Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000 FXUS61 KPHI 290140 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 940 PM EDT THU MAY 28 2015 .SYNOPSIS... A COLD FRONT WILL MOVE ACROSS THE AREA OVERNIGHT. HIGH PRESSURE REESTABLISHES ITSELF OFF THE EAST COAST FRIDAY INTO SATURDAY. ANOTHER COLD FRONT WILL THEN SLOWLY MOVE ACROSS THE REGION SATURDAY NIGHT OR SUNDAY. HIGH PRESSURE WILL BUILD OVER EASTERN CANADA EARLY NEXT WEEK WHILE THE FRONTAL BOUNDARY STALLS TO OUR SOUTH. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... SHOWERS AND THUNDERSTORMS HAVE DISSIPATED WITHIN THE PAST TWO HOURS OVER MOST OF THE REGION. SOME NEW SHOWERS HAVE BROKEN OUT OVER NORTHEAST MARYLAND, BUT COVERAGE IS ISOLATED. ADDITIONAL SHOWERS HAVE DEVELOPED WEST OF THE CHESAPEAKE BAY. RECENT HRRR RUNS SUGGESTS THIS ACTIVITY MAY CONTINUE INTO THE EARLY MORNING HOURS. WIND SHIFT TO THE NORTH (SPEEDS VERY LIGHT) HIGHLIGHTS THE ARRIVAL OF DRIER AIR ACROSS THE REGION. DEWPOINT DISCONTINUITY PROVIDES BEST IDENTIFICATION OF FRONTAL BOUNDARY. THERE MAY BE SOME PATCHY FOG/ST OVERNIGHT IN THE FRONTAL BOUNDARY AREA WITH CONFIDENCE FOR FOG/STRATUS FORMATION BELOW AVG. PATCHY FOG IS IN THE WEATHER GRIDS USING THE UPS CROSSOVER TOOL. OTHERWISE A FAIR NIGHT AND A FEW DEGREES COOLER UP NORTH LATE AT NIGHT DUE TO DRIER AIR. FCST TEMPS ARE BASED ON THE WARMER 12Z/28 NAM MOS AND ALL OTHER GUIDANCE IS DERIVED OFF A 50 50 BLEND OF THE 12Z/28 GFS/NAM MOS. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... A NICER DAY WITH LOWER DEWPOINTS...AN IDEAL SUMMER DAY KPHL NORTHEASTWARD...WARM BUT RELATIVELY COMFORTABLE WITH LIGHT EAST WINDS TURNING SE OR S DURING THE AFTERNOON. COOLER COASTS DUE TO THE UPWELLED COOLER OCEAN WATERS, ESPECIALLY NNJ. WE HAVE SMALL POPS IN DURING THE MORNING DELMARVA AND SPREADING NWD THRU E PA IN THE AFTN BUT CONFIDENCE IS BELOW AVG. IT SHOULD BE RAINFREE MOST OF OUR FORECAST AREA ON FRIDAY. ONLY CALLED IT SHOWERS PER MORE STABLE ENVIRONMENT AND CHANCEY AT WORST IN SW PORTION OF THE FCST AREA FCST TEMPS BASED ON THE WARMER OF THE AVBL 12Z/28 NCEP GUIDANCE. REMAINDER OF THE ELEMENTS DERIVED FROM THE 12Z/28 50 50 BLENDED GFS/NAM MOS. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... HIGH PRES WILL REMAIN OFF THE COAST FOR THE START OF THE PD AS CDFNT ADVANCES FROM THE W. WITH THE LOW OVER QUEBEC, WE WILL BE WELL IN THE WARM SECTOR AND WITH OUT MANY TRIGGERS BESIDES DAYTIME HEATING, EXPECT FRI NIGHT TO BE DRY AND EARLY SAT AS WELL. BY LATER SAT, CUD SEE A FEW SHRA/TSTMS MAINLY N AND W. BY LATER SAT INTO SUN, THIS IS OUR BEST SHOT TO SEE SOME DECENT RAIN ACRS THE AREA, AND WE NEED IT. THE ECMWF, IS STILL A BIT SLOWER WITH THE CFP, BUT OVERALL TIMING DIFFS HAVE DECREASED. SAT NIGHT INTO SUN APPEARS TO BE THE WET TIME PD, THOUGH IT WONT BE RAINING THE WHOLE TIME, AND CERTAINLY NOT EVERYONE WILL GET RAIN AT THE SAME TIMES. BEHIND THE FRONT, HIGH PRES WILL MOVE TO THE N AND BE ANCHORED IN QUEBEC AS THE FRONT STALLS TO OUR S. NELY FLOW WILL SET IN THE FCST WILL BE VERY DEPENDENT ON WHERE THE FRONT SETS UP. EXPECT MON TO BE COOL AND DREARY WHETHER OR NOT IT RAINS, BUT THERE WILL BE SCT SHOWERS AT LEAST, AND PSBLY MORE IN THE WAY OF PRECIP. GUID IS STILL HAVING DIFFICULTY WITH DETERMINING OF WHERE THE STEADIEST RAIN MIGHT BE AND HAS HAD PROBS OVER THE LAST FEW DAYS WITH THE DETAILS OF THE FCST AROUND MON. THOSE STILL CONTINUE. IT SHUD BE NOTED THAT THE CMC IS MUCH DRIER THAN EITHER THE GFS AND ECMWF ON MON. THE GFS HAS A WET BIAS, BUT THE ECMWF, EXCEPT FOR ONE DAY EARLIER THIS WEEK HAS BEEN CONSISTENT WITH SOME PRECIP FOR MON. HIGH PRESSURE SLIDES ACROSS TO THE NORTH AND EAST OF THE REGION MONDAY NIGHT. WITH HIGH PRESSURE REMAINING ENTRENCHED OVER THE ATLANTIC OCEAN, THE COLD FRONT MAKES LITTLE HEADWAY THROUGH THE REGION AND LOOKS LIKELY TO REMAINED STALLED ACROSS OR NEAR OUR AREA THROUGH TUESDAY. AS THE NORTHEASTERN HIGH STARTS TO PUSH BACK INTO OUR AREA, THE FRONT WILL PUSH OFFSHORE, AROUND WEDNESDAY. THE HIGH THEN REMAINS OVER OUR AREA THROUGH THE END OF THE WEEK. WITH THE FRONT REMAINING STALLED IN OUR AREA, A CHANCE FOR SOME SHOWERS WILL CONTINUE THROUGH TUESDAY. AS THE FRONT STARTS TO PUSH OFFSHORE SHOWER ACTIVITY WILL EXIT FROM NORTHWEST TO SOUTHEAST AND AS THE HIGH BUILDS INTO OUR REGION, WE SHOULD REALLY START TO DRY OUT, REMAINING DRY THROUGH THURSDAY. TEMPS START OUT QUITE WARM, THEN TAKE A NOSEDIVE MON AND TUE BEFORE RETURNING TO MORE NRML LEVELS BY THE END OF THE PD. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. TONIGHT...CFP OCCURS WITH WIND SHIFTING TO LIGHT N AND THEN NE. IFR ST/FOG MAY FORM IN THE FRONTAL ZONE OVERNIGHT OTRW PREDICTING GENERALLY VFR. CONFIDENCE: BELOW AVERAGE DUE TO THE UNCERTAINTY REGARDING THE FORMATION OF IFR ST/FOG OVERNIGHT. FRIDAY...VFR WITH ANY LEFTOVER IFR DISSIPATING BY 14Z AND THEN SCT-BKN CLOUDS AOA 4000 FT DURING THE AFTN. LIGHT E WIND DURING THE MORNING BECOMING SE TO S DURING THE AFTERNOON. ISOLATED SHOWERS POSSIBLE FOR KILG AND KRDG DURING THE AFTN. THUNDER UNLIKELY IN OUR AREA. CONFIDENCE: AVERAGE. OUTLOOK... FRI NIGHT...VFR ERLY, THEN LOWERING CIGS/VSBYS WITH STRATUS/FOG PSBL. MDT CONFIDENCE SAT...LOWER CONDITIONS PSBL ERLY, THEN BECOMING VFR DURING THE DAY. SCT SHRA/TSRA MAINLY N AND W. MDT CONFIDENCE. SAT NIGHT-MON...AN EXTENDED PERIOD OF MVFR/IFR CONDITIONS POSSIBLE. A CHANCE OF RAIN EACH DAY. BEST POTENTIAL FOR TSRA IS SUN WITH CFP SAT NIGHT INTO SUN. LOW CONFIDENCE ON EXACT DETAILS. MONDAY NIGHT THROUGH TUESDAY...IMPROVING CONDITIONS FROM NORTHWEST TO SOUTHEAST. LINGERING SHOWERS WITH MVFR CEILINGS/VISIBILITIES MONDAY NIGHT IMPROVING TO VFR BY LATE MORNING/EARLY AFTERNOON ON TUESDAY. && .MARINE... DO NOT ANTICIPATE SCA CONDITIONS THROUGH FRIDAY. SLY FLOW SHOULD TURN NE TO E ALONG THE WATERS OVERNIGHT AND LIGHT ONSHORE FRIDAY. OUTLOOK... FRI NIGHT-SAT...SUB-SCA CONDS EXPECTED, ALTHOUGH WINDS MAY GUST AROUND 20 KNOTS AT TIMES AND SEAS COULD APPROACH 5 FT BY THE END OF THE PD. SAT NIGHT-MON...INCREASING SEAS ESPECIALLY LATER SUN INTO MON WITH WIND INCREASING ABOVE SCA CRITERIA AS WELL. AN SCA WILL LIKELY BE BE NEEDED FOR A PORTION OF THIS TIME WITH THE FRONT TO OUR S AND INCREASING NELY FLOW. MONDAY NIGHT THROUGH TUESDAY...EASTERLY FLOW WILL CONTINUE ACROSS THE WATERS THROUGH TUESDAY. SEAS WILL REMAIN ELEVATED ABOVE 5 FEET ON THE OCEAN WITH WINDS GUSTING UP AROUND 25 KNOTS. && .RIP CURRENTS... NEW WEBLINK, WORKS BEST ON FIREFOX. DISPLAYS THE FCST GRAPHIC ETC. WWW.WEATHER.GOV/PHI/SURFRIP4 LOW RISK CONTINUES THROUGH FRIDAY. SUBSTANTIAL UPWELLING OCCURRED YESTERDAY WITH THE SOUTHERLY FLOW, ESPECIALLY NNJ WATERS WHERE 44065 WATER TEMP DROPPED ALMOST 9 DEGREES IN 24 HRS DOWN INTO THE UPPER 40S EARLIER THIS MORNING. CHILLY TO SWIM MOST OF CENTRAL AND NNJ BEACHES DESPITE WELL ABOVE NORMAL LAND TEMPS. && .CLIMATE... MAY 2015...A TOP 5 WARMEST ON RECORD FOR LARGE PORTIONS OF OUR AREA. CONSERVATIVE VALUES LISTED BELOW FROM OUR 5 AM SFT AND COOLING THE NEAR MIDNIGHT SUNDAY NIGHT MAY 31 LOW TEMP DUE TO NLY FLOW CAA SUNDAY EVENING. ALLENTOWN WILL PROBABLY AVERAGE VERY CLOSE TO 65.9 OR 6 DEGREES ABOVE NORMAL. POR BACK TO 1922. AT LEAST 5TH WARMEST ON RECORD. 1991 67.2 2012 66.1 1944 66.0 2004 65.9 PHILADELPHIA WILL PROBABLY AVERAGE CLOSE TO 69.7 DEGREES OR 5.8 DEGREES ABOVE NORMAL. SECOND WARMEST ON RECORD. 1991 70.8 NUMBER 3 WOULD BE 69.2 IN 2004. ATLANTIC CITY MAY 2015 65.9 OR 4.8 ABOVE NORMAL AND PROBABLE #3 POR BACK TO 1874 2004 66.9 1991 66.0 2015 WILMINGTON DE SOLID POR BACK TO 1916 LOCKED INTO #4 WARMEST 1896 70.1 1991 69.1 2004 68.2 2015 NO AVAILABLE MONTHLY HISTORICAL DATA FOR KMPO KGED KTTN AND KRDG. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...NIERENBERG NEAR TERM...DRAG/SZATKOWSKI SHORT TERM...DRAG LONG TERM...NIERENBERG AVIATION...DRAG/SZATKOWSKI/NIERENBERG/MEOLA MARINE...DRAG/SZATKOWSKI/NIERENBERG/MEOLA RIP CURRENTS... CLIMATE...

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