Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000 FXUS61 KPHI 240932 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 432 AM EST TUE FEB 24 2015 .SYNOPSIS... ARCTIC HIGH PRESSURE WILL CONTINUE TO CROSS THE REGION TODAY BEFORE SHIFTING OFFSHORE THIS EVENING. LOW PRESSURE FORMS OFF THE SOUTHERN MID ATLANTIC COAST TUESDAY NIGHT AND THEN SCOOTS NORTHEASTWARD. A COLD FRONT WILL PASS ACROSS OUR AREA WEDNESDAY, THEN A MORE POTENT LOW PRESSURE SYSTEM ALONG THE GULF COAST WEDNESDAY EVENING RACES OUT TO SEA WELL TO OUR EAST ON THURSDAY. STRONG ARCTIC HIGH PRESSURE CENTERED IN MONTANA WILL ARRIVE ALONG THE MID ATLANTIC COAST NEXT WEEKEND, THEN A COLD FRONT APPROACHES FROM THE WEST NEXT MONDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... LIGHT WINDS WILL BEGIN TO SHIFT FROM NORTHERLY TO SOUTHEASTERLY AS A SURFACE HIGH SLIDES NE OF THE REGION BY MID DAY. UNFORTUNATELY, AS LIGHT AS THE WINDS ARE, THE SOUTHERLY FLOW WON/T BE MUCH HELP FOR GETTING TEMPERATURES BACK TO NEAR NORMAL. HIGHS TODAY WILL CONTINUE TO BE WELL BELOW NORMAL, WITH THE ENTIRE REGION EXPECTED TO STAY BELOW FREEZING, AND MUCH OF THE NORTHERN HALF OF THE REGION STRUGGLING TO GET OUT OF THE TEENS. WENT WITH OR JUST BELOW GUIDANCE TO ACCOUNT FOR THE PERSISTENT SNOW PACK OVER MUCH OF THE REGION. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/... TWO LOWS TO WATCH TONIGHT. FIRST, A COASTAL LOW IS EXPECTED TO DEVELOP OFF THE CAROLINA COAST AND LIFT NE. MODELS TRENDED SLIGHTLY FURTHER WEST WITH THE TRACK. AS SUCH, COASTAL DE AND NJ COULD BE ON THE WESTERN FRINGE OF ANY ASSOCIATED PRECIPITATION. THE SECOND LOW TO WATCH WILL BE CROSSING THE NORTHERN GREAT LAKES REGION. IN THIS CASE, THE POCONOS COULD BE ON THE SOUTHERN FRINGE OF ANY ASSOCIATED PRECIPITATION. HOWEVER, MODELS ARE IN RELATIVELY GOOD AGREEMENT OF THE VORT MAX PASSING NORTH OF THE REGION. DESPITE THE REGION BEING IN BETWEEN THE TWO LOWS, WINDS SHOULD NOT BE MUCH HIGHER THAN DURING DAY AS THE PRESSURE GRADIENT ACROSS THE REGION ISN/T EXPECTED TO INCREASE DRAMATICALLY UNTIL AFTER MIDNIGHT TONIGHT. AS WITH THE HIGHS, GENERALLY UNDERCUT GUIDANCE ON LOWS TONIGHT TO ACCOUNT FOR THE SNOW PACK. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... VERY BROAD TROUGHING ACROSS THE EASTERN HALF OF THE STATES THROUGH THE FIRST PART OF THE EXTENDED FOLLOWED BY ZONAL FLOW/WEAK RIDGING TOWARDS THE WEEKEND. A RETURN TO BROAD SCALE TROUGHING IS EXPECTED AGAIN VERY LATE IN THE PERIOD. WEDNESDAY - THURSDAY... SHOULD BE MOSTLY DRY ON WEDNESDAY WITH AS ONE EMBEDDED MID-LEVEL SHORTWAVE MOVES FARTHER TO OUR NORTHEAST EARLY IN THE DAY. WE ARE WATCHING THE ADVANCEMENT OF ANOTHER SYSTEM, THIS TIME A SOUTHERN STREAM EMBEDDED WAVE THAT FORMS A WEAK LOW PRESSURE OFF THE SOUTHEAST COAST. MODEL CONSENSUS THE PAST FEW DAYS HAS BEEN TO KEEP THIS SYSTEM FAIRLY SUPPRESSED AS IT EJECTS OUT TO SEA, BUT THAT DOES NOT MEAN WE STAY COMPLETELY DRY EITHER. LATE WEDNESDAY NIGHT LIGHT PRECIPITATION, SNOW, SHOULD CLIP THE SOUTHEASTERN PORTION OF THE DELMARVA AND POSSIBLY EXTREME SOUTHEASTERN NEW JERSEY AS IT MOVES BY. UPPER LEVEL JET STREAK DYNAMICS WILL HELP AIDE IN SLIGHTLY WETTER CONDITIONS ACROSS SOUTHERN DELMARVA WITH A LIGHT ACCUMULATION OF SNOW POSSIBLE...WE KEEP TOTALS BELOW AN INCH AT THIS TIME BASED ON THE LOWS TRACK. THE SURFACE WAVE QUICKLY MOVES OUT TO SEA WITH LITTLE DOWNSTREAM BLOCKING IN PLACE AND WE DRY OUT BY THE AFTERNOON HOURS. TEMPERATURES ON WEDNESDAY LOOK TO GET ABOVE FREEZING BEFORE FALLING ONCE AGAIN ON THURSDAY BEHIND THE DEPARTING LOW PRESSURE AND THE PREVIOUS DAYS COLD FRONT PASSAGE. FRIDAY - SATURDAY...HIGH PRESSURE WILL BE IN CONTROL OVER THE REGION WITH ZONALISH FLOW ALOFT TAKING SHAPE. A COUPLE MORE WELL BELOW AVERAGE TEMPERATURE DAYS ARE EXPECTED...WE END METEOROLOGICAL WINTER WITH ANOTHER CLOD SNAP. SUNDAY - MONDAY...ZONAL FLOW TURNS SHARPER AS THE BROAD TROUGH RELOADS TO OUR WEST. DEEP SOUTHWESTERLY FLOW COMMENCES AS SURFACE RIDGING DEPARTS THE COAST. TEMPERATURES BEGIN TO CLIMB CLOSER TO NORMAL, POSSIBLY ABOVE NORMAL FOR THE FIRST TIME IN A WHILE BY MONDAY. SOUTHERN STREAM SYSTEM WITH LOTS OF MOISTURE IS EXPECTED TO PASS THROUGH THE REGION DURING THIS PERIOD AND DEPENDING ON WHEN IT STARTS TO AFFECT THE AREA MIXED-PHASE PRECIPITATION WILL OCCUR. TOO EARLY FOR SPECIFICS THIS FAR OUT BUT A SNOW TO RAIN PROGRESSION LOOKS GOOD. && .AVIATION /09Z TUESDAY THROUGH SATURDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. VFR CONDITIONS ARE EXPECTED THROUGH 00Z. WINDS WILL BE LIGHT THROUGH THE DAY AND COULD AT TIMES BE VRB AS THEY SHIFT FROM NORTHERLY TO SOUTHEASTERLY THROUGH THE DAY. AFTER 00Z, MODELS ARE SHOWING A LAYER AROUND 1000 TO 3000 FT AGL BECOMING NEARLY SATURATED ACROSS MUCH OF THE REGION. GIVEN HOW WEAK THE WINDS ARE, IT SEEMS UNLIKELY AT THIS TIME THAT THIS WILL MEAN PERSISTENT CEILINGS AT THAT LEVEL, BUT HAVE INCLUDED A SCT MENTION AND WILL CONTINUE TO MONITOR THROUGH THE DAY. OTHER THAN THAT POSSIBILITY, VFR CONDITIONS SHOULD CONTINUE OVERNIGHT. OUTLOOK... WEDNESDAY...VFR. GUSTY W WINDS POSSIBLE IN THE AFTERNOON. THURSDAY...MOSTLY VFR. POSSIBLE LIGHT MVFR/IFR SNOW SOUTH AND EAST OF PHL/ILG...COULD AFFECT MIV/ACY LATE THURSDAY MORNING BEFORE MOVING OUT TO SEA. FRIDAY - SATURDAY...VFR. && .MARINE... WINDS AND SEAS HAVE SUBSIDED, SO WILL LET THE SCA GO AT THE TOP OF THE HOUR. WITH WINDS DIMINISHING, FREEZING SPRAY WILL SLOWLY DIMINISH THROUGH THE EARLY MORNING HOURS. HOWEVER, SOME SITES ARE STILL REPORTING MODERATE FREEZING SPRAY, SO WILL KEEP THE FREEZING SPRAY ADVISORY GOING THROUGH 12Z FOR NOW. SUB SCA CONDITIONS SHOULD CONTINUE TODAY INTO TONIGHT. HOWEVER, WINDS INCREASE AFTER MIDNIGHT WITH GUSTS ABOVE 20KT EXPECTED. HOWEVER CONDITIONS ARE EXPECTED TO REMAIN JUST BELOW SCA CRITERIA. OUTLOOK... WEDNESDAY...SUB-SCA EXPECTED, THOUGH VERY MARGINAL SCA GUSTS MAY OCCUR ACROSS OUR NORTHERN ZONES. WEDNESDAY NIGHT THROUGH THURSDAY NIGHT... WINDS TURN NLY AND INCREASE TO AROUND 20 KT WITH NEAR SCA LEVELS. MODERATE FREEZING SPRAY IS ALSO POSSIBLE AS WINDS AND WAVES INCREASE THURSDAY INTO FRIDAY. FRIDAY - SATURDAY...SUB-SCA EXPECTED, THOUGH PERSISTENT NORTHEAST WINDS MAY ALLOW FOR BUILDING SEAS ACROSS OUR SOUTHERN ZONES. && .CLIMATE... THE FORECAST LOW TEMPERATURES FOR THIS MORNING, FEBRUARY 24TH PUTS SEVERAL DAILY LOW TEMPERATURE RECORDS IN JEOPARDY. THE PARTICULARS... POR / SITE / RECORD LOW FEB 24 1872 / KPHL / 2F (1889) 1874 / KACY / 2F (1889) 1894 / KILG / 6F (1923) 1922 / KABE / 4F (1948) 1869 / KRDG / 3F (1914) 1865 / KTTN / -2F (1889,1873) 1948 / KGED / 13F (1956) 1901 / KMPO /-14F (1914) NOTE: POR = PERIOD OF RECORD, THE YEAR OFFICIAL CLIMATE OBS BEGAN. THE FOLLOWING IS A TABLE OF THE ***PROJECTED*** TOP 5 COLDEST FEBRUARY`S ON RECORD, BASED ON THE CURRENT FORECAST, AND THUS SUBJECT TO CHANGE. EACH RANKING DENOTES THE MEAN FEBRUARY TEMPERATURE /F/ AND YEAR OF OCCURRENCE. POR / SITE / 1ST RANK / 2ND RANK / 3RD RANK / 4TH RANK / 5TH RANK 1872 / KPHL / 22.2(1934) 23.0(1979) 24.3(1885) 24.6(1978) 25.3(2015) 1874 / KACY / 21.6(1979) 23.6(2015)*23.8(1978) 25.5(1875) 25.7(1905) 1894 / KILG / 20.2(1934) 22.1(1979) 22.7(1978) 24.1(2015) 24.9(1936) 1922 / KABE / 16.6(1934) 18.5(2015) 20.4(1979) 21.6(1936) 22.0(1963) *KACY TIED WITH 1934 FOR THE PROJECTED SECOND COLDEST FEBRUARY. PER THE ABOVE TABLE, BOTH ABE AND ACY ARE ON TRACK FOR THE SECOND COLDEST FEBRUARY, FOLLOWED BY THE FOURTH COLDEST AT ILG, AND THE FIFTH COLDEST AT PHL. THE FOLLOWING IS A TABLE OF THE ***PROJECTED*** MEAN FEBRUARY 2015 TEMPERATURES /F/ AND DEPARTURES FROM NORMAL. THIS IS ALSO BASED ON THE CURRENT FORECAST, AND THUS SUBJECT TO CHANGE. JANUARY 2015 MEAN TEMPERATURES ARE ALSO INCLUDED FOR COMPARISON PURPOSES. POR / SITE / FEB MEAN(F) / FEB NORMAL(F) / DEPARTURE / JAN MEAN(F) 1872 / KPHL / 25.3 / 35.7 / -10.4 / 30.9 1874 / KACY / 23.6 / 35.3 / -11.7 / 30.2 1894 / KILG/ 24.1 / 35.1 / -11.0 / 30.3 1922 / KABE/ 18.5 / 30.7 / -12.2 / 25.9 IN GENERAL, MEAN TEMPERATURES AT OUR FOUR MAJOR CLIMATE SITES ARE ON TRACK TO BE AROUND 10 TO 12 DEGREES BELOW NORMAL FOR FEBRUARY 2015. IT`S ALSO INTERESTING TO NOTE THAT THE PROJECTED FEBRUARY 2015 MEAN TEMPERATURES WILL BE WELL BELOW THE JANUARY 2015 MEAN TEMPERATURES. TO PUT THIS IN PERSPECTIVE, NORMAL MEAN FEBRUARY TEMPERATURES AT OUR FOUR MAJOR CLIMATE SITES ARE ABOUT 2 TO 3 DEGREES WARMER THAN JANUARY. THE OPPOSITE IS SHAPING UP FOR FEBRUARY 2015. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...WIND CHILL ADVISORY UNTIL 10 AM EST THIS MORNING FOR PAZ054- 055. NJ...NONE. DE...NONE. MD...NONE. MARINE...FREEZING SPRAY ADVISORY UNTIL 7 AM EST THIS MORNING FOR ANZ430- 431-450>455. && $$ SYNOPSIS...HEAVENER NEAR TERM...JOHNSON SHORT TERM...JOHNSON LONG TERM...HEAVENER AVIATION...HEAVENER/JOHNSON MARINE...HEAVENER/JOHNSON CLIMATE...DRAG

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