Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000 FXUS61 KPHI 261949 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 349 PM EDT THU MAR 26 2015 .SYNOPSIS...
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A STRONG COLD FRONT SWEEPS THROUGH THE REGION TONIGHT INTO FRIDAY MORNING. A WEAK LOW PRESSURE SYSTEM MAY FORM ALONG THIS FRONT AS IT RESIDES OFFSHORE ON SATURDAY. STRONG CANADIAN HIGH PRESSURE IS EXPECTED TO MOVE THROUGH THE REGION ON SUNDAY INTO MONDAY BEFORE ANOTHER COLD FRONT PASSAGE LATER ON MONDAY. ANOTHER SHOT OF HIGH PRESSURE FOR TUESDAY AND WEDNESDAY IS EXPECTED AHEAD OF THE NEXT COMPLEX LOW PRESSURE SYSTEM ON THURSDAY.
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&& .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
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SHOWERS WILL CONTINUE TO MOVE THROUGH THE REGION THIS AFTERNOON WITH ISOLATED THUNDER REMAINING POSSIBLE. TEMPERATURES HAVE WARMED BEHIND THE WARM FRONT AND SHOULD RISE A COUPLE OF MORE DEGREES OVER THE NEXT FEW HOURS IN THE CONTINUING WARM ADVECTION BEFORE THE COLD FRONT ARRIVES TONIGHT. THE COLD FRONT WILL CROSS THE REGION TONIGHT BRINGING IN ANOTHER ROUND OF RAIN. INSTABILITY LOOKS LIMITED ALONG THE FRONTAL BOUNDARY BUT THERE IS ENOUGH THAT SOME THUNDERSTORMS MAY DEVELOP AS THE FRONT IS CROSSING THE REGION. THINGS TURN COLDER BEHIND THE COLD FRONT AS WE SEE STRONG COLD AIR ADVECTION TAKING PLACE. TEMPERATURES WILL DROP QUICKLY BEHIND THE FRONT, ABOUT 10 TO 20 DEGREES COLDER. TEMPERATURES WILL FALL INTO THE 30S AND 40S OVERNIGHT, WITH SOME UPPER 20S ACROSS THE SOUTHERN POCONOS. WITH THE COLDER TEMPERATURES, THERE MAY BE A CHANGEOVER TO OR A MIX OF RAIN AND SNOW AS THE FRONT MOVES OFFSHORE AND THE PRECIPITATION STARTS TO DIMINISH. RAINFALL AMOUNTS WILL GENERALLY BE AROUND A HALF OF AN INCH OR LESS WITH LITTLE TO NO SNOW ACCUMULATION.
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&& .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
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THE COLD FRONT MAKES ITS WAY OFF THE COAST FRIDAY WITH SOME LINGERING SHOWERS HANGING AROUND, MAINLY ACROSS THE SOUTHEASTERN PORTIONS OF THE FORECAST AREA. A WAVE LOOKS TO FORM ALONG THE DEPARTING COLD FRONT AND THIS WILL KEEP THE SHOWERS FROM EXITING OFFSHORE ACROSS OUR SOUTHERN AND EASTERN AREAS THROUGH THE AFTERNOON. TEMPERATURES WILL BE MUCH COOLER ON FRIDAY IN MANY AREAS COMPARED TO TODAYS MAX TEMPS. HIGHS WILL BE IN THE 40S TO NEAR 50 ACROSS THE REGION ON FRIDAY WITH PLENTY OF CLOUD COVER AROUND. NORTHWEST WINDS MAY BE GUSTY EARLY BUT SHOULD RELAX AS THE FRONT MOVES OFFSHORE.
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&& .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
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5-WAVE MODEL GUIDANCE SHOWS BROAD TROUGHING IN THE EAST WITH BROAD RIDGING ACROSS THE WESTERN STATES THROUGH MOST OF THE LONGTERM PERIOD. THE PATTERN ALOFT HAS A FAST FLOW LOOK WITHOUT MUCH BLOCKING WHICH ADDS TO A BIT OF THE UNCERTAINTY/TIMING OF EMBEDDED SHORTWAVES WITHIN THE MID-LEVEL FLOW. TOWARDS THE END OF THE PERIOD A NEARLY ZONAL FLOW LOOKS TO TAKE SHAPE. FRIDAY NIGHT - SATURDAY...DEEP ANOMALOUS MID-LEVEL TROUGH WILL BE OVERHEAD AS STRONGER NORTHERN STREAM ENERGY TRIES TO PHASE WITH WEAKER, SLOWER MOVING, SOUTHERN STREAM ENERGY. EVEN WITH MINIMAL PHASING SURFACE CYCLOGENESIS LOOKS TO OCCUR TO THE SOUTH OF OUR REGION LATE ON FRIDAY. THIS WEAK INFLECTION WILL MOVE ALONG THE AFOREMENTIONED COLD FRONT SITTING OFFSHORE ON SATURDAY AND COULD THROW SOME LIGHT PRECIPITATION BACK ACROSS THE REGION DURING THE DAY. THINKING THAT A MAJORITY OF THE LIFT AND MOISTURE WITH THIS SYSTEM WILL REMAIN TO OUR NORTHEAST, OVER NEW ENGLAND, AND FARTHER OFFSHORE. THE PASSAGE OF THE MID-LEVEL LOW COULD ALSO SPARK A FEW INSTABILITY SHOWERS DURING THE AFTERNOON. THERMALLY WE WILL BE DROPPING BELOW FREEZING THROUGHOUT THE COLUMN BY SATURDAY AFTERNOON SO MOST OF THE PRECIPITATION SHOULD FALL AS SNOW. TRYING TO COMBAT ANY DAYTIME HEATING, EVEN WITH A MULTITUDE OF CLOUDS AND NORTHERLY WINDS, WILL BE TOUGH WITH BOUNDARY LAYER TEMPERATURES EXPECTED TO BE IN THE MID TO UPPER-30S...THE ONE CAVEAT WOULD BE STRONGER DYNAMIC COOLING WITH THE PLACEMENT OF AN INVERTED TROUGH/MESOSCALE BANDING FEATURE...THOUGH IT IS ILL-DEFINED ACROSS OUR AREA AT THIS TIME. SUNDAY...RIDGING TO OUR SOUTH RE-ESTABLISHES IT SELF ACROSS THE REGION FOR THE SECOND HALF OF THE WEEKEND. THIS WILL PROVIDE MOSTLY CONDITIONS ACROSS THE REGION AS TEMPERATURES REMAIN WELL BELOW NORMAL. MONDAY...RIDGING SLIDES OFF THE SOUTHEAST COAST AND A RETURN FLOW WITH LOW-LEVEL WARM AIR ADVECTION KICKS IN. TEMPERATURES MAY BE ABLE TO WARM TO ABOVE NORMAL, AS WE CONTINUE THE TUMULTUOUS EARLY SEASON TEMPERATURE SWINGS. THERE DOES NOT APPEAR TO BE A GREAT DEAL IN MOISTURE SURGE WITH THIS NEXT SYSTEM, AS IT APPROACHES FROM THE WEST. WITH THE LACK OF MOISTURE WE KEEP THE SLIGHT CHANCE POPS IN THE FORECAST, THOUGH THE BETTER LIFT WILL ACCOMPANY THE ADVANCING COLD FRONT LATER MONDAY AFTERNOON SO POPS MAY BE INCREASED IN TIME. TUESDAY - THURSDAY...THE FLOW ALOFT, AS MENTIONED ABOVE, REMAINS QUICK AND ACTIVE. NUMEROUS EMBEDDED WAVES OF ENERGY SLIDE THROUGH THE REGION DURING THIS TIMEFRAME, EACH CARRYING THE CHANCE FOR SHOWERY ACTIVITY. THE BETTER CHANCES FOR SHOWERS WILL BE WEDNESDAY INTO THURSDAY AS ANOTHER SYSTEM PUSHES IN FROM THE WEST. ANOTHER LOW- LEVEL MOISTURE SURGE IS EXPECTED WITH THIS SYSTEM AS TEMPERATURES LOOK TO REMAIN AT OR SLIGHTLY ABOVE AVERAGE FOR THE FIRST COUPLE DAYS OF APRIL...THIS COULD EASILY CHANGE WITH TIME.
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&& .AVIATION /20Z THURSDAY THROUGH TUESDAY/...
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THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY, AND SURROUNDING AREAS. TONIGHT...CEILINGS WILL GRADUALLY RISE TO MVFR THIS AFTERNOON. AS SHOWERS MOVE THROUGH THE REGION, BRIEF PERIODS OF LIFR/IFR MAY OCCUR. A COLD FRONT WILL DROP DOWN FROM THE NORTHWEST AND MOVE THROUGH KABE/KRDG BETWEEN 01-3Z, KPHL/KPNE/KTTN/KILG BETWEEN 03-06Z, AND KMIV/KACY BETWEEN 06-08Z. GUSTY SOUTHERLY WINDS THIS AFTERNOON WILL VEER TO THE WEST AND THEN NORTHWEST AS THE FRONT MOVES THROUGH TONIGHT. SHOWERS WILL ACCOMPANY THE FRONTAL PASSAGE AND THERE MAY BE PERIODS OF LOWER CONDITIONS. GENERALLY EXPECT MVFR CONDITIONS TO PREVAIL THROUGH TONIGHT. FRIDAY...IMPROVING CONDITIONS FROM MVFR TO VFR ACROSS THE TERMINALS. WINDS WILL BE OUT OF THE NORTHWEST WITH SPEEDS AROUND 10 KNOTS...DIMINISHING TOWARDS THE AFTERNOON. CEILINGS WILL GENERALLY REMAIN AT OR ABOVE 4000 FEET THROUGH THE DAY. OUTLOOK... FRIDAY NIGHT - SATURDAY...MVFR OR LOWER POSSIBLE IN RAIN/SNOW SHOWERS. NORTHERLY WINDS. SUNDAY - MONDAY...VFR. NORTHERLY WINDS VEER TOWARDS THE SOUTHWEST AND BEGIN TO GUST MONDAY AFTERNOON. TUESDAY...VFR. WINDS VEER TOWARDS THE WEST-NORTHWEST...GUSTS EXPECTED.
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&& .MARINE...
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A SMALL CRAFT ADVISORY REMAINS IN EFFECT ACROSS THE AREA WATERS, ENDING ON THE DELAWARE BAY AT 12Z FRIDAY AND ON THE OCEAN FRONT AT 22Z FRIDAY. SOUTHERLY WINDS ACROSS THE WATERS THIS AFTERNOON WILL START TO VEER TO THE WEST AS A COLD FRONT APPROACHES THE WATERS. THE COLD FRONT WILL REACH THE AREA WATERS IN THE 05-09Z TIME FRAME AND THEN MOVE OFFSHORE, LEAVING US WITH NORTHWEST WINDS. WINDS WILL GUST BEHIND THE FRONTAL PASSAGE BUT SHOULD DIMINISH THROUGH THE DAY. WAVES ARE RUNNING AROUND 4 TO 6 FEET ON THE OCEAN THIS AFTERNOON AND WILL REMAIN ELEVATED THROUGH FRIDAY. WAVES ON THE BAY ARE GENERALLY AROUND 2 TO 4 FEET. OUTLOOK... FRIDAY NIGHT - SATURDAY...SEAS WILL SUBSIDE LATE FRIDAY EVENING BUT COULD INCREASE A TAD SATURDAY WITH A NORTHERLY SURFACE FLOW DEVELOPING. COULD SEE SCA SEAS SATURDAY AFTERNOON. SUNDAY - TUESDAY...POSSIBLE SCA CONDITIONS SUNDAY THROUGH TUESDAY. WINDS VEER TOWARDS THE WEST AND THEN SOUTHWEST BY MONDAY AS HIGH PRESSURE SLIDES OFFSHORE. A COLD FRONT SLIDES THROUGH ON MONDAY EVENING AND WINDS MAY STAY ABOVE SCA THROUGH TUESDAY NIGHT.
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&& .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ450>455. SMALL CRAFT ADVISORY UNTIL 8 AM EDT FRIDAY FOR ANZ430-431. && $$ SYNOPSIS...HEAVENER NEAR TERM...MEOLA SHORT TERM...MEOLA LONG TERM...HEAVENER AVIATION...HEAVENER/MEOLA MARINE...HEAVENER/MEOLA

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