Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000 FXUS61 KPHI 011347 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 947 AM EDT TUE SEP 1 2015 .SYNOPSIS... HIGH PRESSURE WILL BUILD INTO THE MID-ATLANTIC AREA THROUGH MIDWEEK. A WEAK BACKDOOR COLD FRONT WILL MOVE SOUTHWARD INTO OUR REGION THURSDAY INTO FRIDAY. THEN, ANOTHER LARGE HIGH PRESSURE SYSTEM SETS UP ACROSS THE NORTHEASTERN UNITED STATES THROUGH THE WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... CURRENT FORECAST ON TRACK WITH ONLY MINOR ADJUSTMENTS. EARLY MORNING FOG IS DISSIPATING ATTM AS BOUNDARY LAYER MIXING GETS UNDERWAY. WATER VAPOR IMAGERY INDICATES A SUBTLE SHORTWAVE MOVING THRU THE MID-LEVEL RIDGE TODAY...W/SURFACE HIGH PRESSURE CENTERED OVER THE SPINE OF THE APPALACHIANS...AND A WEAK TROUGH IN THE DELAWARE VALLEY. THE IAD AND WAL 12Z SOUNDINGS INDICATE A DRY COLUMN WHICH WILL CONTINUE THRU THE DAY. THE WEAK PRESSURE GRADIENT WILL PROMOTE A SEA-BREEZE ACROSS COASTAL LOCALS THIS AFTERNOON. THIS WILL LEAD TO A BIT MORE HUMIDITY MOVING JUST INLAND FROM THE COAST AND HELP FOCUS MOISTURE CONVERGENCE... BUT EXCEPT FOR SOME MORE ROBUST CU...DO NOT EXPECT ANY PRECIP. 12Z SOUNDINGS INDICATE MIXING POTENTIAL TO 800 HPA TODAY... AND SUPPORT HIGHS GENERALLY IN THE U80S TO L90S BUT COOLER NEAR THE COAST WITH A SEA-BREEZE. ALSO...RELATIVE HUMIDITY VALUES WILL BE LOW ENOUGH TO PRECLUDE HEAT INDEX VALUES FROM ADVISORY CRITERIA LEVELS. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/... TONIGHT SHOULD BE A CARBON COPY OF THE LAST FEW NIGHTS, WITH ONE POSSIBLE EXCEPTION OF INCREASING HIGH CIRRUS CLOUDS OVERNIGHT. OTHERWISE, EXPECT RADIATIONAL COOLING TO LEAD TO LOWS NEAR THE DEW POINT TEMPERATURES. THUS COULD ALSO SEE SOME PATCHY FOG PRIMARILY IN RIVER VALLEYS. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... HIGH PRESSURE WILL BE THE DOMINANT WX FEATURE FOR THE FIRST FEW DAYS OF SEPTEMBER, ALTHOUGH THE TEMPS WILL FEEL MORE LIKE AUGUST. HIGHS ON THU WED AND THU WILL BE ABOUT 10 DEGREES ABV NRML, AND WITH DEW POINTS IN THE MID TO UPPER 60S, IT WILL BE LESS THAN IDEAL. HOWEVER, BY THU AND FRI A BACKDOOR CDFNT WILL MOVE THRU THE REGION AND BRING AT LEAST A CHC OF SOME PRECIP. WE HAVEN`T SEEN MUCH IN THE WAY OF RAIN LATELY, SO ANY IS WELCOME. QPF AMTS ARE LOW AND MANY AREAS WILL REMAIN DRY. HOWEVER, BEHIND THIS FRONT, TEMPS WILL BE MUCH COOLER (CLOSER TO SEASONAL) AND IT LOOKS LIKE WE HAVE A BEAUTIFUL HOLIDAY WEEKEND IN STORE. HIGH PRES WILL BUILD BACK IN AND BRING ABUNDANT SUNSHINE AND LOWER HUMIDITY. SAT CUD BE A TAD BREEZY, ESPECIALLY CLOSER TO THE CST, BUT THAT SHUD BE THE WORST WE WILL HAVE TO DEAL WITH. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY, AND SURROUNDING AREAS. VFR CONDITIONS ARE EXPECTED TODAY. A ROUND OF MVFR FOG IS POSSIBLE AFTER 03Z TONIGHT. AT THIS POINT, THE TAF SITES THAT ARE THE MOST LIKELY TO BE AFFECTED ARE KMIV, KACY, KRDG, KTTN, AND KABE. NORTH TO NORTHWEST WINDS SHOULD REMAIN LIGHT (LESS THAN 10 KT). WITH THE UPPER LEVEL RIDGE MOVING OVERHEAD, IT LOOKS TO BE A PRIME SET UP FOR A WELL DEVELOPED SEA BREEZE THIS AFTERNOON. THUS HAVE INCLUDED A SHIFT TO SOUTHEASTERLY NOT ONLY AT THE COASTAL (KACY AND KMIV) AND DELAWARE VALLEY TAF SITES (KPHL, KPNE, KTTN, AND KILG). THE SEA BREEZE SHOULD DISSIPATE NEAR OR SHORTLY AFTER SUNSET, LEADING TO MOSTLY LIGHT AND VARIABLE WINDS OVERNIGHT. OUTLOOK... WED...MAINLY VFR CONDS EXPECTED. SOME MORNING FOG/STRATUS PSBL MVFR. HIGH CONFIDENCE. THU THROUGH FRI...MAINLY VFR. HOWEVER, SHRA/TSRA ARE PSBL, WITH PERIODS OF SUB-VFR CONDITIONS. THERE CUD ALSO BE SOME FOG AS A CDFNT MOVES THRU THE REGION. MDT TO HIGH CONFIDENCE. SAT...VFR CONDS EXPECTED. HIGH CONFIDENCE. && .MARINE... WINDS AND SEAS SHOULD REMAIN WELL BELOW SMALL CRAFT ADVISORY CRITERIA, WITH PEAK WIND GUSTS ONLY EXPECTED TO BE NEAR 15KT, AND SEAS SHOULD STAY AROUND OR BELOW 2 FT. OUTLOOK... WED THROUGH THU...NO MARINE FLAGS ANTICIPATED. SEAS 2 TO 3 FEET WITH SOUTHERLY WINDS 5 TO 10 KNOTS, SOME GUSTS NEAR 15 KNOTS. FRI THRU SAT...WIND BECOMES MORE ENELY AND INCREASES AS A BACKDOOR CDFNT MOVES THRU THE REGION. SEAS WILL RISE AND THEY COULD APPROACH 5 FEET BY LATE FRI, THEN DECREASING BY LATER SAT. WIND CUD GUST 25 TO 30 KT FRI INTO SAT. BY LATER SAT, CONDS SHUD DROP BELOW SCA CRITERIA. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...NIERENBERG NEAR TERM...FRANCK/JOHNSON SHORT TERM...JOHNSON LONG TERM...NIERENBERG AVIATION...JOHNSON/NIERENBERG/MEOLA MARINE...JOHNSON/NIERENBERG

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