Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000 FXUS61 KPHI 171429 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 1029 AM EDT FRI OCT 17 2014 .SYNOPSIS...
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A COLD FRONT WILL MOVE THROUGH THE GREAT LAKES TODAY AND ACROSS THE FORECAST AREA ON SATURDAY. HIGH PRESSURE WILL THEN BRIEFLY BUILD INTO THE REGION LATE SUNDAY INTO MONDAY. ANOTHER COLD FRONT SHOULD ARRIVE LATE MONDAY INTO TUESDAY. A SECONDARY LOW PRESSURE SYSTEM IS PREDICTED TO DEVELOP JUST EAST OF THE FORECAST AREA ALONG THE FRONT LATER TUESDAY. THIS LOW SHOULD MOVE NORTHEAST VERY SLOWLY REACHING CAPE COD ON THURSDAY.
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&& .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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SOME FOG DID DEVELOP EARLY THIS MORNING OVER PARTS OF THE AREA... BUT IT QUICKLY DISSIPATED AFTER SUNRISE. AS OF MID/LATE MORNING SKIES ARE CLEAR EXCEPT FOR SOME PATCHY LOW CLOUDS OVER THE SOUTHERN POCONOS. SOME DIURNAL ST-CU IS EXPECTED TO DEVELOP THROUGH LATE MORNING INTO THE AFTN...ESPECIALLY N/W OF PHL...BUT SKIES SHOULD REMAIN MOSTLY SUNNY FOR AREAS S/E. TEMPS HAVE RISEN FROM THE MORNING LOWS IN THE 50S TO THE LOW/MID 60S...AND APPEAR WELL ON THEIR WAY TO FCST MAXS IN THE UPPER 60S TO LOW 70S. TEMPS ARE A FEW DEGS COOLER IN THE HIGHER ELEVS NW AS USUAL. WINDS WILL BE WRLY THIS MORNING...THEN BECOME SW THIS AFTERNOON. OVERALL...A PLEASANT DAY EXPECTED.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/... A COLD FRONT WILL APPROACH THE AREA TONIGHT. A SRLY FLOW WILL DEVELOP THIS EVENING AND REMAIN IN PLACE OVERNIGHT. THIS WILL KEEP MILD TEMPS ACROSS THE AREA...SO LOWS TONIGHT WILL BE IN THE LOW/MID 50S IN MOST AREAS...SOME UPPER 40S ACROSS THE FAR NORTH. THERE WILL BE ADDITIONAL CLOUDS OVERNIGHT...BUT NO PCPN IS EXPECTED WITH THE APPROACHING FRONT. && .LONG TERM /SATURDAY THROUGH THURSDAY/... THE LONG TERM CONTINUES TO SHOW A PAIR OF DEEP SYSTEMS AFFECTING OUR CWA WITH THE LATTER ONE LIKELY TO CUT OFF AND ONLY SLOWLY MEANDER TO THE EAST IN THE MIDDLE OF NEXT WEEK. WHILE THE IMPACT/DETAILS REMAIN UNCERTAIN, TEMPERATURE-WISE WE ARE CONFIDENT THIS WILL BE A FAR CRY FROM THE CURRENT SPELL OF UNSEASONABLY WARM WEATHER WE ARE EXPERIENCING. THE INITIALIZATION OF THE CLOSED LOW OVER MN LOOKED SLIGHTLY TOO ROBUST. THE DIGGING SHORT WAVE PASSING THROUGH ON SATURDAY NIGHT LOOKS WELL INITIALIZED IN WESTERN CANADA, WHILE THE PIECE OF ENERGY THAT WILL BECOME OUR MIDWEEK CLOSING LOW IS STILL IN THE EASTERN PACIFIC. THAT LOOKS TO BE WELL SAMPLED STARTING WITH THE 12Z RUN ON SATURDAY. THE RIDGING ON BOTH SIDES OF THAT CLOSING LOW HAVE TAKEN TURNS IN HAVING THE HONORS OF FORCING THE PROCESS. THE ECMWF AND GEFS ENSEMBLE MEANS WHILE SUPPORTIVE OF THEIR OPS HAVE MOST OF THEIR "NOISE" NORTH OF THE SYSTEM SUGGESTING THE MORE NORTHERN 2NDRY CYCLOGEN SOLUTIONS HAVE HIGHER PROBABILITY. LATEST WPC GUIDANCE AND TO THE CLOSEST EXTENT THE OP CAN GGEM LEANS THIS WAY. WE ARE STILL 4 TO 6 DAYS AWAY AND WAY TOO SOON TO BE CONFIDENT ABOUT ANY ONE SOLUTION/EVOLUTION. ON SATURDAY WE ARE EXPECTING THE CDFNT TO PASS EARLY, BUT ADDITIONAL SHORT WAVES WILL BE PASSING THROUGH THE DAY. WITH THE SOUNDING CAP AT A FAIRLY HIGH LEVEL (AROUND 10K) AND DESTABILIZATION OCCURRING BELOW IT, WE KEPT THE LOW CHANCE OF SHOWERS IN THE NORTHWEST PART OF OUR CWA WHERE DEEPER MOISTURE AND ELEVATION MAY BE THE KEY TO GET PRECIPITATION TO REACH THE GROUND. MODELING CAA IS SLIGHTLY FASTER AND WE EDGED MAX TEMPS DOWN EVER SO SLIGHTLY. IT WILL ALSO BE RATHER BREEZY EVEN IF MAX TEMPERATURES HAVE ONE MORE DAY OF BEING MILDER THAN NORMAL. WHILE THE SHORT WAVES ASSOCIATED WITH THE MN CLOSED LOW MOVE THROUGH ON SATURDAY, ANOTHER STRONG SHORT WAVE EMANATING FROM WESTERN CANADA IS GOING TO SHARPEN THE TROF ONCE AGAIN ON SATURDAY NIGHT. THIS SHORT WAVE IS PREDICTED TO REMOVE THE CAP AND POTENTIALLY GIVE A CHANCE/SLIGHT CHANCE OF SHOWERS/SPRINKLES THRUT OUR CWA. THERE ARE DIFFERENCES AS TO WHETHER THE SOUTHERN PIECE OF ENERGY PASSES THRU OR SOUTH OF OUR CWA. THERE IS BETTER CONSENSUS ABOUT THE NORTHERN SHORT WAVE. CLOSER TO THE SURFACE, THE NORTHWEST FLOW OFF OF LAKE ONTARIO SHOULD PRODUCE SHOWERS REGARDLESS OF SAID FEATURE. BUT, WITH BOTH FORCING MECHANISMS ACTING IN CONCERT FOR A LITTLE WHILE, WE INCLUDED A LOW CHANCE OF SHOWERS NORTH. BY LATE SATURDAY NIGHT IF SHOWERS CAN STILL MAKE IT INTO OUR CWA IT COULD BE COLD ENOUGH FOR SOME SNOW IN THE HIGHEST TERRAIN OF THE POCONOS. IRONICALLY THE CLOUD COVER (AND SOME WIND) WITH THE APPROACHING SHORT WAVE WE SHOULD BE TOO CLOUDY FOR FROST/FREEZE CONCERNS. A BLUSTERY OCTOBER SUNDAY IS PREDICTED. ONE LAST CHANNELIZED SHORT WAVE HAS TO MOVE THROUGH DURING THE MORNING AND THEN MOSTLY SUNNY SKIES SHOULD PREVAIL. EXCEPTION MAY BE OUR POCONOS WHERE FORECAST SOUNDINGS ARE SHOWING STRATOCU REMAINING TRAPPED UNDERNEATH A SUBSIDENCE INVERSION. THE DIRECTION/LOCATION OF THE SURFACE HIGH IS NOT THE BEST FOR BRINGING SUNNY SKIES BACK TO OUR NORTHERN CWA. MAX TEMPS CLOSE TO CONTINUITY AND 10 TO 15 DEGREES LOWER THAN SATURDAY. LIKE LOWER MET GUIDANCE AS GFS PREDICTED 925MB/850MB TEMPS SUPPORT THEM. SUNDAY NIGHT STILL HAS THE POTENTIAL TO BE A FROSTY NIGHT. MODEL SOUNDINGS ARE BRINGING SOME CIRRUS LEVEL MOISTURE BACK INTO OUR CWA. NOT CONFIDENT WITH LONG NIGHTS THAT THEY WILL SAVE THE FROST NIGHT AND WE KEPT MIN TEMPS CLOSE TO CONTINUITY. WE CURBED OUR ENTHUSIASM FOR A ROBUST THERMAL RECOVERY ON MONDAY BECAUSE OF THE PREDICTED WAA RETURN FLOW MOISTURE/CLOUDS. CHANGES TO THE REST OF THE LONG TERM WAS IN A PESSIMISTIC DIRECTION WITH GREATER CONSENSUS OF A MILLER B SECONDARY DEVELOPMENT CLOSER TO THE COAST. THE INITIAL LOW AND COLD FRONT COULD TRIGGER SHOWERS ON MONDAY NIGHT. AFTER THAT PRECIPITATION ASSOCIATED WITH 2NDRY DEVELOPMENT COULD BRING MORE RAIN INTO OUR CWA ON TUESDAY AND TUESDAY NIGHT. WRAP AROUND/DEFORMATION ZONE PRECIPITATION COULD HEAD WEST INTO OUR CWA WEDNESDAY INTO WEDNESDAY NIGHT AND POSSIBLY LINGERING INTO THURSDAY AS THE CLOSED UPPER LOW CAPTURES THE SURFACE SYSTEM AND BOTH TRUNDLE EASTWARD THROUGH THE REST OF THE LONG TERM. HIGHEST CHANCES ARE IN THE NORTHEASTERN PART OF OUR CWA LEANING TOWARD THE CAN GGEM/ECMWF CONSENSUS. WITH THE SURFACE HIGH PRESSURE NESTLED IN NEARBY CANADA, A RATHER PROLONGED AND RAW NORTH TO NORTHEAST WIND FLOW IS ALSO EXPECTED. THERMALLY WE ARE SLIGHTLY WARMER THAN LAST NIGHT, SO HARDLY ANY SNOW IS INCLUDED. BUT, TEMPERATURES SHOULD BE AT OR BELOW SEASONAL LEVELS THROUGH THE PERIOD. MORE IN THE DAYS AHEAD. WITH THE NEW MOON APPROACHING WE WILL ALSO HAVE TO KEEP AN EYE ON THE TIDES. && .AVIATION /14Z FRIDAY THROUGH TUESDAY/...
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THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. TODAY WILL FEATURE VFR CONDITIONS AT THE TERMINALS WITH SOME SCT DAYTIME CU/SC. WE HAVE KEPT THE TEMPO GROUP FOR AN AFTER CIG (VFR) AT KRDG AND KABE. WINDS WILL BE WRLY THIS MORNING THEN BECOME SWRLY THIS AFTERNOON. TONIGHT...VFR WITH LIGHT S OR SW WINDS. OUTLOOK... SATURDAY THROUGH SUNDAY NIGHT...MAINLY VFR. WEST TO NORTHWEST WINDS AROUND 15 KNOTS WITH GUSTS TO 25 KNOTS BOTH DAYS, HOWEVER LIGHTER BOTH NIGHTS. MONDAY...VFR. MONDAY NIGHT AND TUESDAY...POSSIBLE SUB-VFR CONDITIONS DEVELOPING MONDAY NIGHT AND MORE LIKELY ON TUESDAY.
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&& .MARINE... SCA FLAG WHICH WAS FOR HAZARDOUS SEAS WILL BE CONVERTED TO A GENERIC SCA FLAG WITH THE 330 AM CWF PACKAGE. SEAS WILL CONTINUE MOSTLY 5 TO 6 FT TODAY AND THEN INCREASE A LITTLE TONIGHT. WINDS WILL BE WRLY THIS MORNING AROUND 10 KTS...THEN SHIFT SW THIS AFTERNOON AND INCREASE TO 15 TO 20 KNOTS OVERNIGHT. SCA GUSTS WILL DEVELOP TONIGHT. WINDS AND SEAS OVER DEL BAY WILL FOLLOW THE SAME TRENDS...BUT WINDS AND SEAS WILL REMAIN BELOW SCA THRESHOLDS. DRY WEATHER IS EXPECTED TODAY AND TONIGHT. OUTLOOK... SATURDAY AND SATURDAY NIGHT...THE SMALL CRAFT ADVISORY HAS BEEN EXTENDED ON THE OCEAN THROUGH SATURDAY NIGHT. THIS WILL FEATURE BOTH WINDS AND SEAS MEETING CRITERIA. A SMALL CRAFT ADVISORY WAS ALSO ISSUED FOR DELAWARE BAY STARTING SATURDAY AFTERNOON AND MORE CONFIDENT ABOUT REACHING THE WIND CRITERIA SATURDAY NIGHT. SUNDAY AND SUNDAY NIGHT...SMALL CRAFT ADVISORY CONDITIONS SHOULD CONTINUE SUNDAY BEFORE WINDS DIMINISH LATE SUNDAY AFTERNOON AND SUNDAY EVENING, FIRST ON DELAWARE BAY AND LATER ON THE OCEAN. SEAS ON THE OCEAN SHOULD ALSO SUBSIDE BELOW SMALL CRAFT ADVISORY CRITERIA BY SUNDAY NIGHT. AN EXTENSION OF THE PRESENT ADVISORY MAY BE NEEDED. MONDAY AND TUESDAY...SUB SMALL CRAFT ADVISORY CONDITIONS EXPECTED. OVERNIGHT TUESDAY WE WILL BE COMING CLOSE TO HEADLINES AGAIN AS THE SECONDARY LOW PRESSURE SYSTEM STARTS TO DEVELOP. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SUNDAY FOR ANZ450>455. SMALL CRAFT ADVISORY FROM 2 PM SATURDAY TO 6 AM EDT SUNDAY FOR ANZ430-431. && $$ SYNOPSIS...GIGI/GORSE NEAR TERM...O`HARA/AMC SHORT TERM...O`HARA LONG TERM...GIGI AVIATION...GIGI/GORSE/O`HARA MARINE...GIGI/GORSE/O`HARA

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