE BUILDING EAST FROM THE OHIO VALLEY WILL ALLOW THE LAKE SNOWS TO DIMINISH TONIGHT...FOLLOWED BY SOME SUNSHINE ON SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... LAKE EFFECT SNOW ADVISORIES/WARNINGS REMAIN IN EFFECT AS OUTLINED BELOW. THE WINTER STORM WARNING FOR JEFFERSON COUNTY HAS BEEN CANCELLED. AREA RADARS HAVE SHOWN A DRAMATIC DECREASE IN SNOW COVERAGE EAST OF LAKE ONTARIO DURING THE PAST FEW HOURS. IT SEEMS THAT MOST OF THE DEEPER SYNOPTIC SCALE MOISTURE HAS SHIFTED EAST WITH THE DEEP LOW THAT IS NOW CENTERED OVER THE CANADIAN MARITIMES. THE STRONG WESTERLY WINDS HAVE ALSO REDUCED THE RESIDENCE OVER LAKE ONTARIO...WHICH HAS FURTHER REDUCED THE INTENSITY OF THE SNOWFALL. THE HRRR WHICH HAS PICKED UP THESE TRENDS DOES HINT AT THE POSSIBILITY OF MORE SNOW SETTING UP OVER OSWEGO COUNTY DURING THE AFTERNOON. THEREFORE...PLAN TO LEAVE UP THE LAKE EFFECT SNOW WARNING THAT IS IN PLACE THERE. UPSTREAM CONNECTIONS TO GEORGIAN BAY AND LAKE ONTARIO HAVE ALLOWED THE NARROW SNOW BANDS OVER THE WESTERN AND CENTRAL PART OF THE LAKE TO REMAIN INTACT. OFF LAKE ERIE...THE CONNECTION TO LAKE HURON AND THE PERSISTENT UPSLOPE FLOW HAS KEPT THE SNOW BANDS INTACT ACROSS THE SOUTHERN TIER. THESE BANDS WILL HOLD TOGETHER UNTIL THE LOW LEVEL MOISTURE BEGINS TO DECREASE LATER THIS AFTERNOON AND THE INVERSION LOWERS. THEREFORE...THE LAKE EFFECT SNOW ADVISORY WILL REMAIN IN EFFECT. TONIGHT...A RAPID DECREASE IN SYNOPTIC MOISTURE AND LOWERING INVERSION HEIGHTS WILL HELP LINGERING LAKE SNOWS TO TAPER OFF AND BE MOSTLY OVER BY 12Z SUNDAY. WESTERLY WINDS WILL CONTINUE TO GUST OVER 30 MPH FOR MOST OF THE DAY. THIS WILL LEAD TO FREQUENT WHITEOUTS IN THE HEAVIER LAKE SNOW AREAS. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... A HIGH PRESSURE RIDGE WILL BUILD ACROSS THE REGION ON SUNDAY. LIGHT SNOW SHOWERS OR FLURRIES MAY LINGER SOUTHEAST OF LAKE ONTARIO SUNDAY MORNING...BUT THESE SHOULD END BY AFTERNOON AS WINDS DIMINISH AND SHIFT. OTHERWISE...EXPECT A CLEARING TREND FOR THE AFTERNOON...WITH HIGHS GENERALLY IN THE LOWER 30S IN MOST LOCATIONS...A BIT COOLER TOWARD THE NORTH COUNTRY. ON SUNDAY NIGHT...THE HIGH WILL SLIDE OFF TO THE EAST...AS A WEAK AREA OF LOW PRESSURE TRACKS ACROSS THE UPPER LAKES. THIS WILL LIFT A WEAK WARM FRONT ACROSS THE REGION OVERNIGHT. THERE WILL BE AN AREA OF WEAK WARM AIR ADVECTION IN THE MID-LEVELS...WHICH MAY BRING A BRIEF PERIOD OF FLURRIES AS IT LIFTS ACROSS THE REGION FROM THE SOUTHWEST TO NORTHEAST. THE BEST CHANCE FOR ANYTHING MEASURABLE WILL LATE SUNDAY NIGHT BE EAST OF LAKE ONTARIO...WHICH IS CLOSEST TO THE TRACK OF THE LOW. THE LOW AND ASSOCIATED SHORTWAVE WILL PASS TO THE NORTH OF THE REGION ON MONDAY. FOR MOST LOCATIONS...THIS LOW WILL BE FAR ENOUGH TO THE NORTH THAT MONDAY WILL REMAIN DRY...WITH NOTABLY WARMER CONDITIONS...AND A MODEST SW BREEZY. HIGHS SHOULD BE QUITE A BIT ABOVE NORMAL...WITH TEMPERATURES LIKELY TO CLIMB WELL INTO THE 40S IN MOST LOCATIONS. HOWEVER...NOTED THAT THE UKMET/EUROPEAN/GGEM MODELS TEND TO BE A BIT MORE GENEROUS WITH QPF EAST OF LAKE ONTARIO THAN THE NAM/GFS MODELS. WITH THE SURFACE LOW AND UPPER SHORTWAVE PASSING FAIRLY CLOSE...DO TREND POPS UP A TAD EAST OF LAKE ONTARIO. THIS IS STILL IN THE CHANCE RANGE...WITH EITHER RAIN OR SNOW SHOWERS A POSSIBILITY. THE LOW WILL TRACK INTO NEW ENGLAND MONDAY NIGHT...WITH THIS USHERING IN SLIGHTLY COLDER AIR BEHIND IT. 850 MB TEMPERATURES WILL BE MARGINAL AT BEST FOR ANY LAKE RESPONSE...WITH AROUND -8C ACROSS LAKE ONTARIO. CAN/T RULE OUT A BRIEF PERIOD OF LIGHT SNOW SHOWERS EAST AND SOUTHEAST OF LAKE ONTARIO MONDAY NIGHT...BUT ANY ACCUMULATIONS SHOULD NOT BE MUCH AT ALL. && .LONG TERM /TUESDAY THROUGH FRIDAY/... THE EXTENDED PERIOD WILL START OFF WITH AN ELONGATED RIDGE OF CANADIAN HIGH PRESSURE SLIDING EAST ACROSS THE AREA ON TUESDAY. COOLER AND DRIER AIR ASSOCIATED WITH THE HIGH WILL RESULT IN A RETURN TO MORE SEASONABLE TEMPERATURES AREAWIDE...ALONG WITH DRY CONDITIONS. AFTER THAT...THE MEDIUM RANGE GUIDANCE IS IN RATHER GOOD AGREEMENT THAT THE TUESDAY NIGHT THROUGH THURSDAY PERIOD WILL LIKELY FEATURE THE APPROACH AND PASSAGE OF ANOTHER SIGNIFICANT "CUTTER" TYPE LOW PRESSURE SYSTEM...WITH A MODEL CONSENSUS TRACKING THIS SYSTEM FROM IOWA NORTHEASTWARD ACROSS THE CENTRAL GREAT LAKES...THEN ON INTO QUEBEC WHILE SLOWLY FILLING. THE 00Z RUN OF THE EUROPEAN DIFFERS FROM THIS SOLUTION...WITH A SLOWER AND COLDER SOLUTION. WITH SUPPORT FROM PREVIOUS RUNS...AND THE 00Z GGEM...WILL CONTINUE WITH A GFS-LIKE SOLUTION...TRENDING A TAD SLOWER AND COLDER TO BLEND WITH THE EUROPEAN MODEL. THIS WILL LIKELY BRING A PERIOD OF PRECIPITATION LATE TUESDAY NIGHT AND WEDNESDAY. EXPECT MOST OF THIS TO FALL AS RAIN...EXCEPT IN THE NORTH COUNTRY WHERE SNOW IS MORE LIKELY. TEMPERATURES WILL BE TRICKY GIVEN UNCERTAINTY IN THE TRACK AND TIMING OF THE LOW...BUT DO FEEL THE SOUTHERN TIER AND POSSIBLY BUFFALO/ROCHESTER WILL BREAK INTO THE WARM SECTOR WITH TEMPERATURES IN THE MID 40S OR WARMER. FOLLOWING THE PASSAGE OF THIS SYSTEM`S COLD FRONT WEDNESDAY EVENING...SEASONABLY COOLER AIR WILL THEN SPREAD BACK ACROSS THE AREA WEDNESDAY NIGHT AND THURSDAY. THIS WILL RESULT IN ANY LINGERING WRAPAROUND PRECIPITATION CHANGING BACK TO MOSTLY SNOW SHOWERS AS THE LOW SLOWLY LIFTS OFF INTO WESTERN QUEBEC AND AWAY FROM OUR REGION...THOUGH BOUNDARY LAYER TEMPS COULD VERY WELL WARM UP ENOUGH AGAIN ON THURSDAY TO ALLOW FOR SOME RAIN SHOWERS TO MIX IN ONCE AGAIN. IN GENERAL...THE PRECIPITATION SHOULD BE LIGHT AND TEND TO TAPER OFF FROM SOUTH TO NORTH THROUGH THURSDAY NIGHT AS THE LOW PULLS FURTHER AWAY...WITH INCREASING RIDGING THEN RESULTING IN A RETURN TO MAINLY DRY WEATHER FOR FRIDAY. TEMPS THROUGH THIS LATTER HALF OF THE PERIOD WILL FALL OFF AGAIN WITH THE REINTRODUCTION OF SOME COOLER AIR...THOUGH WILL LIKELY STILL AVERAGE OUT ABOVE NORMAL WITH NIGHTTIME LOWS RANGING BETWEEN 20 AND 30...AND DAYTIME HIGHS REACHING INTO THE MID AND UPPER 30S. && .AVIATION /13Z SATURDAY THROUGH WEDNESDAY/... WINDS GUST HAVE DIMINISHED ACROSS THE AREA FOR THE 12Z TAF PACKAGE. NARROW BANDS OF SNOW WILL REMAIN INTACT SOUTHEAST OF BOTH LAKES THROUGHOUT THE AFTERNOON. THIS WILL ALLOW CONDITIONS TO DROP TO IFR WHERE THE STEADIER LAKE SNOWS PERSISTS. OTHERWISE...EXPECT MAINLY MVFR CONDITIONS TO PREVAIL. AS DRIER AIR WORKS INTO THE AREA TONIGHT...THE LAKE SNOWS WILL END AND CIGS/VSBYS WILL IMPROVE TO VFR. OUTLOOK... SUNDAY...VFR...SCTD LAKE EFFECT SNOW SOUTHEASTERN LAKE ONTARIO. MONDAY AND TUESDAY...VFR. WEDNESDAY...MFR/IFR IN RAIN. && .MARINE... GALE CONDITIONS WILL DIMINISH FROM WEST TO EAST TODAY AS THE DEEP LOW LIFTS EAST ACROSS THE CANADIAN MARITIMES. WIND AND WAVES WILL SUBSIDE FURTHER TONIGHT AND SUNDAY AS HIGH PRESSURE BUILDS EAST ACROSS NEW YORK STATE. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...LAKE EFFECT SNOW ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR NYZ004-005-008-012-019-020-085. LAKE EFFECT SNOW WARNING UNTIL 5 PM EST THIS AFTERNOON FOR NYZ006. MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR LEZ020. GALE WARNING UNTIL 11 AM EST THIS MORNING FOR LEZ040-041. SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR LOZ030. GALE WARNING UNTIL 4 PM EST THIS AFTERNOON FOR LOZ043>045- 063>065. GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LOZ042-062. && $$ SYNOPSIS...TJP NEAR TERM...TJP SHORT TERM...APFFEL LONG TERM...APFFEL/JJR AVIATION...TJP MARINE...TJP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
641 AM EST SAT FEB 25 2012 .SYNOPSIS... A NORTHWEST FLOW OF SEASONABLY COLD AIR ACROSS THE GREAT LAKES WILL BRING LAKE EFFECT SNOW AND SNOW SHOWERS TO MUCH OF THE AREA TODAY. HIGH PRESSURE WILL BUILD INTO THE AREA ON SUNDAY BRINGING CLEARING SKIES. && .NEAR TERM /THROUGH TONIGHT/... MULTIPLE BAND LE SNOW EVENT UNDERWAY THIS MRNG. MAIN BAND RUNNING ALONG THE LAKE ONTARIO SHORE LINE INTO ONONDAGA AND ONEIDA COUNTIES. BAND SHOWS SOME SHEARING BUT APPEARS TO BE CONNECTED TO A BAND COMING OFF GEORGIAN BAY. TO THE SOUTH...SVRL STREAMERS COMING OFF HURON CROSSING ERN ERIE ARE CURVING CYCLONICALLY INTO THE FINGER ALKES AND SRN TIER...WITH INCRSD REFLECTIVETY OVER THE WRN CATS AS THE BANDS GET LFTD OVER THE MOUNTAINS. BOTH THE WRFARW AND HRRR SHOW CONTD MULTIPLE BANDS THRU THE DAY TODAY. ACTIVITY SHD BE ENHANCED BY A SCNDRY SHRT WV ROTATING THRU THE UPPER TROF DURING THE DAY. CRNTLY HAVE AN ADVISORY FOR THE NRN COUNTIES. BELIEVE THIS IS WELL PLACED AND SHD WRK AS AMTS SHD HOLD BLO WARNING DO TO THE STEADY SWRD MVMT OF THE BAND SHOWN BY THE SHRT RANGE MODELS. SOME CNCRN TO THE SOUTH ACROSS NRN CORTLAND AND CHENANGO FOR ADVISORY CRITERIA SNOWS THERE. NO PRBLMS THERE ATTM AS THE BANDS ARE GNRLY NORTH OF THERE. WHEN THE BAND DOES DROP THRU THE MRNG...DAYLIGHT AND BAND MVMT SHD KEEP AMTS DOWN. TO THE SOUTH...AN INCH OR TWO OF SNOW LOOKS LIKE A GOOD BET. && .SHORT TERM /SUNDAY THROUGH MONDAY/... DRIER AIR...RISING HGTS...AND A CUT OFF FROM THE UPSTREAM CONNECTION WILL QUICKLY HELP THE LE TO WIND DOWN THIS EVE. HIGH PRESSURE BLDS IN ON SUNDAY BRINGING YET ANOTHER QUICK END TO A COLD OUTBREAK. TEMPS WILL RCVR QUICKLY TO NEAR NORMS SUN AFTN...AND EVEN HIER MON. SYSTEM OVER THE WRN LAKES SWINGS A WRM FNT THRU EARLY MON BUT WITH DRY AIR IN PLACE AND UPR SUPPORT WELL WEST...LTL CHANCE FOR ANY REAL PCPN. MON LOOKS QUITE MILD WITH TEMPS ABV NRML AHD OF A WEAK AND DRY COLD FNT LATER MON OR EARLY TUE. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... 3 AM UPDATE... MAIN FEATURE TO MONITOR DURING THE MIDDLE OF NEXT WEEK WILL BE A STORM SYSTEM FORECAST BY ALL MODELS TO TRACK FROM THE ROCKIES TOWARD THE WESTERN GREAT LAKES TUESDAY INTO WEDNESDAY. MEANWHILE HIGH PRESSURE WILL BUILD FROM EASTERN CANADA TOWARD NORTHERN NEW ENGLAND. AFTER A DRY MILD DAY ON TUESDAY... PRECIPITATION APPEARS LIKELY DURING THE MIDDLE OF NEXT WEEK... POSSIBLY AS EARLY AS TUESDAY NIGHT... BUT MOST LIKELY ON WEDNESDAY. P-TYPE THROUGH WEDNESDAY WILL MOST LIKELY BE RAIN... ALTHOUGH STILL CAN`T RULE OUT A START AS SOME MIXED PRECIPITATION EARLY WEDNESDAY AS HIGH PRESSURE OVER EASTERN CANADA COULD SUPPLY A LITTLE LOW-LEVEL COLD AIR. THE EVOLUTION OF THIS SYSTEM AFTER WEDNESDAY COULD BE A LITTLE TRICKY... AS LATEST GFS/ECMWF INDICATE THAT THE UPPER FORCING WILL TRACK EAST- SOUTHEAST TOWARD THE MID-ATLANTIC COAST... WHICH COULD RESULT IN SOME RE- DEVELOPMENT ALONG THE EAST COAST. OBVIOUSLY DETAILS ARE VERY UNCERTAIN AT THIS POINT... BUT IT WOULD SEEM THAT THIS SYSTEM COULD END AS SOME SNOW SHOWERS ON THURSDAY. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... STRONG WESTERLY WINDS AND AREAS OF LAKE EFFECT SNOW WILL EFFECT THE NY TAF SITES THROUGH TODAY. VSBYS AND CIGS WILL BE MAINLY MVFR... WITH PERIODS OF IFR LIKELY IN BRIEF... HEAVIER SQUALLS. BEST CHC FOR THESE HEAVIER SQUALLS WILL BE AT SYR AND RME... WITH A CHC FOR HEAVIER SQUALLS GETTING DOWN TO ITH AND BGM AFTER 14Z. WINDS WILL BE WESTERLY... SHIFTING TO WNW... WITH SPEEDS AVERAGING 15 TO 25 KTS WITH GUSTS 30 TO 40 KTS THROUGH THIS AFTERNOON. MEANWHILE EXPECT JUST SCT SNOW SHOWERS AT ELM AND GENERALLY JUST LIGHT FLURRIES AT AVP. NORTHWEST WINDS WILL BEGIN TO DIMINISH SATURDAY NIGHT... AND WITH MOISTURE DECREASING EXPECT LAKE EFFECT SNOW SHOWER COVERAGE AND INTENSITY TO DIMINISH THROUGH THE NIGHT. A FEW PERIODS OF MVFR VSBYS AND CICS CAN STILL BE EXPECTED THROUGH SATURDAY EVENING... ESPECIALLY AT SYR AND RME. NW WINDS WILL DIMINISH TO 10 TO 20 KTS WITH A FEW GUSTS TO 25 KTS. .OUTLOOK... SUN/MON/TUE...MAINLY VFR. WED...IFR/MVFR IN RAIN. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ038>040-043- 044-047-048-072. NY...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ009-015>018- 022>025-036-037-044>046-055>057-062. LAKE EFFECT SNOW ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR NYZ009-018-036-037. && $$ SYNOPSIS...DGM NEAR TERM...DGM SHORT TERM...DGM LONG TERM...HEDEN/MSE AVIATION...MSE
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
348 AM EST SAT FEB 25 2012 .SYNOPSIS... A NORTHWEST FLOW OF SEASONABLY COLD AIR ACROSS THE GREAT LAKES WILL BRING LAKE EFFECT SNOW AND SNOW SHOWERS TO MUCH OF THE AREA TODAY. HIGH PRESSURE WILL BUILD INTO THE AREA ON SUNDAY BRINGING CLEARING SKIES. && .NEAR TERM /THROUGH TONIGHT/... MULTIPLE BAND LE SNOW EVENT UNDERWAY THIS MRNG. MAIN BAND RUNNING ALONG THE LAKE ONTARIO SHORE LINE INTO ONONDAGA AND ONEIDA COUNTIES. BAND SHOWS SOME SHEARING BUT APPEARS TO BE CONNECTED TO A BAND COMING OFF GEORGIAN BAY. TO THE SOUTH...SVRL STREAMERS COMING OFF HURON CROSSING ERN ERIE ARE CURVING CYCLONICALLY INTO THE FINGER ALKES AND SRN TIER...WITH INCRSD REFLECTIVETY OVER THE WRN CATS AS THE BANDS GET LFTD OVER THE MOUNTAINS. BOTH THE WRFARW AND HRRR SHOW CONTD MULTIPLE BANDS THRU THE DAY TODAY. ACTIVITY SHD BE ENHANCED BY A SCNDRY SHRT WV ROTATING THRU THE UPPER TROF DURING THE DAY. CRNTLY HAVE AN ADVISORY FOR THE NRN COUNTIES. BELIEVE THIS IS WELL PLACED AND SHD WRK AS AMTS SHD HOLD BLO WARNING DO TO THE STEADY SWRD MVMT OF THE BAND SHOWN BY THE SHRT RANGE MODELS. SOME CNCRN TO THE SOUTH ACROSS NRN CORTLAND AND CHENANGO FOR ADVISORY CRITERIA SNOWS THERE. NO PRBLMS THERE ATTM AS THE BANDS ARE GNRLY NORTH OF THERE. WHEN THE BAND DOES DROP THRU THE MRNG...DAYLIGHT AND BAND MVMT SHD KEEP AMTS DOWN. TO THE SOUTH...AN INCH OR TWO OF SNOW LOOKS LIKE A GOOD BET. && .SHORT TERM /SUNDAY THROUGH MONDAY/... DRIER AIR...RISING HGTS...AND A CUT OFF FROM THE UPSTREAM CONNECTION WILL QUICKLY HELP THE LE TO WIND DOWN THIS EVE. HIGH PRESSURE BLDS IN ON SUNDAY BRINGING YET ANOTHER QUICK END TO A COLD OUTBREAK. TEMPS WILL RCVR QUICKLY TO NEAR NORMS SUN AFTN...AND EVEN HIER MON. SYSTEM OVER THE WRN LAKES SWINGS A WRM FNT THRU EARLY MON BUT WITH DRY AIR IN PLACE AND UPR SUPPORT WELL WEST...LTL CHANCE FOR ANY REAL PCPN. MON LOOKS QUITE MILD WITH TEMPS ABV NRML AHD OF A WEAK AND DRY COLD FNT LATER MON OR EARLY TUE. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... 3 AM UPDATE... MAIN FEATURE TO MONITOR DURING THE MIDDLE OF NEXT WEEK WILL BE A STORM SYSTEM FORECAST BY ALL MODELS TO TRACK FROM THE ROCKIES TOWARD THE WESTERN GREAT LAKES TUESDAY INTO WEDNESDAY. MEANWHILE HIGH PRESSURE WILL BUILD FROM EASTERN CANADA TOWARD NORTHERN NEW ENGLAND. AFTER A DRY MILD DAY ON TUESDAY... PRECIPITATION APPEARS LIKELY DURING THE MIDDLE OF NEXT WEEK... POSSIBLY AS EARLY AS TUESDAY NIGHT... BUT MOST LIKELY ON WEDNESDAY. P-TYPE THROUGH WEDNESDAY WILL MOST LIKELY BE RAIN... ALTHOUGH STILL CAN`T RULE OUT A START AS SOME MIXED PRECIPITATION EARLY WEDNESDAY AS HIGH PRESSURE OVER EASTERN CANADA COULD SUPPLY A LITTLE LOW-LEVEL COLD AIR. THE EVOLUTION OF THIS SYSTEM AFTER WEDNESDAY COULD BE A LITTLE TRICKY... AS LATEST GFS/ECMWF INDICATE THAT THE UPPER FORCING WILL TRACK EAST- SOUTHEAST TOWARD THE MID-ATLANTIC COAST... WHICH COULD RESULT IN SOME RE- DEVELOPMENT ALONG THE EAST COAST. OBVIOUSLY DETAILS ARE VERY UNCERTAIN AT THIS POINT... BUT IT WOULD SEEM THAT THIS SYSTEM COULD END AS SOME SNOW SHOWERS ON THURSDAY. && .AVIATION /09Z SATURDAY THROUGH WEDNESDAY/... STRONG WESTERLY WINDS AND AREAS OF LAKE EFFECT SNOW WILL EFFECT THE NY TAF SITES THROUGH SATURDAY. VSBYS AND CIGS WILL BE MAINLY MVFR... WITH PERIODS OF IFR LIKELY IN BRIEF... HEAVIER SQUALLS. BEST CHC FOR THESE HEAVIER SQUALLS WILL BE AT SYR AND RME... WITH A CHC FOR HEAVIER SQUALLS GETTING DOWN TO ITH AND BGM AFTER 14Z. WINDS WILL BE WESTERLY... SHIFTING TO WNW... WITH SPEEDS AVERAGING 15 TO 25 KTS WITH GUSTS 30 TO 40 KTS THROUGH THIS AFTERNOON. MEANWHILE EXPECT JUST SCT SNOW SHOWERS AT ELM AND GENERALLY JUST LIGHT FLURRIES AT AVP. NORTHWEST WINDS WILL BEGIN TO DIMINISH SATURDAY NIGHT... AND WITH MOISTURE DECREASING EXPECT LAKE EFFECT SNOW SHOWER COVERAGE AND INTENSITY TO DIMINISH THROUGH THE NIGHT. A FEW PERIODS OF MVFR VSBYS AND CICS CAN STILL BE EXPECTED THROUGH SATURDAY EVENING... ESPECIALLY AT SYR AND RME. NW WINDS WILL DIMINISH TO 10 TO 20 KTS WITH A FEW GUSTS TO 25 KTS. .OUTLOOK... SUN/MON/TUE...MAINLY VFR. WED...IFR/MVFR IN RAIN. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ038>040-043- 044-047-048-072. NY...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NYZ009-015>018- 022>025-036-037-044>046-055>057-062. LAKE EFFECT SNOW ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR NYZ009-018-036-037. && $$ SYNOPSIS...DGM NEAR TERM...DGM SHORT TERM...DGM LONG TERM...HEDEN/MSE AVIATION...MSE
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
919 PM CST SUN FEB 26 2012 .DISCUSSION... MAIN ISSUE FOR THE UPDATE IS HOW TO HANDLE THE CURRENT HEADLINES. SFC LOW HAS MOVED OFF TO OVER DLH...AND NORTH WINDS HAVE CONTINUED TO BLOW AT 15 TO 25 MPH WITH SOME GUSTS ABOVE 30 MPH. WINDS HAVE NOT BEEN AS STRONG IN THE AREA WITH TREES IN OUR EASTERN COUNTIES...AND RADAR AND SFC OBS SHOW THAT THE SNOW HAS PRETTY MUCH ENDED IN THAT AREA. 00Z NAM12 AND HRRR CAPTURE WELL THE SNOW ENDING IN THE EAST FIRST AND HANGING AROUND THE VALLEY AND FURTHER WEST COUNTIES UNTIL AFTER 06Z. WINDS AND SNOW IN THE VALLEY HAVE AND PARTS OF DEVILS LAKE BASIN HAVE KEPT VIS DOWN AROUND 1SM OR LESS AT TIMES...ALTHOUGH THERE HAS BEEN SOME IMPROVEMENT. WILL TRIM THE EASTERN COUNTIES OUT BUT KEEP THE WEST GOING FOR THE TIME BEING. WILL KEEP AN EYE ON THE WEST AND IF IT STARTS TO SEE MORE SNOW TAPERING OFF AND IMPROVING VISIBILBITIES BEFORE MIDNIGHT MAY ALSO END THING EARLY. && .AVIATION... CONDITIONS HAVE IMPROVED TO VFR IN KBJI...BUT WITH A SCATTERED LOWER DECK THINK IT WILL GO BACK DOWN TO MVFR SHORTLY. CEILINGS AND VIS AROUND 3SM WITH LIGHT SNOW HAVE KEPT REST OF THE TAF SITES MOSTLY MVFR...ALTHOUGH A FEW LOCATIONS HAVE SEEN DIPS DOWN TO IFR. CEILINGS AND VIS WILL GRADUALLY IMPROVE AFTER 06Z AND CONDITIONS SHOULD BECOME VFR ACROSS THE ENTIRE FORECAST AREA AFTER 15Z OR SO. NORTHERLY WINDS WITH GUSTS OVER 20 KTS WILL DECREASE BELOW 10 KTS AND BECOME SOUTHERLY LATE IN THE PERIOD. && .PREV DISCUSSION... /ISSUED 308 PM CST SUN FEB 26 2012/ SHORT TERM... A VERY CHALLENGING FORECAST THIS AFTERNOON...WITH CURRENT SYSTEM SLOWLY WINDING DOWN AND A MAJOR STORM ON THE HORIZON FOR TUE/WED. MODELS ARE IN PRETTY GOOD OVERALL AGREEMENT...AND WILL SIDE WITH THE CONSISTENT GFS. FOR TONIGHT...EXPECT SOME BLOWING AND DRIFTING SNOW THROUGH THIS EVENING WITH SOME LIGHT SNOW IN WRAPAROUND DEFORMATION ZONE. ADDITIONAL ACCUMULATIONS SHOULD BE AN INCH OR LESS. WE WILL KEEP ALL CURRENT HEADLINES IN TACT WITH LOW VSBYS STILL IN OPEN COUNTRY...AND THE EVENING CREW CAN RE-EVALUATE TO SEE IF HEADLINES CAN BE CANCELLED EARLY. WINDS SHOULD QUICKLY SUBSIDE LATER TONIGHT...WITH PERHAPS SOME CLEARING MOVING INTO THE FAR WEST LATE. ON MONDAY...THIS SHOULD BE A QUIET DAY WITH SFC HIGH PRESSURE MOVING INTO THE EAST BY MONDAY EVENING. TEMPS WILL BE BELOW NORMAL GIVEN FRESH SNOW AND LIMITED MIXING...ALTHOUGH LATE FEB INSOLATION SHOULD HELP WARM THINGS UP A BIT. ON MONDAY NIGHT...AN INITIAL BAND OF ISENTROPIC LIFT AND WARM ADVECTION COULD SPREAD SOME LIGHT SNOW THROUGH ALL BUT THE FAR NORTH. HAVE INCLUDED SOME LOW POPS TO ACCOUNT FOR THIS INITIAL BAND OF LIGHT SNOW NOT ASSOCIATED WITH THE MAIN LOW. FOR TUE/WED...A COLORADO LOW WILL TRACK INTO SOUTHERN MN BY WED AFTERNOON. THIS WILL SPREAD PLENTIFUL MOISTURE INTO MOST OF THE REGION EXCEPT THE FAR NORTH...WITH PWATS OF AN INCH IN SOUTHERN IOWA. FORCING FOR ASCENT WILL BE STRONG WITH DEEP LAYERED OMEGA AND Q VECTOR CONVERGENCE. THERE WILL BE A 50KT 850MB EASTERLY JET AND STRONG MID LEVEL CONVERGENCE OVER THE AREA. HEAVY SNOW WILL LIKELY RESULT IN AT LEAST THE SOUTHERN AREAS WITH A FOOT OR MORE POSSIBLE HERE. TO THE NORTH...EXPECT A SHARP CUTOFF TO THE SNOW WITH LITTLE TO NO SNOW NEAR THE CANADIAN BORDER. WINDS WILL BECOME QUITE STRONG WITH ABOUT 40KT TO MIX FROM 925MB...ALTHOUGH THE EASTERLY COMPONENT WOULD NOT MEAN THE BEST WIND POTENTIAL. WHEN THE WIND COUPLES WITH THE POTENTIAL HEAVY SNOW...BLIZZARD CONDITIONS MAY RESULT. IT IS INTERESTING TO NOTE THAT THE SREF MODEL AND NOW THE 12Z ECMWF DOES BRING SATURATION AND SNOW MUCH FURTHER NORTH...SO WE WILL SEE JUST HOW FAR NORTH THE SNOW BAND GOES. FOR NOW WE ARE CONFIDENT IN POTENTIAL BLIZZARD CONDITIONS FROM EDDY COUNTY TO GRAND FORKS COUNTY TO CLEARWATER COUNTY AND POINTS SOUTH...AND WE HAVE ISSUED A BLIZZARD WATCH HERE FOR 12Z TUE- 00Z WED. WE WILL NEED TO MONITOR ANY SUBTLE TRACK DEVIATIONS WITH THIS SYSTEM...BUT IT APPEARS THE BIGGEST WINTER STORM OF THE SEASON IS ON TRACK WITH SIGNIFICANT SNOW AND BLOWING SNOW CREATING HAZARDOUS CONDITIONS TUESDAY AND WEDNESDAY. LONG TERM (THU-SUN)... TUE/WED STORM SYSTEM SHOULD BE EAST OF THE AREA BY THE BEGINNING OF THE LONG TERM FORECAST. HOWEVER THERE APPEARS TO BE VERY LITTLE BREAK IN THE PARADE OF WEATHER SYSTEMS THAT LOOK TO AFFECT THE NORTHERN PLAINS. THE NEXT UPPER LOW MOVES DOWN THE NORTHWEST FLOW INTO THE NORTHERN PLAINS ON FRI/SAT. NOT LOOKING LIKE MUCH MORE THAN LIGHT SNOW OR FLURRIES EARLY ON THU BEFORE CHANCES START TO INCREASE MORE SUBSTANTIALLY BY THU AFTERNOON INTO FRIDAY. THERE COULD EVEN BE WRAPAROUND PCPN OCCURRING INTO FRI NIGHT/SAT. THIS IS NOT LOOKING LIKE A BIG TIME SNOW PRODUCER BUT RATHER A STEADY LIGHT SNOW OVER A LONG DURATION OF TIME. THINGS SHOULD IMPROVE ON SUNDAY BUT OPERATIONAL MODELS START TO DIVERGE FAIRLY SIGNIFICANTLY ON TRENDS BY THIS POINT. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...BLIZZARD WATCH FROM TUESDAY MORNING THROUGH WEDNESDAY AFTERNOON FOR NDZ024-026>030-038-039-049-052-053. WINTER STORM WARNING UNTIL 3 AM CST MONDAY FOR NDZ006>008- 014>016-024-026>030-038-039-049-052>054. MN...BLIZZARD WATCH FROM TUESDAY MORNING THROUGH WEDNESDAY AFTERNOON FOR MNZ001>003-013>016-022>024-027>032-040. WINTER STORM WARNING UNTIL 3 AM CST MONDAY FOR MNZ001>004-007- 029. && $$ JR
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
349 PM EST SAT FEB 25 2012 .SYNOPSIS... A TROUGH OF LOW PRESSURE OVER THE REGION WILL QUICKLY SWING EAST OF THE AREA EARLY TONIGHT...AND RIDGING WILL BUILD OVER THE AREA. HIGH PRESSURE OVER THE AREA EARLY SUNDAY WILL WEAKEN AS LOW PRESSURE MOVES OVER THE CENTRAL GREAT LAKES. THIS LOW WILL PASS NORTH OF THE AREA ON MONDAY...FOLLOWED BY ANOTHER AREA OF HIGH PRESSURE FOR TUESDAY. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... LATEST RADAR SHOWING DISORGANIZED AREA OF LAKE EFFECT SNOW SHOWERS ACROSS MUCH OF THE EASTERN 2/3 OF THE FORECAST AREA THIS AFTERNOON. GIVEN LATEST OBS ACROSS THE AREA COMBINED WITH RADAR...WILL NOT MAKE ANY CHANGES TO HEADLINES GOING INTO THE EVENING HOURS...AND WILL KEEP EARLY MENTION OF LIKELY TO CATEGORICAL POPS ACROSS THIS AREA. ACROSS WESTERN AREAS MENTION CHC AND SLGT CHC ACROSS THE FAR WEST. WITH THE FORECAST FOR TONIGHT BEGINNING AT 7PM...ACCUMS MENTIONED FOR TONIGHT WILL BE RATHER LIGHT AS THE BULK OF THE MORE SIGNIFICANT SNOWFALL IS EXPECTED TO BE DIMINISHING BY THAT POINT. WITH LAKE EFFECT SNOW SHOWERS CONTINUING TO BECOME MORE DISORGANIZED AND MOVING THINKING ANOTHER INCH OR TWO ACROSS MOST LOCATIONS. AFTER MIDNIGHT RIDGING BUILDING INTO THE AREA WILL CAUSE SNOW SHOWERS TO DIMINISH FURTHER TO PERHAPS SOME LINGERING FLURRIES THROUGH AROUND 3AM AT THE LATEST ACROSS THE FAR EAST. LOCAL MODELS AS WELL AS THE HRRR HAVE HANDLED THIS SITUATION REASONABLY WELL THIS AFTERNOON...SO THOSE ALONG WITH MAV AND MET POPS INDICATING LITTLE FOR SNOW SHOWERS LATE TONIGHT. WENT SLIGHTLY WARMER THAN GUIDANCE ON TEMPS MAINLY ACROSS THE EAST. WINDS WILL REMAIN UP A BIT OVERNIGHT COMBINED WITH CLOUD COVER AND LINGERING SNOW SHOWERS/FLURRIES. ACROSS THE WEST SOME CLEARING MAY HELP BRING TEMPS DOWN A BIT BUT WINDS MAY STILL BE A FACTOR THERE. OVERALL WENT MID 20S ALONG THE LAKESHORE...LOWER 20S ACROSS THE EAST TO PERHAPS UPPER TEEN TO AROUND 20 FOR WESTERN AREAS. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY NIGHT/... THE NEXT FEW DAYS WILL CONTAIN PROGRESSIVE FEATURES MOVING ACROSS THE REGION. HIGH PRESSURE WILL RIDGE INTO THE AREA FOR SUNDAY ALLOWING FOR SOME SUNSHINE ACROSS THE AREA AND MODERATING TEMPS. WILL SEE HOW WELL NE OH/NW PA LOCATIONS MODERATE...SO DIDN/T GO QUITE AS WARM THERE. THINKING MOST LOCATIONS SHOULD MODERATE TO NEAR 40 OR BETTER ESPECIALLY ACROSS THE WEST. MEANWHILE MODELS FAIRLY SIMILAR WITH LOW PRESSURE APPROACHING THE CENTRAL GREAT LAKES THROUGH SUNDAY. THIS MAY SPREAD SOME CLOUDS INTO THE NORTHERN HALF OF THE AREA SUNDAY...BUT OTHERWISE DRY. LOW PRESSURE MOVES NORTH OF THE AREA SUNDAY NIGHT AND MONDAY. BULK OF ENERGY AND PRECIP WITH THE LOW EXPECTED TO REMAIN NORTH OF THE FORECAST AREA WITH A WEAK COLD FRONT PUSHING THROUGH THE AREA MONDAY. LITTLE CHANGE OF AIRMASS EXPECTED WITH THIS FRONT. HIGH PRESSURE BUILDS IN MONDAY NIGHT AND THEN QUICKLY MOVES EAST OF THE AREA TUESDAY. GFS AND ECMWF SHOWING CLOUDS BUILDING IN AHEAD OF THE NEXT LOW THROUGH TUESDAY MORNING. KEPT POPS LOW ACROSS THE AREA EARLY TUESDAY...BUT THEN MOST MODELS INDICATING RAIN MOVING INTO THE AREA BY THE END OF THE DAY. WITH THAT INCREASE POPS TO HIGH CHC/LIKELY ACROSS MUCH OF THE AREA. TEMPS MONDAY NIGHT WILL BE TRICKY GIVEN THE POTENTIAL FOR SOME RADIATING WITH HIGH PRESSURE OVERHEAD. GFS STRONGER WITH WAA ON TUESDAY AND TUESDAY NIGHT PUSHING WARM FRONT WELL NORTH OF THE AREA. MEANWHILE ECMWF SHOWING WARM FRONT STILL ACROSS THE AREA TUESDAY NIGHT SUGGESTING COOLER TEMPS. FOR NOW BLENDED THE TWO WITH TEMPS. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... WEDNESDAY WILL START OFF WARM (TEMPERATURES IN THE 50S) AS WE LIE IN THE WARM SECTOR OF A LOW PRESSURE SYSTEM TRACKING THROUGH THE CENTRAL GREAT LAKES. MODELS CONTINUE TO ADVERTISE SOME DIFFERENCES IN TIMING REGARDING THE PRECIPITATION ALONG THE OCCLUDED FRONT AND WILL MAINTAIN LIKELY POPS INTO WEDNESDAY MORNING WITH A DRYING TREND FROM WEST TO EAST DURING THE AFTERNOON. THE CHANCE OF RAIN AND SNOW SHOWERS WILL CONTINUE INTO WEDNESDAY NIGHT ALTHOUGH TEMPERATURES BEHIND THE COLD FRONT WILL NOT BE COOL ENOUGH FOR LAKE EFFECT SNOW TO DEVELOP. A DRYING TREND WILL OCCUR ON THURSDAY AS HIGH PRESSURE BUILDS OVERHEAD WITH ANOTHER OPPORTUNITY FOR SHOWERS ON FRIDAY AS THE NEXT LOW PRESSURE SYSTEM APPROACHES THE REGION. && .AVIATION /20Z SATURDAY THROUGH THURSDAY/... DOMINANT LAKE EFFECT SNOW BAND HAS BECOME MORE CELLULAR IN NATURE AS IT SLOWLY PUSHES SOUTH ACROSS LAKE ERIE. THIS SOUTHERN TREND IS EXPECTED TO CONTINUE THIS AFTERNOON AS WINDS ALOFT VEER TO MORE NORTHWESTERLY. YNG/CLE/ERI WILL SEE AN INCREASE IN SNOW SHOWERS THROUGH ROUGHLY 21Z AND MAY SEE VISIBILITIES DROP BELOW 1 MILE IF ANY OF THE HEAVIER SQUALLS IMPACT THE AIRPORTS. FURTHER INLAND AT TOL/MFD/CAK SNOW SHOWERS WILL BE MUCH LIGHTER IN NATURE BUT COULD BRIEFLY DROP VISIBILITIES INTO THE IFR RANGE THIS AFTERNOON. LAKE EFFECT SNOW SHOWERS ARE EXPECTED TO DECREASE IN INTENSITY LATE THIS AFTERNOON AS DRIER AIR PUSHES SOUTH ACROSS LAKE ERIE. CLOUDS WILL GRADUALLY SCATTER OUT FROM WEST TO EAST DURING THE OVERNIGHT HOURS AS A RIDGE BUILDS OVERHEAD. GUSTY WESTERLY WINDS WILL CONTINUE THROUGH AROUND 22Z WITH WINDS BECOMING LIGHT TONIGHT AS THEY SHIFT AROUND TO THE SOUTH. SOUTHERLY WINDS WILL BECOME BREEZY BY SUNDAY AFTERNOON. OUTLOOK...PERIODS OF NON-VFR WILL RETURN TUESDAY NIGHT AND CONTINUE AT TIMES THROUGH THURSDAY. && .MARINE... WINDS THIS AFTERNOON RANGE FROM NEAR 20 KNOTS ON THE WEST END OF LAKE ERIE TO NEAR 30 KNOTS THE EAST END OF THE LAKE. WILL MAINTAIN THE SMALL CRAFT ADVISORIES WHICH CONTINUE ON THE WEST END OF THE LAKE INTO THIS EVENING AND THROUGH 4 AM ON THE EAST END OF THE LAKE. WINDS WILL DECREASE CONSIDERABLY OVERNIGHT AS THE RIDGE BUILDS WITH WAVES BEING A LITTLE SLOWER TO SUBSIDE. A WARM FRONT WILL LIFT NORTH ACROSS THE LAKE ON SUNDAY WITH CONDITIONS BECOMING MORE STABLE DESPITE STRONG WINDS IN THE COLUMN ALOFT. CONDITIONS MAY APPROACH SMALL CRAFT ADVISORY ON THE WESTERN END OF THE LAKE BY SUNDAY NIGHT WITH WINDS INCREASING ON THE EASTERN HALF OF THE LAKE BEHIND A COLD FRONT ON MONDAY. SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED EAST OF CLEVELAND AND WE MAY EVEN APPROACH GALES FOR A BRIEF WHILE. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR OHZ012-013-023-089. LAKE EFFECT SNOW WARNING UNTIL 10 PM EST THIS EVENING FOR OHZ014. PA...LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR PAZ001. LAKE EFFECT SNOW WARNING UNTIL 10 PM EST THIS EVENING FOR PAZ002-003. MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST SUNDAY FOR LEZ147>149. SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR LEZ142>144. SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR LEZ145- 146. && $$ SYNOPSIS...ABE NEAR TERM...ABE SHORT TERM...ABE LONG TERM...KEC AVIATION...KEC MARINE...KEC
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1035 AM EST SAT FEB 25 2012 .SYNOPSIS... LOW PRESSURE WILL MOVE WELL NORTHEAST OF THE AREA TODAY. A TROUGH OVER THE REGION WILL ROTATE SOUTH OF THE AREA LATER TODAY. HIGH PRESSURE WILL QUICKLY BUILD EAST TONIGHT OVER THE REGION AND THEN CAROLINA COAST BY SUNDAY AFTERNOON. LOW PRESSURE WILL MOVE EAST ACROSS THE NORTHERN GREAT LAKES SUNDAY NIGHT FORCING A WEAK WARM FRONT TO MOVE THROUGH THE AREA. A COLD FRONT WILL MOVE EAST ACROSS THE AREA MONDAY AFTERNOON. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... HEAVY LAKE EFFECT SNOW BAND SETTING UP FROM LAKE COUNTY STRETCHING INTO ASHTABULA COUNTY AND INTERIOR NW PA THIS MORNING. GIVEN SNOW OBSERVER REPORTS THIS MORNING COMBINED WITH POTENTIAL FOR ADDITIONAL LAKE EFFECT SNOW THIS AFTERNOON HAVE GONE WITH AN UPGRADE TO WARNING FOR INTERIOR NW PA AS WELL AS INTERIOR ASHTABULA COUNTY. ADVISORIES FOR LAKESHORE ZONES AS WELL AS TRUMBULL COUNTY. ALL LE SNOW HEADLINES THROUGH 10PM TONIGHT. CAN SEE SNOW DIMINISHING A BIT AFTER 7-8PM TONIGHT BUT WILL KEEP FOR A FEW MORE HOURS. OVERALL...HEAVIER BAND SETTING UP FROM LAKE COUNTY INTO ASHTABULA THIS MORNING. OBS ACROSS NW PA INDICATING SNOW CONTINUING THERE ALSO IN THE UPSLOPE FLOW DESPITE WEAK APPEARANCE ON RADAR. LOCAL MODELS AS WELL AS HRRR INDICATING THIS CONTINUING THROUGH AT LEAST EARLY TO MID AFTERNOON. LATEST SURFACE OBS SHOWING DECENT SFC CONVERGENCE ACROSS NE OH AND NW PA WITH WSW WINDS ONSHORE OF THE LAKE WITH WSW WINDS OVER LAND. BUFKIT SHOWING GOOD MOISTURE AND NOT MUCH FOR AN INVERSION UNTIL THIS EVENING. ALL COMBINED WERE REASONS FOR THE UPGRADE AND EXPANSION OF THE ADVISORIES/WARNINGS. BASED ON MODELS AND AND LATEST ANALYSIS EXPECTING EVOLUTION OF THE LAKE EFFECT SNOW BANDS TO GRADUALLY SAG SOUTHWARD INTO GEAUGA...CUYAHOGA AND CENTRAL TRUMBULL COUNTIES LATER THIS AFTERNOON...THEN EFFECTS CONTINUE TO EXPAND TO LORAIN...MEDINA SUMMIT AND PORTAGE COUNTIES ALSO LATER IN AFTERNOON. MOST ARE TRYING TO INDICATE BY THIS TIME THE BANDS WILL NOT BE AS INTENSE AS THIS MORNING SO WILL KEEP THOSE MENTIONED COUNTIES OUT OF ADVISORY CRITERIA SNOW. HOWEVER...BECAUSE OF THIS EXPANDED THE CATEGORICAL POPS ACROSS MUCH OF THE EASTERN HALF OF THE FORECAST AREA INTO EARLY TONIGHT. MADE MINOR ADJUSTMENTS DOWNWARD FOR MAX TEMPS TODAY. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/... HIGH PRESSURE QUICKLY MOVES EAST INTO THE REGION FROM THE WEST AND THIS SHOULD BRING A FAIRLY RAPID END TO THE LAKE EFFECT SNOW SHOWERS. FAIR WEATHER WILL DOMINATE THE FORECAST AREA INTO TUESDAY EVEN THOUGH LOW PRESSURE MOVES BY TO THE NORTH OF THE REGION. MODELS SUGGEST MOISTURE WILL BE VERY LIMITED TO THE SOUTH OF THE FEATURE SO WILL KEEP CURRENT FORECAST OF DRY WEATHER GOING. AFTER STORM SYSTEM MOVES BY TO THE EAST...YET ANOTHER HIGH PRESSURE BUILDS EAST INTO THE REGION FOR TUESDAY KEEPING THE FAIR WEATHER HOLDING STRONG. THE NEXT CHANCE OF PRECIPITATION WILL NOT ARRIVE UNTIL TUESDAY NIGHT WHEN THE NEXT FAIRLY LARGE STORM SYSTEM APPROACHES FROM THE WEST. THE DIFFERENCE MAKER IS THIS STORM SYSTEM HAS A BIT MORE PUNCH ASSOCIATED WITH IT AS UPPER LEVEL TROUGH DIGS INTO THE CENTRAL UNITED STATES. THE STORM SYSTEM WILL ALSO TAP INTO THE GULF OF MEXICO STREAMING MOISTURE INTO THE REGION. WARM FRONT LIFTS NORTH OVER THE FORECAST AREA BY TUESDAY NIGHT AND PLACES THE FORECAST AREA IN THE WARM SECTOR...AND PROBABLY THE WARMEST AIR OF THE SEASON SO FAR. DEPENDING ON TIMING...WE COULD VERY WELL SEE THE LOWS OCCURRING SHORTLY AFTER SUNSET TUESDAY NIGHT WITH WARMING TAKING PLACE OVERNIGHT. FOR NOW WILL GO WITH THE DIURNAL TREND IN CASE WARM FRONT SLOWS IN FORWARD PROGRESS. && .LONG TERM /WEDNESDAY THROUGH FRIDAY/... ONLY MINOR CHANGES TO THE LONG TERM TODAY. THE NEW ECMWF IS A TAD SLOWER THAN THE 00Z GFS TRACKING A STRONG SURFACE LOW ACROSS THE AREA ON WEDNESDAY. THE GFS TRIES TO DRY SLOT THE AREA BY MIDDAY BUT THE ECMWF KEEPS THE MAIN PRECIP SHIELD OVER THE AREA THROUGH LATE AFTERNOON. WILL JUST LEAVE HIGH POPS IN ALL DAY FOR THE TIME BEING. SOME COLD AIR ADVECTION PRECIP IS LIKELY BEHIND THIS SYSTEM WEDNESDAY NIGHT INTO THURSDAY. RIDGING WILL OCCUR LATE THURSDAY INTO MIDDAY FRIDAY WITH DRY WEATHER EXPECTED. ANOTHER STORM WILL QUICKLY APPROACH FROM THE WEST ON FRIDAY AND WILL NEED PRECIP CHANCES FOR THE ENTIRE AREA BY THE END OF THE DAY. SO FAR...THE GUIDANCE IS PRETTY SIMILAR WITH THIS SCENARIO. WEDNESDAY WILL BE THE WARMEST DAY OF THE PERIOD WITH TEMPS A GOOD 10 TO 15 DEGREES ABOVE NORMAL. SEASONABLE VALUES ARE EXPECTED ON THURSDAY WITH ANOTHER WARM UP EXPECTED FOR FRIDAY. && .AVIATION /16Z SATURDAY THROUGH WEDNESDAY/... A PERSISTENT BAND OF LAKE EFFECT SNOW CONTINUES TO PASS JUST TO THE N OF KCLE TO NEAR KYNG. THIS BAND HAS FINALLY STARTED TO SHIFT NE AND SHOULD LIFT N OF KYNG SHORTLY. OTHER BANDS OF LIGHT SNOW CONTINUE TO AFFECT THE OTHER TAF SITES. THIS WILL BE THE TREND FOR THE DAY WITH OCCASIONAL BANDS OF SNOW HITTING THE TAFS. KERI SHOULD GET INTO THE ACTION IN A COUPLE OF HOURS. THINGS BEGIN TO DRY OUT TOWARD EVENING AND EXPECT VFR WEATHER ALL AREAS BY 00Z. SOME CLEARING LIKELY IN THE WEST THIS EVENING. EXPECT CIGS AND VSBYS TO BE MAINLY MVFR THROUGH MID AFTERNOON WITH BRIEF IFR CONDITIONS WITH THE HEAVIER BANDS. GUSTY W FLOW WILL GRADUALLY DIMINISH TODAY. GUSTS OF 25 TO 30 KNOTS POSSIBLE AT LEAST THROUGH 18Z. OUTLOOK...PERIODS OF NON-VFR LIKELY SATURDAY THROUGH SATURDAY NIGHT. && .MARINE... WINDS CONTINUE TO SLOWLY DIMINISH BUT STILL GETTING SOME GALES ON THE EAST HALF. WILL LET THE GALE WARNING GO AS IS AND WILL LIKELY NEED SMALL CRAFTS THROUGH THE AFTERNOON. SPEEDS SHOULD CONTINUE TO DIMINISH TODAY. HIGH PRESSURE WILL PASS TO THE SOUTH OF THE LAKE TONIGHT AND SUNDAY MORNING CAUSING THE FLOW TO TURN TO THE SW BY MID MORNING ON SUNDAY. INCREASING S TO SW FLOW IS EXPECTED SUNDAY NIGHT INTO MONDAY. A COLD FRONT WILL CROSS THE LAKE ON MONDAY CAUSING THE FLOW TO BECOME W TO NW. ANOTHER HIGH WILL MOVE OVER THE LAKE MONDAY NIGHT CAUSING A PERIOD OF LIGHT AND VARIABLE FLOW. A WARM FRONT WILL LIFT NORTH ACROSS THE LAKE EARLY WEDNESDAY WITH INCREASING S TO SW FLOW BEHIND THE FRONT. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR OHZ012-013-023-089. LAKE EFFECT SNOW WARNING UNTIL 10 PM EST THIS EVENING FOR OHZ014. PA...LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR PAZ001. LAKE EFFECT SNOW WARNING UNTIL 10 PM EST THIS EVENING FOR PAZ002-003. MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR LEZ142>144-164. SMALL CRAFT ADVISORY UNTIL 4 AM EST SUNDAY FOR LEZ147>149. SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR LEZ145- 146. && $$ SYNOPSIS...LOMBARDY/ABE NEAR TERM...ABE SHORT TERM...LOMBARDY LONG TERM...KUBINA AVIATION...KUBINA MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
437 PM EST SAT FEB 25 2012 .SYNOPSIS... A SEASONABLY COLD AND BRISK NORTHWEST FLOW WILL PERSIST TODAY IN THE WAKE OF AN INTENSIFYING STORM MOVING THROUGH THE CANADIAN MARITIMES. THE PATTERN WILL QUICKLY MODERATE BY EARLY NEXT WEEK...WITH A MILD WEST-SOUTHWEST FLOW ALOFT RETURNING ABOVE NORMAL TEMPERATURES TO THE REGION. TWO LOW PRESSURE SYSTEMS WILL TRACK THROUGH THE GREAT LAKES AND NORTH OF PENNSYLVANIA...WITH THE BEST CHANCE FOR WIDESPREAD PRECIPITATION OCCURRING AROUND MID- WEEK. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... DECIDED TO EXTEND THE ADVISORIES FOR A FEW HOURS THIS AFTERNOON TO COVER THE ACTIVITY THAT IS ONGOING...BUT EXPECTED TO BEGIN TAPRING OFF LATER TODAY AND THIS EVE. LATEST RADAR SHOWS ANOTHER HEAVY LAKE EFFECT BAND FROM ABOUT ST MARYS ESE THRU FAR NORTHERN CENTRE COUNTY DOWN TO AROUND MIFFLINBURG. THIS BAND HAS BEEN SLOWER TO SETTLE SOUTH THAN THE HEAVY BURST WE SAW EARLIER TODAY. SO FAR IT IS PRETTY MUCH MOVING DOWN ALONG ITS AXIS LIKELY BRINGING A QUICK INCH OR TWO OF SNOW TO LOCATIONS UNDER THE BAND. THE HRRR DOES SETTLE IT SOUTH IN TIME WHILE HINTING THAT THE LATER IN THE DAY WE GET THE MORE CELLULAR THE ORGANIZATION WILL BECOME. OPERATIONAL MODELS BEGIN TO REPLACE THE CYCLONIC FLOW WE ARE UNDER NOW WITH INCREASINGLY ANTICYCLONIC FLOW THIS EVENING AND INTO SUNDAY. THIS SHOULD ALSO HELP SHUT OFF THE LAKE EFFECT AS A LOWERING INVERSION HEIGHTS PUT A LID ON THINGS. WHILE LOW CLOUDS HAVE A TENDENCY TO GET TRAPPED UNDER THESE CONDITIONS...THE DEEPER INSTABILITY WILL DWINDLE LEAVING MAINLY LIGHTER SNOW SHOWERS AND FLURRIES THE DEEPER INTO THE EVENING AND OVERNIGHT WE GET. LOWS GENERALLY IN THE TEENS AND 20S TONIGHT WILL BE VERY CLOSE TO CLIMO NORMS. HAVE DECIDED TO KILL THE WIND ADVISORY. WHILE WE WILL STAY GUSTY...GUSTS OVER 40KT/46MPH HAVEN`T BEEN OBSERVED FOR A WHILE AND IF ANY RECUR THEY WILL BE ISOLATED. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/... SUNDAY WILL FEATURE HIGH PRESSURE EXERTING AN INCREASING INFLUENCE ON OUR WEATHER. ANY LOW CLOUDS EARLY IN THE DAY WILL MIX OUT AS THE HIGH MOVES OVERHEAD LEAVING A MAINLY PARTLY CLOUDY AFTERNOON EVERYWHERE. HIGHS IN THE 30S AND 40S WILL ACTUALLY BE SEVERAL DEG BELOW NORMAL FOR A CHANGE. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... MILDER TEMPS RETURN FOR MONDAY AND TUESDAY AS THE FLOW ALOFT BECOMES HIGHLY ZONAL...AND A SFC HIGH PRESSURE RIDGE SLIDES OFF THE EAST COAST CREATING A SOUTHERLY FLOW OF AIR INTO THE COMMONWEALTH. VIRTUALLY NO CHC OF PRECIP ANYWHERE ACROSS CENTRAL AND SOUTHERN PENN FOR THE PERIOD 12Z SUNDAY THROUGH 00Z WEDNESDAY. EVEN POPS ACRS THE NRN MTNS WILL ONLY CLIMB SLIGHTLY TO AROUND 10 PERCENT AT TIMES. THERE WILL BE A FEW...SEVERAL-HOUR PERIODS OF MID CLOUDS /AND PERHAPS EVEN SOME HIGH BASED STRATO CU/ SLIDING EAST ACROSS THE REGION SUNDAY AND MONDAY AS LOW PRESSURE MOVES EAST FROM THE NRN PLAINS AND ACROSS THE UPPER GLAKES REGION. THE SOUTHWEST TO WESTERLY FLOW MONDAY COULD BECOME QUITE GUSTY...AND OVER 30 MPH AT TIMES AS THE AFOREMENTIONED LOW DRIFTS BY TO THE NORTH OF LAKE ONTARIO. TEMPS MONDAY SHOULD BE THE MILDEST READINGS THAT WE/LL SEE IN AT LEAST A WEEK OR SO. HIGHS WILL VARY FROM THE MID 40S ACROSS THE NORTHERN MTNS...TO THE LOWER AND MID 50S IN THE CENTRAL AND LOWER SUSQ VALLEY. ANOTHER MORE SIGNIFICANT SYSTEM LIKELY IMPACTS THE REGION FOR WEDNESDAY INTO THURSDAY. SFC LOW TRACKS WELL TO OUR NW...THRU THE UPPER MIDWEST/UPPER GLAKES REGION DURING THIS PERIOD A RATHER STRONG...1035MB SFC HIGH WILL ATTEMPT TO FUNNEL LLVL COLD AIR SOUTH INTO THE REGION FOR THE TUESDAY NIGHT - THURSDAY PERIOD. THE 00Z EC MODEL APPEARS TO PAINT THIS LLVL COLD AIR DAMMING MORE SO THAN THE GFS OR GEFS SOLUTIONS. EC SHOWS A LONGER DURATION/FEW DAY EVENT WEDNESDAY THROUGH THURSDAY ASSOCIATED WITH SECONDARY SFC LOW DEVELOPMENT NEAR THE DELMARVA COAST /ALONG IT EASTWARD EXTENDING LLVL QUASI STNRY FRONT/. IN CONTRAST...THE GEFS AND GFS ARE MORE PROGRESSIVE WITH THIS SYSTEM AND CARRY A MORE CONSOLIDATED/SINGLE SFC LOW ENE ACROSS THE UPPER GREAT LAKES...WHILE LIFTING A SFC-850 MB WARM FRONT GRADUALLY NORTH ACROSS THE STATE ON WEDNESDAY. GEFS PLUMES AND GFS THERMAL AND WET BULB PROFILES PAINT MAINLY RAIN FOR THE REGION...WHILE THE EC SUGGESTS AN EXTENDING PERIOD OF MIXED PRECIP AND EVEN SOME ACCUMULATING WET SNOW LIKELY ACROSS MAINLY THE NORTH CENTRAL AND EASTERN MTNS OF THE STATE WEDNESDAY INTO THURSDAY. PAINTED A FEW INCHES OF ACCUMULATION IN OUR GRIDS ACROSS THE REGION NORTH OF KUNV AND KIPT. MEDIAN RAINFALL/LEQ AMOUNTS ARE BETWEEN 0.75 AND 1.00 INCH. NEXT WEEK CLOSES OUT MAINLY DRY...WITH ABOVE NORMAL TEMPS AND PARTLY CLOUDY SKIES AS HIGH PRESSURE AT THE SFC AND ALOFT MOVES ACROSS THE REGION. && .AVIATION /22Z SATURDAY THROUGH THURSDAY/... SQUALLS AND HIGH WINDS STILL A PROBLEM...WENT WITH MORE ADVERSE CONDITIONS IN THE 21Z TAFS FOR A FEW MORE HOURS. EARLIER DISCUSSION BELOW. HIGH WESTERN TERRAIN FROM JST TO BFD WILL CONTINUE WITH VFR/IFR CONDITIONS AND FREQUENT SNOW SHOWERS/HEAVIER LAKE EFFECT SQUALLS INTO THE EVENING HOURS BEFORE CONDITIONS BEGIN TO SLOWLY IMPROVE. ELSEWHERE TRANSIENT LAKE EFFECT BANDS HAVE BEEN UNUSUALLY EFFICIENT AT WORKING DOWN EVEN INTO CENTRAL AND SOME EASTERN AREAS TODAY. SOME OF THESE HAVE MANAGED TO BRING LOCAL NEAR WHITEOUT CONDITIONS FOR A SHORT TIME AS THEY DROP SE ACROSS THE REGION. EXPECT THESE ORGANIZED BANDS TO SLOWLY BEGIN BREAKING DOWN AND BECOMING MORE CELLULAR AS WE MOVE INTO THE EVENING AND OVERNIGHT. HIGH PRESSURE AND LOWERING INVERSION HEIGHTS WILL EVENTUALLY BRING AN END TO THE STRONGEST SNOW SHOWERS WITH LITTLE MORE THAN A FEW SCATTERED FLURRIES LEFT OVER BY LATE NIGHT EARLY SUNDAY MORNING. MVFR LOW CLOUDS ARE POSSIBLE LATER TONIGHT AND EARLY SUNDAY MORNING OVER WESTERN HIGH TERRAIN...BUT EVERYONE SHOULD GE VFR BEFORE THE MORNING IS OVER...LEADING TO A BRIGHT SUNNY AFTERNOON AS HIGH PRESSURE MOVES OVER THE STATE. A WEAK LOW PRESSURE SYSTEM WILL MOVE NORTH OF PENNSYLVANIA MONDAY NIGHT DRAGGING A WEAK COLD FRONT THROUGH THE REGION. A STRONGER LOW PRESSURE SYSTEM AND TRAILING COLD FRONT WILL FOLLOW A SIMILAR TRACK WED-THUR. OUTLOOK... MON...VFR. SCHC OF MVFR -SHRA NRN TERMINALS. TUE...VFR. RESTRICTIONS PSBL TUE NGT. WED/THU...RESTRICTIONS LKLY. && .CTP WATCHES/WARNINGS/ADVISORIES... LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ004-005. WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ024- 033. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...LAMBERT/GARTNER AVIATION...LA CORTE/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
404 PM EST SAT FEB 25 2012 .SYNOPSIS... A SEASONABLY COLD AND BRISK NORTHWEST FLOW WILL PERSIST TODAY IN THE WAKE OF AN INTENSIFYING STORM MOVING THROUGH THE CANADIAN MARITIMES. THE PATTERN WILL QUICKLY MODERATE BY EARLY NEXT WEEK...WITH A MILD WEST-SOUTHWEST FLOW ALOFT RETURNING ABOVE NORMAL TEMPERATURES TO THE REGION. TWO LOW PRESSURE SYSTEMS WILL TRACK THROUGH THE GREAT LAKES AND NORTH OF PENNSYLVANIA...WITH THE BEST CHANCE FOR WIDESPREAD PRECIPITATION OCCURRING AROUND MID- WEEK. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... DECIDED TO EXTEND THE ADVISORIES FOR A FEW HOURS THIS AFTERNOON TO COVER THE ACTIVITY THAT IS ONGOING...BUT EXPECTED TO BEGIN TAPRING OFF LATER TODAY AND THIS EVE. LATEST RADAR SHOWS ANOTHER HEAVY LAKE EFFECT BAND FROM ABOUT ST MARYS ESE THRU FAR NORTHERN CENTRE COUNTY DOWN TO AROUND MIFFLINBURG. THIS BAND HAS BEEN SLOWER TO SETTLE SOUTH THAN THE HEAVY BURST WE SAW EARLIER TODAY. SO FAR IT IS PRETTY MUCH MOVING DOWN ALONG ITS AXIS LIKELY BRINGING A QUICK INCH OR TWO OF SNOW TO LOCATIONS UNDER THE BAND. THE HRRR DOES SETTLE IT SOUTH IN TIME WHILE HINTING THAT THE LATER IN THE DAY WE GET THE MORE CELLULAR THE ORGANIZATION WILL BECOME. OPERATIONAL MODELS BEGIN TO REPLACE THE CYCLONIC FLOW WE ARE UNDER NOW WITH INCREASINGLY ANTICYCLONIC FLOW THIS EVENING AND INTO SUNDAY. THIS SHOULD ALSO HELP SHUT OFF THE LAKE EFFECT AS A LOWERING INVERSION HEIGHTS PUT A LID ON THINGS. WHILE LOW CLOUDS HAVE A TENDENCY TO GET TRAPPED UNDER THESE CONDITIONS...THE DEEPER INSTABILITY WILL DWINDLE LEAVING MAINLY LIGHTER SNOW SHOWERS AND FLURRIES THE DEEPER INTO THE EVENING AND OVERNIGHT WE GET. LOWS GENERALLY IN THE TEENS AND 20S TONIGHT WILL BE VERY CLOSE TO CLIMO NORMS. HAVE DECIDED TO KILL THE WIND ADVISORY. WHILE WE WILL STAY GUSTY...GUSTS OVER 40KT/46MPH HAVEN`T BEEN OBSERVED FOR A WHILE AND IF ANY RECUR THEY WILL BE ISOLATED. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/... SUNDAY WILL FEATURE HIGH PRESSURE EXERTING AN INCREASING INFLUENCE ON OUR WEATHER. ANY LOW CLOUDS EARLY IN THE DAY WILL MIX OUT AS THE HIGH MOVES OVERHEAD LEAVING A MAINLY PARTLY CLOUDY AFTERNOON EVERYWHERE. HIGHS IN THE 30S AND 40S WILL ACTUALLY BE SEVERAL DEG BELOW NORMAL FOR A CHANGE. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... MILDER TEMPS RETURN FOR MONDAY AND TUESDAY AS THE FLOW ALOFT BECOMES HIGHLY ZONAL...AND A SFC HIGH PRESSURE RIDGE SLIDES OFF THE EAST COAST CREATING A SOUTHERLY FLOW OF AIR INTO THE COMMONWEALTH. VIRTUALLY NO CHC OF PRECIP ANYWHERE ACROSS CENTRAL AND SOUTHERN PENN FOR THE PERIOD 12Z SUNDAY THROUGH 00Z WEDNESDAY. EVEN POPS ACRS THE NRN MTNS WILL ONLY CLIMB SLIGHTLY TO AROUND 10 PERCENT AT TIMES. THERE WILL BE A FEW...SEVERAL-HOUR PERIODS OF MID CLOUDS /AND PERHAPS EVEN SOME HIGH BASED STRATO CU/ SLIDING EAST ACROSS THE REGION SUNDAY AND MONDAY AS LOW PRESSURE MOVES EAST FROM THE NRN PLAINS AND ACROSS THE UPPER GLAKES REGION. THE SOUTHWEST TO WESTERLY FLOW MONDAY COULD BECOME QUITE GUSTY...AND OVER 30 MPH AT TIMES AS THE AFOREMENTIONED LOW DRIFTS BY TO THE NORTH OF LAKE ONTARIO. TEMPS MONDAY SHOULD BE THE MILDEST READINGS THAT WE/LL SEE IN AT LEAST A WEEK OR SO. HIGHS WILL VARY FROM THE MID 40S ACROSS THE NORTHERN MTNS...TO THE LOWER AND MID 50S IN THE CENTRAL AND LOWER SUSQ VALLEY. ANOTHER MORE SIGNIFICANT SYSTEM LIKELY IMPACTS THE REGION FOR WEDNESDAY INTO THURSDAY. SFC LOW TRACKS WELL TO OUR NW...THRU THE UPPER MIDWEST/UPPER GLAKES REGION DURING THIS PERIOD A RATHER STRONG...1035MB SFC HIGH WILL ATTEMPT TO FUNNEL LLVL COLD AIR SOUTH INTO THE REGION FOR THE TUESDAY NIGHT - THURSDAY PERIOD. THE 00Z EC MODEL APPEARS TO PAINT THIS LLVL COLD AIR DAMMING MORE SO THAN THE GFS OR GEFS SOLUTIONS. EC SHOWS A LONGER DURATION/FEW DAY EVENT WEDNESDAY THROUGH THURSDAY ASSOCIATED WITH SECONDARY SFC LOW DEVELOPMENT NEAR THE DELMARVA COAST /ALONG IT EASTWARD EXTENDING LLVL QUASI STNRY FRONT/. IN CONTRAST...THE GEFS AND GFS ARE MORE PROGRESSIVE WITH THIS SYSTEM AND CARRY A MORE CONSOLIDATED/SINGLE SFC LOW ENE ACROSS THE UPPER GREAT LAKES...WHILE LIFTING A SFC-850 MB WARM FRONT GRADUALLY NORTH ACROSS THE STATE ON WEDNESDAY. GEFS PLUMES AND GFS THERMAL AND WET BULB PROFILES PAINT MAINLY RAIN FOR THE REGION...WHILE THE EC SUGGESTS AN EXTENDING PERIOD OF MIXED PRECIP AND EVEN SOME ACCUMULATING WET SNOW LIKELY ACROSS MAINLY THE NORTH CENTRAL AND EASTERN MTNS OF THE STATE WEDNESDAY INTO THURSDAY. PAINTED A FEW INCHES OF ACCUMULATION IN OUR GRIDS ACROSS THE REGION NORTH OF KUNV AND KIPT. MEDIAN RAINFALL/LEQ AMOUNTS ARE BETWEEN 0.75 AND 1.00 INCH. NEXT WEEK CLOSES OUT MAINLY DRY...WITH ABOVE NORMAL TEMPS AND PARTLY CLOUDY SKIES AS HIGH PRESSURE AT THE SFC AND ALOFT MOVES ACROSS THE REGION. && .AVIATION /21Z SATURDAY THROUGH THURSDAY/... HIGH WESTERN TERRAIN FROM JST TO BFD WILL CONTINUE WITH VFR/IFR CONDITIONS AND FREQUENT SNOW SHOWERS/HEAVIER LAKE EFFECT SQUALLS INTO THE EVENING HOURS BEFORE CONDITIONS BEGIN TO SLOWLY IMPROVE. ELSEWHERE TRANSIENT LAKE EFFECT BANDS HAVE BEEN UNUSUALLY EFFICIENT AT WORKING DOWN EVEN INTO CENTRAL AND SOME EASTERN AREAS TODAY. SOME OF THESE HAVE MANAGED TO BRING LOCAL NEAR WHITEOUT CONDITIONS FOR A SHORT TIME AS THEY DROP SE ACROSS THE REGION. EXPECT THESE ORGANIZED BANDS TO SLOWLY BEGIN BREAKING DOWN AND BECOMING MORE CELLULAR AS WE MOVE INTO THE EVENING AND OVERNIGHT. HIGH PRESSURE AND LOWERING INVERSION HEIGHTS WILL EVENTUALLY BRING AN END TO THE STRONGEST SNOW SHOWERS WITH LITTLE MORE THAN A FEW SCATTERED FLURRIES LEFT OVER BY LATE NIGHT EARLY SUNDAY MORNING. MVFR LOW CLOUDS ARE POSSIBLE LATER TONIGHT AND EARLY SUNDAY MORNING OVER WESTERN HIGH TERRAIN...BUT EVERYONE SHOULD GE VFR BEFORE THE MORNING IS OVER...LEADING TO A BRIGHT SUNNY AFTERNOON AS HIGH PRESSURE MOVES OVER THE STATE. A WEAK LOW PRESSURE SYSTEM WILL MOVE NORTH OF PENNSYLVANIA MONDAY NIGHT DRAGGING A WEAK COLD FRONT THROUGH THE REGION. A STRONGER LOW PRESSURE SYSTEM AND TRAILING COLD FRONT WILL FOLLOW A SIMILAR TRACK WED-THUR. OUTLOOK... MON...VFR. SCHC OF MVFR -SHRA NRN TERMINALS. TUE...VFR. RESTRICTIONS PSBL TUE NGT. WED/THU...RESTRICTIONS LKLY. && .CTP WATCHES/WARNINGS/ADVISORIES... LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ004-005. WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ024- 033. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...LAMBERT/GARTNER AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
227 PM EST SAT FEB 25 2012 .SYNOPSIS... A SEASONABLY COLD AND BRISK NORTHWEST FLOW WILL PERSIST TODAY IN THE WAKE OF AN INTENSIFYING STORM MOVING THROUGH THE CANADIAN MARITIMES. THE PATTERN WILL QUICKLY MODERATE BY EARLY NEXT WEEK...WITH A MILD WEST-SOUTHWEST FLOW ALOFT RETURNING ABOVE NORMAL TEMPERATURES TO THE REGION. TWO LOW PRESSURE SYSTEMS WILL TRACK THROUGH THE GREAT LAKES AND NORTH OF PENNSYLVANIA...WITH THE BEST CHANCE FOR WIDESPREAD PRECIPITATION OCCURRING AROUND MID- WEEK. && .NEAR TERM /THROUGH TONIGHT/... DECIDED TO EXTEND THE ADVISORIES FOR A FEW HOURS THIS AFTERNOON TO COVER THE ACTIVITY THAT IS ONGOING...BUT EXPECTED TO BEGIN TAPRING OFF LATER TODAY AND THIS EVE. LATEST RADAR SHOWS ANOTHER HEAVY LAKE EFFECT BAND FROM ABOUT ST MARYS ESE THRU FAR NORTHERN CENTRE COUNTY DOWN TO AROUND MIFFLINBURG. THIS BAND HAS BEEN SLOWER TO SETTLE SOUTH THAN THE HEAVY BURST WE SAW EARLIER TODAY. SO FAR IT IS PRETTY MUCH MOVING DOWN ALONG ITS AXIS LIKELY BRINGING A QUICK INCH OR TWO OF SNOW TO LOCATIONS UNDER THE BAND. THE HRRR DOES SETTLE IT SOUTH IN TIME WHILE HINTING THAT THE LATER IN THE DAY WE GET THE MORE CELLULAR THE ORGANIZATION WILL BECOME. OPERATIONAL MODELS BEGIN TO REPLACE THE CYCLONIC FLOW WE ARE UNDER NOW WITH INCREASINGLY ANTICYCLONIC FLOW THIS EVENING AND INTO SUNDAY. THIS SHOULD ALSO HELP SHUT OFF THE LAKE EFFECT AS A LOWERING INVERSION HEIGHTS PUT A LID ON THINGS. WHILE LOW CLOUDS HAVE A TENDENCY TO GET TRAPPED UNDER THESE CONDITIONS...THE DEEPER INSTABILITY WILL DWINDLE LEAVING MAINLY LIGHTER SNOW SHOWERS AND FLURRIES THE DEEPER INTO THE EVENING AND OVERNIGHT WE GET. LOWS GENERALLY IN THE TEENS AND 20S TONIGHT WILL BE VERY CLOSE TO CLIMO NORMS. HAVE DECIDED TO KILL THE WIND ADVISORY. WHILE WE WILL STAY GUSTY...GUSTS OVER 40KT/46MPH HAVEN`T BEEN OBSERVED FOR A WHILE AND IF ANY RECUR THEY WILL BE ISOLATED. && .SHORT TERM /SUNDAY/... SUNDAY WILL FEATURE HIGH PRESSURE EXERTING AN INCREASING INFLUENCE ON OUR WEATHER. ANY LOW CLOUDS EARLY IN THE DAY WILL MIX OUT AS THE HIGH MOVES OVERHEAD LEAVING A MAINLY PARTLY CLOUDY AFTERNOON EVERYWHERE. HIGHS IN THE 30S AND 40S WILL ACTUALLY BE SEVERAL DEG BELOW NORMAL FOR A CHANGE. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... MILDER TEMPS RETURN FOR MONDAY AND TUESDAY AS THE FLOW ALOFT BECOMES HIGHLY ZONAL...AND A SFC HIGH PRESSURE RIDGE SLIDES OFF THE EAST COAST CREATING A SOUTHERLY FLOW OF AIR INTO THE COMMONWEALTH. VIRTUALLY NO CHC OF PRECIP ANYWHERE ACROSS CENTRAL AND SOUTHERN PENN FOR THE PERIOD 12Z SUNDAY THROUGH 00Z WEDNESDAY. EVEN POPS ACRS THE NRN MTNS WILL ONLY CLIMB SLIGHTLY TO AROUND 10 PERCENT AT TIMES. THERE WILL BE A FEW...SEVERAL-HOUR PERIODS OF MID CLOUDS /AND PERHAPS EVEN SOME HIGH BASED STRATO CU/ SLIDING EAST ACROSS THE REGION SUNDAY AND MONDAY AS LOW PRESSURE MOVES EAST FROM THE NRN PLAINS AND ACROSS THE UPPER GLAKES REGION. THE SOUTHWEST TO WESTERLY FLOW MONDAY COULD BECOME QUITE GUSTY...AND OVER 30 MPH AT TIMES AS THE AFOREMENTIONED LOW DRIFTS BY TO THE NORTH OF LAKE ONTARIO. TEMPS MONDAY SHOULD BE THE MILDEST READINGS THAT WE/LL SEE IN AT LEAST A WEEK OR SO. HIGHS WILL VARY FROM THE MID 40S ACROSS THE NORTHERN MTNS...TO THE LOWER AND MID 50S IN THE CENTRAL AND LOWER SUSQ VALLEY. ANOTHER MORE SIGNIFICANT SYSTEM LIKELY IMPACTS THE REGION FOR WEDNESDAY INTO THURSDAY. SFC LOW TRACKS WELL TO OUR NW...THRU THE UPPER MIDWEST/UPPER GLAKES REGION DURING THIS PERIOD A RATHER STRONG...1035MB SFC HIGH WILL ATTEMPT TO FUNNEL LLVL COLD AIR SOUTH INTO THE REGION FOR THE TUESDAY NIGHT - THURSDAY PERIOD. THE 00Z EC MODEL APPEARS TO PAINT THIS LLVL COLD AIR DAMMING MORE SO THAN THE GFS OR GEFS SOLUTIONS. EC SHOWS A LONGER DURATION/FEW DAY EVENT WEDNESDAY THROUGH THURSDAY ASSOCIATED WITH SECONDARY SFC LOW DEVELOPMENT NEAR THE DELMARVA COAST /ALONG IT EASTWARD EXTENDING LLVL QUASI STNRY FRONT/. IN CONTRAST...THE GEFS AND GFS ARE MORE PROGRESSIVE WITH THIS SYSTEM AND CARRY A MORE CONSOLIDATED/SINGLE SFC LOW ENE ACROSS THE UPPER GREAT LAKES...WHILE LIFTING A SFC-850 MB WARM FRONT GRADUALLY NORTH ACROSS THE STATE ON WEDNESDAY. GEFS PLUMES AND GFS THERMAL AND WET BULB PROFILES PAINT MAINLY RAIN FOR THE REGION...WHILE THE EC SUGGESTS AN EXTENDING PERIOD OF MIXED PRECIP AND EVEN SOME ACCUMULATING WET SNOW LIKELY ACROSS MAINLY THE NORTH CENTRAL AND EASTERN MTNS OF THE STATE WEDNESDAY INTO THURSDAY. PAINTED A FEW INCHES OF ACCUMULATION IN OUR GRIDS ACROSS THE REGION NORTH OF KUNV AND KIPT. MEDIAN RAINFALL/LEQ AMOUNTS ARE BETWEEN 0.75 AND 1.00 INCH. NEXT WEEK CLOSES OUT MAINLY DRY...WITH ABOVE NORMAL TEMPS AND PARTLY CLOUDY SKIES AS HIGH PRESSURE AT THE SFC AND ALOFT MOVES ACROSS THE REGION. && .AVIATION /20Z SATURDAY THROUGH THURSDAY/... HIGH WESTERN TERRAIN FROM JST TO BFD WILL CONTINUE WITH VFR/IFR CONDITIONS AND FREQUENT SNOW SHOWERS/HEAVIER LAKE EFFECT SQUALLS INTO THE EVENING HOURS BEFORE CONDITIONS BEGIN TO SLOWLY IMPROVE. ELSEWHERE TRANSIENT LAKE EFFECT BANDS HAVE BEEN UNUSUALLY EFFICIENT AT WORKING DOWN EVEN INTO CENTRAL AND SOME EASTERN AREAS TODAY. SOME OF THESE HAVE MANAGED TO BRING LOCAL NEAR WHITEOUT CONDITIONS FOR A SHORT TIME AS THEY DROP SE ACROSS THE REGION. EXPECT THESE ORGANIZED BANDS TO SLOWLY BEGIN BREAKING DOWN AND BECOMING MORE CELLULAR AS WE MOVE INTO THE EVENING AND OVERNIGHT. HIGH PRESSURE AND LOWERING INVERSION HEIGHTS WILL EVENTUALLY BRING AN END TO THE STRONGEST SNOW SHOWERS WITH LITTLE MORE THAN A FEW SCATTERED FLURRIES LEFT OVER BY LATE NIGHT EARLY SUNDAY MORNING. MVFR LOW CLOUDS ARE POSSIBLE LATER TONIGHT AND EARLY SUNDAY MORNING OVER WESTERN HIGH TERRAIN...BUT EVERYONE SHOULD GE VFR BEFORE THE MORNING IS OVER...LEADING TO A BRIGHT SUNNY AFTERNOON AS HIGH PRESSURE MOVES OVER THE STATE. A WEAK LOW PRESSURE SYSTEM WILL MOVE NORTH OF PENNSYLVANIA MONDAY NIGHT DRAGGING A WEAK COLD FRONT THROUGH THE REGION. A STRONGER LOW PRESSURE SYSTEM AND TRAILING COLD FRONT WILL FOLLOW A SIMILAR TRACK WED-THUR. OUTLOOK... MON...VFR. SCHC OF MVFR -SHRA NRN TERMINALS. TUE...VFR. RESTRICTIONS PSBL TUE NGT. WED/THU...RESTRICTIONS LKLY. && .CTP WATCHES/WARNINGS/ADVISORIES... LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ004-005. WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ024- 033. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...LAMBERT/RXR AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1136 AM EST SAT FEB 25 2012 .SYNOPSIS... A SEASONABLY COLD AND BRISK NORTHWEST FLOW WILL PERSIST TODAY IN THE WAKE OF AN INTENSIFYING STORM MOVING THROUGH THE CANADIAN MARITIMES. THE PATTERN WILL QUICKLY MODERATE BY EARLY NEXT WEEK...WITH A MILD WEST-SOUTHWEST FLOW ALOFT RETURNING ABOVE NORMAL TEMPERATURES TO THE REGION. TWO LOW PRESSURE SYSTEMS WILL TRACK THROUGH THE GREAT LAKES AND NORTH OF PENNSYLVANIA...WITH THE BEST CHANCE FOR WIDESPREAD PRECIPITATION OCCURRING AROUND MID- WEEK. && .NEAR TERM /THROUGH TONIGHT/... LATEST RADAR SHOWS ANOTHER HEAVY LAKE EFFECT BAND FROM ABOUT ST MARYS ESE THRU FAR NORTHERN CENTRE COUNTY DOWN TO AROUND MIFFLINBURG. THIS BAND HAS BEEN SLOWER TO SETTLE SOUTH THAN THE HEAVY BURST WE SAW EARLIER TODAY. SO FAR IT IS PRETTY MUCH MOVING DOWN ALONG ITS AXIS LIKELY BRINGING A QUICK INCH OR TWO OF SNOW TO LOCATIONS UNDER THE BAND. THE HRRR DOES SETTLE IT SOUTH IN TIME WHILE HINTING THAT THE LATER IN THE DAY WE GET THE MORE CELLULAR THE ORGANIZATION WILL BECOME. OPERATIONAL MODELS BEGIN TO REPLACE THE CYCLONIC FLOW WE ARE UNDER NOW WITH INCREASINGLY ANTICYCLONIC FLOW THIS EVENING AND INTO SUNDAY. THIS SHOULD ALSO HELP SHUT OFF THE LAKE EFFECT AS A LOWERING INVERSION HEIGHTS PUT A LID ON THINGS. WHILE LOW CLOUDS HAVE A TENDENCY TO GET TRAPPED UNDER THESE CONDITIONS...THE DEEPER INSTABILITY WILL DWINDLE LEAVING MAINLY LIGHTER SNOW SHOWERS AND FLURRIES THE DEEPER INTO THE EVENING AND OVERNIGHT WE GET. LOWS GENERALLY IN THE TEENS AND 20S TONIGHT WILL BE VERY CLOSE TO CLIMO NORMS. HAVE DECIDED TO KILL THE WIND ADVISORY. WHILE WE WILL STAY GUSTY...GUSTS OVER 40KT/46MPH HAVEN`T BEEN OBSERVED FOR A WHILE AND IF ANY RECUR THEY WILL BE ISOLATED. && .SHORT TERM /SUNDAY/... SUNDAY WILL FEATURE HIGH PRESSURE EXERTING AN INCREASING INFLUENCE ON OUR WEATHER. ANY LOW CLOUDS EARLY IN THE DAY WILL MIX OUT AS THE HIGH MOVES OVERHEAD LEAVING A MAINLY PARTLY CLOUDY AFTERNOON EVERYWHERE. HIGHS IN THE 30S AND 40S WILL ACTUALLY BE SEVERAL DEG BELOW NORMAL FOR A CHANGE. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... MILDER TEMPS RETURN FOR MONDAY AND TUESDAY AS THE FLOW ALOFT BECOMES HIGHLY ZONAL...AND A SFC HIGH PRESSURE RIDGE SLIDES OFF THE EAST COAST CREATING A SOUTHERLY FLOW OF AIR INTO THE COMMONWEALTH. VIRTUALLY NO CHC OF PRECIP ANYWHERE ACROSS CENTRAL AND SOUTHERN PENN FOR THE PERIOD 12Z SUNDAY THROUGH 00Z WEDNESDAY. EVEN POPS ACRS THE NRN MTNS WILL ONLY CLIMB SLIGHTLY TO AROUND 10 PERCENT AT TIMES. THERE WILL BE A FEW...SEVERAL-HOUR PERIODS OF MID CLOUDS /AND PERHAPS EVEN SOME HIGH BASED STRATO CU/ SLIDING EAST ACROSS THE REGION SUNDAY AND MONDAY AS LOW PRESSURE MOVES EAST FROM THE NRN PLAINS AND ACROSS THE UPPER GLAKES REGION. THE SOUTHWEST TO WESTERLY FLOW MONDAY COULD BECOME QUITE GUSTY...AND OVER 30 MPH AT TIMES AS THE AFOREMENTIONED LOW DRIFTS BY TO THE NORTH OF LAKE ONTARIO. TEMPS MONDAY SHOULD BE THE MILDEST READINGS THAT WE/LL SEE IN AT LEAST A WEEK OR SO. HIGHS WILL VARY FROM THE MID 40S ACROSS THE NORTHERN MTNS...TO THE LOWER AND MID 50S IN THE CENTRAL AND LOWER SUSQ VALLEY. ANOTHER MORE SIGNIFICANT SYSTEM LIKELY IMPACTS THE REGION FOR WEDNESDAY INTO THURSDAY. SFC LOW TRACKS WELL TO OUR NW...THRU THE UPPER MIDWEST/UPPER GLAKES REGION DURING THIS PERIOD A RATHER STRONG...1035MB SFC HIGH WILL ATTEMPT TO FUNNEL LLVL COLD AIR SOUTH INTO THE REGION FOR THE TUESDAY NIGHT - THURSDAY PERIOD. THE 00Z EC MODEL APPEARS TO PAINT THIS LLVL COLD AIR DAMMING MORE SO THAN THE GFS OR GEFS SOLUTIONS. EC SHOWS A LONGER DURATION/FEW DAY EVENT WEDNESDAY THROUGH THURSDAY ASSOCIATED WITH SECONDARY SFC LOW DEVELOPMENT NEAR THE DELMARVA COAST /ALONG IT EASTWARD EXTENDING LLVL QUASI STNRY FRONT/. IN CONTRAST...THE GEFS AND GFS ARE MORE PROGRESSIVE WITH THIS SYSTEM AND CARRY A MORE CONSOLIDATED/SINGLE SFC LOW ENE ACROSS THE UPPER GREAT LAKES...WHILE LIFTING A SFC-850 MB WARM FRONT GRADUALLY NORTH ACROSS THE STATE ON WEDNESDAY. GEFS PLUMES AND GFS THERMAL AND WET BULB PROFILES PAINT MAINLY RAIN FOR THE REGION...WHILE THE EC SUGGESTS AN EXTENDING PERIOD OF MIXED PRECIP AND EVEN SOME ACCUMULATING WET SNOW LIKELY ACROSS MAINLY THE NORTH CENTRAL AND EASTERN MTNS OF THE STATE WEDNESDAY INTO THURSDAY. PAINTED A FEW INCHES OF ACCUMULATION IN OUR GRIDS ACROSS THE REGION NORTH OF KUNV AND KIPT. MEDIAN RAINFALL/LEQ AMOUNTS ARE BETWEEN 0.75 AND 1.00 INCH. NEXT WEEK CLOSES OUT MAINLY DRY...WITH ABOVE NORMAL TEMPS AND PARTLY CLOUDY SKIES AS HIGH PRESSURE AT THE SFC AND ALOFT MOVES ACROSS THE REGION. && .AVIATION /16Z SATURDAY THROUGH WEDNESDAY/... HIGH WESTERN TERRAIN FROM JST TO BFD WILL CONTINUE WITH VFR/IFR CONDITIONS AND FREQUENT SNOW SHOWERS/HEAVIER LAKE EFFECT SQUALLS INTO THE EVENING HOURS BEFORE CONDITIONS BEGIN TO SLOWLY IMPROVE. ELSEWHERE TRANSIENT LAKE EFFECT BANDS HAVE BEEN UNUSUALLY EFFICIENT AT WORKING DOWN EVEN INTO CENTRAL AND SOME EASTERN AREAS TODAY. SOME OF THESE HAVE MANAGED TO BRING LOCAL NEAR WHITEOUT CONDITIONS FOR A SHORT TIME AS THEY DROP SE ACROSS THE REGION. EXPECT THESE ORGANIZED BANDS TO SLOWLY BEGIN BREAKING DOWN AND BECOMING MORE CELLULAR AS WE MOVE INTO THE EVENING AND OVERNIGHT. HIGH PRESSURE AND LOWERING INVERSION HEIGHTS WILL EVENTUALLY BRING AN END TO THE STRONGEST SNOW SHOWERS WITH LITTLE MORE THAN A FEW SCATTERED FLURRIES LEFT OVER BY LATE NIGHT EARLY SUNDAY MORNING. MVFR LOW CLOUDS ARE POSSIBLE LATER TONIGHT AND EARLY SUNDAY MORNING OVER WESTERN HIGH TERRAIN...BUT EVERYONE SHOULD GE VFR BEFORE THE MORNING IS OVER...LEADING TO A BRIGHT SUNNY AFTERNOON AS HIGH PRESSURE MOVES OVER THE STATE. A WEAK LOW PRESSURE SYSTEM WILL MOVE NORTH OF PENNSYLVANIA MONDAY NIGHT DRAGGING A WEAK COLD FRONT THROUGH THE REGION. A STRONGER LOW PRESSURE SYSTEM AND TRAILING COLD FRONT WILL FOLLOW A SIMILAR TRACK WED-THUR. OUTLOOK... MON...VFR. SCHC OF MVFR -SHRA NRN TERMINALS. TUE...VFR. RESTRICTIONS PSBL TUE NGT. WED...RESTRICTIONS LKLY. && .CTP WATCHES/WARNINGS/ADVISORIES... LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR PAZ004-005. WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR PAZ024-033. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...LAMBERT/RXR AVIATION...LA CORTE
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1022 AM MST SAT FEB 25 2012 .UPDATE... ADDED WIND ADVISORY FOR TODAY. RUC BUFKIT SOUNDINGS WITH SUPPORT FROM NAM FORECAST SOUNDINGS INDICATE POTENTIAL FOR STRONG DOWNWARD MOMENTUM TRANSFER OVER MUCH OF THE AREA. FAIRLY STRONG WINDS JUST ABOVE THE SURFACE AND ALREADY OBSERVED STRONG AND GUSTY SURFACE WINDS SUGGEST THE MOMENTUM TRANSFER IS ALREADY UNDERWAY. OBSERVED STRONG SFC WINDS AND EXPECTED FURTHER INCREASE IN WINDS IN NORTHEAST WY ALSO PROMPTED ISSUANCE OF AN AIR QUALITY ALERT FOR THE POWDER RIVER BASIN. WIND SPEEDS SHOULD DECREASE THIS EVENING EVEN AS STRONG PRESSURE RISES APPROACH FROM THE WEST AND WINDS GO MOSTLY WESTERLY OVER OUR CWA. SUNDAY...WE EXPECT STRONG WINDS AGAIN...BUT FROM THE NORTHWEST BEHIND THE SURFACE LOW. BUMPED WINDS UP FOR TODAY AND MADE MINOR CHANGES IN SKY...POP AND WEATHER GRIDS TO FIT PRESENT TRENDS. OTHERWISE FORECAST IS ON TRACK. && .AVIATION...18Z TAFS STRONG WINDS WILL DOMINATE THE FORECAST TODAY INTO SUNDAY. GUSTY SOUTHERLY WINDS CONTINUE ACROSS CENTRAL SOUTH DAKOTA TODAY. MEANWHILE...SOUTHWEST WINDS OVER NORTHEAST WYOMING WILL SPREAD ACROSS SOUTHWEST SOUTH DAKOTA THIS AFTERNOON AND EVENING AS A TROF OF LOW PRESSURE MOVES THROUGH. AN AREA OF LOW PRESSURE WILL TRACK ALONG THE ND/SD BORDER OVERNIGHT...WITH STRONG NORTHWEST WINDS IN THE WAKE OF A COLD FRONT. THE STRONG NORTHWEST WINDS WILL CONTINUE THROUGH SUNDAY MORNING ACROSS THE PLAINS NORTH AND EAST OF THE BLACK HILLS. A FEW -SHRA/-SHSN POSSIBLE LATE THIS AFTERNOON ACROSS NORTHEAST WYOMING AND NORTHWEST SOUTH DAKOTA...WITH SCATTERED SNOW SHOWERS OVERNIGHT. IFR VSBY EXPECTED WITH SNOW SHOWERS...ESPECIALLY ACROSS THE NORTHERN BLACK HILLS AND BEAR LODGE MOUNTAINS. && .PREV DISCUSSION... /ISSUED 316 AM MST SAT FEB 25 2012/ DISCUSSION...CURRENT SURFACE ANALYSIS SHOWS HIGH PRESSURE OVER THE CENTRAL DAKOTAS...WITH LOW PRESSURE OVER SOUTHERN AB. A NEARLY STATIONARY FRONTAL BOUNDARY IS IN PLACE OVER THE AREA. UPPER LEVEL ANALYSIS HAS SHORTWAVE RIDGE OVER THE NORTHERN ROCKIES MOVING QUICKLY EAST INTO THE HIGH PLAINS...WITH A SHORTWAVE TROF OVER THE PACIFIC NW. SKIES ARE MOSTLY CLEAR ACROSS MUCH OF THE AREA...WITH SOME PATCHY LOW CLOUDS ACROSS WESTERN SD. TEMPS ARE IN THE TEENS AND LOWER 20S ACROSS THE AREA...WITH WINDS INCREASING IN THE GCC AREA. A MILD DAY IS ON TAP FOR THE AREA AS RIDGE QUICKLY CROSSES THE REGION. THE SHORTWAVE TROF AND A COLD FRONT WILL APPROACH WESTERN AREAS LATE TODAY AND QUICKLY CROSS THE AREA TONIGHT. MAIN CHANCES FOR PCPN STILL LOOK TO BE ACROSS NORTHERN PORTIONS OF THE CWA...ESPECIALLY THE WESTERN AND NORTHERN BLACK HILLS AREA...THIS EVENING. STRONG WEST-NORTHWEST WINDS WILL DEVELOP ACROSS THE PLAINS LATER TONIGHT AND ESPECIALLY ON SUNDAY. AFTER THIS...MAIN CONCERN WILL BE WITH PROJECTED WINTER STORM THAT WILL IMPACT THE REGION MONDAY NIGHT AND TUESDAY. FOR TODAY...CLOUDS WILL GENERALLY INCREASE ACROSS THE AREA...WITH A GOOD DEAL OF SUN STILL EXPECTED IN THE MORNING...ESPECIALLY ACROSS SOUTHERN AND EASTERN PORTIONS OF THE CWA. WARMER AIR WILL PUSH INTO THE AREA AS FRONTAL BOUNDARY MOVES OFF TO THE EAST. TEMPS WILL MOSTLY BE IN THE 40S...WITH SOME LOWER 50S ACROSS SOUTHWESTERN SD. SOUTH-SOUTHEAST WINDS WILL BE GUSTY ACROSS PORTIONS OF THE AREA...MAINLY SOUTHERN AND EASTERN PORTIONS OF THE CWA. THE WINDS COULD APPROACH ADVISORY CRITERIA FOR A TIME DURING THE MIDDAY AND EARLY AFTERNOON HOURS TOWARD CENTRAL SD. CHANCES FOR SHOWERS SHOULD HOLD OFF UNTIL LATE AFTERNOON ACROSS NORTHEASTERN WY INTO FAR NORTHWESTERN SD AS COLD FRONT APPROACHES. THE BEST CHANCES FOR PCPN TONIGHT...MAINLY SNOW SHOWERS...WILL BE ACROSS FAR NORTHEASTERN WY...THE BLACK HILLS...AND NORTHWESTERN SD. A LIGHT ACCUMULATION OF SNOW LOOKS LIKE A GOOD BET FROM PORTIONS OF FAR NORTHEASTERN WY INTO THE NORTHERN BLACK HILLS...UP TO A COUPLE OF INCHES OR SO. FAR NORTHWESTERN SD COULD ALSO SEE A DUSTING OF SNOW TONIGHT. COLD FRONT WILL PASS QUICKLY ACROSS THE REST OF THE CWA THIS EVENING. PRESSURE GRADIENT WILL TIGHTEN BEHIND THE FRONT OVERNIGHT AND EARLY SUNDAY. SUNDAY WILL BE VERY WINDY AS STRONG LOW LEVEL JET AND COLD ADVECTION COMBINE TO PRODUCE GUSTY WINDS ACROSS MUCH OF THE AREA. THE STRONGEST WINDS WILL BE ACROSS THE USUAL WINDY AREAS OF THE NORTHWEST AND WEST CENTRAL SD PLAINS...WHERE GUSTS OVER 50 MPH CAN BE EXPECTED. CHANCES FOR SNOW SHOWERS WILL BE RATHER LOW...MAINLY CONFINED TO THE NORTHERN BLACK HILLS AND FAR NORTHWESTERN SD. WINDS AND PCPN CHANCES WILL DIMINISH LATE IN THE DAY. HIGHS WILL BE MOSTLY IN THE 30S. MONDAY WILL SEE AN INCREASE IN CLOUDS AS A MUCH STRONGER TROF MOVES ACROSS THE WESTERN CONUS. THERE IS A CHANCE FOR SNOW LATE IN THE DAY AS SOUTHWEST FLOW AHEAD OF DEVELOPING SYSTEM BRINGS SOME UPPER LEVEL ENERGY ACROSS THE AREA. HOWEVER...IT LOOKS LIKE MAIN CHANCES FOR SNOW WILL HOLD OFF UNTIL MONDAY NIGHT. DEVELOPING UPPER LOW WILL MOVE QUICKLY ACROSS THE ROCKIES MONDAY NIGHT... LIKELY REACHING THE CENTRAL HIGH PLAINS BY TUESDAY MORNING. UPPER LEVEL WAVE AHEAD OF THE LOW WILL MOVE NORTHEAST ACROSS THE REGION MONDAY NIGHT AND BRING SNOW TO MUCH IF NOT ALL OF THE AREA. MOST OF THE MEDIUM RANGE MODELS ARE IN RELATIVELY GOOD AGREEMENT ON THE TRACK OF THE SYSTEM...BUT 00Z MODEL RUNS CONTINUE TO SHOW TIMING ISSUES. ECMWF IS MUCH SLOWER THAN GFS AND CANADIAN...HOLDING OFF GENERAL SNOWFALL UNTIL LATE TONIGHT OR TUESDAY MORNING. EVEN WITH THESE ISSUES...THEY ALL ARE IN AGREEMENT ON A GOOD PORTION OF THE AREA SEEING SOME SIGNIFICANT SNOWFALL...WITH THE HIGHER AMOUNTS GENERALLY THE FURTHER EAST YOU GO. IF THE TRENDS HOLD...A WINTER STORM WATCH WILL LIKELY BE ISSUED FOR MOST OR ALL OF THE CWA LATER TODAY OR EARLY SUNDAY FOR THIS SYSTEM. EXTENDED...MODELS REMAIN IN GOOD AGREEMENT WITH THE TRACK OF THE LOW PRESSURE SYSTEM FROM SOUTHWESTERN NEBRASKA ON TUESDAY MORNING...TO NORTHEASTERN NEBRASKA ON TUESDAY EVENING. HOWEVER TIMING DIFFERENCES REMAIN...WITH THE 00Z ECMWF SOLUTION NOW ABOUT 6 HOURS BEHIND THE 00Z GFS TIMING. EITHER WAY...MOST MODELS AND MEMBERS CONTINUE TO SHOW THE PROBABILITY OF SW/NE ORIENTED BAND OF SIGNIFICANT SNOWFALL DEVELOPING SOMEWHERE ACROSS SOUTH DAKOTA ON TUESDAY INTO TUESDAY NIGHT...ALTHOUGH IT/S STILL TOO EARLY TO DETERMINE EXACTLY WHERE THAT BAND MAY DEVELOP AND WHAT THE PRECISE SNOWFALL AMOUNTS WILL BE. WIND COULD ALSO BE A BIG FACTOR...ESPECIALLY ACROSS CENTRAL SOUTH DAKOTA...DEPENDING ON STRENGTH OF SURFACE LOW. THE LOW PRESSURE SYSTEM WILL DEPART THE AREA WEDNESDAY...WITH FLAT UPPER RIDGE ACROSS THE NORTHERN HIGH PLAINS. THE NEXT...MUCH WEAKER...UPPER TROF WILL AFFECT THE AREA ON THURSDAY. TEMPERATURES WILL REMAIN SLIGHTLY COOLER THAN NORMAL. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...WIND ADVISORY UNTIL 6 PM MST /7 PM CST/ THIS EVENING FOR BENNETT- BUTTE-CUSTER CO PLAINS-HAAKON-HARDING-JACKSON-MELLETTE- NORTHERN MEADE CO PLAINS-PENNINGTON CO PLAINS-PERKINS- SHANNON-SOUTHERN MEADE CO PLAINS-TODD-TRIPP-ZIEBACH. WIND ADVISORY FROM 8 AM TO 5 PM MST SUNDAY FOR BUTTE-HAAKON- HARDING-NORTHERN FOOT HILLS-NORTHERN MEADE CO PLAINS- PENNINGTON CO PLAINS-PERKINS-RAPID CITY-SOUTHERN MEADE CO PLAINS-STURGIS/PIEDMONT FOOT HILLS-ZIEBACH. WY...NONE. && $$ SHORT TERM...15 AND BARBER LONG TERM....07 AVIATION...07
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
940 PM MST FRI FEB 24 2012 .AVIATION...06Z TAFS VFR CONDITIONS ARE EXPECTED TONIGHT AS SOME SCT MID/HIGH CLOUDS PASS OVERHEAD. CLOUDS WILL INCREASE SATURDAY FROM WEST TO EAST WITH AREAS CIGS LOWERING TO 4-6KFT AND THE WEST...SOME SHOWERS MAY DEVELOP IN THE NORTH AND WEST. GUSTY SOUTHWEST WINDS WILL DEVELOP OVER NORTHEASTERN WY AND THE BLACK HILLS LATER TONIGHT...LASTING INTO SATURDAY AFTERNOON. GUSTY SOUTHERLY WINDS WILL DEVELOP ON THE SD PLAINS BY MIDDAY SATURDAY. WINDS WILL SWITCH TO THE NORTHWEST BEHIND A COLD FRONT SATURDAY NIGHT. && .PREV DISCUSSION... /ISSUED 852 PM MST FRI FEB 24 2012/ DISCUSSION...03Z SURFACE ANALYSIS HAD WEAK RIDGE OVER THE DAKOTA WITH SURFACE TROUGH FORMING FROM MT INTO CENTRAL WY...COINCIDENT WITH INCREASE SURFACE PRESSURE FALLS. UPPER RIDGE OVER THE ROCKIES WILL MOVE OVER THE CWA INTO SATURDAY WITH WELL-DEFINED WARM AIR ADVECTION. SOUTHERLY GRADIENT INCREASES WHICH WILL BRING GUSTY SOUTHWEST WINDS LATER TONIGHT OVER NORTHEASTERN WY/BLACK HILLS AND THEN GUSTY SOUTHERLY WINDS ON THE SD PLAINS SATURDAY. WILL UPDATE FORECAST TO HAVE STRONG WINDS ON THE PLAINS FOR SATURDAY. WILL ALSO TWEAK TEMPERATURES FOR LATEST TRENDS. PREV DISCUSSION... /ISSUED 345 PM MST FRI FEB 24 2012/ DISCUSSION...THE STRONG LOW PRESSURE SYSTEM CROSSING THE NORTHERN PLAINS ON SUNDAY WILL PRODUCE WEST TO NORTHWEST WINDS OF 25 TO 40 MPH WITH WIND GUSTS UP TO 55 MPH. HAVE ISSUED A WIND ADVISORY FOR THE NORTHWEST AND WEST CENTRAL SOUTH DAKOTA PLAINS. PREV DISCUSSION... /ISSUED 240 PM MST FRI FEB 24 2012/ DISCUSSION... LONG WAVE RIDGE NEAR 130W AND TROF NEAR 95W WITH CONTINUED FLOW OF COOL...UNSTABLE AIR OVER THE AREA TODAY. SHORT WAVE RIDGE APPROACHING FROM THE WEST FORECAST TO BE OVER THE AREA FRIDAY NIGHT AND EARLY SATURDAY. NEXT UPSTREAM TROF WILL CROSS THE PACIFIC NW COAST LATE TONIGHT AND MOVE QUICKLY EAST WARD. STEEP LAPSE RATES AND A BIT OF MID TROPOSPHERIC Q VECTOR CONVERGENCE HAVE SUPPORTED THE DEVELOPMENT OF SNOW SHOWERS AGAIN TODAY. MID AFTERNOON RADAR AND SATELLITE OBS INDICATE THESE ARE FINALLY WINDING DOWN AS SUBSIDENCE WARMING FORECAST BY BOTH THE NAM AND RUC MODELS SEEMS TO BE HAPPENING. REMNANT CLOUDS AND A LITTLE PRECIP WILL PERSIST INTO THE EVENING HOURS OVER UPSLOPE AREAS OF THE BLACK HILLS. A FEW SHOWERS ARE LIKELY TO RETURN TO NW WY AND THE NW PORTIONS OF SD WITH APPROACH OF NEXT SHORT WAVE TROF. NAM AND MESO MODELS INDICATE POTENTIAL FOR FAIRLY STRONG DOWNSLOPE WINDS OVER THE NE SLOPES OF THE BLACK HILLS SATURDAY MORNING INTO EARLY AFTERNOON. MODELS INDICATE ABOUT A 6MB PRESSURE DIFFERENCE ACROSS THE HILLS AT 18Z AND THE NAM FORECAST SOUNDINGS SHOW 50KT WINDS AT ABOUT 2000FT AGL OVER THE NORTHERN BLACK HILLS. SATURDAY NIGHT...TRANSIENT UPPER RIDGE SHIFTS QUICKLY EAST AS NEXT STRONG UPPER SHORTWAVE CROSSES THE NORTHERN ROCKIES. BOTH 500MB AND 700MB CLOSED LOWS TRACK NORTH OF THE FORECAST AREA...WITH BEST CHANCES OF SNOW ACROSS NORTHEAST WYOMING...THE BLACK HILLS...AND NORTHWESTERN SOUTH DAKOTA AS COLD FRONT MOVES THROUGH. BEST CHANCES OF ACCUMULATING SNOWS WILL BE ACROSS THE NORTHERN BLACK HILLS. LOW TEMPERATURES WILL FALL INTO THE TEENS AND 20S. SUNDAY...UPPER LOW SLIDES INTO MINNESOTA AS BOUNDARY LAYER FLOW BECOMES MORE WEST TO NORTHWEST. PRECIP CHANCES DIMINISH QUICKLY ON SUNDAY MORNING...BUT VERY WINDY CONDITIONS WILL BE FOUND BEHIND THE EXITING LOW ACROSS THE AREA. WINDS IN EXCESS OF 25 TO 35 MPH WITH HIGHER GUSTS WILL BE POSSIBLE. HIGH TEMPERATURES WILL BE IN THE 30S TO LOWER 40S. EXTENDED...POTENTIAL FOR A STRONG WINTER STORM TO AFFECT THE AREA EARLY NEXT WEEK. GFS/GEFS/ECMWF IN VERY GOOD AGREEMENT MONDAY/TUESDAY WITH UPPER TROF SWINGING THROUGH THE CENTRAL ROCKIES AND INTO THE PLAINS. GFS/GEFS/ECMWF SFC-500MB LOW TRACKS SIMILAR...ACROSS WESTERN NEBRASKA TO SOUTHEAST SOUTH DAKOTA/NORTHWEST IOWA. EVEN THOUGH TRACK IS SIMILAR...THERE IS SOME STRENGTH AND TIMING DIFFERENCES. ALL GEFS MEMBERS SHOW MEASURABLE PRECIPITATION ACROSS NORTHEAST WYOMING AND WESTERN SOUTH DAKOTA MONDAY NIGHT/TUESDAY. GIVEN HIGHER MODEL CONFIDENCE...HAVE BOOSTED POPS FOR MONDAY NIGHT/TUESDAY. WIND COULD ALSO BE A BIG FACTOR DEPENDING ON STRENGTH OF SURFACE LOW. UPPER LOW DEPARTS THE AREA WEDNESDAY...WITH FLAT UPPER RIDGE ACROSS THE NORTHERN HIGH PLAINS. NEXT UPPER TROF TO AFFECT THE AREA THURSDAY. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...WIND ADVISORY FROM 8 AM TO 5 PM MST SUNDAY FOR BUTTE-HAAKON- HARDING-NORTHERN FOOT HILLS-NORTHERN MEADE CO PLAINS- PENNINGTON CO PLAINS-PERKINS-RAPID CITY-SOUTHERN MEADE CO PLAINS-STURGIS/PIEDMONT FOOT HILLS-ZIEBACH. WY...NONE. && $$ SHORT TERM...WFO UNR LONG TERM....WFO UNR AVIATION...HELGESON
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1221 PM CST SAT FEB 25 2012 .DISCUSSION...RAIN SHOWERS ARE ENDING ACROSS THE AREA THIS AFTERNOON AS THE MID LEVEL LOW EXITS THE AREA. HAVE DECREASED POPS OVER THE AREA FOR THIS AFTERNOON AS MOST OF THE SHOWER ACTIVITY IS CURRENTLY OVER THE GULF...SOUTH PADRE ISLAND...AND EASTERN CAMERON COUNTY. SURFACE OBSERVATIONS ALONG WITH LAPS AND RUC DATA INDICATE THAT CURRENT TEMPERATURES ARE IN THE THE UPPER 40S AND LOW 50S ACROSS THE AREA. ABUNDANT CLOUD COVER THIS AFTERNOON SHOULD KEEP TEMPERATURES TO NEAR STEADY THROUGH THE REST OF TODAY SO HAVE LOWERED MAX TEMPERATURES A FEW DEGREES. UPDATED PRODUCTS WILL BE OUT SHORTLY. && .DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. && .AVIATION...VFR CONDITIONS ARE EXPECTED FOR THE NEXT 24 HOURS. MVRF CEILINGS SHOULD IMPROVE IN THE NEXT HOUR OR SO AS LOW CLOUDS AND LIGHT RAIN AT BRO MOVES OUT OF THE AREA. SKIES WILL BEGIN TO CLEAR THIS EVENING BUT LOW LEVEL MOISTURE IS EXPECTED TO BRING A RETURN TO LOWER CLOUD CEILINGS SUNDAY MORNING. CEILINGS SHOULD REMAIN ABOVE MVFR CONDITIONS. && .PREV DISCUSSION... /ISSUED 545 AM CST SAT FEB 25 2012/ DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. AVIATION...AN OVERRUNNING SITUATION NOW WITH COOLER NORTH WINDS UNDER SOUTHWEST FLOW ALOFT. THE TRAJECTORY OF A MID LEVEL LOW JUST TO THE WEST KEEPS MORNING RAIN SHOWERS PRIMARILY OVER THE MID VALLEY. OVC VFR CEILINGS EXPECTED WHILE LOW ALOFT LIFTS NORTHEAST. RAIN SHOULD END THIS AFTERNOON WITH MODERATE NORTH WINDS BECOMING LIGHT TO MODERATE NORTHEAST. PREV DISCUSSION... /ISSUED 233 AM CST SAT FEB 25 2012/ SHORT TERM /TODAY THROUGH SUNDAY/...SATELLITE SHOWS A MID LEVEL FEATURE LIFTING NORTHEAST OUT OF NORTHEAST MEXICO INTO THE RIO GRANDE PLAINS...WITH DIVERGENCE OVER DEEP SOUTH TEXAS AND THE RIO GRANDE VALLEY. LOW LEVEL COLD AIR ADVECTION IS STABILIZING THE BOUNDARY LAYER...WHILE SOUTHWEST FLOW ALOFT IS BRINGING MOISTURE ACROSS AND IS RESULTING IN THE ELEVATED RAINFALL OVERSPREADING THE MID AND UPPER VALLEY EARLY THIS MORNING. THE BEST LIFT IS FORECAST THROUGH ABOUT NOON WITH QPF AMOUNTS OF UP TO ONE HALF AN INCH FOR THE LOWER VALLEY. THUNDER IS NOT IN THE FORECAST RIGHT NOW...BUT SOME EMBEDDED STORMS MAY DEVELOP. OTHERWISE...OVERCAST SKIES WILL CONTINUE WITH HIGH TEMPS TODAY IN THE UPPER 50S TO LOWER 60S. AS THE MID LEVEL FEATURE MOVES NORTHEAST UP THE TEXAS COASTLINE LATER TODAY...RAIN CHANCES OVER THE CWA WILL END WITH LOW TEMPS TONIGHT AGAIN MAINLY IN THE 40S. WE SHOULD SEE PARTIAL CLEARING ON SUNDAY WITH LIGHT ONSHORE WINDS AND WITH HIGH TEMPS IN THE UPPER 60S TO AROUND 70. THE FORECAST HAS NOT CHANGED MUCH WITH AT LEAST AVERAGE CONFIDENCE IN MODEL RELIABILITY. LONG TERM.../SUNDAY NIGHT THROUGH SATURDAY. SUNDAY NIGHT EASTERLY ONSHORE FLOW WILL BE IN PLACE GRADUALLY INCREASING LOW LEVEL MOISTURE AND DEW POINTS. CONTINUING TO GO A LITTLE BELOW GUIDANCE IN TERMS OF SURFACE DEW POINT HOWEVER GIVEN THE EXTENSIVE AIR MASS MODIFICATION THAT OCCURRED WITH THE RECENT FRONTAL PASSAGE. WINDS SLACKEN OVERNIGHT SUNDAY AND SOME AREAS OF FOG WILL LIKELY RETURN BY MONDAY MORNING. WINDS WILL SHIFT MORE SOUTHERLY TUESDAY AND WEDNESDAY AS UPPER RIDGING BUILDS TO THE SOUTH AND A STORM SYSTEM MOVES OVER THE PLAINS STATES. THIS SHOULD CONTINUE TO GRADUALLY INCREASE LOW LEVEL MOISTURE AND HAVE CONTINUED A SLIGHT CHANCE FOR AFTERNOON SHOWERS. IT LOOKS FOR NOW THAT LARGE SCALE SUBSIDENCE AND SOUTHWESTERLY WINDS WILL WARM TEMPS IN THE MID LEVELS SUFFICIENTLY TO PREVENT MUCH IN THE WAY OF SHOWER AND ESPECIALLY THUNDERSTORM ACTIVITY IN THE FORM OF CAPPING...BUT MOISTURE IN PLACE AND OUR POSITION ON THE RIGHT EXIT REGION OF THE BROAD JET OVER THE CENTRAL US SUGGESTS AT LEAST SOME POSSIBILITY OF PRECIS. 00Z ECMWF/GFS IN GOOD AGREEMENT WITH DRAGGING A FRONTAL BOUNDARY RIGHT TO ABOUT OR NORTHERN CWA BORDER WEDNESDAY AFTERNOON BEFORE SOUTH WINDS INCREASE AHEAD OF THE NEXT STORM SYSTEM. WITH THE FRONTAL BOUNDARY AND LOW LEVEL MOISTURE IN PLACE BUMPED UP POPS FOR THURSDAY AFTERNOON JUST A BIT AS THE TREND OVER THE LAST 24 HOURS OR SO IN GUIDANCE HAS BEEN FOR THAT PERIOD TO HAVE THE BEST CHANCE FOR SHOWERS AND POSSIBLY A RUMBLE OF THUNDER. MODEL AGREEMENT GETS MORE MUDDIED FROM THAT POINT. STRONG SOUTHERLY WINDS SHOULD WARM US UP QUITE A BIT ON FRIDAY. THE ECMWF IS THEN FASTER AND STRONGER WITH A FRONTAL PASSAGE FRIDAY AFTERNOON AND EVENING...WHEREAS THE GFS IS MORE IN THE SUNDAY MORNING CATEGORY FOR NOW. GFS IS MORE ZONAL WITH THE FLOW WHEREAS ECMWF IS MORE AMPLIFIED...WILL HOLD WITH THE GOING TIMING FOR NOW WHICH IS MORE IN LINE WITH THE GFS. KEPT POPS FAIRLY LOW AT THE END OF THE PERIOD GIVEN TIMING CONCERNS AND LACK OF LARGE SCALE ASCENT AND WARM TEMPERATURES IN THE MID LEVELS. MARINE... TODAY THROUGH SUNDAY...BUOY020 REPORTS NORTH NORTHEAST WINDS AT 20 KTS WITH GUSTS TO 23 KNOTS AND WAVE HEIGHTS OF 9.5 FEET EARLY THIS MORNING. WINDS WILL SLOWLY DIMINISH TODAY AS THE PRESSURE GRADIENT RELAXES. SHOWERS AND EMBEDDED THUNDERSTORMS WILL CONTINUE THIS MORNING UNTIL A MID LEVEL DISTURBANCE MOVES OVER THE AREA AND EXITS TO THE NORTHEAST LATER TODAY. WAVE HEIGHTS WILL REMAIN HIGH TODAY AND TONIGHT WITH THE SMALL CRAFT ADVISORY NOW EXTENDED THROUGH THIS EVENING. WINDS WILL DECREASE TO LIGHT EAST NORTHEAST TONIGHT AND SUNDAY. SUNDAY NIGHT THROUGH THURSDAY...MODERATE EAST WINDS WILL CONTINUE SUNDAY NIGHT THROUGH MONDAY. STRONGER EAST WINDS IN THE NORTH CENTRAL GULF OF MEXICO MAY LEAD TO PERIODS OF ROUGH SEAS IN THE OFFSHORE WATERS THROUGH LATE MONDAY. MODERATE...GENERALLY SOUTH WINDS AND SEAS ARE EXPECTED TUESDAY THROUGH THURSDAY WITH WIND BECOMING GUSTY IN THE AFTERNOON. && .PRELIMINARY POINT TEMPS/POPS... BAYVIEW/PORT ISABEL 57 51 68 64 / 70 10 10 10 BROWNSVILLE 58 49 69 62 / 70 10 10 10 HARLINGEN 57 48 70 63 / 70 10 10 10 MCALLEN 58 49 70 64 / 60 10 10 10 RIO GRANDE CITY 59 46 70 62 / 30 10 10 10 SOUTH PADRE ISLAND 59 52 68 64 / 70 10 10 10 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR GMZ150-155- 170-175. && $$ THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT: HTTP://WEATHER.GOV/RGV 63
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1039 PM CST FRI FEB 24 2012 .UPDATE... A BREAK IN THE SNOW SHOWERS...WITH ISOLATED SNOW SHOWERS DROPPING SE FROM SE MN/W CNTRL WI TOWARD THE NW CWA IN THE DIFFERENTIAL CVA AHEAD OF STRONG VORT/26 UNITS ON RUC ANALYSIS/NEAR MSP. WILL NOT SEE MUCH IN THE WAY OF ACCUMULATIONS...BUT WILL SEE BRIEF VISBILITY REDUCTIONS IN THE HEAVIER SNOW SHOWERS. && .AVIATION/06Z TAFS/... WILL REMOVE CATEGORICAL MENTION OF P6SM -SHSN/FLURRIES FROM TAFS AND TRY AND TIME THE BRIEF PERIOD OF ISOLATED LIGHT SNOW SHOWERS THAT WILL MOVE ACROSS THE TAF SITES BETWEEN 06Z AND 11Z. NO ACCUMULATIONS...BUT COULD SEE A BRIEF 4-5SM VSBY WITH A HEAVIER SNOW SHOWER. STILL TAPPING 25 TO 29 KNOT WINDS ALOFT SO WINDS WILL STAY UP THOUGH GUSTS A BIT MORE INFREQUENT THAN DURING THE DAY. MORE FREQUENT WIND GUSTS RETURN WITH MIXING IN THE MORNING SATURDAY...WITH WINDS SLOWLY DIMINISHING DURING THE AFTERNOON. ONLY SCT MVFR CIGS UPSTREAM WITH MOST CIGS IN THE 3500 TO 4500 FT RANGE. WILL KEEP CIGS JUST AT VFR...WITH A SCT 2500 FT TO ACCOUNT FOR POTENTIAL OF A BRIEF MVFR CIG WITH A HEAVIER SNOW SHOWER IF THEY PASS OVER A TAF SITE. WILL SCATTER OUT CIGS LATE AFTERNOON/EARLY EVENING AS CYCLONIC FLOW SHIFTS EAST AND RIDGING BUILDS IN. && .MARINE... NO CHANGE TO CURRENT SMALL CRAFT ADVISORY. STILL TAPPING 25 TO 29 KNOT WINDS ALOFT SO WINDS WILL STAY UP...THOUGH GUSTS A BIT MORE INFREQUENT AT LAKE SHORE OB SITES THAN DURING THE DAY. DEEPER MIXNG OVER RELATIVELY WARMER LAKE WATERS WILL LEAD TO MORE FREQUENT WIND GUSTS PER THE CHICAGO CRIB SITE. WINDS SLOWLY EASE THROUGH THE EARLY MORNING...WITH WINDS AT OR BELOW 20 KTS BY 16Z. && .PREV DISCUSSION... /ISSUED 310 PM CST FRI FEB 24 2012/ VERY SHORT TERM...TONIGHT AND SATURDAY. CYCLONIC FLOW CONTINUES ALOFT WITH A SHORTWAVE DROPPING DOWN FROM MN THIS EVENING. WIDESPREAD LIGHT SNOW SHOWERS ASSOCIATED WITH THE LEADING EDGE OF THIS SHORTWAVE ARE APPARENT ON REGIONAL RADAR...CAN BE TRACED BACK TO MINNEAPOLIS AREA. THESE SNOW SHOWERS MAY LIGHTEN UP A LITTLE WITH THE LOSS OF DAYTIME HEATING AS THE LOW LEVEL LAPSE RATES DECREASE A BIT...BUT SHOULD CONTINUE THROUGH MUCH OF THE EVENING...ESPECIALLY IN EASTERN FORECAST AREA. THEN THE SHOWERS SHOULD TAPER OFF FROM WEST TO EAST AFTER MIDNIGHT...WITH A FEW FLURRIES LINGERING HERE AND THERE THROUGH MORNING. THERE IS ANOTHER AREA OF RADAR RETURNS OVER EASTERN SD ASSOCIATED WITH A SFC TROUGH AND UPPER SHORTWAVE THAT SHOULD STAY SOUTH OF WI TONIGHT. COLD AIR ADVECTION WILL ALLOW FOR TEMPS TO DROP INTO THE UPPER TEENS TO AROUND 20 TONIGHT...WHICH IS WARMER THAN WHAT 850MB AND 925MB TEMPS WOULD SUGGEST DUE TO EXPECTED CLOUD COVER. WINDS SHOULD REMAIN FAIRLY BRISK OVERNIGHT AS A TIGHT PRESSURE GRADIENT LINGERS OVER THE REGION. DESPITE HIGH PRESSURE WORKING ITS WAY INTO SOUTHERN WI...CLOUDS WILL BE SLOW TO CLEAR DURING THE DAY SINCE THE UPPER LEVEL TROUGH WILL BE SLOW TO MOVE EASTWARD. WITH THE CYCLONIC FLOW HANGING AROUND...WIDESPREAD SCATTERED TO BROKEN CUMULUS CLOUDS ARE EXPECTED THROUGH AT LEAST NOON IN SOUTH CENTRAL WI AND THROUGH AT LEAST 3 PM IN SOUTHEAST WI. THERE WILL BE SOME BREAKS IN THE CLOUDS AS THE DAY GOES ON. MODEL SNDGS DRY OUT EARLY SAT MORNING AT MADISON AND BY 12Z SAT AT MILWAUKEE. FINAL VORT MAX CLEARING EASTERN WI 12-18Z SAT...WITH NO REMAINING Q-VECTOR CONV OR UPPER LEVEL DIVERGENCE TO SUPPORT LINGERNING SNOW SHOWERS. NONETHELESS...A FEW FLURRIES DROPPING OUT OF THE MORNING CLOUDS ARE NOT OUT OF THE QUESTION. AS FOR TEMPERATURES...AFTER A COLD START SAT MORNING...TEMPS WILL GRADUALLY WARM THROUGH THE DAY WITH WEAK WARM AIR ADVECTION ALOFT. ANY SUNSHINE IN THE AFTERNOON WILL HELP INCREASE THE TEMPS TO ABOVE FREEZING...BUT AT THIS TIME...EXPECTING HIGHS AROUND 29 TO 31 DEGREES. SHORT TERM...SATURDAY NIGHT THROUGH MONDAY. SHORT WAVE RIDGING AHEAD OF STRENGTHENING PLAINS LOW PRESSURE WILL RESULT IN QUIET WX ACROSS SRN WI SAT NGT. FRESH SNOW COVER OVER MOST OF THE CWA SHOULD ALLOW TEMPS TO FALL RAPIDLY LATE SAT AFTN AND EVE...HOWEVER INCREASING MID/HIGH CLOUDS ASSOCIATED WITH UPSTREAM WARM AIR ADVECTION WL TEMPER OVERNIGHT TEMPS DURING THE LATE EVENING AND LATE NIGHT. SHORT TERM GUIDANCE SHOWING GOOD RUN TO RUN CONSISTENCY AS WELL AS THE ENSEMBLES IN CARRYING LOW PRESSURE ACROSS THE NORTHERN PLAINS AND THROUGH MN INTO FAR NRN WI BY 00Z/MON...SO CONFIDENCE INCREASING ON THIS SCENARIO. EXPECT PROGRESSIVE SCENARIO WITH THIS NEXT EVENT AS UPSTREAM KICKER BEGINS DIGGING INTO PACIFIC NORTHWEST LATE IN THE WEEKEND. BEST AVAILABLE MOISTURE AND FORCING LINES UP TO THE NORTH OVER NRN WI ON SUNDAY. HOWEVER...STRONG PUSH OF LOW TO MID LEVEL WARM AIR ADVECTION ON SUNDAY WITH MID-LEVEL LAPSE RATES OF 6-7 DEGREES AND SOME MID LEVEL MOISTURE. HAVE TO CONSIDER SMALL CHANCE FOR LIGHT PRECIPITATION WITH INITIAL SURGE OF WARM AIR ADVECTION AS WELL AS SFC OCCLUSION MOVING THRU IN THE AFTN/EVE. LAYER Q-VECTOR CONVERGENCE EXCEEDING 10 UNITS ALSO MOVES THROUGH DURING THE DAY. HENCE WL KEEP LOW POPS GOING ON SUNDAY. STRONGEST LOW LEVEL WINDS EXPECTED IN THE MORNING AND EARLY AFTN DURING GREATEST CLOUD COVER WHICH WOULD RETARD MIXING. NEVER THE LESS...WITH EXPCD THIN SPOTS IN CLOUD COVER...COULD BE A FEW WIND GUSTS APPROACHING WIND ADVY CRITERIA IN THE LATE MRNG AND EARLY AFTN BEFORE THE STRONGEST WINDS SHIFT EAST IN THE AFTN. WINDS AND LOWER DEWPTS SHOULD PREVENT THICKER ADVECTION FOG FROM FORMING OVER SNOWFIELD. AS THE WINDS BACK TO THE WEST BEHIND THE SFC OCCLUSION...DRIER AIR WL POUR BACK INTO SRN WI SUN EVE. LESS WINDY CONDITIONS WL RETURN ON MONDAY AS WEAK HIGH PRESSURE MOVES ACROSS THE WESTERN GTLAKES. LONG TERM...MONDAY NIGHT THROUGH FRIDAY. PRIMARY FOCUS OF THIS PERIOD ON STRONG LOW PRESSURE EXPECTED TO TRACK ACROSS THE CENTRAL PLAINS INTO SOUTHERN MINNESOTA AND NORTHERN WISCONSIN TUESDAY AND WEDNESDAY. LONG TERM GUIDANCE IN REASONABLE AGREEMENT ON THIS TRACK...AND LAST SEVERAL RUNS OF THE HI RES ECMWF HAVE BEEN TRENDING NORTH...MORE IN LINE WITH GFS AND GEM-NHEM. STRONG SOUTH WINDS AHEAD OF THIS SYSTEM WILL QUICKLY PULL DEEPER MOISTURE NORTHWARD INTO SOUTHERN WISCONSIN. GFS PWAT VALUES INCREASE TO AROUND 1.0. INITIAL WARM AIR ADVECTION SURGE ON TUESDAY MAY BRING A MIXTURE OF RAIN...SLEET AND SNOW TO SOUTHERN WI BEFORE WARMER AIR CHANGES MIXTURE OVER TO ALL RAIN. IF LOW TAKES PLANNED TRACK INTO NORTHERN WI TUE NGT AND EARLY WED...THEN SOUTHEAST SFC WINDS WOULD SHIFT TO THE WEST AFTER SFC OCCLUSION MOVES THROUGH TUE NIGHT. WL NEED TO WATCH FOR BURST OF HEAVIER RAINFALL AHEAD OF OCCLUSION TUE EVENING ON TOP OF FRESH SNOW COVER ENHANCING FLOODING POTENTIAL. AREAS OF LIGHT SNOW OR SNOW SHOWERS MAY SPREAD ACROSS SOUTHERN WI ON WEDNESDAY AS OCCLUDING LOW PRESSURE PASSES ACROSS NRN WI. EXTENDED GUIDANCE HINTING AT ANOTHER CLIPPER-TYPE SYSTEM BRINGING -SN BACK TO SOUTHERN WI SOMETIME THU NGT OR FRI. GFS 5 DAY 500H MEANS SHOW FAST W-NW FLOW CONTINUING OVER THE UPPER MIDWEST INTO THE FIRST DAYS OF MARCH...RESULTING IN CONTINUED UNSETTLED CONDITIONS. AVIATION /00Z TAFS/... SCATTERED LIGHT SNOW SHOWERS ARE EXPECTED TO CONTINUE INTO THIS EVENING AND GRADUALLY DIMINISH FROM WEST TO EAST FROM LATE EVENING THROUGH JUST AFTER MIDNIGHT...POSSIBLY LINGERING THROUGH EARLY SAT MORNING NEAR THE LAKESHORE. VISIBILITIES MAY DROP TO THE 4 TO 5 MI RANGE AT TIMES WITHIN THESE SNOW SHOWERS...BUT GENERALLY SHOULD STAY ABOVE 6 MI. TEMPS WILL COOL THROUGH THE NIGHT...ALLOWING LIGHT SNOW SHOWERS TO POSSIBLY ACCUMULATE...WITH TOTAL ADDITIONAL SNOW ACCUMULATIONS AROUND 0.1 INCH. CEILINGS WILL BE VARIABLE LATE THIS AFTERNOON AND EARLY EVENING...BUT SHOULD SETTLE TO AROUND 2500 TO 3500 FT AGL BY LATE EVENING AND STAY THAT WAY THROUGH MID SAT MORNING. THERE IS PLENTY OF UNCERTAINTY IN CEILING HEIGHTS. CLOUDS WILL BECOME BROKEN BY LATE MORNING NEAR MSN AND MID AFTERNOON NEAR MKE...BUT WILL BE SLOW TO CLEAR. MARINE... THE SMALL CRAFT ADVISORY WILL CONTINUE THROUGH TONIGHT INTO SATURDAY MORNING DUE TO BRISK WESTERLY WINDS SLOW TO DIMINISH. HIGH PRESSURE MOVING INTO SOUTHERN WI SAT MIDDAY WILL RELAX THE TIGHT PRESSURE GRADIENT AND ALLOW WINDS AND WAVES TO DIMINISH. 3 TO 5 FOOT WAVES WILL TAKE TIME TO DIMINISH OVERNIGHT...DESPITE THE OFFSHORE FLOW. THE NEXT CHANCE FOR A SMALL CRAFT ADVISORY WILL BE SUNDAY INTO SUNDAY NIGHT AS A STRONG LOW MOVES ACROSS NORTHWEST WISCONSIN. BRISK SOUTHEAST WINDS WILL BUILD LARGE WAVES. CONFIDENCE... TONIGHT AND SATURDAY...HIGH. SATURDAY NIGHT...HIGH. SUNDAY THROUGH MONDAY...MEDIUM. MONDAY NIGHT...HIGH. TUESDAY THROUGH WEDNESDAY...MEDIUM. THURSDAY AND FRIDAY...LOW TO MEDIUM. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY UNTIL 10 AM CST SATURDAY FOR LMZ643>646. && $$ UPDATE...REM TONIGHT/SATURDAY AND AVIATION/MARINE...MRC SATURDAY NIGHT THROUGH FRIDAY...MBK
AREA FORECAST DISCUSSION
NWS MIAMI FL
245 AM EST MON FEB 27 2012 .DISCUSSION...ZONAL FLOW PERSISTS ACROSS MUCH OF EASTERN NORTH AMERICA AND THIS IS NOT CONDUCIVE FOR ANY SIGNIFICANT COLD FRONTS MOVING DOWN THE PENINSULA ANY TIME SOON. EMBEDDED IN THE FLOW IS A WEAK MID LEVEL TROUGH IN THE NE GOFMEX AND THIS WILL MOVE ACROSS NORTH AND CENTRAL FL TODAY WITH LITTLE AFFECTS ON OUR CWA. BOTH MAV AND MET GUIDANCE SHOW LESS THAN 50 PERCENT POPS FOR ANY OF THE REGION WITH THE MET HAVING THE LOWEST NUMBERS. THE HRRR DOES SHOW AN INCREASE IN SHRA COVERAGE BY LATE THIS MORNING ACROSS PALM BEACH COUNTY AND CONSIDERING IT DOES VERY WELL DURING THE WINTER MONTHS, HAVE ADJUSTED THE POPS BASED ON THIS GUIDANCE AND THIS DOES SEEM REASONABLE GIVEN THE LOW IMPACT THIS TROUGH WILL HAVE FOR S FL. A SFC RIDGE CURRENTLY STRETCHES ACROSS THE SOUTHEAST STATES INTO THE ATLANTIC AND THIS WILL SHIFT SOUTH OVER THE NEXT FEW DAYS REACHING S FL BY THE END OF THIS WEEK. THIS WILL MAINTAIN A BREEZY EAST WIND FLOW THIS MORNING AND SLOWLY WEAKENING THEREAFTER. ONCE THE TROUGH MOVES TO THE NORTHEAST OF THE AREA, THE SUBTROPICAL RIDGE WILL BUILD BACK NORTH AS SEVERAL STRONG MID LEVEL TROUGHS MOVE THROUGH THE ZONAL PATTERN ACROSS THE NORTHERN TIER OF STATES. ALL OF THIS WILL MAINTAIN A QUIET WX PATTERN ACROSS FL THROUGH THE WEEK. BY NEXT WEEKEND, ONE OF THE AFOREMENTIONED TROUGHS WILL BEGIN TO CARVE OUT A LARGE SCALE TROUGH ACROSS THE EASTERN STATES AND BOTH THE ECMWF AND GFS SHOW A COLD FRONT MOVING INTO S FL SOMETIME SUNDAY BUT WITH MOST OF THE ENERGY WITH THIS SYSTEM REMAINING WELL NORTH OF OUR CWA IT APPEARS THAT IT WILL PROVIDE FOR JUST A SLIGHT CHANCE OF SHRA. && .MARINE...THE GRADIENT FLOW WILL WEAKEN THIS MORNING AS THE RIDGE OF THE RIDGE OF PRESSURE OVER THE SOUTHEAST STATES BEGINS TO SHIFT SOUTH. STILL, THERE WILL BE A SCEC STATEMENT FOR AT LEAST THE FIRST FEW HOURS OF THE FCST AS AN EAST WIND WILL CONTINUE AT AROUND 15-20 KNOTS BEFORE WEAKENING THIS AFTERNOON. && .FIRE WEATHER...NO PROBLEMS OR CONCERNS. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 82 70 83 69 / 40 20 10 10 FORT LAUDERDALE 82 73 83 72 / 30 20 10 10 MIAMI 83 72 84 71 / 20 20 10 10 NAPLES 85 66 86 65 / 30 10 10 10 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...30/KOB AVIATION/RADAR...15/JR
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
414 AM EST MON FEB 27 2012 .SHORT TERM /TODAY THROUGH TUESDAY NIGHT/... CURRENT RADAR LOOP SHOWS SOME SCATTERED TO NUMEROUS SHOWERS MOVING EAST ACROSS SOUTH GA THIS MORNING. THERE IS A WEAK SHORTWAVE OVER THE NORTHERN GULF THAT WILL MOVE ACROSS NORTH FL AND INTO THE ATLANTIC BY 18Z TODAY. THE LOCAL WRF AND HRRR MODELS SHOW SOME SHOWERS MOVING A BIT NE OVER THE NEXT FEW HOURS BEFORE MOVING INTO THE CAROLINAS THROUGH THIS AFTERNOON. THEY BOTH SHOW SHOWERS MOVING INTO CENTRAL GA BUT STAYING SOUTH OF THE ATL AREA. ONCE THE WAVE MOVES OUT INTO THE ATLANTIC...HIGH PRESSURE OVER THE GREAT LAKES STATES BUILDS SOUTHWARD BRINGING A BIT OF DRIER AIR INTO THE REGION. THIS DRIER AIRMASS WILL BE SHORT LIVED AS THE NEXT DEVELOPING WEATHER SYSTEM MOVES INTO THE AREA. BY 12Z TUE... A CLOSED LOW DEVELOPS OVER CO AND MOVES NE INTO THE WESTERN GREAT LAKES STATES BY 12Z WED. THIS LOW CONTINUES TO MOVE EAST INTI THE NEW ENGLAND STATES THROUGH 12Z THU. THIS LOW CENTERS ASSOCIATED COLD FRONT MOVES INTO THE MS RIVER VALLEY BY 00Z WED AND INTO NW GA BY 18Z WED. PRECIPITATION BEGINS MOVING INTO THE STATE WELL AHEAD OF THE FRONT WITH SHRA/TSRA ACROSS NORTH AND CENTRAL GA BEGINNING TUESDAY AFTERNOON/EVENING. THE BEST INSTABILITY WITH THIS SYSTEM WILL BE ASSOCIATED WITH THE FRONTAL PASSAGE BUT ONLY EXPECTING ISOLATED THUNDERSTORMS AT BEST. CAPES GET INTO THE 300-500 J/KG RANGE BETWEEN 18Z WED AND 00Z THU WITH 0-6KM BULK SHEAR AROUND 50-60. TEMPS WILL BE ABOUT 8-10 DEG ABOVE SEASONAL NORMS THROUGH THE SHORT TERM. .LONG TERM /WEDNESDAY THROUGH SUNDAY/... THE FRONTAL SYSTEM MENTIONED IN THE SHORT TERM FINALLY MOVES SOUTH AND EAST OF THE AREA BY 12-18Z THU. THE FRONT LOOKS TO STALL ACROSS N FL THEN MOVE BACK NORTHWARD AS A WARM FRONT FRI. ANOTHER LOW PRESSURE CENTER DEVELOPS OVER CO BY 18Z THU AND IT MOVES RAPIDLY NE INTO THE GREAT LAKE STATES BY 00Z SAT. THIS SECOND LOW CENTER IS WHAT ALLOWS THE WARM FRONT TO MOVE BACK ACROSS THE AREA. THIS LOW CENTERS COLD FRONT MOVES INTI GA LATE FRIDAY NIGHT AND SHOULD BE SOUTH AND EAST OF THE AREA BY 00Z SUN. THERE IS SOME INSTABILITY WITH THIS FRONT SO HAVE INTRODUCED THUNDER INTO THE FORECAST BUT JUST TOO FAR OUT TO DETERMINE JUST HOW INTENSE THIS SECOND SYSTEM WILL BE. TEMPS CONTINUE TO BE 5-10 DEG ABOVE SEASONAL NORMS THROUGH DAY 7. && .AVIATION... 06Z UPDATE... LOWERING CIGS WILL BE THE RULE FOR TODAY AS CLOUD SHIELD HAS ALREADY INFILTRATED ALL OF THE TAF SITES. EXPECTING MVFR TO TRANSITION TO IFR FOR ALL SITES THROUGH 12Z WITH DEVELOPING -RA AS WELL. MAIN QUESTION INVOLVES THE CHANCES OF SEEING LIFR FOR THE ATL SITES OR EVEN VLIFR FOR CSG AND MCN. AT THIS TIME...BASED ON DEVELOPING CLOUD DECK AND OBSERVATIONS TO THE SOUTH...WILL KEEP ATL AT IFR BUT ANY DEVELOPING DZ SHORTLY AFTER DAYBREAK COULD TAKE CONDITIONS EVEN LOWER. AS FOR WINDS...MOST MODELS ARE TAKING WINDS TO NW LATER TODAY WITH THE EXCEPTIONS OF THE LOCAL WRF. BASED ON ITS GOOD PERFORMANCE IN SUCH EVENTS...HAVE ELECTED TO KEEP WINDS E TO NE FOR THIS TAF CYCLE BUT WILL LOOK AT CLOSER WITH 12Z ISSUANCE. //ATL CONFIDENCE...06Z UPDATE... MEDIUM ON WINDS AND POTENTIAL FOR LIFR. HIGH ON IFR DEVELOPMENT AND REMAINING ELEMENTS. DEESE && .PRELIMINARY POINT TEMPS/POPS... ATHENS 65 44 71 53 / 30 0 20 30 ATLANTA 64 50 71 57 / 20 0 20 30 BLAIRSVILLE 63 40 66 50 / 10 0 20 50 CARTERSVILLE 64 42 71 53 / 10 0 20 40 COLUMBUS 66 50 75 58 / 30 5 10 20 GAINESVILLE 63 47 67 54 / 20 0 20 40 MACON 65 47 73 56 / 50 5 10 10 ROME 66 42 72 54 / 5 0 20 50 PEACHTREE CITY 64 42 71 55 / 20 0 20 30 VIDALIA 65 52 73 57 / 80 5 10 5 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 01
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
229 AM CST MON FEB 27 2012 .DISCUSSION... 916 PM CST SLIGHT ADJUSTMENTS MADE TO THE GOING FORECAST WITH A SOMEWHAT DIFFUSE YET MARKED COLD FRONT NOW MOVING EAST ACROSS THE FORECAST AREA. WINDS HAD DIMINISHED AHEAD OF THE FRONT WITH LESS MIXING AFTER SUNDOWN...BUT BEHIND THE FRONT THE WEST NORTHWEST WINDS ARE AGAIN GUSTING UPSTREAM...INCLUDING EVEN A FEW 25 TO 30 KT GUSTS IN NORTHEAST IA AND SOUTHWEST WI. NAM AND RUC SOUNDINGS BOTH DO NOT ADVERTISE THERMAL PROFILES TO HAVE THESE BROUGHT DOWN IN THE FORECAST AREA BUT BELIEVE BOTH MODELS MAY NOT BE ADEQUATELY ANALYZING THE COLD AIR ADVECTION PROFILES WITH THE FRONTAL PASSAGE. SO OCCASIONAL GUSTS BEING QUITE A WAYS HIGHER THAN GUIDANCE ADVERTISES ARE POSSIBLE THROUGH THE REST OF TONIGHT AFTER THE FRONT. A STRONG 130 KT JET SEEN ON WATER VAPOR AND UPPER AIR ANALYSIS IS DIRECTLY NORTH OF THE AREA OFFERING SOME FAVORABLE BROAD QG FOR WEAK ASCENT OVER THE AREA. THE MID TO UPPER LEVELS APPEAR TO BE MOISTENING ON SATELLITE CHANNELS AND STARTING TO SEE THE FIRST CLOUD OBSERVATIONS AROUND 8K TO 12K FT. THE RUC SEEMS TO HAVE A GOOD HANDLE ON THE EVOLUTION GIVEN THE PATTERN...AND EXPECT CLOUDS TO DEVELOP OVER THE SOUTHEAST FORECAST AREA THROUGH EARLY OVERNIGHT AND SLOWLY SHIFT EAST. THE CLOUDS AND WIND FIELD AND ASSOCIATED ADVECTION ARE OF COURSE DIRECTLY IMPACTING THE TEMPERATURES WHICH HAVE BEEN SOMEWHAT ERRATICALLY DROPPING...EVEN CLIMBING SLIGHTLY AS MIXING RE-ENSUES BEFORE DROPPING WITHIN THE APPARENT COLD AIR ADVECTION. HAVE DONE BEST AS ABLE TO ADJUST HOURLY TRENDS...BUT ALL IN ALL GOING MINIMUM TEMPERATURE FORECAST STILL LOOKS VERY REASONABLE. //PREV DISCUSSION... 320 PM CST FOR THE REMAINDER OF THE AFTERNOON AND EVENING...THE MAIN CONCERN WILL CONTINUE TO FOCUS ON WINDS. WILL LET THE WIND ADVISORY RIDE UNTIL EXPIRATION. THE ONLY SITE TO REMAIN NEAR ADVISORY CRITERIA IS PONTIAC WITH GUSTS TO 35KT/40MPH AT 20Z WITH HIGHER GUSTS OBSERVED FARTHER SOUTH. SINCE THERE WILL STILL BE A COUPLE MORE HOURS WITH STRONG GUST POTENTIAL...WILL LET THE ADVISORY RIDE RATHER THAN CANCEL EARLY. OTHERWISE...THE FORECAST IS GENERALLY ON TRACK WITH MILD CONDITIONS OVER THE REGION. TEMPERATURES OVER THE NORTHWESTERN PORTIONS OF THE CWA...INCLUDING THE ROCKFORD AREA...REMAIN A BIT COOLER THAT THE REST OF THE AREA DUE TO THE RESIDUAL SNOW COVER. HOWEVER...STRONG WARM ADVECTION AHEAD OF THE STRONG LOW PRESSURE SYSTEM APPROACHING THE UPPER MISSISSIPPI VALLEY HAS ALLOWED TEMPERATURES TO REACH WELL INTO THE 50S ELSEWHERE. EXPECT WINDS TO BEGIN TO DROP OFF EARLY THIS EVENING AS THE FRONTAL TROUGH CROSSES THE MISSISSIPPI RIVER...RELAXING THE PRESSURE GRADIENT. STILL EXPECT A WEAK COLD FRONT TO PUSH SEWD THROUGH THE CWA OVERNIGHT TONIGHT. GIVEN GENERALLY DRY CONDITIONS IN PLACE...DO NOT EXPECT ANY PCPN WITH THE FROPA...AND ACTUALLY ONLY SOME INCREASING CLOUD COVER OVER NWRN IL WITH SOME BACKWASH CLOUD WRAPPING AROUND THE SWRN PERIPHERY OF THE LOW. COOLER AIR AND HIGH PRESSURE WILL BUILD IN BEHIND THE EXITING LOW AND TEMPS OVERNIGHT TONIGHT SHOULD DROP INTO THE MIDDLE 20S ALG AND WEST OF THE I-39 CORRIDOR AND THE THE UPPER 20S TO LOWER 30S ELSEWHERE. FOR THE SHORT TERM FORECAST PERIOD...FROM MONDAY THROUGH WEDNESDAY...THE PERIOD WILL START OUT QUIET ON MONDAY AS HIGH PRESSURE PASSES THROUGH THE UPPER MIDWEST AND GREAT LAKES REGIONS. SKIES WILL GENERALLY BE MOSTLY SUNNY...THOUGH TEMPERATURES WILL BE NEAR OR SLIGHTLY BELOW NORMAL...RANGING FROM THE UPPER 30S NORTH OF I-80 AND THE LOWER 40S TO THE SOUTH AND LOWS TUESDAY MORNING WILL DROP INTO THE 20S. THE NEXT CHANCE FOR PCPN WILL COME ON TUESDAY AS THE STRONG PACIFIC SYSTEM LIFTS OUT OF THE CENTRAL ROCKIES AND ACROSS THE UPPER MISSISSIPPI VALLEY. THE LATEST MODEL TRENDS CONTINUE TO SLOW DOWN THE PROGRESS OF THE SYSTEM SLIGHTLY...WITH THE MODELS IN GENERALLY GOOD AGREEMENT ON NOT INTRODUCING PCPN INTO THE WRN PORTIONS OF THE CWA UNTIL LATE TUESDAY MORNING...AND THEN SPREADING EWD ACROSS THE CWA THROUGH THE DAY. THE STRONGEST SFC AND UPPER LEVEL FORCING WILL NOT BE IN PLACE UNTIL TUESDAY NIGHT. WHILE THERE WILL AN INCREASE IN LOW LEVEL MOISTURE AS THE GULF OF MEXICO OPENS UP IN ADVANCE OF THE SFC LOW...HAVE SOME CONCERN ABOUT THE THUNDER POTENTIAL WITH THE SYSTEM. FOR ONE THING...THE BEST FORCING WILL NOT BE IN PLACE UNTIL THE EVENING HOURS AND THE CWA WILL BE NORTH OF THE ASSOCIATED WARM FRONT. SOME MODEST ISENTROPIC LIFT AND MODEST ELEVATED INSTABILITY SHOULD BE IN PLACE...BUT GIVEN THE EXPECTED TRACK OF THE SFC LOW THROUGH THE UPPER MISSISSIPPI VALLEY AND WISCONSIN...AT THIS POINT...IT DOES NOT LOOK LIKE THE CWA WILL EVER BE IN A WARM SECTOR ENVIRONMENT. SO...WILL KEEP THE CHANCE THUNDER IN THE FORECAST FOR TUESDAY EVENING...BUT HAVE TRIMMED BACK THE TS POTENTIAL FOR THE OVERNIGHT HOURS AS THE COLD FRONT CROSSES THE AREA AT AN UNFAVORABLE TIME AND THEN A MID LEVEL DRY SLOT PUSHES IN VERY QUICKLY FOLLOWING THE FROPA. THERE SHOULD BE A BREAK IN THE PCPN BY WEDNESDAY MORNING AS THE DRY SLOT MOVES OVERHEAD...BUT AS THE SFC LOW MOVES OFF TO THE EAST...THERE WILL BE A CHANCE OF SOME LIGHT SNOW OR A RAIN/SNOW MIX ON THE BACKSIDE OF THE EXITING SYSTEM FOR WEDNESDAY AFTERNOON AND EVENING. FOR THE LONGER TERM FORECAST PERIOD...FROM THURSDAY THROUGH SUNDAY...THE MEDIUM RANGE GUIDANCE IS RELATIVELY CONSISTENT IN INDICATING A FAIRLY PROGRESSIVE PATTERN WITH INCREASING AMPLITUDE. THE STORM TRACK SHOULD BE A SERIES OF PACIFIC ORIGIN SYSTEMS WITH NO SIGNIFICANT ARCTIC INFLUENCE. THE TREND THROUGH THE LONGER TERM WILL BE FOR ABOVE NORMAL TEMPERATURES THROUGH FRIDAY WITH PERIODIC LOW PCPN CHANCES. THE STRONGEST UPPER LEVEL LOW IS ADVERTISED TO CROSS THE UPPER MIDWEST BY NEXT WEEKEND...WHICH SHOULD BRING COOLER CONDITIONS AND PERHAPS A CHANCE FOR SOME LIGHT SNOW...ESPECIALLY FOR THE NORTHERN PORTIONS OF THE CWA. KREIN && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 08Z... * LIGHT SW-WSW WIND BECOMING W WITH SPORADIC GUSTS 15-20 KTS DURING PREDAWN...THEN BECOMING GUSTY 20-25 KTS AFTER SUNRISE BEFORE DIMINISHING STEADILY IN THE AFTERNOON. * LOW PROBABILITY FOR A BRIEF FEW HOUR PERIOD OF A BROKEN HIGH MVR CEILING IN THE 2500-3000 FT AGL RANGE MID-MORNING TO MIDDAY MONDAY. TRS //DISCUSSION...UPDATED 06Z... LOW PRESSURE OVER FAR NORTHWEST WISCONSIN LATE THIS EVENING...WITH SURGING COLD FRONT ARCING SOUTH THROUGH LAKE MICHIGAN TO ABOUT THE IL/IN STATE LINE AT 05Z. WINDS HAVE SHIFTED WEST BEHIND THE FRONT...THOUGH DIRECTION DOES VARY A BIT 260-280 DEGREES. MODEST BUT NOTICEABLE PRESSURE RISE BUBBLE SPREADING ACROSS NORTHERN IL MAY ALLOW SITES TO GUST A LITTLE SPORADICALLY PRIOR TO SUNRISE. AFTER SUNRISE...DEEPENING OF LOW LEVEL MIXED LAYER AND STRONGER PUSH OF COLD ADVECTION SHOULD ALLOW MORE UNIFORMLY GUSTY WEST WINDS WITH GUSTS AROUND 25 KTS DURING THE MORNING. SURFACE LOW MOVES OFF INTO SOUTHERN ONTARIO BY EARLY AFTERNOON...AND SPRAWLING AREA OF HIGH PRESSURE BUILDS IN FROM THE WEST THROUGH THE EVENING WHICH WILL ALLOW WINDS TO DECREASE STEADILY DURING THE AFTERNOON HOURS. THE SURFACE HIGH PRESSURE RIDGE WILL MOVE ACROSS THE TERMINALS DURING THE LATE EVENING/OVERNIGHT HOURS...WITH WINDS LIKELY BECOMING LIGHT/VARIABLE AFTER SUNSET. WITH FAIRLY DRY MID/LOW LEVELS...ONLY SOME PATCHY SPARSE VFR MID/HIGH CLOUD TO CONTEND WITH OVERNIGHT. WITH STEEPENING OF LOW LEVEL LAPSE RATES AFTER SUNRISE MONDAY THERE WILL LIKELY BE SOME FLAT STRATOCU DEVELOPMENT WITH BASES IN THE 2000-3000 FT AGL RANGE. THERE IS SOME POTENTIAL THAT THIS WOULD DEVELOP BRIEFLY INTO AN MVFR CEILING IN THE 2500-3000 FT RANGE LATE MORNING... THOUGH CONFIDENCE IS LOW ENOUGH AND THE CEILING WOULD LIKELY LAST A SHORT ENOUGH TIME TO LEAVE IT OUT OF THE TAFS AT THIS TIME. ANY CU/STRATOCU WOULD LIKELY CLEAR OUT BY MID AFTERNOON. RATZER //ORD AND MDW CONFIDENCE...UPDATED 08Z... * HIGH CONFIDENCE IN WIND TRENDS...THOUGH MODERATE CONFIDENCE IN SPORADIC GUST SPEEDS PRIOR TO SUNRISE. * HIGH CONFIDENCE IN PREVAILING VFR CONDITIONS THROUGH PERIOD. * LOW CONFIDENCE IN BRIEF PERIOD OF MVFR 2500-3000 FT BROKEN STRATOCU DECK MID-MORNING/MIDDAY. TRS //OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z... TUESDAY...CHANCE OF RAIN/SNOW CHANGING TO RAIN BY AFTERNOON. MVFR POSSIBLE. MORE RAIN AND POSSIBLY A THUNDERSTORM TUESDAY NIGHT. WEDNESDAY...CHANCE OF RAIN/SNOW WEDNESDAY AFTERNOON THEN A CHANCE OF SNOW SHOWERS WEDNESDAY NIGHT. MVFR POSSIBLE. THURSDAY...VFR. FRIDAY...CHANCE OF RAIN/SNOW...MVFR POSSIBLE. SATURDAY...CHANCE OF LIGHT SNOW...MVFR POSSIBLE. RATZER && .MARINE... 227 AM CST AN ACTIVE WEATHER PATTERN IS EXPECTED OVER THE UPCOMING WEEK. THIS MORNING...LOW PRESSURE OVER THE UPPER PENINSULA OF MICHIGAN WILL CONTINUE TO PUSH EAST WITH A TRAILING COLD FRONT SWEEPING ACROSS LAKE MICHIGAN. WINDS WITHIN THE FRONTAL TROUGH HAVE WEAKENED...BUT ARE EXPECTED TO PICK UP AGAIN OUT OF THE WEST-NORTHWEST BEHIND THE FRONT AS THE PRESSURE GRADIENT ONCE AGAIN TIGHTENS. WINDS TO AROUND 30 KT ARE EXPECTED OVER THE OPEN WATERS. WILL ISSUE A SMALL CRAFT ADVISORY FOR LATE THIS MORNING THROUGH EARLY THIS EVENING FOR THE INDIANA AND ILLINOIS NEARSHORE WATERS. HIGH PRESSURE BUILDS ACROSS THE LAKE LATE TONIGHT AND WILL ALLOW WINDS TO DIMINISH BRIEFLY. NEXT LOW PRESSURE SYSTEM BEGINS TO DEEPEN OVER THE PLAINS TUESDAY AND PASSES OVER SOUTHERN LAKE MICHIGAN WEDNESDAY. THIS SYSTEM MAY BRING A FEW THUNDERSTORMS TO SOUTHERN LAKE MICHIGAN...WITH SOUTHEAST TO EASTERLY GALES AHEAD OF THE LOW ON WEDNESDAY. ANOTHER AREA OF LOW PRESSURE WILL PASS OVER LAKE MICHIGAN LATE FRIDAY INTO SATURDAY. DETAILS OF THIS SYSTEM ARE STILL UNCERTAIN...BUT THERE IS ONCE AGAIN POTENTIAL FOR GALES ACROSS THE LAKE. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744- LMZ745...6 AM MONDAY TO 4 PM MONDAY. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
156 AM CST MON FEB 27 2012 .DISCUSSION... 916 PM CST SLIGHT ADJUSTMENTS MADE TO THE GOING FORECAST WITH A SOMEWHAT DIFFUSE YET MARKED COLD FRONT NOW MOVING EAST ACROSS THE FORECAST AREA. WINDS HAD DIMINISHED AHEAD OF THE FRONT WITH LESS MIXING AFTER SUNDOWN...BUT BEHIND THE FRONT THE WEST NORTHWEST WINDS ARE AGAIN GUSTING UPSTREAM...INCLUDING EVEN A FEW 25 TO 30 KT GUSTS IN NORTHEAST IA AND SOUTHWEST WI. NAM AND RUC SOUNDINGS BOTH DO NOT ADVERTISE THERMAL PROFILES TO HAVE THESE BROUGHT DOWN IN THE FORECAST AREA BUT BELIEVE BOTH MODELS MAY NOT BE ADEQUATELY ANALYZING THE COLD AIR ADVECTION PROFILES WITH THE FRONTAL PASSAGE. SO OCCASIONAL GUSTS BEING QUITE A WAYS HIGHER THAN GUIDANCE ADVERTISES ARE POSSIBLE THROUGH THE REST OF TONIGHT AFTER THE FRONT. A STRONG 130 KT JET SEEN ON WATER VAPOR AND UPPER AIR ANALYSIS IS DIRECTLY NORTH OF THE AREA OFFERING SOME FAVORABLE BROAD QG FOR WEAK ASCENT OVER THE AREA. THE MID TO UPPER LEVELS APPEAR TO BE MOISTENING ON SATELLITE CHANNELS AND STARTING TO SEE THE FIRST CLOUD OBSERVATIONS AROUND 8K TO 12K FT. THE RUC SEEMS TO HAVE A GOOD HANDLE ON THE EVOLUTION GIVEN THE PATTERN...AND EXPECT CLOUDS TO DEVELOP OVER THE SOUTHEAST FORECAST AREA THROUGH EARLY OVERNIGHT AND SLOWLY SHIFT EAST. THE CLOUDS AND WIND FIELD AND ASSOCIATED ADVECTION ARE OF COURSE DIRECTLY IMPACTING THE TEMPERATURES WHICH HAVE BEEN SOMEWHAT ERRATICALLY DROPPING...EVEN CLIMBING SLIGHTLY AS MIXING RE-ENSUES BEFORE DROPPING WITHIN THE APPARENT COLD AIR ADVECTION. HAVE DONE BEST AS ABLE TO ADJUST HOURLY TRENDS...BUT ALL IN ALL GOING MINIMUM TEMPERATURE FORECAST STILL LOOKS VERY REASONABLE. //PREV DISCUSSION... 320 PM CST FOR THE REMAINDER OF THE AFTERNOON AND EVENING...THE MAIN CONCERN WILL CONTINUE TO FOCUS ON WINDS. WILL LET THE WIND ADVISORY RIDE UNTIL EXPIRATION. THE ONLY SITE TO REMAIN NEAR ADVISORY CRITERIA IS PONTIAC WITH GUSTS TO 35KT/40MPH AT 20Z WITH HIGHER GUSTS OBSERVED FARTHER SOUTH. SINCE THERE WILL STILL BE A COUPLE MORE HOURS WITH STRONG GUST POTENTIAL...WILL LET THE ADVISORY RIDE RATHER THAN CANCEL EARLY. OTHERWISE...THE FORECAST IS GENERALLY ON TRACK WITH MILD CONDITIONS OVER THE REGION. TEMPERATURES OVER THE NORTHWESTERN PORTIONS OF THE CWA...INCLUDING THE ROCKFORD AREA...REMAIN A BIT COOLER THAT THE REST OF THE AREA DUE TO THE RESIDUAL SNOW COVER. HOWEVER...STRONG WARM ADVECTION AHEAD OF THE STRONG LOW PRESSURE SYSTEM APPROACHING THE UPPER MISSISSIPPI VALLEY HAS ALLOWED TEMPERATURES TO REACH WELL INTO THE 50S ELSEWHERE. EXPECT WINDS TO BEGIN TO DROP OFF EARLY THIS EVENING AS THE FRONTAL TROUGH CROSSES THE MISSISSIPPI RIVER...RELAXING THE PRESSURE GRADIENT. STILL EXPECT A WEAK COLD FRONT TO PUSH SEWD THROUGH THE CWA OVERNIGHT TONIGHT. GIVEN GENERALLY DRY CONDITIONS IN PLACE...DO NOT EXPECT ANY PCPN WITH THE FROPA...AND ACTUALLY ONLY SOME INCREASING CLOUD COVER OVER NWRN IL WITH SOME BACKWASH CLOUD WRAPPING AROUND THE SWRN PERIPHERY OF THE LOW. COOLER AIR AND HIGH PRESSURE WILL BUILD IN BEHIND THE EXITING LOW AND TEMPS OVERNIGHT TONIGHT SHOULD DROP INTO THE MIDDLE 20S ALG AND WEST OF THE I-39 CORRIDOR AND THE THE UPPER 20S TO LOWER 30S ELSEWHERE. FOR THE SHORT TERM FORECAST PERIOD...FROM MONDAY THROUGH WEDNESDAY...THE PERIOD WILL START OUT QUIET ON MONDAY AS HIGH PRESSURE PASSES THROUGH THE UPPER MIDWEST AND GREAT LAKES REGIONS. SKIES WILL GENERALLY BE MOSTLY SUNNY...THOUGH TEMPERATURES WILL BE NEAR OR SLIGHTLY BELOW NORMAL...RANGING FROM THE UPPER 30S NORTH OF I-80 AND THE LOWER 40S TO THE SOUTH AND LOWS TUESDAY MORNING WILL DROP INTO THE 20S. THE NEXT CHANCE FOR PCPN WILL COME ON TUESDAY AS THE STRONG PACIFIC SYSTEM LIFTS OUT OF THE CENTRAL ROCKIES AND ACROSS THE UPPER MISSISSIPPI VALLEY. THE LATEST MODEL TRENDS CONTINUE TO SLOW DOWN THE PROGRESS OF THE SYSTEM SLIGHTLY...WITH THE MODELS IN GENERALLY GOOD AGREEMENT ON NOT INTRODUCING PCPN INTO THE WRN PORTIONS OF THE CWA UNTIL LATE TUESDAY MORNING...AND THEN SPREADING EWD ACROSS THE CWA THROUGH THE DAY. THE STRONGEST SFC AND UPPER LEVEL FORCING WILL NOT BE IN PLACE UNTIL TUESDAY NIGHT. WHILE THERE WILL AN INCREASE IN LOW LEVEL MOISTURE AS THE GULF OF MEXICO OPENS UP IN ADVANCE OF THE SFC LOW...HAVE SOME CONCERN ABOUT THE THUNDER POTENTIAL WITH THE SYSTEM. FOR ONE THING...THE BEST FORCING WILL NOT BE IN PLACE UNTIL THE EVENING HOURS AND THE CWA WILL BE NORTH OF THE ASSOCIATED WARM FRONT. SOME MODEST ISENTROPIC LIFT AND MODEST ELEVATED INSTABILITY SHOULD BE IN PLACE...BUT GIVEN THE EXPECTED TRACK OF THE SFC LOW THROUGH THE UPPER MISSISSIPPI VALLEY AND WISCONSIN...AT THIS POINT...IT DOES NOT LOOK LIKE THE CWA WILL EVER BE IN A WARM SECTOR ENVIRONMENT. SO...WILL KEEP THE CHANCE THUNDER IN THE FORECAST FOR TUESDAY EVENING...BUT HAVE TRIMMED BACK THE TS POTENTIAL FOR THE OVERNIGHT HOURS AS THE COLD FRONT CROSSES THE AREA AT AN UNFAVORABLE TIME AND THEN A MID LEVEL DRY SLOT PUSHES IN VERY QUICKLY FOLLOWING THE FROPA. THERE SHOULD BE A BREAK IN THE PCPN BY WEDNESDAY MORNING AS THE DRY SLOT MOVES OVERHEAD...BUT AS THE SFC LOW MOVES OFF TO THE EAST...THERE WILL BE A CHANCE OF SOME LIGHT SNOW OR A RAIN/SNOW MIX ON THE BACKSIDE OF THE EXITING SYSTEM FOR WEDNESDAY AFTERNOON AND EVENING. FOR THE LONGER TERM FORECAST PERIOD...FROM THURSDAY THROUGH SUNDAY...THE MEDIUM RANGE GUIDANCE IS RELATIVELY CONSISTENT IN INDICATING A FAIRLY PROGRESSIVE PATTERN WITH INCREASING AMPLITUDE. THE STORM TRACK SHOULD BE A SERIES OF PACIFIC ORIGIN SYSTEMS WITH NO SIGNIFICANT ARCTIC INFLUENCE. THE TREND THROUGH THE LONGER TERM WILL BE FOR ABOVE NORMAL TEMPERATURES THROUGH FRIDAY WITH PERIODIC LOW PCPN CHANCES. THE STRONGEST UPPER LEVEL LOW IS ADVERTISED TO CROSS THE UPPER MIDWEST BY NEXT WEEKEND...WHICH SHOULD BRING COOLER CONDITIONS AND PERHAPS A CHANCE FOR SOME LIGHT SNOW...ESPECIALLY FOR THE NORTHERN PORTIONS OF THE CWA. KREIN && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 08Z... * LIGHT SW-WSW WIND BECOMING W WITH SPORADIC GUSTS 15-20 KTS DURING PREDAWN...THEN BECOMING GUSTY 20-25 KTS AFTER SUNRISE BEFORE DIMINISHING STEADILY IN THE AFTERNOON. * LOW PROBABILITY FOR A BRIEF FEW HOUR PERIOD OF A BROKEN HIGH MVR CEILING IN THE 2500-3000 FT AGL RANGE MID-MORNING TO MIDDAY MONDAY. TRS //DISCUSSION...UPDATED 06Z... LOW PRESSURE OVER FAR NORTHWEST WISCONSIN LATE THIS EVENING...WITH SURGING COLD FRONT ARCING SOUTH THROUGH LAKE MICHIGAN TO ABOUT THE IL/IN STATE LINE AT 05Z. WINDS HAVE SHIFTED WEST BEHIND THE FRONT...THOUGH DIRECTION DOES VARY A BIT 260-280 DEGREES. MODEST BUT NOTICEABLE PRESSURE RISE BUBBLE SPREADING ACROSS NORTHERN IL MAY ALLOW SITES TO GUST A LITTLE SPORADICALLY PRIOR TO SUNRISE. AFTER SUNRISE...DEEPENING OF LOW LEVEL MIXED LAYER AND STRONGER PUSH OF COLD ADVECTION SHOULD ALLOW MORE UNIFORMLY GUSTY WEST WINDS WITH GUSTS AROUND 25 KTS DURING THE MORNING. SURFACE LOW MOVES OFF INTO SOUTHERN ONTARIO BY EARLY AFTERNOON...AND SPRAWLING AREA OF HIGH PRESSURE BUILDS IN FROM THE WEST THROUGH THE EVENING WHICH WILL ALLOW WINDS TO DECREASE STEADILY DURING THE AFTERNOON HOURS. THE SURFACE HIGH PRESSURE RIDGE WILL MOVE ACROSS THE TERMINALS DURING THE LATE EVENING/OVERNIGHT HOURS...WITH WINDS LIKELY BECOMING LIGHT/VARIABLE AFTER SUNSET. WITH FAIRLY DRY MID/LOW LEVELS...ONLY SOME PATCHY SPARSE VFR MID/HIGH CLOUD TO CONTEND WITH OVERNIGHT. WITH STEEPENING OF LOW LEVEL LAPSE RATES AFTER SUNRISE MONDAY THERE WILL LIKELY BE SOME FLAT STRATOCU DEVELOPMENT WITH BASES IN THE 2000-3000 FT AGL RANGE. THERE IS SOME POTENTIAL THAT THIS WOULD DEVELOP BRIEFLY INTO AN MVFR CEILING IN THE 2500-3000 FT RANGE LATE MORNING... THOUGH CONFIDENCE IS LOW ENOUGH AND THE CEILING WOULD LIKELY LAST A SHORT ENOUGH TIME TO LEAVE IT OUT OF THE TAFS AT THIS TIME. ANY CU/STRATOCU WOULD LIKELY CLEAR OUT BY MID AFTERNOON. RATZER //ORD AND MDW CONFIDENCE...UPDATED 08Z... * HIGH CONFIDENCE IN WIND TRENDS...THOUGH MODERATE CONFIDENCE IN SPORADIC GUST SPEEDS PRIOR TO SUNRISE. * HIGH CONFIDENCE IN PREVAILING VFR CONDITIONS THROUGH PERIOD. * LOW CONFIDENCE IN BRIEF PERIOD OF MVFR 2500-3000 FT BROKEN STRATOCU DECK MID-MORNING/MIDDAY. TRS //OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z... TUESDAY...CHANCE OF RAIN/SNOW CHANGING TO RAIN BY AFTERNOON. MVFR POSSIBLE. MORE RAIN AND POSSIBLY A THUNDERSTORM TUESDAY NIGHT. WEDNESDAY...CHANCE OF RAIN/SNOW WEDNESDAY AFTERNOON THEN A CHANCE OF SNOW SHOWERS WEDNESDAY NIGHT. MVFR POSSIBLE. THURSDAY...VFR. FRIDAY...CHANCE OF RAIN/SNOW...MVFR POSSIBLE. SATURDAY...CHANCE OF LIGHT SNOW...MVFR POSSIBLE. RATZER && .MARINE... 320 PM CST WINDS HAVE STRUGGLED TO STRENGTHEN TO GALES TODAY...WITH ONLY A FEW GALES REPORTED ALONG THE SOUTHERN END OF LAKE MICHIGAN. WILL CONTINUE THE GALE WARNING AS PLANNED...AND EVEN EXTEND IT BY AN HOUR. WINDS WILL STAY STRONG AS THE LOW PASSES OVER THE UPPER PENINSULA OF MICHIGAN TONIGHT...AND THEN DIMINISH BEHIND THE LOW. WINDS WILL ALSO SHIFT FROM SOUTH TO WEST BEHIND THE COLD FRONT THAT PASSES OVER THE LAKE AROUND MIDNIGHT. HIGH PRESSURE MOVES INTO THE NORTHERN GREAT PLAINS MONDAY AFTERNOON AND MOVES OVER LAKE MICHIGAN MONDAY NIGHT. WINDS VEER FROM NORTHWEST TO SOUTHEAST AS THE LOW PASSES OVER THE LAKE AND REMAIN LIGHT THROUGH EARLY TUESDAY MORNING. THE NEXT CHANCE OF GALES ARRIVES AHEAD OF THE NEXT LOW PRESSURE SYSTEM LATE TUESDAY EVENING. WINDS BECOME SOUTHWEST AND WEAKEN AS THE LOW PASSES OVER LAKE MICHIGAN ON WEDNESDAY. MODELS INDICATE EITHER THE LOW WILL STRENGTHEN SLIGHTLY AS IS MOVES OVERHEAD OR IT WILL ACT LIKE THE SYSTEM TODAY AND WEAKEN. ALSO KEPT WINDS LOWER THAN GUIDANCE BECAUSE WARM AIR ADVECTION AHEAD OF THE LOW MAY CREATE A STABLE LAYER OVER THE LAKE. HOWEVER DUE TO THE INCONSISTENCIES IN MODEL SOLUTIONS...KEPT WINDS AT LOW GALES. IN EXTENDED LAND...ANOTHER LOW PRESSURE SYSTEM ARRIVES FROM THE SOUTHWEST LATE ON FRIDAY. MODELS ARE INCONSISTENT WITH THIS SYSTEM...THEREFORE WHILE GALES ARE POSSIBLE WITH THIS LOW...KEPT WINDS AT SUB GALES FOR NOW. && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1057 PM CST SUN FEB 26 2012 .DISCUSSION... 916 PM CST SLIGHT ADJUSTMENTS MADE TO THE GOING FORECAST WITH A SOMEWHAT DIFFUSE YET MARKED COLD FRONT NOW MOVING EAST ACROSS THE FORECAST AREA. WINDS HAD DIMINISHED AHEAD OF THE FRONT WITH LESS MIXING AFTER SUNDOWN...BUT BEHIND THE FRONT THE WEST NORTHWEST WINDS ARE AGAIN GUSTING UPSTREAM...INCLUDING EVEN A FEW 25 TO 30 KT GUSTS IN NORTHEAST IA AND SOUTHWEST WI. NAM AND RUC SOUNDINGS BOTH DO NOT ADVERTISE THERMAL PROFILES TO HAVE THESE BROUGHT DOWN IN THE FORECAST AREA BUT BELIEVE BOTH MODELS MAY NOT BE ADEQUATELY ANALYZING THE COLD AIR ADVECTION PROFILES WITH THE FRONTAL PASSAGE. SO OCCASIONAL GUSTS BEING QUITE A WAYS HIGHER THAN GUIDANCE ADVERTISES ARE POSSIBLE THROUGH THE REST OF TONIGHT AFTER THE FRONT. A STRONG 130 KT JET SEEN ON WATER VAPOR AND UPPER AIR ANALYSIS IS DIRECTLY NORTH OF THE AREA OFFERING SOME FAVORABLE BROAD QG FOR WEAK ASCENT OVER THE AREA. THE MID TO UPPER LEVELS APPEAR TO BE MOISTENING ON SATELLITE CHANNELS AND STARTING TO SEE THE FIRST CLOUD OBSERVATIONS AROUND 8K TO 12K FT. THE RUC SEEMS TO HAVE A GOOD HANDLE ON THE EVOLUTION GIVEN THE PATTERN...AND EXPECT CLOUDS TO DEVELOP OVER THE SOUTHEAST FORECAST AREA THROUGH EARLY OVERNIGHT AND SLOWLY SHIFT EAST. THE CLOUDS AND WIND FIELD AND ASSOCIATED ADVECTION ARE OF COURSE DIRECTLY IMPACTING THE TEMPERATURES WHICH HAVE BEEN SOMEWHAT ERRATICALLY DROPPING...EVEN CLIMBING SLIGHTLY AS MIXING RE-ENSUES BEFORE DROPPING WITHIN THE APPARENT COLD AIR ADVECTION. HAVE DONE BEST AS ABLE TO ADJUST HOURLY TRENDS...BUT ALL IN ALL GOING MINIMUM TEMPERATURE FORECAST STILL LOOKS VERY REASONABLE. //PREV DISCUSSION... 320 PM CST FOR THE REMAINDER OF THE AFTERNOON AND EVENING...THE MAIN CONCERN WILL CONTINUE TO FOCUS ON WINDS. WILL LET THE WIND ADVISORY RIDE UNTIL EXPIRATION. THE ONLY SITE TO REMAIN NEAR ADVISORY CRITERIA IS PONTIAC WITH GUSTS TO 35KT/40MPH AT 20Z WITH HIGHER GUSTS OBSERVED FARTHER SOUTH. SINCE THERE WILL STILL BE A COUPLE MORE HOURS WITH STRONG GUST POTENTIAL...WILL LET THE ADVISORY RIDE RATHER THAN CANCEL EARLY. OTHERWISE...THE FORECAST IS GENERALLY ON TRACK WITH MILD CONDITIONS OVER THE REGION. TEMPERATURES OVER THE NORTHWESTERN PORTIONS OF THE CWA...INCLUDING THE ROCKFORD AREA...REMAIN A BIT COOLER THAT THE REST OF THE AREA DUE TO THE RESIDUAL SNOW COVER. HOWEVER...STRONG WARM ADVECTION AHEAD OF THE STRONG LOW PRESSURE SYSTEM APPROACHING THE UPPER MISSISSIPPI VALLEY HAS ALLOWED TEMPERATURES TO REACH WELL INTO THE 50S ELSEWHERE. EXPECT WINDS TO BEGIN TO DROP OFF EARLY THIS EVENING AS THE FRONTAL TROUGH CROSSES THE MISSISSIPPI RIVER...RELAXING THE PRESSURE GRADIENT. STILL EXPECT A WEAK COLD FRONT TO PUSH SEWD THROUGH THE CWA OVERNIGHT TONIGHT. GIVEN GENERALLY DRY CONDITIONS IN PLACE...DO NOT EXPECT ANY PCPN WITH THE FROPA...AND ACTUALLY ONLY SOME INCREASING CLOUD COVER OVER NWRN IL WITH SOME BACKWASH CLOUD WRAPPING AROUND THE SWRN PERIPHERY OF THE LOW. COOLER AIR AND HIGH PRESSURE WILL BUILD IN BEHIND THE EXITING LOW AND TEMPS OVERNIGHT TONIGHT SHOULD DROP INTO THE MIDDLE 20S ALG AND WEST OF THE I-39 CORRIDOR AND THE THE UPPER 20S TO LOWER 30S ELSEWHERE. FOR THE SHORT TERM FORECAST PERIOD...FROM MONDAY THROUGH WEDNESDAY...THE PERIOD WILL START OUT QUIET ON MONDAY AS HIGH PRESSURE PASSES THROUGH THE UPPER MIDWEST AND GREAT LAKES REGIONS. SKIES WILL GENERALLY BE MOSTLY SUNNY...THOUGH TEMPERATURES WILL BE NEAR OR SLIGHTLY BELOW NORMAL...RANGING FROM THE UPPER 30S NORTH OF I-80 AND THE LOWER 40S TO THE SOUTH AND LOWS TUESDAY MORNING WILL DROP INTO THE 20S. THE NEXT CHANCE FOR PCPN WILL COME ON TUESDAY AS THE STRONG PACIFIC SYSTEM LIFTS OUT OF THE CENTRAL ROCKIES AND ACROSS THE UPPER MISSISSIPPI VALLEY. THE LATEST MODEL TRENDS CONTINUE TO SLOW DOWN THE PROGRESS OF THE SYSTEM SLIGHTLY...WITH THE MODELS IN GENERALLY GOOD AGREEMENT ON NOT INTRODUCING PCPN INTO THE WRN PORTIONS OF THE CWA UNTIL LATE TUESDAY MORNING...AND THEN SPREADING EWD ACROSS THE CWA THROUGH THE DAY. THE STRONGEST SFC AND UPPER LEVEL FORCING WILL NOT BE IN PLACE UNTIL TUESDAY NIGHT. WHILE THERE WILL AN INCREASE IN LOW LEVEL MOISTURE AS THE GULF OF MEXICO OPENS UP IN ADVANCE OF THE SFC LOW...HAVE SOME CONCERN ABOUT THE THUNDER POTENTIAL WITH THE SYSTEM. FOR ONE THING...THE BEST FORCING WILL NOT BE IN PLACE UNTIL THE EVENING HOURS AND THE CWA WILL BE NORTH OF THE ASSOCIATED WARM FRONT. SOME MODEST ISENTROPIC LIFT AND MODEST ELEVATED INSTABILITY SHOULD BE IN PLACE...BUT GIVEN THE EXPECTED TRACK OF THE SFC LOW THROUGH THE UPPER MISSISSIPPI VALLEY AND WISCONSIN...AT THIS POINT...IT DOES NOT LOOK LIKE THE CWA WILL EVER BE IN A WARM SECTOR ENVIRONMENT. SO...WILL KEEP THE CHANCE THUNDER IN THE FORECAST FOR TUESDAY EVENING...BUT HAVE TRIMMED BACK THE TS POTENTIAL FOR THE OVERNIGHT HOURS AS THE COLD FRONT CROSSES THE AREA AT AN UNFAVORABLE TIME AND THEN A MID LEVEL DRY SLOT PUSHES IN VERY QUICKLY FOLLOWING THE FROPA. THERE SHOULD BE A BREAK IN THE PCPN BY WEDNESDAY MORNING AS THE DRY SLOT MOVES OVERHEAD...BUT AS THE SFC LOW MOVES OFF TO THE EAST...THERE WILL BE A CHANCE OF SOME LIGHT SNOW OR A RAIN/SNOW MIX ON THE BACKSIDE OF THE EXITING SYSTEM FOR WEDNESDAY AFTERNOON AND EVENING. FOR THE LONGER TERM FORECAST PERIOD...FROM THURSDAY THROUGH SUNDAY...THE MEDIUM RANGE GUIDANCE IS RELATIVELY CONSISTENT IN INDICATING A FAIRLY PROGRESSIVE PATTERN WITH INCREASING AMPLITUDE. THE STORM TRACK SHOULD BE A SERIES OF PACIFIC ORIGIN SYSTEMS WITH NO SIGNIFICANT ARCTIC INFLUENCE. THE TREND THROUGH THE LONGER TERM WILL BE FOR ABOVE NORMAL TEMPERATURES THROUGH FRIDAY WITH PERIODIC LOW PCPN CHANCES. THE STRONGEST UPPER LEVEL LOW IS ADVERTISED TO CROSS THE UPPER MIDWEST BY NEXT WEEKEND...WHICH SHOULD BRING COOLER CONDITIONS AND PERHAPS A CHANCE FOR SOME LIGHT SNOW...ESPECIALLY FOR THE NORTHERN PORTIONS OF THE CWA. KREIN && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * WEST WINDS...SPORADIC GUSTS 15-20 KTS POSSIBLE OVERNIGHT BECOMING MORE GUSTY 20-25 KTS AFTER SUNRISE BEFORE DIMINISHING STEADILY IN THE AFTERNOON. * LOW PROBABILITY FOR A BRIEF FEW HOUR PERIOD OF A BROKEN HIGH MVR CEILING IN THE 2500-3000 FT AGL RANGE MID-MORNING TO MIDDAY MONDAY. RATZER //DISCUSSION...UPDATED 06Z... LOW PRESSURE OVER FAR NORTHWEST WISCONSIN LATE THIS EVENING...WITH SURGING COLD FRONT ARCING SOUTH THROUGH LAKE MICHIGAN TO ABOUT THE IL/IN STATE LINE AT 05Z. WINDS HAVE SHIFTED WEST BEHIND THE FRONT...THOUGH DIRECTION DOES VARY A BIT 260-280 DEGREES. MODEST BUT NOTICEABLE PRESSURE RISE BUBBLE SPREADING ACROSS NORTHERN IL MAY ALLOW SITES TO GUST A LITTLE SPORADICALLY PRIOR TO SUNRISE. AFTER SUNRISE...DEEPENING OF LOW LEVEL MIXED LAYER AND STRONGER PUSH OF COLD ADVECTION SHOULD ALLOW MORE UNIFORMLY GUSTY WEST WINDS WITH GUSTS AROUND 25 KTS DURING THE MORNING. SURFACE LOW MOVES OFF INTO SOUTHERN ONTARIO BY EARLY AFTERNOON...AND SPRAWLING AREA OF HIGH PRESSURE BUILDS IN FROM THE WEST THROUGH THE EVENING WHICH WILL ALLOW WINDS TO DECREASE STEADILY DURING THE AFTERNOON HOURS. THE SURFACE HIGH PRESSURE RIDGE WILL MOVE ACROSS THE TERMINALS DURING THE LATE EVENING/OVERNIGHT HOURS...WITH WINDS LIKELY BECOMING LIGHT/VARIABLE AFTER SUNSET. WITH FAIRLY DRY MID/LOW LEVELS...ONLY SOME PATCHY SPARSE VFR MID/HIGH CLOUD TO CONTEND WITH OVERNIGHT. WITH STEEPENING OF LOW LEVEL LAPSE RATES AFTER SUNRISE MONDAY THERE WILL LIKELY BE SOME FLAT STRATOCU DEVELOPMENT WITH BASES IN THE 2000-3000 FT AGL RANGE. THERE IS SOME POTENTIAL THAT THIS WOULD DEVELOP BRIEFLY INTO AN MVFR CEILING IN THE 2500-3000 FT RANGE LATE MORNING... THOUGH CONFIDENCE IS LOW ENOUGH AND THE CEILING WOULD LIKELY LAST A SHORT ENOUGH TIME TO LEAVE IT OUT OF THE TAFS AT THIS TIME. ANY CU/STRATOCU WOULD LIKELY CLEAR OUT BY MID AFTERNOON. RATZER //ORD AND MDW CONFIDENCE...UPDATED 06Z... * HIGH CONFIDENCE IN OVERALL WIND TREND...THOUGH LOW CONFIDENCE IN SPORADIC GUST SPEEDS PRIOR TO SUNRISE. * HIGH CONFIDENCE IN PREVAILING VFR CONDITIONS THROUGH PERIOD. * LOW CONFIDENCE IN BRIEF PERIOD OF MVFR 2500-3000 FT BROKEN STRATOCU DECK MONDAY MID-MORNING/MIDDAY. RATZER //OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z... TUESDAY...CHANCE OF RAIN/SNOW CHANGING TO RAIN BY AFTERNOON. MVFR POSSIBLE. MORE RAIN AND POSSIBLY A THUNDERSTORM TUESDAY NIGHT. WEDNESDAY...CHANCE OF RAIN/SNOW WEDNESDAY AFTERNOON THEN A CHANCE OF SNOW SHOWERS WEDNESDAY NIGHT. MVFR POSSIBLE. THURSDAY...VFR. FRIDAY...CHANCE OF RAIN/SNOW...MVFR POSSIBLE. SATURDAY...CHANCE OF LIGHT SNOW...MVFR POSSIBLE. RATZER && .MARINE... 320 PM CST WINDS HAVE STRUGGLED TO STRENGTHEN TO GALES TODAY...WITH ONLY A FEW GALES REPORTED ALONG THE SOUTHERN END OF LAKE MICHIGAN. WILL CONTINUE THE GALE WARNING AS PLANNED...AND EVEN EXTEND IT BY AN HOUR. WINDS WILL STAY STRONG AS THE LOW PASSES OVER THE UPPER PENINSULA OF MICHIGAN TONIGHT...AND THEN DIMINISH BEHIND THE LOW. WINDS WILL ALSO SHIFT FROM SOUTH TO WEST BEHIND THE COLD FRONT THAT PASSES OVER THE LAKE AROUND MIDNIGHT. HIGH PRESSURE MOVES INTO THE NORTHERN GREAT PLAINS MONDAY AFTERNOON AND MOVES OVER LAKE MICHIGAN MONDAY NIGHT. WINDS VEER FROM NORTHWEST TO SOUTHEAST AS THE LOW PASSES OVER THE LAKE AND REMAIN LIGHT THROUGH EARLY TUESDAY MORNING. THE NEXT CHANCE OF GALES ARRIVES AHEAD OF THE NEXT LOW PRESSURE SYSTEM LATE TUESDAY EVENING. WINDS BECOME SOUTHWEST AND WEAKEN AS THE LOW PASSES OVER LAKE MICHIGAN ON WEDNESDAY. MODELS INDICATE EITHER THE LOW WILL STRENGTHEN SLIGHTLY AS IS MOVES OVERHEAD OR IT WILL ACT LIKE THE SYSTEM TODAY AND WEAKEN. ALSO KEPT WINDS LOWER THAN GUIDANCE BECAUSE WARM AIR ADVECTION AHEAD OF THE LOW MAY CREATE A STABLE LAYER OVER THE LAKE. HOWEVER DUE TO THE INCONSISTENCIES IN MODEL SOLUTIONS...KEPT WINDS AT LOW GALES. IN EXTENDED LAND...ANOTHER LOW PRESSURE SYSTEM ARRIVES FROM THE SOUTHWEST LATE ON FRIDAY. MODELS ARE INCONSISTENT WITH THIS SYSTEM...THEREFORE WHILE GALES ARE POSSIBLE WITH THIS LOW...KEPT WINDS AT SUB GALES FOR NOW. && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS TOPEKA KS
1137 PM CST SUN FEB 26 2012 ...UPDATE TO AVIATION... .DISCUSSION... SHORT RANGE FORECAST - TONIGHT AND MONDAY... CLEAR SKIES AND W-NW DOWNSLOPE WINDS HAVE ALLOWED SURFACE TEMPERATURES TO RISE INTO THE UPPER 50S TO MID 60S ACROSS MOST OF NORTHEAST KANSAS. EXPECT THE WARM AND DRY CONDITIONS TO PERSIST FOR THE REST OF THE AFTERNOON. SURFACE HIGH PRESSURE WILL BUILD INTO THE NORTHERN PLAINS AND NOSE INTO THE FORECAST AREA BRINGING CLEAR SKIES OVERNIGHT WITH CALM WINDS. DO NOT EXPECT MUCH IN THE WAY OF COLD AIR ADVECTION...BUT RADIATIONAL COOLING WILL ALLOW THE BOUNDARY LAYER TO COOL TO BELOW FREEZING. EXPECT SOME COLD AIR ADVECTION TO TRICKLE INTO THE AREA BEHIND THE VERY LIGHT NORTHERLY FLOW FOR MONDAY. MIXING NOT QUITE AS DEEP ON MONDAY AS SUNDAY...SO THAT FACTOR IN COMBINATION WITH THE WEAK COLD AIR ADVECTION WILL KEEP TEMPS ON MONDAY MORE SEASONAL. CLOUDS WILL BE ON THE INCREASE BY MONDAY AFTERNOON/EVENING AS WARM/MOIST AIR GETS ADVECTED NORTHWARD. CONDENSATION AS A RESULT OF THE ISENTROPIC LIFT ASSOCIATED WITH THE WARM AIR ADVECTION WILL LIKELY BEGIN SHORTLY AFTER NOON...WHICH WILL ALSO AID IN KEEPING TEMPERATURES FROM RISING MUCH HIGHER THAN THE LOWER 50S. JL LEIGHTON LONG TERM - MONDAY NIGHT THROUGH SUNDAY... MONDAY NIGHT THROUGH TUESDAY NIGHT... MODEL AGREEMENT IS NOW FAIRLY GOOD IN THE TRACK OF A POTENT NEGATIVELY TILTED UPPER LEVEL TROUGH. THE SURFACE LOW WILL TRACK WELL NORTH OF THE LOCAL FORECAST AREA WITH A SHARP FAST MOVING DRY LINE CROSSING THE AREA BETWEEN 21Z TUESDAY AND 03Z WEDNESDAY. WARM MOIST ADVECTION WILL TAKE PLACE ON MONDAY NIGHT AND TUESDAY MORNING AHEAD OF THE SYSTEM WITH SHOWERS AND A FEW ELEVATED THUNDERSTORMS EXPECTED TO DEVELOP AND MOVE INTO THE AREA MONDAY NIGHT. THIS ACTIVITY SHOULD ALL REMAIN BELOW SEVERE LIMITS WITH SOME LOW END POTENTIAL FOR SMALL HAIL THROUGH NOON ON TUESDAY. WHILE CLOUD COVER WILL BE ABUNDANT THROUGH THE DAY ON TUESDAY... TEMPERATURES WILL WARM NICELY WITH AMPLE WARM ADVECTION. THE CLOUD LAYER WILL ALSO BE RELATIVELY SHALLOW AND LOW BY TUESDAY AFTERNOON...AND A FEW BREAKS WILL BE POSSIBLE AHEAD OF THE DRY LINE BY LATE AFTERNOON. SURFACE DEWPOINTS WILL CLIMB INTO THE MID 50S BY LATE TUESDAY ACROSS MUCH OF THE FORECAST AREA WITH TEMPS IN THE UPPER 50S AND LOW 60S. EXPECT THE DRY LINE TO ENTER THE FORECAST AREA SOMETIME BETWEEN 21Z AND 00Z...AND PUSH EAST INTO MISSOURI ONLY 3 TO 4 HOURS LATER. CONVECTION IS EXPECTED TO DEVELOP IMMEDIATELY ALONG THE DRY LINE BOUNDARY BY LATE AFTERNOON AND CROSS THE FORECAST AREA...BUT SUBSTANTIAL UNCERTAINTY EXISTS REGARDING THE POTENTIAL FOR STRONG TO SEVERE STORMS. CURRENT INDICATIONS ARE THAT 200-500 J/KG OF SURFACE BASED CAPE WILL BE PRESENT IN A NARROW BAND NEAR THE BOUNDARY. THOSE ARE MEAGER VALUES BUT THE MAJORITY OF THIS INSTABILITY WILL BE IN THE LOWEST 15000 FEET OF THE ATMOSPHERE WITH MAX LIFTED INDEX VALUES IN THAT LAYER APPROACHING -5. THIS WOULD SUGGEST THE POTENTIAL FOR SOME STRONGER SHALLOW UPDRAFTS. SHEAR THROUGH THE DEPTH OF THE CONVECTIVE LAYER...ABOUT 0-4 KM...IS 50-60 KTS WHILE 0-1 KM SHEAR IS 30-40 KTS. THESE VALUES ARE MORE THAN SUFFICIENT TO PRODUCE ORGANIZED STORMS WITH SOME POTENTIAL FOR LOW TOPPED SUPERCELL DEVELOPMENT. HOWEVER...THE UNIDIRECTIONAL NATURE OF THE SHEAR MAY SUGGEST MORE OF A QUASI-LINEAR DEVELOPMENT WITH A BIT MORE POTENTIAL FOR DAMAGING WINDS AT THE SURFACE. IT WILL BE DIFFICULT TO GET LARGE HAIL WITH SUCH SHALLOW UPDRAFTS PERHAPS HAVING TROUBLE CLIMBING ABOVE THE -20C LEVEL...BUT AT LEAST SMALL HAIL WOULD REMAIN POSSIBLE. TORNADO POTENTIAL IS NON-ZERO...BUT HIGHLY DEPENDENT UPON DEVELOPMENT OF MORE ROBUST UPDRAFTS...AND STRONG UPDRAFT POTENTIAL IS THE MOST SIGNIFICANT UNCERTAINTY WITH THIS FORECAST. WEDNESDAY THROUGH SUNDAY... WILL DRY OUT QUICKLY BEHIND THIS SYSTEM AND REMAIN DRY WITH A SLIGHT COOL DOWN FOR WEDNESDAY AND A QUICK RECOVERY WITH WARM TEMPS AGAIN ON THURSDAY. A WEAKER STORM SYSTEM WILL THEN CROSS THE PLAINS THURSDAY NIGHT INTO FRIDAY. THIS SYSTEM DOES NOT HAVE A PARTICULARLY STRONG PRECIP SIGNAL BUT APPEARS WORTHY OF AT LEAST A SLIGHT CHANCE OF LIGHT RAIN WITH PERHAPS A MIX TO LIGHT SNOW THURSDAY NIGHT. IT DOES NOT APPEAR TO BE A HIGH IMPACT EVENT AT THIS TIME. EXPECT DRY CONDITIONS AND NEAR NORMAL TEMPERATURES FOR SATURDAY AND SUNDAY. BARJENBRUCH && .AVIATION... VFR CONDITIONS WILL CONTINUE THROUGH THE TERMINAL FCST PERIOD WITH ONLY SCT HIGH CLOUDS EXPECTED. WILL KEEP WINDS NORTH 6 TO 8 KTS OVERNIGHT WITH SECOND PUSH OF COOLER AIR. WILL THEN GRADUALLY VEER TO THE NORTHEAST 6-10KTS BEYOND 12Z...THEN EASTERLY AROUND 10 KTS ON THE BACKSIDE OF RETREATING SFC HIGH. FOR NOW WILL ONLY INCLUDE SCT CIRRUS UNTIL 12Z FOLLOWED BY BKN MID LEVEL DECK BY 00Z/28 AROUND 10 KFT...ALTHOUGH LOWER CIGS EXPECTED JUST BEYOND THE END OF THIS FCST PERIOD. && .FIRE WEATHER... DEEP MIXING HAS COMMENCED ACROSS ALL OF NORTHEAST KANSAS BRINGING VERY DRY LOW LEVEL AIR TO THE SURFACE. RUC SOUNDINGS INDICATE THAT THE ATMOSPHERE HAS MIXED TO APPROXIMATELY 800 MB OR 5600 FEET. W-NW WINDS AT THE SURFACE CONTAIN QUITE A BIT OF A DOWNSLOPE TRAJECTORY WHICH HAS AIDED IN WARMING AND DRYING THE AIR. AS A RESULT RELATIVE HUMIDITY VALUES HAVE DROPPED INTO THE MID TEENS THIS AFTERNOON...AND WILL LIKELY REMAIN IN THE MIDDLE TEENS THROUGH AT LEAST SUNSET. WINDS THROUGHOUT THE DAY HAVE BEEN RELATIVELY LIGHT AS OBSERVATIONS HAVE INDICATED 10 TO 15 MPH W-NW WINDS. DUE TO THE DEEP MIXING SOME WIND GUSTS OF UP TO 20-25 MPH ARE POSSIBLE...BUT THOSE GUSTS WILL BE RATHER INFREQUENT. RH VALUES WILL START TO RISE ONCE SURFACE TEMPERATURES BEGIN TO COOL RIGHT AROUND SUNSET. JL && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
951 PM MST SUN FEB 26 2012 .UPDATE... ISSUED AT 651 PM MST SUN FEB 26 2012 SFC HIGH NOW SETTLING OVER THE AREA AS WINDS HAVE RAPIDLY DECREASED. 00Z SOUNDINGS INDICATE DRY AIR MASS IN PLACE AT DNR AND TO A LESSER EXTENT DDC...WITH LOW LEVEL MIXING RATIOS NOTICEABLY HIGHER AT KLBF. WITH THESE OBSERVATIONS AND EXPECTED WIND FIELD...STILL EXPECT A FAIRLY SHARP NORTHEAST TO SOUTHWEST TD GRADIENT THROUGH THE EVENING...ALTHOUGH THERE WILL BE SOME RECOVERY WITH LOSS OF DEEP MIXING. WHILE THINGS WILL BE SLIGHTLY MORE HUMID...MOISTURE PROFILES DO NOT LOOK DEEP ENOUGH TO PREVENT TEMPS FROM DROPPING SHARPLY GIVEN LIGHT WINDS...DRY AIR AND MINIMAL HIGH CLOUD COVER. HAVE LOWERED TEMPS 4-5 DEGREES AT SEVERAL LOCATIONS...ESPECIALLY NORMAL COLD SPOTS LIKE WESTERN CHEYENNE COUNTY. && .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 236 PM MST SUN FEB 26 2012 LATEST VISIBLE SATELLITE IMAGERY AND RUC UPPER AIR ANALYSIS SHOW AN UPPER LEVEL TROUGH OVER THE NORTHERN CONUS WITH AN UPPER LEVEL JET OVER NORTHWEST KANSAS AND SOUTHERN NEBRASKA. SURFACE OBSERVATIONS REPORT NORTHWEST WINDS GUSTING 35 TO 45 MPH AS THE STRONGER WINDS ABOVE THE SURFACE MIX DOWN. THE STRONG WINDS THAT PLAGUED THE NORTHERN PORTIONS OF THE TRI-STATE AREA WILL COME TO AN END AROUND SUNSET AS TEMPERATURES COOL. DURING THE NIGHT A SURFACE HIGH PRESSURE WILL MOVE EAST THROUGH NEBRASKA...CAUSING THE WINDS TO SWING TO THE NORTH. DURING THE OVERNIGHT HOURS ISENTROPIC ANALYSIS AND RELATIVE HUMIDITY PLOTS SHOW SOME LIFT AND SATURATED AIR MOVING INTO THE AREA FROM THE SOUTH...WHICH WILL LEAD INCREASED CLOUD COVER FROM NORTH TO SOUTH. WITH DRIER AIR IN PLACE AND LIGHT WINDS...TEMPERATURES WILL BE COOLER THAN LAST NIGHT...RANGING FROM THE UPPER TEENS IN SOUTHWEST NEBRASKA TO THE LOWER 20S IN WEST CENTRAL KANSAS. MONDAY THROUGH MONDAY NIGHT...UPPER LOW WILL BE OVER PACIFIC COAST EARLY MONDAY MORNING...AND WILL STILL BE OVER GREAT BASIN EARLY MONDAY EVENING. OVERALL TREND WITH GUIDANCE HAS BEEN TO SLOW DOWN THIS FEATURE. WHILE THERE IS DECENT H7-H5 MOISTURE IN PLACE BY 18Z MONDAY...WITH LIMITED LIFT AND DRY LAYER BELOW H7...I DECIDED AGAINST MENTION OF SPRINKLES MONDAY AFTERNOON. I ADJUSTED TIMING TO KEEP FORECAST DRY THROUGH 03Z...AND TO LIMIT BEST CHANCES IN THE FAR EASTERN PART OF THE CWA...TRIMMING POPS IN THE WEST. WAA OVERNIGHT MONDAY WILL RESULT IN TEMPS INCREASING AFTER MIDNIGHT...WITH LOWS LIKELY LATE MONDAY EVENING. AS A RESULT PRECIP SHOULD MAINLY FALL AS RAIN...THOUGH A BRIEF RAIN/SNOW MIX COULDNT BE RULED OUT IN EASTERN COLORADO. WHILE WINDY CONDITIONS ARE EXPECTED MONDAY...LIMITED MIXING DUE TO CLOUD COVER SHOULD KEEP CONDITIONS BELOW ADVISORY LEVELS. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 236 PM MST SUN FEB 26 2012 TUESDAY...THE UPPER LOW WILL DEEPEN AS IT MOVES OUT OF THE INTER-MOUNTAIN WEST TOWARDS THE NEBRASKA PANHANDLE BY MIDDAY TUESDAY. GUIDANCE HAS COME IN GOOD AGREEMENT WITH A NORTHERN TRACK...SPEEDING UP THE EASTWARD THE UPPER LOW. THIS RESULTS IN A DRY SLOT QUICKLY PROGRESSING NORTH OVER THE CWA BY 18Z. I ADJUSTED POPS ACCORDINGLY WITH HIGHEST POPS TUESDAY MORNING...AND THEN DECREASING IN COVERAGE TUESDAY AFTERNOON. I LEFT ISOLATED THUNDERSTORMS IN FORECAST WITH GUIDANCE STILL SHOWING INSTABILITY AXIS ACROSS EASTERN HALF OF CWA. STRONG WINDS ALOFT WILL ALSO LEAD TO STRONG WINDS TUESDAY AS THE SYSTEM MOVES THROUGH THE REGION...WHICH COULD RESULT IN WARNING CRITERIA WINDS (GUSTS 60MPH OR GREATER). WEDNESDAY THROUGH SUNDAY...SHORTWAVE RIDGE WILL BUILD IN THE REGION WEDNESDAY AND THURSDAY...WITH DRY CONDITIONS AND MILD TEMPS CONTINUING. A SHORTWAVE TROUGH IS STILL EXPECTED TO PASS OVER THE REGION THURSDAY NIGHT. MEASURABLE PRECIP CANT BE RULED OUT...SO SLIGHT CHANCE POPS WERE LEFT IN PLACE. THE REMAINDER OF THE FORECAST PERIOD IS EXPECTED TO REMAIN DRY. SEASONAL HIGH TEMPERATURES (MID/UPPER 40S) WILL RETURN FRIDAY AND SATURDAY...WITH NW FLOW OVER THE CENTRAL HIGH PLAINS. RIDGE WILL BEGIN TO DEEPEN SUNDAY ACROSS THE WESTERN US...WITH MILD TEMPERATURES RETURNING TO THE CWA. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 951 PM MST SUN FEB 26 2012 PREVAILING WINDS WILL BE LIGHT AND VARIABLE OVERNIGHT...BECOMING SOUTHEASTERLY AFTER SUNRISE. AS DAYTIME MIXING INCREASES...WINDS WILL INCREASE AND BEGIN GUSTING...TAKING ON MORE OF A SOUTHERLY COMPONENT BY MIDDAY. CEILINGS WILL DECREASE IN THE LATE AFTERNOON INTO THE EVENING AHEAD OF AN UPPER LEVEL LOW...LOWERING INTO THE MVFR RANGE BY LATE IN THE PERIOD. PRECIPITATION WILL ALSO BE POSSIBLE LATE IN THE PERIOD...BUT CONFIDENCE IS TOO LOW AT THIS TIME TO PLACE PRECIPITATION AT THE TERMINALS DURING THIS TAF CYCLE. && .GLD WATCHES/WARNINGS/ADVISORIES... CO...NONE. KS...NONE. NE...NONE. && $$ UPDATE...JRM SHORT TERM...JTL/DR LONG TERM....DR AVIATION...CJS
AREA FORECAST DISCUSSION
NWS DULUTH MN
1143 PM CST SUN FEB 26 2012 .AVIATION.../06Z TAF ISSUANCE/ IFR/MVFR CONDITIONS WILL SLOWLY IMPROVE BY DAYBREAK AS THE SNOW DIMINISHES FROM WEST TO EAST. INCLUDED TEMPO GROUPS AT DLH AND HYR FOR IFR CEILINGS FROM 06Z TO 10Z. GUSTY NORTHWEST WINDS OVER BRD WILL CONTINUE THROUGH 10Z. MAINLY MVFR CEILINGS FOR THE FIRST HALF OF MONDAY BEFORE THE CLOUDS BREAK AND LIFT BY LATE MONDAY AFTERNOON. WINDS WILL ALSO DECREASE THROUGHOUT THE DAY. && .PREV DISCUSSION... /ISSUED 1033 PM CST SUN FEB 26 2012/ SHORT TERM... RADAR AND OBSERVATIONS CONTINUE TO SHOW THE SNOW DECREASING IN INTENSITY...WITH THE EXCEPTION OF OVER THE SOUTH SHORE OF LAKE SUPERIOR...AND OVER PARTS OF THE ARROWHEAD. THE LOW WAS MOVING TOWARD UPPER MICHIGAN/LAKE SUPERIOR THIS EVENING AND HAD WEAKENED TO 1008MB. IF CURRENT TRENDS CONTINUE...WE WILL DROP THE HEADLINES FOR CARLTON/SOUTHERN SAINT LOUIS AND PERHAPS THE REST OF NORTHERN AND CENTRAL SAINT LOUIS COUNTIES AS WELL SHORTLY. WE WILL LEAVE THE HEADLINES GOING FOR THE ARROWHEAD...AND SOUTH SHORE. WE`RE STILL ON THE FENCE REGARDING PINE COUNTY. KDLH VELOCITY REVEALS WINDS HAVE COME AROUND TO NORTH-NORTHWEST WITH SPEEDS AROUND 20 KT IN THE LOWEST COUPLE THOUSAND FEET. NO CLEAR EVIDENCE YET IN RADAR OF THE GRAVITY WAVE INDUCED AREA OF SNOWFALL...BUT RUC SUGGESTED IT MAY TAKE A FEW MORE HOURS TO DEVELOP. WE ALSO MAY HAVE TO INCREASE SNOW TOTALS A BIT ALONG THE SOUTH SHORE AS SPOTTERS HAVE REPORTED HEAVIER SNOW THERE OVER THE PAST FEW HOURS...IRON BELT HAD 2 INCHES IN A 3 HOUR PERIOD. NORTHERLY WINDS WITH DELTA-T`S AROUND 13-15C AND THE LOW PRESSURE WILL CONTINUE TO PRODUCE MODERATE SNOW SHOWERS ALONG PORTIONS OF THE SOUTH SHORE TONIGHT. PREV DISCUSSION... /ISSUED 701 PM CST SUN FEB 26 2012/ SHORT TERM... MODERATE TO HEAVY SNOW CONTINUED TO FALL OVER THE ARROWHEAD/IRON RANGE...WITH LIGHTER SNOW OVER THE REST OF THE NORTHLAND. THE SURFACE LOW IN NORTHWEST WISCONSIN WAS FILLING WITH NEAR 5 MB PRESSURE RISES OVER THE EASTERN DAKOTAS AND 2 MB FALLS OVER THE UP OF MICHIGAN. AREA RADARS AND OBSERVATIONS REVEAL SNOW INTENSITY DIMINISHING OVER THE WESTERN CWA WHERE VSBYS HAVE CLIMBED TO 5SM AT KPWC...3SM AT KXVG...8SM AT KGPZ AND 4SM AT KINL. WE WILL WAIT A BIT LONGER...BUT WE SHOULD BE ABLE TO CANCEL SOME OF THE HEADLINES IN THE WEST. SPOTTERS IN PINE COUNTY REPORTED SOME MIXED SLEET/SNOW/FREEZING DRIZZLE THIS EVENING. RUC13 SOUNDINGS REVEAL SEVERAL HOURS THIS EVENING WHERE DRIER AIR WILL BE PRESENT ABOVE A MOIST LAYER THAT REMAINS AT OR WARMER THAN -13C...SO A MIX WILL CONTINUE TO BE POSSIBLE. SATELLITE IMAGERY ALSO SHOWS WARMER CLOUD TOPS PRESENT OVER THAT AREA...INTO NORTHWEST WISCONSIN. SNOW SHOULD GRADUALLY DIMINISH FROM WEST TO EAST TONIGHT...REMAINING HEAVIEST IN THE ARROWHEAD. WE`LL ALSO HAVE TO KEEP AN EYE ON THE SOUTH SHORE AS WINDS BACK AROUND TO THE NORTH THEN NORTHWEST TONIGHT FOR SOME LAKE EFFECT SNOW SHOWERS. DELTA-T VALUES ARE NOT ALL THAT HIGH...BUT THE COMBINATION OF LIFT FROM THE SYSTEM AND THE LAKE WILL KEEP SNOW SHOWERS GOING LATER TONIGHT. A GRAVITY WAVE INDUCED AREA OF ENHANCED SNOWFALL WILL ALSO BE POSSIBLE SOUTH THROUGH PORTIONS OF DOUGLAS AND NORTHEAST PINE COUNTIES LATE THIS EVENING AND OVERNIGHT AS WINDS BECOME NORTHWEST. FLOW IS NOT ALL THAT STRONG...SO NOT SURE HOW STRONG A WAVE WILL RESULT. PREV DISCUSSION... /ISSUED 537 PM CST SUN FEB 26 2012/ AVIATION.../0Z TAF ISSUANCE/ CURRENT LIFR CONDITIONS OVER THE NORTHERN AERODROMES WILL SLIGHTLY IMPROVE LATER THIS EVENING. SLIGHTLY BETTER CONDITIONS AT BRD AND HYR WILL PREVAIL THROUGH THE EVENING. EXPECT THE LIGHT SNOW TO SLOWLY DIMINISH OVERNIGHT WITH WINDS SHIFTING FROM THE NORTHWEST LATER THIS EVENING. SNOW WILL END MONDAY MORNING WITH CEILINGS IMPROVING TO LOW END VFR BY MONDAY AFTERNOON. PREV DISCUSSION... /ISSUED 347 PM CST SUN FEB 26 2012/ WINTER WEATHER ADVISORIES MAY BE CANCELLED EARLY OVER SWRN CWA WINTER STORM WARNING MAY BE DOWNGRADED TO ADVISORY OVER SRN ST LOUIS/CARLTON COUNTIES... SHORT TERM...A GENERAL AREA OF 6 TO 10" HAS OCCURRED FROM NRN CASS COUNTY ACROSS ITASCA COUNTY AND SCTRL ST LOUIS CO TO TWO HARBORS. LESSER AMOUNTS ALONG BORDER IN NRN KOOCH CO AND NRN ST LOUIS COUNTY. MSAS SHOWS MAIN SFC LOW NEAR KJMR TRACKING ENE TOWARDS PRICE COUNTY AS OF MID AFTERNOON. MAIN FORCING HAS BEEN IN AREA OF MESOSCALE LIFT ALONG NSHORE AND EXTENDING WEST UNDERNEATH A DEFORMATION AXIS FROM THE IRON RANGE TO THE LEECH LAKE VICINITY. 85H LOW IS MOVING ACROSS BRD LAKES VICINITY TOWARDS DOUGLAS COUNTY. 88D RETURNS INCREASING SIGNIFICANTLY IN THE PAST HR OVER AITKIN COUNTY...AHEAD OF 85H LOW. PATCHY FREEZING DRIZZLE REPORTS FROM NEAR BRUNO NORTH TO MOOSE LAKE AND INTO ADJACENT WISCONSIN AS WARM ADVECTION LAYER HAS INCREASED ALOFT AHEAD OF MID LVL LOW. A SECONDARY MID LVL SHORTWAVE TROF OVER CTRL NDAK HAS KEPT AN EXTENSIVE AREA OF LIGHT SNOW WELL WEST OF REGION TODAY. TONIGHT/TOMORROW...85H LOW WILL PASS ACROSS APOSTLE ISLANDS BY MIDNIGHT. EXPECT BACKING OF BDRY LYR WIND TO AUGMENT SNOW ACROSS TWIN PORTS AND INTO SOUTH SHORE THROUGH THE EVENING. SECONDARY SHORTWAVE TROF WILL PASS ACROSS CWA LATE TONIGHT/EARLY TOMORROW. DEFORMATION AXIS WILL PIVOT SOUTHEAST WITH SNOW DECREASING ACROSS WRN AND NWRN CWA. SNOW SHOULD CONTINUE THROUGHOUT THE NIGHT OVER ERN HALF OF CWA. HIGHEST ACCUMULATIONS WILL OCCUR ALONG NSHORE AND INLAND TO IRON RANGE AND SHIFT MORE TOWARDS SOUTH SHORE BY EARLY MONDAY. PRECIP SHOULD DIMINISH QUICKLY BY MID MORNING MOST AREAS AS UPPER TROF MOVES EAST AND SUBSIDENT FLOW ALOFT DEVELOPS. TOMORROW NIGHT...SFC HIGH WILL MOVE INTO REGION TEMPORARILY UNDER BUILDING RIDGE ALOFT. MAY STILL HAVE SIGNIFICANT AMOUNT OF CLOUD COVER ACROSS CWA AS MID/HIGH CLOUDS SNEAK INTO RIDGE ALOFT. EXTENDED...TUESDAY THROUGH SUNDAY. THE MAJOR FOCUS FOR THE EXTENDED TIME PERIOD IS THE MAJOR WINTER STORM SHAPING UP FOR TUESDAY THROUGH WEDNESDAY NIGHT. THE MODELS ARE STARTING TO COME INTO BETTER AGREEMENT CONCERNING A VERY HEAVY SNOWFALL EVENT. THERE IS SOME DISAGREEMENT CONCERNING THE SPEED AT WHICH THE PRECIPITATION ARRIVES ON TUESDAY. THE GFS...UKMET AND NAM QUICKLY BRING QPF ACROSS THE CWA ON TUESDAY...WHILE THE ECMWF AND GEM ARE SLOWER IN BRINGING SNOW BACK INTO THE AREA. WILL ISSUE A WINTER STORM WATCH FOR THE ENTIRE SOUTHERN HALF OF THE CWA STARTING MIDDAY TUESDAY AND CONTINUING THROUGH WEDNESDAY. THINK THE HEAVIEST SNOW WILL MOVE INTO THE REGION TUESDAY NIGHT AND CONTINUE INTO WEDNESDAY. HAD A TOUGH TIME DECIDING ON THE LOCATION OF THE WATCH. THE MODELS ARE IN A BIT BETTER AGREEMENT CONCERNING HEAVY QPF VALUES IN THE SOUTHERN CWA...BUT THEY HAVE ALL SHIFTED NORTHWARD OVER THE PAST FEW RUNS. THINK AT SOME POINT WE MAY NEED TO EXTEND THE WATCH FURTHER NORTHWARD...AND INTO THE NORTH SHORE AS WELL...BUT THIS SHOULD BE A GOOD START. ALSO TRIED TO WATCH THE EXTENT OF THE DOUBLE HEADLINES IN THE AREA THAT WAS SEEING VERY HEAVY SNOWFALL TODAY...FROM THE IRON RANGE INTO THE ARROWHEAD/NORTH SHORE. THE STRENGTH OF THE SYSTEM...AND THE AVAILABLE MOISTURE COULD LEAD TO IMPRESSIVE SNOWFALL RATES...VERY STRONG WINDS AND A GREAT DEAL OF BLOWING AND DRIFTING SNOW. HAVE NOT RULED OUT THE POSSIBILITY OF BLIZZARD CONDITIONS IN AREAS BORDERING LAKE SUPERIOR...BUT WILL HOLD OFF FOR NOW ON ANY BLIZZARD WATCH. I WOULD NOT BE SURPRISED TO SEE AMOUNTS WELL IN EXCESS OF ONE FOOT SOMEWHERE IN THE NORTHLAND...BUT SPECIFIC AMOUNTS DEFINITELY TOO TOUGH TO PINPOINT FOR ANY ONE LOCATION AT THIS POINT. THE STORM SYSTEM MOVES OUT OF THE AREA WEDNESDAY NIGHT...AND SOME UNSETTLED WEATHER MOVES IN LATER IN THE WEEK AND INTO THE WEEKEND. THE MODELS ARE ALL OVER THE PLACE CONCERNING SPECIFIC PCPN CHANCES...BUT AT THIS POINT IT LOOKS LIKE THERE COULD BE SOME MIXED PCPN. && .POINT TEMPS/POPS... DLH 27 15 23 12 / 100 100 10 10 INL 24 9 19 4 / 100 90 20 10 BRD 27 15 22 16 / 100 70 10 10 HYR 34 20 26 10 / 70 70 10 10 ASX 30 23 26 11 / 70 90 30 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR MNZ038. WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY AFTERNOON FOR MNZ025-033>038. WINTER STORM WARNING UNTIL 6 AM CST MONDAY FOR MNZ012-020-021. WI...WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR WIZ001>004. WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY AFTERNOON FOR WIZ001>004-006>009. && $$ SHORT TERM...MELDE AVIATION...KK
AREA FORECAST DISCUSSION
NWS DULUTH MN
1033 PM CST SUN FEB 26 2012 .SHORT TERM... RADAR AND OBSERVATIONS CONTINUE TO SHOW THE SNOW DECREASING IN INTENSITY...WITH THE EXCEPTION OF OVER THE SOUTH SHORE OF LAKE SUPERIOR...AND OVER PARTS OF THE ARROWHEAD. THE LOW WAS MOVING TOWARD UPPER MICHIGAN/LAKE SUPERIOR THIS EVENING AND HAD WEAKENED TO 1008MB. IF CURRENT TRENDS CONTINUE...WE WILL DROP THE HEADLINES FOR CARLTON/SOUTHERN SAINT LOUIS AND PERHAPS THE REST OF NORTHERN AND CENTRAL SAINT LOUIS COUNTIES AS WELL SHORTLY. WE WILL LEAVE THE HEADLINES GOING FOR THE ARROWHEAD...AND SOUTH SHORE. WE`RE STILL ON THE FENCE REGARDING PINE COUNTY. KDLH VELOCITY REVEALS WINDS HAVE COME AROUND TO NORTH-NORTHWEST WITH SPEEDS AROUND 20 KT IN THE LOWEST COUPLE THOUSAND FEET. NO CLEAR EVIDENCE YET IN RADAR OF THE GRAVITY WAVE INDUCED AREA OF SNOWFALL...BUT RUC SUGGESTED IT MAY TAKE A FEW MORE HOURS TO DEVELOP. WE ALSO MAY HAVE TO INCREASE SNOW TOTALS A BIT ALONG THE SOUTH SHORE AS SPOTTERS HAVE REPORTED HEAVIER SNOW THERE OVER THE PAST FEW HOURS...IRON BELT HAD 2 INCHES IN A 3 HOUR PERIOD. NORTHERLY WINDS WITH DELTA-T`S AROUND 13-15C AND THE LOW PRESSURE WILL CONTINUE TO PRODUCE MODERATE SNOW SHOWERS ALONG PORTIONS OF THE SOUTH SHORE TONIGHT. .PREV DISCUSSION... /ISSUED 701 PM CST SUN FEB 26 2012/ SHORT TERM... MODERATE TO HEAVY SNOW CONTINUED TO FALL OVER THE ARROWHEAD/IRON RANGE...WITH LIGHTER SNOW OVER THE REST OF THE NORTHLAND. THE SURFACE LOW IN NORTHWEST WISCONSIN WAS FILLING WITH NEAR 5 MB PRESSURE RISES OVER THE EASTERN DAKOTAS AND 2 MB FALLS OVER THE UP OF MICHIGAN. AREA RADARS AND OBSERVATIONS REVEAL SNOW INTENSITY DIMINISHING OVER THE WESTERN CWA WHERE VSBYS HAVE CLIMBED TO 5SM AT KPWC...3SM AT KXVG...8SM AT KGPZ AND 4SM AT KINL. WE WILL WAIT A BIT LONGER...BUT WE SHOULD BE ABLE TO CANCEL SOME OF THE HEADLINES IN THE WEST. SPOTTERS IN PINE COUNTY REPORTED SOME MIXED SLEET/SNOW/FREEZING DRIZZLE THIS EVENING. RUC13 SOUNDINGS REVEAL SEVERAL HOURS THIS EVENING WHERE DRIER AIR WILL BE PRESENT ABOVE A MOIST LAYER THAT REMAINS AT OR WARMER THAN -13C...SO A MIX WILL CONTINUE TO BE POSSIBLE. SATELLITE IMAGERY ALSO SHOWS WARMER CLOUD TOPS PRESENT OVER THAT AREA...INTO NORTHWEST WISCONSIN. SNOW SHOULD GRADUALLY DIMINISH FROM WEST TO EAST TONIGHT...REMAINING HEAVIEST IN THE ARROWHEAD. WE`LL ALSO HAVE TO KEEP AN EYE ON THE SOUTH SHORE AS WINDS BACK AROUND TO THE NORTH THEN NORTHWEST TONIGHT FOR SOME LAKE EFFECT SNOW SHOWERS. DELTA-T VALUES ARE NOT ALL THAT HIGH...BUT THE COMBINATION OF LIFT FROM THE SYSTEM AND THE LAKE WILL KEEP SNOW SHOWERS GOING LATER TONIGHT. A GRAVITY WAVE INDUCED AREA OF ENHANCED SNOWFALL WILL ALSO BE POSSIBLE SOUTH THROUGH PORTIONS OF DOUGLAS AND NORTHEAST PINE COUNTIES LATE THIS EVENING AND OVERNIGHT AS WINDS BECOME NORTHWEST. FLOW IS NOT ALL THAT STRONG...SO NOT SURE HOW STRONG A WAVE WILL RESULT. PREV DISCUSSION... /ISSUED 537 PM CST SUN FEB 26 2012/ AVIATION.../0Z TAF ISSUANCE/ CURRENT LIFR CONDITIONS OVER THE NORTHERN AERODROMES WILL SLIGHTLY IMPROVE LATER THIS EVENING. SLIGHTLY BETTER CONDITIONS AT BRD AND HYR WILL PREVAIL THROUGH THE EVENING. EXPECT THE LIGHT SNOW TO SLOWLY DIMINISH OVERNIGHT WITH WINDS SHIFTING FROM THE NORTHWEST LATER THIS EVENING. SNOW WILL END MONDAY MORNING WITH CEILINGS IMPROVING TO LOW END VFR BY MONDAY AFTERNOON. PREV DISCUSSION... /ISSUED 347 PM CST SUN FEB 26 2012/ WINTER WEATHER ADVISORIES MAY BE CANCELLED EARLY OVER SWRN CWA .WINTER STORM WARNING MAY BE DOWNGRADED TO ADVISORY OVER SRN ST LOUIS/CARLTON COUNTIES... SHORT TERM...A GENERAL AREA OF 6 TO 10" HAS OCCURRED FROM NRN CASS COUNTY ACROSS ITASCA COUNTY AND SCTRL ST LOUIS CO TO TWO HARBORS. LESSER AMOUNTS ALONG BORDER IN NRN KOOCH CO AND NRN ST LOUIS COUNTY. MSAS SHOWS MAIN SFC LOW NEAR KJMR TRACKING ENE TOWARDS PRICE COUNTY AS OF MID AFTERNOON. MAIN FORCING HAS BEEN IN AREA OF MESOSCALE LIFT ALONG NSHORE AND EXTENDING WEST UNDERNEATH A DEFORMATION AXIS FROM THE IRON RANGE TO THE LEECH LAKE VICINITY. 85H LOW IS MOVING ACROSS BRD LAKES VICINITY TOWARDS DOUGLAS COUNTY. 88D RETURNS INCREASING SIGNIFICANTLY IN THE PAST HR OVER AITKIN COUNTY...AHEAD OF 85H LOW. PATCHY FREEZING DRIZZLE REPORTS FROM NEAR BRUNO NORTH TO MOOSE LAKE AND INTO ADJACENT WISCONSIN AS WARM ADVECTION LAYER HAS INCREASED ALOFT AHEAD OF MID LVL LOW. A SECONDARY MID LVL SHORTWAVE TROF OVER CTRL NDAK HAS KEPT AN EXTENSIVE AREA OF LIGHT SNOW WELL WEST OF REGION TODAY. TONIGHT/TOMORROW...85H LOW WILL PASS ACROSS APOSTLE ISLANDS BY MIDNIGHT. EXPECT BACKING OF BDRY LYR WIND TO AUGMENT SNOW ACROSS TWIN PORTS AND INTO SOUTH SHORE THROUGH THE EVENING. SECONDARY SHORTWAVE TROF WILL PASS ACROSS CWA LATE TONIGHT/EARLY TOMORROW. DEFORMATION AXIS WILL PIVOT SOUTHEAST WITH SNOW DECREASING ACROSS WRN AND NWRN CWA. SNOW SHOULD CONTINUE THROUGHOUT THE NIGHT OVER ERN HALF OF CWA. HIGHEST ACCUMULATIONS WILL OCCUR ALONG NSHORE AND INLAND TO IRON RANGE AND SHIFT MORE TOWARDS SOUTH SHORE BY EARLY MONDAY. PRECIP SHOULD DIMINISH QUICKLY BY MID MORNING MOST AREAS AS UPPER TROF MOVES EAST AND SUBSIDENT FLOW ALOFT DEVELOPS. TOMORROW NIGHT...SFC HIGH WILL MOVE INTO REGION TEMPORARILY UNDER BUILDING RIDGE ALOFT. MAY STILL HAVE SIGNIFICANT AMOUNT OF CLOUD COVER ACROSS CWA AS MID/HIGH CLOUDS SNEAK INTO RIDGE ALOFT. EXTENDED...TUESDAY THROUGH SUNDAY. THE MAJOR FOCUS FOR THE EXTENDED TIME PERIOD IS THE MAJOR WINTER STORM SHAPING UP FOR TUESDAY THROUGH WEDNESDAY NIGHT. THE MODELS ARE STARTING TO COME INTO BETTER AGREEMENT CONCERNING A VERY HEAVY SNOWFALL EVENT. THERE IS SOME DISAGREEMENT CONCERNING THE SPEED AT WHICH THE PRECIPITATION ARRIVES ON TUESDAY. THE GFS...UKMET AND NAM QUICKLY BRING QPF ACROSS THE CWA ON TUESDAY...WHILE THE ECMWF AND GEM ARE SLOWER IN BRINGING SNOW BACK INTO THE AREA. WILL ISSUE A WINTER STORM WATCH FOR THE ENTIRE SOUTHERN HALF OF THE CWA STARTING MIDDAY TUESDAY AND CONTINUING THROUGH WEDNESDAY. THINK THE HEAVIEST SNOW WILL MOVE INTO THE REGION TUESDAY NIGHT AND CONTINUE INTO WEDNESDAY. HAD A TOUGH TIME DECIDING ON THE LOCATION OF THE WATCH. THE MODELS ARE IN A BIT BETTER AGREEMENT CONCERNING HEAVY QPF VALUES IN THE SOUTHERN CWA...BUT THEY HAVE ALL SHIFTED NORTHWARD OVER THE PAST FEW RUNS. THINK AT SOME POINT WE MAY NEED TO EXTEND THE WATCH FURTHER NORTHWARD...AND INTO THE NORTH SHORE AS WELL...BUT THIS SHOULD BE A GOOD START. ALSO TRIED TO WATCH THE EXTENT OF THE DOUBLE HEADLINES IN THE AREA THAT WAS SEEING VERY HEAVY SNOWFALL TODAY...FROM THE IRON RANGE INTO THE ARROWHEAD/NORTH SHORE. THE STRENGTH OF THE SYSTEM...AND THE AVAILABLE MOISTURE COULD LEAD TO IMPRESSIVE SNOWFALL RATES...VERY STRONG WINDS AND A GREAT DEAL OF BLOWING AND DRIFTING SNOW. HAVE NOT RULED OUT THE POSSIBILITY OF BLIZZARD CONDITIONS IN AREAS BORDERING LAKE SUPERIOR...BUT WILL HOLD OFF FOR NOW ON ANY BLIZZARD WATCH. I WOULD NOT BE SURPRISED TO SEE AMOUNTS WELL IN EXCESS OF ONE FOOT SOMEWHERE IN THE NORTHLAND...BUT SPECIFIC AMOUNTS DEFINITELY TOO TOUGH TO PINPOINT FOR ANY ONE LOCATION AT THIS POINT. THE STORM SYSTEM MOVES OUT OF THE AREA WEDNESDAY NIGHT...AND SOME UNSETTLED WEATHER MOVES IN LATER IN THE WEEK AND INTO THE WEEKEND. THE MODELS ARE ALL OVER THE PLACE CONCERNING SPECIFIC PCPN CHANCES...BUT AT THIS POINT IT LOOKS LIKE THERE COULD BE SOME MIXED PCPN. AVIATION.../18Z TAF ISSUANCE/ A WINTER STORM WILL CONTINUE TO IMPACT THE NORTHLAND OVER MUCH OF THE TAF PERIOD. AT THIS POINT...IT APPEARS THAT THE MOST DRAMATIC VISIBILITY RESTRICTIONS WOULD BE ACROSS THE IRON RANGE AND THE ARROWHEAD...WHERE A DEFORMATION AXIS WILL SET UP AND ROTATE THROUGH THAT AREA. AREAS TO THE SOUTH AND FAR NORTH WILL SEE MORE EPISODIC PERIODS OF HEAVIER SNOW. KHIB LOOKS TO SEE THE MOST DRAMATIC VSBY RESTRICTIONS. OVERALL...FAIRLY WIDESPREAD MVFR TO EVEN LIFR CONDITIONS CAN BE EXPECTED. CONDITIONS WILL IMPROVE LATER TONIGHT AND ON MONDAY MORNING. && .POINT TEMPS/POPS... DLH 15 23 12 28 / 100 10 10 60 INL 9 19 4 28 / 90 20 10 10 BRD 15 22 16 30 / 70 10 10 70 HYR 18 26 10 32 / 70 10 10 60 ASX 21 26 11 31 / 90 30 10 60 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR MNZ038. WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY AFTERNOON FOR MNZ025-033>038. WINTER STORM WARNING UNTIL 6 AM CST MONDAY FOR MNZ011-012- 019>021-037. WI...WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR WIZ001>004. WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY AFTERNOON FOR WIZ001>004-006>009. && $$ SHORT TERM...MELDE LONG TERM....DAP
AREA FORECAST DISCUSSION
NWS MIAMI FL
947 AM EST MON FEB 27 2012 .UPDATE... WE ADDED THE POSSIBILITY OF ISOLATED THUNDERSTORMS FOR THE CENTRAL AND WESTERN SECTIONS OF SOUTH FLORIDA WITH THIS MORNING UPDATE. THE MAIN PRECLUDING FACTOR FOR THE FORMATION OF ISOLATED THUNDERSTORMS IS A MID LEVEL CAP AROUND 700 MB. HOWEVER, SOME OF THE CAP COULD BE ERODED BY THE COMBINATION OF COLD ADVECTION WEST OF THE TROUGH LINE AND WARM SURFACE TEMPERATURES IN THE MID 80S COMBINED WITH BOUNDARY COLLISIONS. THE COMBINATION OF THE EAST FLOW WITH THE FORMATION OF A WEST COAST SEA BREEZE AND LAKE BREEZE WILL ENHANCE THE THUNDERSTORM POTENTIAL FOR GLADES, HENDRY, CENTRAL-WESTERN COLLIER, AS WELL AS WESTERN PALM BEACH AND BROWARD COUNTIES. RELATED TO THIS CHANGE POPS AND SKY WERE ALSO UPDATED. IF ALL THE CORRECT INGREDIENTS COME TOGETHER SUCH AS SIGNIFICANT EROSION OF THE CAP, ENHANCED BOUNDARY COLLISIONS, AND STRONGER COLD ADVECTION ALOFT THAN FORECAST, AS THE MOST IMPORTANT FACTORS...SMALL HAIL COULD OCCUR IN SOME SPOTS OF THE NORTHERN COUNTIES. HOWEVER, THE CONFIDENCE FOR HAIL IS LOW AT THIS TIME FOR SOUTH FLORIDA. && .PREV DISCUSSION... /ISSUED 515 AM EST MON FEB 27 2012/ AVIATION...LOW PRES IN THE NE GUF OF MEX WL MOV NE OVR N FLA WHL HIGH PRES MOVS OFF OF THE MID ATLC COAST INTO THE ATLC. THIS KEEPS THE PRES GRADIENT ACRS S FLA RATHER HIGH. FAST MOVG WDLY SCT SHRA WL MOV ONSHR FM THE ATLC WITH BRIEF MVFR CIGS AND PSBL MVFR VSBY BUT DUE TO THE SPEED OF THE SHRA WL ONLY HV VCSH IN AFFECTED E COAST TAFS. AN XCPTN WL BE KPBI WHR SHRA MAY BCM SCT AFT 18Z. SCT020-025 LCLLY BKN BKN040-060 WI HIR LYRS. SFC WND E COAST E-ESE 9-13G20+ KTS THRU 28/00Z THEN DCRG 8-12KTS. AT KAPF SCT025 BKN050-070 WITH BRIEF BKN025 BUT NOT IN TAF. SFC WND E 5-8 KTS BCMG AFT 13Z ESE-SE 10-13G18KTS. AFT 18Z VCSH INVOF KAPF. PREV DISCUSSION... /ISSUED 245 AM EST MON FEB 27 2012/ DISCUSSION...ZONAL FLOW PERSISTS ACROSS MUCH OF EASTERN NORTH AMERICA AND THIS IS NOT CONDUCIVE FOR ANY SIGNIFICANT COLD FRONTS MOVING DOWN THE PENINSULA ANY TIME SOON. EMBEDDED IN THE FLOW IS A WEAK MID LEVEL TROUGH IN THE NE GOFMEX AND THIS WILL MOVE ACROSS NORTH AND CENTRAL FL TODAY WITH LITTLE AFFECTS ON OUR CWA. BOTH MAV AND MET GUIDANCE SHOW LESS THAN 50 PERCENT POPS FOR ANY OF THE REGION WITH THE MET HAVING THE LOWEST NUMBERS. THE HRRR DOES SHOW AN INCREASE IN SHRA COVERAGE BY LATE THIS MORNING ACROSS PALM BEACH COUNTY AND CONSIDERING IT DOES VERY WELL DURING THE WINTER MONTHS, HAVE ADJUSTED THE POPS BASED ON THIS GUIDANCE AND THIS DOES SEEM REASONABLE GIVEN THE LOW IMPACT THIS TROUGH WILL HAVE FOR S FL. A SFC RIDGE CURRENTLY STRETCHES ACROSS THE SOUTHEAST STATES INTO THE ATLANTIC AND THIS WILL SHIFT SOUTH OVER THE NEXT FEW DAYS REACHING S FL BY THE END OF THIS WEEK. THIS WILL MAINTAIN A BREEZY EAST WIND FLOW THIS MORNING AND SLOWLY WEAKENING THEREAFTER. ONCE THE TROUGH MOVES TO THE NORTHEAST OF THE AREA, THE SUBTROPICAL RIDGE WILL BUILD BACK NORTH AS SEVERAL STRONG MID LEVEL TROUGHS MOVE THROUGH THE ZONAL PATTERN ACROSS THE NORTHERN TIER OF STATES. ALL OF THIS WILL MAINTAIN A QUIET WX PATTERN ACROSS FL THROUGH THE WEEK. BY NEXT WEEKEND, ONE OF THE AFOREMENTIONED TROUGHS WILL BEGIN TO CARVE OUT A LARGE SCALE TROUGH ACROSS THE EASTERN STATES AND BOTH THE ECMWF AND GFS SHOW A COLD FRONT MOVING INTO S FL SOMETIME SUNDAY BUT WITH MOST OF THE ENERGY WITH THIS SYSTEM REMAINING WELL NORTH OF OUR CWA IT APPEARS THAT IT WILL PROVIDE FOR JUST A SLIGHT CHANCE OF SHRA. MARINE...THE GRADIENT FLOW WILL WEAKEN THIS MORNING AS THE RIDGE OF THE RIDGE OF PRESSURE OVER THE SOUTHEAST STATES BEGINS TO SHIFT SOUTH. STILL, THERE WILL BE A SCEC STATEMENT FOR AT LEAST THE FIRST FEW HOURS OF THE FCST AS AN EAST WIND WILL CONTINUE AT AROUND 15-20 KNOTS BEFORE WEAKENING THIS AFTERNOON. FIRE WEATHER...NO PROBLEMS OR CONCERNS. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 82 70 83 69 / 30 20 10 10 FORT LAUDERDALE 82 73 83 72 / 30 20 10 10 MIAMI 83 72 84 71 / 20 20 10 10 NAPLES 85 66 86 65 / 30 10 10 10 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...71/JE AVIATION/RADAR...54/BNB
AREA FORECAST DISCUSSION
NWS MIAMI FL
515 AM EST MON FEB 27 2012 .AVIATION...LOW PRES IN THE NE GUF OF MEX WL MOV NE OVR N FLA WHL HIGH PRES MOVS OFF OF THE MID ATLC COAST INTO THE ATLC. THIS KEEPS THE PRES GRADIENT ACRS S FLA RATHER HIGH. FAST MOVG WDLY SCT SHRA WL MOV ONSHR FM THE ATLC WITH BRIEF MVFR CIGS AND PSBL MVFR VSBY BUT DUE TO THE SPEED OF THE SHRA WL ONLY HV VCSH IN AFFECTED E COAST TAFS. AN XCPTN WL BE KPBI WHR SHRA MAY BCM SCT AFT 18Z. SCT020-025 LCLLY BKN BKN040-060 WI HIR LYRS. SFC WND E COAST E-ESE 9-13G20+ KTS THRU 28/00Z THEN DCRG 8-12KTS. AT KAPF SCT025 BKN050-070 WITH BRIEF BKN025 BUT NOT IN TAF. SFC WND E 5-8 KTS BCMG AFT 13Z ESE-SE 10-13G18KTS. AFT 18Z VCSH INVOF KAPF. && .PREV DISCUSSION... /ISSUED 245 AM EST MON FEB 27 2012/ DISCUSSION...ZONAL FLOW PERSISTS ACROSS MUCH OF EASTERN NORTH AMERICA AND THIS IS NOT CONDUCIVE FOR ANY SIGNIFICANT COLD FRONTS MOVING DOWN THE PENINSULA ANY TIME SOON. EMBEDDED IN THE FLOW IS A WEAK MID LEVEL TROUGH IN THE NE GOFMEX AND THIS WILL MOVE ACROSS NORTH AND CENTRAL FL TODAY WITH LITTLE AFFECTS ON OUR CWA. BOTH MAV AND MET GUIDANCE SHOW LESS THAN 50 PERCENT POPS FOR ANY OF THE REGION WITH THE MET HAVING THE LOWEST NUMBERS. THE HRRR DOES SHOW AN INCREASE IN SHRA COVERAGE BY LATE THIS MORNING ACROSS PALM BEACH COUNTY AND CONSIDERING IT DOES VERY WELL DURING THE WINTER MONTHS, HAVE ADJUSTED THE POPS BASED ON THIS GUIDANCE AND THIS DOES SEEM REASONABLE GIVEN THE LOW IMPACT THIS TROUGH WILL HAVE FOR S FL. A SFC RIDGE CURRENTLY STRETCHES ACROSS THE SOUTHEAST STATES INTO THE ATLANTIC AND THIS WILL SHIFT SOUTH OVER THE NEXT FEW DAYS REACHING S FL BY THE END OF THIS WEEK. THIS WILL MAINTAIN A BREEZY EAST WIND FLOW THIS MORNING AND SLOWLY WEAKENING THEREAFTER. ONCE THE TROUGH MOVES TO THE NORTHEAST OF THE AREA, THE SUBTROPICAL RIDGE WILL BUILD BACK NORTH AS SEVERAL STRONG MID LEVEL TROUGHS MOVE THROUGH THE ZONAL PATTERN ACROSS THE NORTHERN TIER OF STATES. ALL OF THIS WILL MAINTAIN A QUIET WX PATTERN ACROSS FL THROUGH THE WEEK. BY NEXT WEEKEND, ONE OF THE AFOREMENTIONED TROUGHS WILL BEGIN TO CARVE OUT A LARGE SCALE TROUGH ACROSS THE EASTERN STATES AND BOTH THE ECMWF AND GFS SHOW A COLD FRONT MOVING INTO S FL SOMETIME SUNDAY BUT WITH MOST OF THE ENERGY WITH THIS SYSTEM REMAINING WELL NORTH OF OUR CWA IT APPEARS THAT IT WILL PROVIDE FOR JUST A SLIGHT CHANCE OF SHRA. MARINE...THE GRADIENT FLOW WILL WEAKEN THIS MORNING AS THE RIDGE OF THE RIDGE OF PRESSURE OVER THE SOUTHEAST STATES BEGINS TO SHIFT SOUTH. STILL, THERE WILL BE A SCEC STATEMENT FOR AT LEAST THE FIRST FEW HOURS OF THE FCST AS AN EAST WIND WILL CONTINUE AT AROUND 15-20 KNOTS BEFORE WEAKENING THIS AFTERNOON. FIRE WEATHER...NO PROBLEMS OR CONCERNS. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 82 70 83 69 / 40 20 10 10 FORT LAUDERDALE 82 73 83 72 / 30 20 10 10 MIAMI 83 72 84 71 / 20 20 10 10 NAPLES 85 66 86 65 / 30 10 10 10 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...30/KOB AVIATION/RADAR...15/JR
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
1004 AM EST MON FEB 27 2012 .UPDATE... BEST MOISTURE AND LIFT EXITING CENTRAL GA WITH PRECIP CHANCES DIMINISHING OR HAVE ENDED. STILL GOOD MOISTURE IN PLACE ACROSS CENTRAL GA AND YOU CAN NOT COMPLETELY RULE OUT SPRINKLES...BRIEF LIGHT RAIN OR DRIZZLE FOR SOME AREAS. FORECAST HIGH TEMPERATURES RUNNING NEAR TO SLIGHTLY ABOVE NORMAL. BDL && .PREV DISCUSSION... /ISSUED 639 AM EST MON FEB 27 2012/ SHORT TERM /TODAY THROUGH TUESDAY NIGHT/... CURRENT RADAR LOOP SHOWS SOME SCATTERED TO NUMEROUS SHOWERS MOVING EAST ACROSS SOUTH GA THIS MORNING. THERE IS A WEAK SHORTWAVE OVER THE NORTHERN GULF THAT WILL MOVE ACROSS NORTH FL AND INTO THE ATLANTIC BY 18Z TODAY. THE LOCAL WRF AND HRRR MODELS SHOW SOME SHOWERS MOVING A BIT NE OVER THE NEXT FEW HOURS BEFORE MOVING INTO THE CAROLINAS THROUGH THIS AFTERNOON. THEY BOTH SHOW SHOWERS MOVING INTO CENTRAL GA BUT STAYING SOUTH OF THE ATL AREA. ONCE THE WAVE MOVES OUT INTO THE ATLANTIC...HIGH PRESSURE OVER THE GREAT LAKES STATES BUILDS SOUTHWARD BRINGING A BIT OF DRIER AIR INTO THE REGION. THIS DRIER AIRMASS WILL BE SHORT LIVED AS THE NEXT DEVELOPING WEATHER SYSTEM MOVES INTO THE AREA. BY 12Z TUE... A CLOSED LOW DEVELOPS OVER CO AND MOVES NE INTO THE WESTERN GREAT LAKES STATES BY 12Z WED. THIS LOW CONTINUES TO MOVE EAST INTI THE NEW ENGLAND STATES THROUGH 12Z THU. THIS LOW CENTERS ASSOCIATED COLD FRONT MOVES INTO THE MS RIVER VALLEY BY 00Z WED AND INTO NW GA BY 18Z WED. PRECIPITATION BEGINS MOVING INTO THE STATE WELL AHEAD OF THE FRONT WITH SHRA/TSRA ACROSS NORTH AND CENTRAL GA BEGINNING TUESDAY AFTERNOON/EVENING. THE BEST INSTABILITY WITH THIS SYSTEM WILL BE ASSOCIATED WITH THE FRONTAL PASSAGE BUT ONLY EXPECTING ISOLATED THUNDERSTORMS AT BEST. CAPES GET INTO THE 300-500 J/KG RANGE BETWEEN 18Z WED AND 00Z THU WITH 0-6KM BULK SHEAR AROUND 50-60. TEMPS WILL BE ABOUT 8-10 DEG ABOVE SEASONAL NORMS THROUGH THE SHORT TERM. LONG TERM /WEDNESDAY THROUGH SUNDAY/... THE FRONTAL SYSTEM MENTIONED IN THE SHORT TERM FINALLY MOVES SOUTH AND EAST OF THE AREA BY 12-18Z THU. THE FRONT LOOKS TO STALL ACROSS N FL THEN MOVE BACK NORTHWARD AS A WARM FRONT FRI. ANOTHER LOW PRESSURE CENTER DEVELOPS OVER CO BY 18Z THU AND IT MOVES RAPIDLY NE INTO THE GREAT LAKE STATES BY 00Z SAT. THIS SECOND LOW CENTER IS WHAT ALLOWS THE WARM FRONT TO MOVE BACK ACROSS THE AREA. THIS LOW CENTERS COLD FRONT MOVES INTI GA LATE FRIDAY NIGHT AND SHOULD BE SOUTH AND EAST OF THE AREA BY 00Z SUN. THERE IS SOME INSTABILITY WITH THIS FRONT SO HAVE INTRODUCED THUNDER INTO THE FORECAST BUT JUST TOO FAR OUT TO DETERMINE JUST HOW INTENSE THIS SECOND SYSTEM WILL BE. TEMPS CONTINUE TO BE 5-10 DEG ABOVE SEASONAL NORMS THROUGH DAY 7. AVIATION... 12Z UPDATE... CIGS HAVE BEEN COMING DOWN ALL NIGHT AS ADVERTISED WITH MOST SITES IFR...BUT ATL BRIEFLY IN LIFR AT TIMES. FEEL PRESENCE OF DZ AT ATL WILL LEAD TO ADDITIONAL INSTANCES OF LIFR THROUGH 14Z AND WILL CARRY IN TEMPO. SLOW IMPROVEMENT FOR ALL SITES THEREAFTER WITH MVFR BY 18Z. LOCAL MODELS FINALLY COMING AROUND TO INDICATE A SHIFT TO NW WINDS THIS AFTERNOON AND HAVE INDICATED SUCH IN NEWEST TAF SET. SHOULD BE BRIEF THOUGH AS A SHIFT BACK TO NE IS IN STORE FOR THE OVERNIGHT HOURS. SOME INDICATIONS ALREADY OF SOME LOWERING CIGS FOR TONIGHT INTO TUE MORNING AND WILL BEGIN TO INDICATE A DETERIORATING TREND. //ATL CONFIDENCE...12Z UPDATE... MEDIUM ON CIG IMPROVEMENT AND WIND SHIFT. HIGH ON REMAINING ELEMENTS. DEESE && .PRELIMINARY POINT TEMPS/POPS... ATHENS 65 44 71 53 / 5 0 20 30 ATLANTA 64 50 71 57 / 0 0 20 30 BLAIRSVILLE 63 40 66 50 / 0 0 20 50 CARTERSVILLE 64 42 71 53 / 0 0 20 40 COLUMBUS 66 50 75 58 / 20 5 10 20 GAINESVILLE 63 47 67 54 / 0 0 20 40 MACON 65 47 73 56 / 20 5 10 10 ROME 66 42 72 54 / 0 0 20 50 PEACHTREE CITY 64 42 71 55 / 5 0 20 30 VIDALIA 65 52 73 57 / 30 5 10 5 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
639 AM EST MON FEB 27 2012 .PREV DISCUSSION... /ISSUED 414 AM EST MON FEB 27 2012/ SHORT TERM /TODAY THROUGH TUESDAY NIGHT/... CURRENT RADAR LOOP SHOWS SOME SCATTERED TO NUMEROUS SHOWERS MOVING EAST ACROSS SOUTH GA THIS MORNING. THERE IS A WEAK SHORTWAVE OVER THE NORTHERN GULF THAT WILL MOVE ACROSS NORTH FL AND INTO THE ATLANTIC BY 18Z TODAY. THE LOCAL WRF AND HRRR MODELS SHOW SOME SHOWERS MOVING A BIT NE OVER THE NEXT FEW HOURS BEFORE MOVING INTO THE CAROLINAS THROUGH THIS AFTERNOON. THEY BOTH SHOW SHOWERS MOVING INTO CENTRAL GA BUT STAYING SOUTH OF THE ATL AREA. ONCE THE WAVE MOVES OUT INTO THE ATLANTIC...HIGH PRESSURE OVER THE GREAT LAKES STATES BUILDS SOUTHWARD BRINGING A BIT OF DRIER AIR INTO THE REGION. THIS DRIER AIRMASS WILL BE SHORT LIVED AS THE NEXT DEVELOPING WEATHER SYSTEM MOVES INTO THE AREA. BY 12Z TUE... A CLOSED LOW DEVELOPS OVER CO AND MOVES NE INTO THE WESTERN GREAT LAKES STATES BY 12Z WED. THIS LOW CONTINUES TO MOVE EAST INTI THE NEW ENGLAND STATES THROUGH 12Z THU. THIS LOW CENTERS ASSOCIATED COLD FRONT MOVES INTO THE MS RIVER VALLEY BY 00Z WED AND INTO NW GA BY 18Z WED. PRECIPITATION BEGINS MOVING INTO THE STATE WELL AHEAD OF THE FRONT WITH SHRA/TSRA ACROSS NORTH AND CENTRAL GA BEGINNING TUESDAY AFTERNOON/EVENING. THE BEST INSTABILITY WITH THIS SYSTEM WILL BE ASSOCIATED WITH THE FRONTAL PASSAGE BUT ONLY EXPECTING ISOLATED THUNDERSTORMS AT BEST. CAPES GET INTO THE 300-500 J/KG RANGE BETWEEN 18Z WED AND 00Z THU WITH 0-6KM BULK SHEAR AROUND 50-60. TEMPS WILL BE ABOUT 8-10 DEG ABOVE SEASONAL NORMS THROUGH THE SHORT TERM. LONG TERM /WEDNESDAY THROUGH SUNDAY/... THE FRONTAL SYSTEM MENTIONED IN THE SHORT TERM FINALLY MOVES SOUTH AND EAST OF THE AREA BY 12-18Z THU. THE FRONT LOOKS TO STALL ACROSS N FL THEN MOVE BACK NORTHWARD AS A WARM FRONT FRI. ANOTHER LOW PRESSURE CENTER DEVELOPS OVER CO BY 18Z THU AND IT MOVES RAPIDLY NE INTO THE GREAT LAKE STATES BY 00Z SAT. THIS SECOND LOW CENTER IS WHAT ALLOWS THE WARM FRONT TO MOVE BACK ACROSS THE AREA. THIS LOW CENTERS COLD FRONT MOVES INTI GA LATE FRIDAY NIGHT AND SHOULD BE SOUTH AND EAST OF THE AREA BY 00Z SUN. THERE IS SOME INSTABILITY WITH THIS FRONT SO HAVE INTRODUCED THUNDER INTO THE FORECAST BUT JUST TOO FAR OUT TO DETERMINE JUST HOW INTENSE THIS SECOND SYSTEM WILL BE. TEMPS CONTINUE TO BE 5-10 DEG ABOVE SEASONAL NORMS THROUGH DAY 7. && .AVIATION... 12Z UPDATE... CIGS HAVE BEEN COMING DOWN ALL NIGHT AS ADVERTISED WITH MOST SITES IFR...BUT ATL BRIEFLY IN LIFR AT TIMES. FEEL PRESENCE OF DZ AT ATL WILL LEAD TO ADDITIONAL INSTANCES OF LIFR THROUGH 14Z AND WILL CARRY IN TEMPO. SLOW IMPROVEMENT FOR ALL SITES THEREAFTER WITH MVFR BY 18Z. LOCAL MODELS FINALLY COMING AROUND TO INDICATE A SHIFT TO NW WINDS THIS AFTERNOON AND HAVE INDICATED SUCH IN NEWEST TAF SET. SHOULD BE BRIEF THOUGH AS A SHIFT BACK TO NE IS IN STORE FOR THE OVERNIGHT HOURS. SOME INDICATIONS ALREADY OF SOME LOWERING CIGS FOR TONIGHT INTO TUE MORNING AND WILL BEGIN TO INDICATE A DETERIORATING TREND. //ATL CONFIDENCE...12Z UPDATE... MEDIUM ON CIG IMPROVEMENT AND WIND SHIFT. HIGH ON REMAINING ELEMENTS. DEESE && .PRELIMINARY POINT TEMPS/POPS... ATHENS 65 44 71 53 / 30 0 20 30 ATLANTA 64 50 71 57 / 20 0 20 30 BLAIRSVILLE 63 40 66 50 / 10 0 20 50 CARTERSVILLE 64 42 71 53 / 10 0 20 40 COLUMBUS 66 50 75 58 / 30 5 10 20 GAINESVILLE 63 47 67 54 / 20 0 20 40 MACON 65 47 73 56 / 50 5 10 10 ROME 66 42 72 54 / 5 0 20 50 PEACHTREE CITY 64 42 71 55 / 20 0 20 30 VIDALIA 65 52 73 57 / 80 5 10 5 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
552 AM CST MON FEB 27 2012 .UPDATE... 12Z AVIATION DISCUSSION ADDED BELOW. && .DISCUSSION... THIS MORNING...AN UPPER LOW OVER THE UPPER GREAT LAKES WILL CONTINUE TO MOVE EAST OVER THE NEW ENGLAND STATES BY MIDNIGHT TONIGHT. A SFC HIGH PRESSURE RIDGE WILL ADVANCE OVER THE WESTERN GREAT LAKES AND MIDWEST TODAY. SO A QUIET AND COOL DAY TODAY WITH AFTERNOON HIGH TEMPERATURES IN THE 20S. THE LATEST WATER VAPOR SATELLITE IMAGERY SHOWED A DEEPENING UPPER LOW OVER THE WEST COAST WITH A STRONG UPPER LEVEL JET ROUNDING THE BASE OF THE UPPER LOW. THIS LOW WILL CONTINUE TO STRENGTHEN OVER THE SOUTHERN ROCKIES TODAY...BEFORE LIFTING INTO THE CENTRAL PLAINS ON TUESDAY. TUESDAY AND WEDNESDAY TIMEFRAME...MODELS ARE IN GENERAL AGREEMENT WITH THE POTENTIAL WINTER STORM. THE ONLY CHALLENGE IS DETERMINING PRECIPITATION TYPES TUESDAY NIGHT. STILL BELIEVE THE BULK OF THE PRECIPITATION WILL BE MAINLY SNOW FOR MUCH OF OUR AREA. THE LATEST GEM-NHEM MODEL HAS THE SURFACE LOW OVER SOUTHEAST MN...LITTLE FURTHER NORTH THAN THE NAM..GFS AND EC MODELS. THUS PREFERRED A BLEND OF THE EC/GFS/NAM FOR POSITION AND TRACK OF THE SURFACE LOW. THESE MODELS BRING THE SURFACE LOW ALONG THE IOWA/MINNESOTA BORDER. THIS WILL PLACE MUCH OF OUR FORECAST IN BULLS-EYE OR CLOSE IN RECEIVING 8+ INCHES OF SNOW...WITH PARTS OF WEST CENTRAL- CENTRAL MN AND WESTERN WISCONSIN POSSIBLY OVER A FOOT. MODELS CONTINUE TO SUPPORT LIQUID PRECIP TOTALS OF ONE TO TWO INCHES OVER CENTRAL MN. WITH MIXING RATIOS IN THE 3-4 G/KG RANGE AND SNOW ACCUMULATIONS VARYING 1.0-1.5 INCHES PER HOUR...SIX HOURLY ACCUMULATION TOTALS COULD EASILY EXCEED OVER 10 INCHES. DUE TO UNCERTAINTY ON THE TRACK AND PRECIPITATION TYPES DUE THE ENTIRE EVENT...WILL HOLD OFF FROM UPGRADING THE BLIZZARD WATCH AND WINTER STORM WATCH TO WARNINGS. DAY SHIFT SHOULD HAVE A FIRM GRASP ON THE TRACK OF THE STORM. THE SNOW WILL BEGIN TO DIMINISH OVER WESTERN MN DURING THE AFTERNOON WEDNESDAY AS THE SURFACE LOW MOVES TOWARD THE LOWER GREAT LAKES...WHILE MODERATE SNOW IS LIKELY TO CONTINUE OVER THE EASTERN HALF OF THE FORECAST AREA. ANOTHER LOW PRESSURE SYSTEM IS FORECAST TO DEVELOP OVER THE CENTRAL PLAINS THURSDAY. ECMWF INTENSIFIES THIS LOW PRESSURE SYSTEM AS IT LIFTS NORTHEAST OVER THE GREAT LAKES FRIDAY NIGHT. THIS SYSTEM COULD BRING SOME MORE ACCUMULATING SNOWS TO THE EASTERN HALF OF OUR FORECAST AREA FRIDAY AND FRIDAY NIGHT. SUNDAY INTO MONDAY...LOOKS DRY AS AN UPPER RIDGE BUILDS OVER THE NATIONS MIDSECTION. && .AVIATION.../12Z TAF ISSUANCE/ SFC HIGH TO MOVE ACROSS THE TERMINALS...TODAY...RESULTING IN A RELATIVELY CALM TAF PERIOD...BEFORE A SIGNIFICANT WINTER STORM IMPACTS THE TERMINALS TUESDAY AFTERNOON INTO WEDNESDAY. BIGGEST CHALLENGE THIS MORNING DEALS WITH TIMING BACK EDGE OF THE CLOUDS THROUGH THE TERMINALS. LATEST 11-3.9 SAT IMAGERY SHOWS CLOUDS OVER WRN MN...AND IN PARTICULAR AROUND RWF ALREADY BREAKING DOWN. LEANED CLEARING IN TAFS MORE TOWARD THE RUC. LATE IN THE TAF...WILL JUST SEE MID LEVEL CLOUDS INCREASE AS NEXT STORM SYSTEM APPROACHES...THOUGH MOST OF THE PRECIP ASSOCIATED WITH IT LOOKS TO HOLD OFF UNTIL AFTER 18Z TUE. WINDS WILL REMAIN GUSTY FOR THE FIRST COUPLE HOURS IN THE EAST THIS MORNING...BUT SPEEDS WILL QUICKLY COME DOWN UNDER 10 KTS AS THE SFC RIDGE MOVES IN. GIVEN THE SPEED THE RIDGE MOVES THROUGH...WILL SEE WINDS QUICKLY BACK OVER TO THE SE THIS AFTERNOON/EVENING. KMSP...BASED ON SURROUNDING OBS...CIGS SHOULD REMAIN ABOVE 017 THIS MORNING...THOUGH A BRIEF PERIOD BELOW THIS LEVEL CAN NOT BE RULED OUT THROUGH 15Z. BASED ON RUC TIMING...EXPECT CIGS TO CLEAR BETWEEN 15Z AND 18Z. ARRIVAL OF NEXT SYSTEM CONTINUES TO SLOW IN THE MODELS...AND SEEING ANY PRECIP EVEN IN THE 15-18Z PERIOD TUESDAY MAY BE PUSHING IT...BULK OF THE PRECIP LOOKS TO ARRIVE AFTER 21Z TUE. //OUTLOOK...TUESDAY THROUGH FRIDAY... .TUE-WED...CIGS/VSBY BECOMING LIFR. -SN DEV TUESDAY AFTERNOON... LIKELY TRANSITIONS TO A MIX TUE NIGHT BEFORE GOING BACK TO SN WED MORNING. .WED NIGHT-THU...BECOMING VFR. .FRI...IFR OR LOWER CIGS/VSBY POSSIBLE WITH CHANCE OF -SN. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY AFTERNOON FOR ANOKA-BENTON-BLUE EARTH-BROWN-CARVER-CHISAGO- DAKOTA-FARIBAULT-FREEBORN-GOODHUE-HENNEPIN-ISANTI-KANABEC- KANDIYOHI-LE SUEUR-MARTIN-MCLEOD-MEEKER-MILLE LACS-MORRISON- NICOLLET-RAMSEY-REDWOOD-RENVILLE-RICE-SCOTT-SHERBURNE- SIBLEY-STEARNS-STEELE-WASECA-WASHINGTON-WATONWAN-WRIGHT. BLIZZARD WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY AFTERNOON FOR CHIPPEWA-DOUGLAS-LAC QUI PARLE-POPE-STEVENS- SWIFT-TODD-YELLOW MEDICINE. WI...WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY AFTERNOON FOR BARRON-CHIPPEWA-DUNN-EAU CLAIRE-PEPIN-PIERCE- POLK-RUSK-ST. CROIX. && $$ JVM/MPG
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
323 PM MST MON FEB 27 2012 .SHORT TERM...UPPER TROUGH HEADING TOWARDS THE GREAT BASIN AT THIS TIME WITH FAIRLY TIGHT SOUTHERLY FLOW ALOFT OVER THE REGION. AT THE SURFACE...GUSTY SOUTHERLY WINDS CONTINING ACROSS THE PLAINS MAINLY FROM DENVER EASTWARD. MODELS STILL PERSISTANT WITH WEAKENING THAT GRADIENT DURING THE EVENING...WITH SURFACE WINDS DECREASING A RESULT. WILL CONTINUE THIS TREND. SATELLITE SHOWING MOISTURE CONTINUING TO SPREAD INTO WESTERN COLORADO...WITH RADAR SHOWING SOME ECHOES ACROSS THE WESTERN MOUNTAINS. NOT ALOT CURRENTLY HAPPENING OVER THE NORTHERN AND CENTRAL MOUNTAINS... PERHAPS A FEW ECHOES ACROSS ZONE 31. AS TROUGH MOVES INTO THE GREAT BASIN THIS EVENING...SHOULD SEE MOISTURE INCREASE AND SNOW SPREAD ACROSS THE AREA. SOUTHWEST FLOW ALOFT NOT FAVORABLE FOR GOOD SNOWFALL AND ACCUMULATIONS...BUT WITH INCREASING ASCENT AND LAPSE RATES...LIKELY POPS SEEM WARRANTED WITH THE HIGHEST POPS FOR FAVORED ZONE 31. SNOW AMOUNTS TO BE IN THE 1 TO 3 INCH RANGE. ACROSS PLAINS....SURFACE WINDS TO BECOME SOUTHWEST DURING THE EVENING AS THE SOUTHWEST GRADIENT INCREASES. MOISTURE TO INCREASE ACROSS THE AREA BY MIDNIGHT. LOW LEVELS SLOWING MOISTEN OVERNIGHT AS LOW LEVEL MOISTURE SPREADS NORTHWEST. QUESTION REMAINS HOW MUCH LOW LEVEL MOISTURE MAKES IT TO THE FOOTHILLS. LATEST RUC AS WELL AS THE HI RESOLUTION MODELS BRING THE LOW LEVEL MOISTURE INTO EASTERN ADAMS AND EASTERN ARAPAHOE COUNTIES AROUND 10Z...ENOUGH PERHAPS FOR PATCHY FOG. THIS ALREADY IN THE GRIDS. PRECIP CHANCES LOW OVERNIGHT...WITH THE BEST CHANCE ACROSS ZONE 38 WHERE SOME BANDED PRECIP IS POSSIBLE. MAY BE A RAIN/SNOW MIX FOR A FEW HOURS. ON TUESDAY...THE TROUGH IS EXPECTED TO MOVE ACROSS THE REGION WITH THE BEST DYNAMICS OCCURRING DURING THE MORNING. OROGRAPHICS IMPROVE DURING THE AFTERNOON BUT LIFT IS EAST OF THE MOUNTAINS AND MOISTURE DEPTH DECREASES. STILL A DECENT SHOT OF SNOW EXPECTED FOR THE MOUNTAINS...ESPECIALLY FOR THE MORNING HOURS...WITH ANOTHER 2 TO 5 INCHES. ACROSS PLAINS...BEST CHANCE FOR SNOW LOOKS TO BE DURING THE MORNING WHEN THE DYNAMICS MOVES OVERHEAD. BUT DOWNSLOPE WINDS WILL OFFSET THE SNOW POTENTIAL. SO ANY ACCUMULATION SHOULD BE LESS THAN AN INCH....MAINLY ACROSS ZONE 38. SNOW CHANCES DECREASE DURING THE AFTERNOON AS TROUGH MOVES INTO THE CENTRAL PLAINS AND DOWNSLOPE INCREASES. LATEST MODELS STILL SHOW SOME LIGHT ACCUMULATION ACROSS FAR NORTHEAST CORNER DURING THE AFTERNOON. WILL KEEP CHANCE POPS THERE...BUT AMOUNTS WILL BE LIGHT. AS FOR PRECIP TYPE...THICKESS PROGS SUGGEST ALL SNOW. .LONG TERM...A CLOSED UPPER LEVEL LOW MOVING ACROSS THE NORTHERN PLAINS WILL BRING A NORTHWEST FLOW ALOFT TO COLORADO TUESDAY NIGHT. AS THIS SYSTEM EXITS THE REGION...MOUNTAIN SNOW WILL COME TO AN END DURING THE NIGHT. A STABLE LAYER WILL FORM JUST ABOVE RIDGE TOP AND CREATE A MOUNTAIN WAVE. WINDS AT RIDGE TOP WILL BE AROUND 50 KNOTS. THE WAVE WILL ACCELERATE THESE WINDS DOWN THE FOOTHILLS RESUTLING IN WIND GUSTS UP TO 80 MPH. WILL ISSUE A HIGH WIND WATCH FOR THE FOOTHILLS AND AREAS AT THE BASE OF THE FOOTHILLS FOR TUESDAY NIGHT AND EARLY WEDNESDAY MORNING. THE WINDS WILL QUICKLY DIE OFF WEDNESDAY AS AN UPPER LEVEL RIDGE QUICKLY PASSES OVER THE STATE. THIS WILL BRING MILD AND DRY CONDITIONS TO NORTHEAST COLORADO. NEXT STORM SYSTEM WILL DIG SOUTH ACROSS THE PACIFIC NORTHWEST AND NORTHERN ROCKIES THURSDAY. THIS SYSTEM WILL LIKELY BRING ANOTHER SHOT OF SNOW TO THE MOUNTAINS...THURSDAY AND FRIDAY. COLD FRONT WILL PUSH SOUTH ACROSS NORTHEAST COLORADO THURSDAY. WINDS WILL BECOME NORTHEAST BEHIND THE FRONT...PRODUCING AN UPSLOPE FLOW. WILL HAVE SCATTERED POPS IN THE FORECAST THURSDAY AFTERNOON THROUGH THURSDAY NIGHT. THE AREA WILL BE ON THE BACKSIDE OF THIS SYSTEM ON FRIDAY. AIRMASS WILL BE SOMEWHAT UNSTABLE AND WILL KEEP LOW POPS FOR NORTHEAST COLORADO IN THE FORECAST. FOR THE MOUNTAINS...THE SLIGHTLY UNSTABLE FLOW OVER THE MOUNTAINS WILL PRODUCE SNOW SHOWERS...THUS WILL HAVE HIGHER POPS OVER THE MOUNTAINS. UPPER LEVEL RIDGE WILL BE ALONG THE WEST COAST SATURDAY. THIS WILL PRODUCE A DRY AND MILD NORTHWEST FLOW OVER COLORADO. THE RIDGE WILL SHIFT EAST THROUGH THE WEEKEND AND EARLY NEXT WEEK. THIS WILL ALLOW TEMPERATURES TO CLIMB ABOVE NORMAL SUNDAY AND MONDAY AS DRY CONDITIONS CONTINUE. ON MONDAY...SOME 60S WILL BE POSSIBLE OVER NORTHEAST COLORADO. && .AVIATION..STRONG SOUTHERLY GRADIENT TO SLOWLY WEAKEN ACROSS PLAINS THIS EVENING...WITH WINDS DECREASING AT DEN AND APA. WINDS TO BECOME SOUTHWEST AT ALL THE AREA AIRPORTS BY 05Z AS SOUTHWEST FLOW ALOFT INCREASES. MOISTURE TO GRADUALLY INCREASE THIS EVENING...WITH CEILINGS OF 5000-6000 FEET AGL PREVAILING. CHANCE FOR MVFR CEILINGS AT DEN AND APA AFTER 07Z IF LOW LEVEL MOISTURE INCREASES FROM THE SOUTHEAST. SLIGHT CHANCE OF SNOW SHOWERS AFTER 06Z...POSSIBLY MIXED WITH RAIN. BEST CHANCE FOR SNOW TUESDAY MORNING...AS TROUGH MOVES OVERHEAD. VFR CONDITIONS TO PREVAIL...WITH POSSIBLE MVFR CONDITIONS WITH PASSING SNOW SHOWERS. WINDS TO SHIFT TO THE NORTHWEST AFTER 16Z...CONTINUING THROUGH THE DAY WITH SOME GUSTS TO 20 KTS POSSIBLE DURING THE AFTERNOON. && .BOU WATCHES/WARNINGS/ADVISORIES... HIGH WIND WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY MORNING FOR COZ035-036-038-039. && $$ SHORT TERM...D-L LONG TERM....MEIER AVIATION...D-L
AREA FORECAST DISCUSSION
NWS MIAMI FL
237 PM EST MON FEB 27 2012 .DISCUSSION... AS THE AFTERNOON PROGRESSES THE CHANCES FOR STRONG ISOLATED THUNDERSTORMS IS SOLIDIFYING MORE BASED ON RADAR, SATELLITE AND SURFACE OBSERVATIONS AROUND THE REGION. THE RUC RAPID REFRESH MODEL INSISTS IN THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS OVER INTERIOR SECTIONS OF SOUTH FLORIDA THIS EVENING. THE RUC SHOWS THE HIGHEST COVERAGE AFTER 4 PM EST. CURRENTLY, THE RADAR IS SHOWING AN INCREASE IN SHOWERS SOUTHWEST OF THE LAKE. AT THE PRESENT TIME THE ONLY LIGHTNING IN THE AREA IS ASSOCIATED WITH THE STORMS NORTH OF THE LAKE OUTSIDE OF OUR CWA. ANOTHER IMPORTANT FACTOR IS THE WEST COAST SEA BREEZE, WHICH IS CURRENTLY INLAND PASSED NAPLES, IS FORECAST TO CONTINUE TO MOVE EAST AND COLLIDE WITH THE EAST AND SOUTHEAST WINDS OVER THE EASTERN TWO THIRDS OF SOUTH FLORIDA. TEMPERATURE MEASUREMENTS FROM DIFFERENT AIRPLANES ACROSS SOUTH FLORIDA INDICATE THAT THE CAP BETWEEN 600 TO 700 MB IS STILL PRESENT WITH SOME HINTS OF SOME CAP EROSION AS FORECAST BY THE RUC MODEL. WITH THESE CONDITIONS THERE IS A SLIGHT CHANCE OF THUNDERSTORMS LATE THIS AFTERNOON INTO THIS EVENING OVER INTERIOR AREAS OF SOUTH FLORIDA. THE PRIMARY IMPACTS FROM THE STORMS WILL BE LIGHTNING STRIKES, HAIL, GUSTY WINDS, AND LOCALLY HEAVY RAINFALL. THE STRONGEST STORMS WILL BE CAPABLE OF PRODUCING HAIL UP TO NICKEL SIZE HAIL ESPECIALLY AROUND THE LAKE OKEECHOBEE AREA WHERE THE SEA BREEZE AND LAKE BREEZES COLLIDE LATE THIS AFTERNOON INTO EARLY THIS EVENING. THE MOST LIKELY TIME PERIOD FOR CONVECTION WILL BE FROM 4 TO 8 PM SINCE WE STILL NEED MORE TIME FOR THE CAP TO ERODE FURTHER. CURRENT SATELLITE IMAGE SHOWS THAT THE CLOUD TOPS OF MOST OF THE SHOWERS ARE BEGINNING TO BLOW TO THE EAST SOUTHEAST AT AROUND 20000 FEET, WHICH SHOWS THAT SOME OF THESE SHOWERS ARE BEGINNING TO BREAK THROUGH THE CAP. AFTER TODAY THE REST OF THE WEEK LOOKS DRY WITH THE EXCEPTION OF A FEW SHOWERS STILL POSSIBLE FOR TUESDAY ESPECIALLY OVER THE EAST AND CENTRAL SECTION OF SOUTH FLORIDA. THE NEXT TIME FOR SHOWERS IS EXPECTED FOR SUNDAY AS A COLD FRONT IS FORECAST TO APPROACH SOUTH FLORIDA. HOWEVER, THERE IS STILL CONSIDERABLE UNCERTAINTY ABOUT THE STRENGTH AND TIMING OF THIS FRONT. && .MARINE... BENIGN MARINE CONDITIONS WILL ESTABLISH ON TUESDAY WITH THE REST OF THE WEEK HAVING SEAS OF 2 TO 3 FEET. && NO FIRE WEATHER CONCERNS ARE EXPECTED THIS WEEK. A FEW HOURS OF RELATIVE HUMIDITY VALUES IN THE 40S ARE POSSIBLE THURSDAY AND FRIDAY OVER GLADES AND HENDRY...OTHERWISE THE NEXT CHANCE FOR LOWER RELATIVE HUMIDITY VALUES, BUT STILL ABOVE FIRE THRESHOLDS IS FOR SUNDAY WITH A LOT OF UNCERTAINTY STILL WITH THIS FORECAST. && .AVIATION...(ISSUED AT 1228 PM EST MON FEB 27 2012) THE EAST AND WEST COAST SEA BREEZES WILL CONTINUE TO DEVELOP AND PUSH INLAND THIS AFTERNOON. THIS WILL KEEP THE EAST COAST TAF SITES IN A SOUTHEAST WIND FLOW AT 15 TO 20 KNOTS...WHILE KAPF TAF SITE BECOMES SOUTHWEST AT 5 TO 10 KNOTS AROUND 19Z THIS AFTERNOON. THERE COULD BE A FEW SHOWERS AROUND THE TAF SITES OF KPBI...KFLL...KFXE...AND KAPF THIS AFTERNOON AS THE SEA BREEZES PUSHES INLAND. THE WINDS WILL THEN DECREASE TO LESS THAN 5 KNOTS AT ALL OF THE TAF SITES THIS EVENING INTO TONIGHT AND CONTINUE TO BE EASTERLY. THE WEATHER WILL ALSO REMAIN DRY TONIGHT AT ALL OF THE TAF SITES. THE CEILING AND VIS WILL ALSO REMAIN IN THE VFR CONDITIONS THIS AFTERNOON INTO TONIGHT AT ALL OF THE TAF SITES. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 70 83 69 82 / 20 10 10 10 FORT LAUDERDALE 73 83 72 82 / 20 10 10 10 MIAMI 72 84 71 83 / 20 10 10 10 NAPLES 66 86 65 85 / 10 10 10 10 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...71/JE AVIATION/RADAR...54/BNB
AREA FORECAST DISCUSSION...UPDATED
NWS MIAMI FL
1228 PM EST MON FEB 27 2012 .AVIATION... THE EAST AND WEST COAST SEA BREEZES WILL CONTINUE TO DEVELOP AND PUSH INLAND THIS AFTERNOON. THIS WILL KEEP THE EAST COAST TAF SITES IN A SOUTHEAST WIND FLOW AT 15 TO 20 KNOTS...WHILE KAPF TAF SITE BECOMES SOUTHWEST AT 5 TO 10 KNOTS AROUND 19Z THIS AFTERNOON. THERE COULD BE A FEW SHOWERS AROUND THE TAF SITES OF KPBI...KFLL...KFXE...AND KAPF THIS AFTERNOON AS THE SEA BREEZES PUSHES INLAND. THE WINDS WILL THEN DECREASE TO LESS THAN 5 KNOTS AT ALL OF THE TAF SITES THIS EVENING INTO TONIGHT WHILE BE EASTERLY DIRECTION. THE WEATHER WILL ALSO REMAIN DRY TONIGHT AT ALL OF THE TAF SITES. THE CEILING AND VIS WILL ALSO REMAIN IN THE VFR CONDITIONS THIS AFTERNOON INTO TONIGHT AT ALL OF THE TAF SITES. && .AVIATION...54/BNB .PREV DISCUSSION... /ISSUED 947 AM EST MON FEB 27 2012/ UPDATE... WE ADDED THE POSSIBILITY OF ISOLATED THUNDERSTORMS FOR THE CENTRAL AND WESTERN SECTIONS OF SOUTH FLORIDA WITH THIS MORNING UPDATE. THE MAIN PRECLUDING FACTOR FOR THE FORMATION OF ISOLATED THUNDERSTORMS IS A MID LEVEL CAP AROUND 700 MB. HOWEVER, SOME OF THE CAP COULD BE ERODED BY THE COMBINATION OF COLD ADVECTION WEST OF THE TROUGH LINE AND WARM SURFACE TEMPERATURES IN THE MID 80S COMBINED WITH BOUNDARY COLLISIONS. THE COMBINATION OF THE EAST FLOW WITH THE FORMATION OF A WEST COAST SEA BREEZE AND LAKE BREEZE WILL ENHANCE THE THUNDERSTORM POTENTIAL FOR GLADES, HENDRY, CENTRAL-WESTERN COLLIER, AS WELL AS WESTERN PALM BEACH AND BROWARD COUNTIES. RELATED TO THIS CHANGE POPS AND SKY WERE ALSO UPDATED. IF ALL THE CORRECT INGREDIENTS COME TOGETHER SUCH AS SIGNIFICANT EROSION OF THE CAP, ENHANCED BOUNDARY COLLISIONS, AND STRONGER COLD ADVECTION ALOFT THAN FORECAST, AS THE MOST IMPORTANT FACTORS...SMALL HAIL COULD OCCUR IN SOME SPOTS OF THE NORTHERN COUNTIES. HOWEVER, THE CONFIDENCE FOR HAIL IS LOW AT THIS TIME FOR SOUTH FLORIDA. && PREV DISCUSSION... /ISSUED 515 AM EST MON FEB 27 2012/ AVIATION...LOW PRES IN THE NE GUF OF MEX WL MOV NE OVR N FLA WHL HIGH PRES MOVS OFF OF THE MID ATLC COAST INTO THE ATLC. THIS KEEPS THE PRES GRADIENT ACRS S FLA RATHER HIGH. FAST MOVG WDLY SCT SHRA WL MOV ONSHR FM THE ATLC WITH BRIEF MVFR CIGS AND PSBL MVFR VSBY BUT DUE TO THE SPEED OF THE SHRA WL ONLY HV VCSH IN AFFECTED E COAST TAFS. AN XCPTN WL BE KPBI WHR SHRA MAY BCM SCT AFT 18Z. SCT020-025 LCLLY BKN BKN040-060 WI HIR LYRS. SFC WND E COAST E-ESE 9-13G20+ KTS THRU 28/00Z THEN DCRG 8-12KTS. AT KAPF SCT025 BKN050-070 WITH BRIEF BKN025 BUT NOT IN TAF. SFC WND E 5-8 KTS BCMG AFT 13Z ESE-SE 10-13G18KTS. AFT 18Z VCSH INVOF KAPF. && PREV DISCUSSION... /ISSUED 245 AM EST MON FEB 27 2012/ DISCUSSION...ZONAL FLOW PERSISTS ACROSS MUCH OF EASTERN NORTH AMERICA AND THIS IS NOT CONDUCIVE FOR ANY SIGNIFICANT COLD FRONTS MOVING DOWN THE PENINSULA ANY TIME SOON. EMBEDDED IN THE FLOW IS A WEAK MID LEVEL TROUGH IN THE NE GOFMEX AND THIS WILL MOVE ACROSS NORTH AND CENTRAL FL TODAY WITH LITTLE AFFECTS ON OUR CWA. BOTH MAV AND MET GUIDANCE SHOW LESS THAN 50 PERCENT POPS FOR ANY OF THE REGION WITH THE MET HAVING THE LOWEST NUMBERS. THE HRRR DOES SHOW AN INCREASE IN SHRA COVERAGE BY LATE THIS MORNING ACROSS PALM BEACH COUNTY AND CONSIDERING IT DOES VERY WELL DURING THE WINTER MONTHS, HAVE ADJUSTED THE POPS BASED ON THIS GUIDANCE AND THIS DOES SEEM REASONABLE GIVEN THE LOW IMPACT THIS TROUGH WILL HAVE FOR S FL. A SFC RIDGE CURRENTLY STRETCHES ACROSS THE SOUTHEAST STATES INTO THE ATLANTIC AND THIS WILL SHIFT SOUTH OVER THE NEXT FEW DAYS REACHING S FL BY THE END OF THIS WEEK. THIS WILL MAINTAIN A BREEZY EAST WIND FLOW THIS MORNING AND SLOWLY WEAKENING THEREAFTER. ONCE THE TROUGH MOVES TO THE NORTHEAST OF THE AREA, THE SUBTROPICAL RIDGE WILL BUILD BACK NORTH AS SEVERAL STRONG MID LEVEL TROUGHS MOVE THROUGH THE ZONAL PATTERN ACROSS THE NORTHERN TIER OF STATES. ALL OF THIS WILL MAINTAIN A QUIET WX PATTERN ACROSS FL THROUGH THE WEEK. BY NEXT WEEKEND, ONE OF THE AFOREMENTIONED TROUGHS WILL BEGIN TO CARVE OUT A LARGE SCALE TROUGH ACROSS THE EASTERN STATES AND BOTH THE ECMWF AND GFS SHOW A COLD FRONT MOVING INTO S FL SOMETIME SUNDAY BUT WITH MOST OF THE ENERGY WITH THIS SYSTEM REMAINING WELL NORTH OF OUR CWA IT APPEARS THAT IT WILL PROVIDE FOR JUST A SLIGHT CHANCE OF SHRA. MARINE...THE GRADIENT FLOW WILL WEAKEN THIS MORNING AS THE RIDGE OF THE RIDGE OF PRESSURE OVER THE SOUTHEAST STATES BEGINS TO SHIFT SOUTH. STILL, THERE WILL BE A SCEC STATEMENT FOR AT LEAST THE FIRST FEW HOURS OF THE FCST AS AN EAST WIND WILL CONTINUE AT AROUND 15-20 KNOTS BEFORE WEAKENING THIS AFTERNOON. FIRE WEATHER...NO PROBLEMS OR CONCERNS. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 82 70 83 69 / 30 20 10 10 FORT LAUDERDALE 82 73 83 72 / 30 20 10 10 MIAMI 83 72 84 71 / 20 20 10 10 NAPLES 85 66 86 65 / 30 10 10 10 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...30/KOB AVIATION/RADAR...15/JR
AREA FORECAST DISCUSSION...UPDATED FOR AVIATION
NWS PEACHTREE CITY GA
1247 PM EST MON FEB 27 2012 .UPDATE... /ISSUED AT 1004 AM EST MON FEB 27 2012/ BEST MOISTURE AND LIFT EXITING CENTRAL GA WITH PRECIP CHANCES DIMINISHING OR HAVE ENDED. STILL GOOD MOISTURE IN PLACE ACROSS CENTRAL GA AND YOU CAN NOT COMPLETELY RULE OUT SPRINKLES...BRIEF LIGHT RAIN OR DRIZZLE FOR SOME AREAS. FORECAST HIGH TEMPERATURES RUNNING NEAR TO SLIGHTLY ABOVE NORMAL. BDL && .PREV DISCUSSION... /ISSUED 639 AM EST MON FEB 27 2012/ SHORT TERM /TODAY THROUGH TUESDAY NIGHT/... CURRENT RADAR LOOP SHOWS SOME SCATTERED TO NUMEROUS SHOWERS MOVING EAST ACROSS SOUTH GA THIS MORNING. THERE IS A WEAK SHORTWAVE OVER THE NORTHERN GULF THAT WILL MOVE ACROSS NORTH FL AND INTO THE ATLANTIC BY 18Z TODAY. THE LOCAL WRF AND HRRR MODELS SHOW SOME SHOWERS MOVING A BIT NE OVER THE NEXT FEW HOURS BEFORE MOVING INTO THE CAROLINAS THROUGH THIS AFTERNOON. THEY BOTH SHOW SHOWERS MOVING INTO CENTRAL GA BUT STAYING SOUTH OF THE ATL AREA. ONCE THE WAVE MOVES OUT INTO THE ATLANTIC...HIGH PRESSURE OVER THE GREAT LAKES STATES BUILDS SOUTHWARD BRINGING A BIT OF DRIER AIR INTO THE REGION. THIS DRIER AIRMASS WILL BE SHORT LIVED AS THE NEXT DEVELOPING WEATHER SYSTEM MOVES INTO THE AREA. BY 12Z TUE... A CLOSED LOW DEVELOPS OVER CO AND MOVES NE INTO THE WESTERN GREAT LAKES STATES BY 12Z WED. THIS LOW CONTINUES TO MOVE EAST INTI THE NEW ENGLAND STATES THROUGH 12Z THU. THIS LOW CENTERS ASSOCIATED COLD FRONT MOVES INTO THE MS RIVER VALLEY BY 00Z WED AND INTO NW GA BY 18Z WED. PRECIPITATION BEGINS MOVING INTO THE STATE WELL AHEAD OF THE FRONT WITH SHRA/TSRA ACROSS NORTH AND CENTRAL GA BEGINNING TUESDAY AFTERNOON/EVENING. THE BEST INSTABILITY WITH THIS SYSTEM WILL BE ASSOCIATED WITH THE FRONTAL PASSAGE BUT ONLY EXPECTING ISOLATED THUNDERSTORMS AT BEST. CAPES GET INTO THE 300-500 J/KG RANGE BETWEEN 18Z WED AND 00Z THU WITH 0-6KM BULK SHEAR AROUND 50-60. TEMPS WILL BE ABOUT 8-10 DEG ABOVE SEASONAL NORMS THROUGH THE SHORT TERM. LONG TERM /WEDNESDAY THROUGH SUNDAY/... THE FRONTAL SYSTEM MENTIONED IN THE SHORT TERM FINALLY MOVES SOUTH AND EAST OF THE AREA BY 12-18Z THU. THE FRONT LOOKS TO STALL ACROSS N FL THEN MOVE BACK NORTHWARD AS A WARM FRONT FRI. ANOTHER LOW PRESSURE CENTER DEVELOPS OVER CO BY 18Z THU AND IT MOVES RAPIDLY NE INTO THE GREAT LAKE STATES BY 00Z SAT. THIS SECOND LOW CENTER IS WHAT ALLOWS THE WARM FRONT TO MOVE BACK ACROSS THE AREA. THIS LOW CENTERS COLD FRONT MOVES INTI GA LATE FRIDAY NIGHT AND SHOULD BE SOUTH AND EAST OF THE AREA BY 00Z SUN. THERE IS SOME INSTABILITY WITH THIS FRONT SO HAVE INTRODUCED THUNDER INTO THE FORECAST BUT JUST TOO FAR OUT TO DETERMINE JUST HOW INTENSE THIS SECOND SYSTEM WILL BE. TEMPS CONTINUE TO BE 5-10 DEG ABOVE SEASONAL NORMS THROUGH DAY 7. && .AVIATION... 18Z UPDATE... VIS SATL AND AREA OBS TRENDING TOWARD VFR BY 19-20Z THIS AFTN IF NOT SOONER. LATEST SFC ANALYSIS SHOWS A COLD FRONT SLOWLY PUSHING ACROSS WEST TN. THE SFC RIDGE TO THE EAST WILL BATTLE WITH WEAK SFC TROUGH MOVING IN FROM THE NW TO RESULT IN LIGHT 3-4KT WINDS VARYING FROM NNW TO NNE AT TIMES THROUGH THE AFTERNOON. MODELS AGREE ON FRONT PUSHING ACROSS ATL AROUND 03Z THIS EVENING... SO WIND DIRECTIONS SHOULD SETTLE AT 4-5KTS NNE BY THEN. NO -RA OR LOW CIGS EXPECTED WITH THE FRONT AT ATL FOR NOW... BUT BEHIND THE FRONT... WILL HAVE TO WATCH THE POTENTIAL FOR MVFR CIGS CLOSELY. MID LEVEL CIGS MOVE INTO THE AREA BY 19-21Z TUE AS MOIST SW MID LEVEL FLOW OVERRUNS AN EASTERLY SFC FLOW. //ATL CONFIDENCE...18Z UPDATE... MEDIUM ON VFR TONIGHT. HIGH ON REMAINING ELEMENTS. /39 && .PRELIMINARY POINT TEMPS/POPS... ATHENS 65 44 71 53 / 5 0 20 30 ATLANTA 64 50 71 57 / 0 0 20 30 BLAIRSVILLE 63 40 66 50 / 0 0 20 50 CARTERSVILLE 64 42 71 53 / 0 0 20 40 COLUMBUS 66 50 75 58 / 20 5 10 20 GAINESVILLE 63 47 67 54 / 0 0 20 40 MACON 65 47 73 56 / 20 5 10 10 ROME 66 42 72 54 / 0 0 20 50 PEACHTREE CITY 64 42 71 55 / 5 0 20 30 VIDALIA 65 52 73 57 / 30 5 10 5 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
332 PM EST MON FEB 27 2012 .SYNOPSIS... HIGH PRESSURE TO THE WEST WILL QUICKLY BUILD EAST OVER THE AREA TONIGHT. THE HIGH WILL MOVE TO THE EAST COAST BY LATE TUESDAY. ANOTHER STRONG LOW PRESSURE SYSTEM WILL MOVE ACROSS THE CENTRAL GREAT LAKES WEDNESDAY INTO THURSDAY. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... BIG ISSUE IN THE SHORT TERM WILL BE THE WINDS THIS EVENING IN RESPONSE TO A RATHER TIGHT GRADIENT BETWEEN LOW PRESSURE OVER THE NORTHERN GREAT LAKES AND STRONG HIGH PRESSURE OVER THE PLAINS QUICKLY BUILDING TOWARD THE AREA. HAVE EXPANDED THE WIND ADVISORY ACROSS EASTERN COUNTIES WITH EXCEPTION FOR THE FAR SOUTH THROUGH THIS EVENING. HRRR MODEL RUNS HAVE BEEN HANDLING THE WINDS RATHER WELL THIS AFTERNOON...AND THEY HAVE ADVISORY WIND GUSTS PUSHING THROUGH NORTHEAST OHIO COUNTIES OVER THE NEXT SEVERAL HOURS. WINDS SHOULD DIMINISH QUICKLY FROM WEST TO EAST ESPECIALLY AFTER SUNSET TONIGHT. AFTER MIDNIGHT EXPECTING WINDS TO BE DOWN BELOW 10 MPH. ASIDE FROM THAT A DRY AND MOSTLY CLEAR NIGHT EXPECTED WITH TEMPS DROPPING BACK TO THE LOWER TO MID 20S. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/... HIGH PRESSURE OVER THE AREA TUESDAY MORNING...THEN MOVING TO THE EAST WILL ALLOW FOR A QUIET AND DRY WEATHER DAY WITH SEASONABLE TEMPERATURES. LATEST MODELS SEEM TO BE DELAYING THE ONSET OF THE PRECIP ACROSS THE AREA TUESDAY NIGHT. WHILE CLOUDS ARE EXPECTED TO OVERSPREAD THE REGION EARLY ON...THINKING PERHAPS NOT TOWARD 06Z ACROSS THE SOUTHWEST AREAS AND NOT UNTIL CLOSE TO 12Z WED FOR PRECIP ACROSS NW PA. DO BRING UP POPS QUICKLY ACROSS THE AREA THOUGH AFTER 06Z. STILL SOME QUESTION AS TO PRECIP TYPE AT THE ONSET ESPECIALLY FROM CLE-CAK NORTHEAST. ACROSS OH THINKING THAT THERE MAY BE A RAIN/SNOW MIX WITH BEST CONFIDENCE OF ALL SNOW AT THE ONSET FOR FAR NE OH AND NW PA. MODELS SHOWING LOWER LEVELS WARMING UP ENOUGH BY 12Z WED THOUGH THAT MANY LOCATIONS WILL SWITCH OVER TO RAIN. MODELS LEANING TOWARD A MORE NORTHERN TRACK OF THE LOW CENTER ALLOWING MUCH OF THE AREA TO GET WARM ON WED. LEFT THE HIGH POPS AND MENTION OF THUNDER IN THE MORNING...BUT THEN CONCERNED ABOUT DRY SLOT MOVING ESPECIALLY INTO WESTERN AREAS FOR THE AFTERNOON SO REDUCED POPS AND CLOUDS A BIT ACROSS THE WEST. TEMPS WILL ALSO BE TRICKIEST DURING WED SO FOR NOW USED A BLEND OF MAV AND MET NUMBERS. CONCERNED MOST ABOUT NORTHERN AREAS WHICH MAY GET WARMER THAN FORECAST. ALSO CONCERNED ABOUT WIND POTENTIAL ON WED ESPECIALLY ACROSS THE WEST WHERE BETTER MIXING IS POSSIBLE. LOW PRESSURE NORTH OF THE AREA WEDNESDAY NIGHT AND THROUGH MUCH OF THURSDAY WILL ALLOW FOR SOME RAIN/SNOW SHOWERS MAINLY ACROSS THE NORTH WEDNESDAY NIGHT...THEN CONTINUED CHANCES FOR SHOWERS ACROSS NE OH AND NW PA THROUGH MUCH OF THURSDAY. HIGH PRESSURE RIDGING IN WILL DRY OUT THE AREA THURSDAY NIGHT. && .LONG TERM /FRIDAY THROUGH MONDAY/... SOUTHERLY WINDS WILL BE ON THE INCREASE ON FRIDAY AS LOW PRESSURE MOVES FROM THE CENTRAL PLAINS TO THE CENTRAL GREAT LAKES BY FRIDAY EVENING. THIS WILL PROVIDE WARM CONDITIONS FOR THE REGION WITH HIGHS INTO THE 50S FOR MOST LOCATIONS. RAIN CHANCES WILL BE ON THE INCREASE FRIDAY EVENING INTO THE OVERNIGHT. SOME RAIN MAY LINGER INTO SATURDAY MORNING. COOLER AIR WILL SPILL ACROSS THE LAKE SATURDAY NIGHT INTO EARLY SUNDAY AND COULD BE JUST COLD ENOUGH TO PROVIDE A FEW SNOW SHOWERS OFF OF LAKE ERIE. ANOTHER FAST MOVING STORM SYSTEM MAY AFFECT THE REGION SUNDAY NIGHT AND MAY ENHANCE ANY SNOW SHOWERS THAT ARE IN THE AREA. SLIGHTLY COOLER ON SATURDAY WITH HIGHS BACK INTO THE 40S. EVEN COOLER BY SUNDAY INTO MONDAY WITH HIGHS AT MOST LOCATIONS WITHIN A COUPLE DEGREES OF 40. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... GUSTY WINDS WILL CONTINUE TO MOVE ACROSS NORTHERN OHIO THROUGH THE AFTERNOON. EASTERN AREAS WILL SEE THESE STRONGER WINDS ARRIVE AS THE MIDDLE LEVEL CLOUD COVER GIVES WAY TO CLEAR SKIES. IT APPEARS AT THIS TIME THAT WESTERLY WINDS WILL GUST IN THE 25 TO NEAR 40 KNOT RANGE. THE STRONGEST GUSTS WILL GENERALLY BE NEAR AND NORTH OF A LINE FROM FINDLAY TO ERIE. THE WINDS WILL DECREASE SHORTLY AFTER SUNSET WITH VFR CONDITIONS ANTICIPATED THROUGH THE NIGHT. WE WILL HAVE TO MONITOR NE OH INTO NW PA FOR SOME LOWER LEVEL VFR CEILINGS FOR A BRIEF PERIOD AFTER MIDNIGHT. OTHERWISE EXPECT TO SEE SOME MIDDLE AND HIGH LEVEL CLOUD COVER RETURN FROM WEST TO EAST TUESDAY MORNING INTO THE EARLY AFTERNOON. OUTLOOK...PERIODS OF NON-VFR WILL RETURN TUESDAY NIGHT AND CONTINUE AT TIMES THROUGH THURSDAY. NON-VFR MAY RETURN BY FRIDAY NIGHT INTO SATURDAY. && .MARINE... A COLD FRONT MOVING ACROSS LAKE ERIE THIS AFTERNOON IS RESPONSIBLE FOR STRONG WESTERLY WINDS OF 20 TO 30 KNOTS. WINDS ARE APPROACHING GALE FORCE ON THE EAST END OF THE LAKE BUT SHOULD REMAIN JUST BELOW GIVEN THAT THE COLD ADVECTION BEHIND THE FRONT IS NOT THAT STRONG. SMALL CRAFT ADVISORIES ARE IN EFFECT FOR ALL NEARSHORE WATERS AND WILL COME TO AN END FROM WEST TO EAST OVERNIGHT AS HIGH PRESSURE BUILDS OVERHEAD AND WINDS/WAVES QUICKLY DECREASE. EASTERLY WINDS WILL INCREASE ON TUESDAY NIGHT AHEAD OF THE NEXT LOW PRESSURE SYSTEM TRACKING OUT OF THE PLAINS. WE WILL HAVE TO MONITOR THE EXACT TRACK AND STRENGTH OF THE SURFACE LOW FROM WEDNESDAY INTO THURSDAY TO DETERMINE MOST LIKELY WINDOW OF SMALL CRAFT ADVISORY CONDITIONS. A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED ON THE EAST END OF THE LAKE FOR THURSDAY BUT MAY NEED TO BE EXPANDED TO THE WEST. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...WIND ADVISORY UNTIL 8 PM EST THIS EVENING FOR OHZ012>014- 021>023-031>033-089. WIND ADVISORY UNTIL 6 PM EST THIS EVENING FOR OHZ003-006>011- 017>020-027>030. PA...WIND ADVISORY UNTIL 8 PM EST THIS EVENING FOR PAZ001>003. MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST TUESDAY FOR LEZ144>149. SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR LEZ142- 143. && $$ SYNOPSIS...ABE NEAR TERM...ABE SHORT TERM...ABE LONG TERM...MULLEN AVIATION...MULLEN MARINE...KEC