Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000 FXUS61 KPHI 270137 AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 937 PM EDT FRI SEP 26 2014 .SYNOPSIS... HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH THE WEEKEND. A COLD FRONT IS EXPECTED TO MOVE ACROSS THE AREA MONDAY, THEN PUSH TO OUR SOUTH BY TUESDAY MORNING. A LOW PRESSURE SYSTEM MAY MOVE OFF THE SOUTHEAST COAST EARLY NEXT WEEK AND THEN MOVE NORTHWARD AND MAY IMPACT OUR REGION TUESDAY OR WEDNESDAY. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... THE MID-ATLANTIC REGION IS POSITIONED AROUND THE EASTERN PERIPHERY OF A 1026 MB SFC HIGH CENTERED OVER THE GREAT LAKES. ONCE THE SUN WENT DOWN, NORTHERLY WINDS DIMINISHED AND TEMPERATURES DROPPED QUICKLY (ABOUT 10-15 DEGREES IN 2 HOURS). ADJUSTED MIN TEMPS DOWN A FEW DEGREES FROM PREVIOUS FORECAST AS RADIATIONAL COOLING WILL CONTINUE TO BE EFFECTIVE UNDER CLEAR SKIES AND CALM WINDS THRU THE REMAINDER OF TONIGHT. THE AIRMASS IS DRY SO FOG SHOULD BE CONFINED TO THE SHELTERED RIVER VALLEYS (WHERE WATER TEMPS ARE STILL RELATIVELY WARM THIS TIME OF YEAR COMPARED TO THE AIR). && .SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/... ANOTHER BEAUTIFUL DAY IS EXPECTED AS HIGH PRESSURE CONTINUES TO OVERSPREAD THE MID ATLANTIC REGION. BOTH MOS GUIDANCE AND 850/925 MB MODEL TEMPS INDICATE SATURDAY TO BE A FEW DEGREES WARMER ACROSS THE REGION. SKIES ARE EXPECTED TO REMAIN MOSTLY CLEAR THROUGH THE DAY, WITH LIGHT BREEZES MAINLY IN THE 5 TO 10 MPH RANGE. WE BLENDED THE MET/MAV GUIDANCE WITH CONTINUITY FOR MAX TEMPERATURES AND EXPECT HIGHS TO RANGE FROM THE MID/UPPER 70S ALONG THE COAST AND IN THE POCONOS TO THE LOWER 80S ELSEWHERE. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... THE EXTENDD PD STARTS OF QUIET, THEN THERE IS ANOTHER POTENTIAL SHOT OF RAIN FOLLOWED LIKELY BY MORE QUIET. A LARGE AREA OF HIGH PRESSURE WILL BE OVER THE REGION SAT NIGHT THRU SUN NIGHT BEFORE MOVG OFFSHORE. THIS HIGH WILL KEEP BOTH WEEKEND DAYS DRY AND VERY PLEASANT FOR LATE SEPTEMBER, WITH TEMPS AVERAGING 5 TO 10 DEGREES ABOVE NRML. A WK CDFNT WILL CROSS THE REGION ON MONDAY AS A LARGE HIGH BUILDS TO THE N OVER ERN CANADA. AS IT DOES, THE MDLS BEGIN TO DIVERGE ON WHAT HAPPENS AFTER MON, AND CONFIDENCE IS QUITE LOW. EVERY PIECE OF AVAILABLE GUIDANCE ANOTHER CSTL LOW OFF THE CAROLINA CST LATER MON INTO TUE. HOWEVER, THE GFS AND CMC KEEP THIS LOW WELL ENOUGH OFF THE CST FOR LITTLE IF ANY IMPACT TO OUR REGION. THE CMC IS VIRTUALLY DRY, AND THE GFS KEEPS SOME PRECIP CONFINED TO THE CST MAINLY MON NIGHT INTO TUE THEN MOVES IT FAIRLY QUICKLY AWAY WITH HIGH PRES BUILDING IN FOR THE REST OF THE WEEK. ON THE OTHER HAND, THE ECMWF IS FURTHER W, SLOWER AND BRINGS MORE IMPACT TO OUR REGION IN THE PD MON NIGHT THRU WED. IT ALSO KEEPS THE LOW SPINNING OFF THE CST FOR A GOOD PORTION OF THE WEEK, THOUGH HIGH PRES WILL BUILD IN. THE ECMWF IS ALONE IN ITS SOLN, BUT CERTAINLY CAN NOT BE RULED OUT, ESPECIALLY SINCE IT WAS FIRST TO THE GAME WITH THIS WEEK`S CSTL LOW. THE UKMET IS STRONGER AND MORE CLOSED OFF THAN THE GFS/CMC BUT FASTER AND FURTHER E. SO AGAIN, WOULD LIKE TO SEE MORE MDL AGREEMENT AND THIS REMAINS A LOW CONFIDENCE FCST. FOR NOW, WILL MAINTAIN LOW POPS THRU THE PD, BUT TIMING AND POSN WILL HAVE TO BE ADJUSTED. ULTIMATELY LATER IN THE WEEK MAY NEED TO BE ADJUSTED AS WELL, BUT WILL MAINTAIN A DRY FCST FOR NOW AS THERE IS AMPLE TIME FOR CHANGES AND THE HOPE IS THE MDLS WILL COME INTO BETTER AGREEMENT. TEMPS WILL START OUT ABV NRML, BEFORE RETURNING TO NR NRML BY THE END OF THE PD. && .AVIATION /01Z SATURDAY THROUGH WEDNESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. VFR THIS EVE AT ALL TERMINALS. RADIATIONAL FOG MAY DEVELOP AT THE THE USUAL TERMINAL (RDG, ABE, MIV) DURING THE EARLY MORNING SATURDAY. VFR CONDITIONS AND CONTINUED MAINLY CLEAR SKIES ON SATURDAY. ANY PATCHY EARLY MORNING FOG SHOULD DISSIPATE RATHER QUICKLY BY ABOUT 12Z OR 13Z. LIGHT AND VARIABLE WINDS EARLY ARE EXPECTED TO INCREASE INTO THE 5 TO 8 KNOT RANGE, MAINLY OUT OF THE NORTH- NORTHEAST. OUTLOOK... SAT NIGHT-MON...VFR EXPECTED EXCEPT POSSIBLE PATCHY FOG AT NIGHT AND EARLY MORNING HOURS WITH HIGH PRESSURE IN CONTROL. HIGH CONFIDENCE MON NIGHT-WED ...MVFR/IFR CIGS/VSBYS, RAIN, AND GUSTY WINDS POSSIBLE, ESPECIALLY FOR COASTAL SITES, AS POSSIBLE COASTAL LOW PASSES BY. BEST CHCS FOR REDUCED CIGS/VSBYS WOULD BE ON TUE. LOW CONFIDENCE. && .MARINE... WINDS HAVE DIMINISHED EVEN FURTHER AND ARE BELOW 5 KT OVER THE WATERS. WAVE HEIGHTS AT BUOY AT 44025 AND 44065 WERE 5 FT AT 9 PM AND 6 FT OFF THE DE COAST AT 44009. WITH WINDS NOT BEING A FACTOR AT ALL, SCA WAS REPLACED BY A SCA FOR HAZARDOUS SEAS THRU SATURDAY. FOR DELAWARE BAY, WINDS AND SEAS WILL REMAIN BELOW SCA CRITERIA THROUGH TONIGHT AND SATURDAY. OUTLOOK... SAT NIGHT-MON NIGHT...SUB-ADVISORY CONDITIONS EXPECTED OVER THE WEEKEND INTO MONDAY. TUE-WED...WINDS AND SEAS MAY INCREASE AHEAD OF A POSSIBLE APPROACHING COASTAL LOW PRESSURE SYSTEM. MARINE FLAGS MAY BE NEEDED FOR AT LEAST A PART OF THE AREA DURG A POTION OF THIS TIME, BUT CONFIDENCE REMAINS LOW ON HOW THIS ALL DEVELOPS ATTM. && .RIP CURRENTS... MODERATE RIP CURRENT THREAT THIS EVENING. THE RIP CURRENT RISK ARE FORECAST TO BE LOW ON SATURDAY AS SEAS DIMINISH AND WINDS WILL BE LIGHT. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 8 PM EDT SATURDAY FOR ANZ450>455. && $$ SYNOPSIS...NIERENBERG NEAR TERM...KLEIN SHORT TERM...KLINE LONG TERM...NIERENBERG AVIATION...KLEIN/NIERENBERG MARINE...KLEIN/NIERENBERG RIP CURRENTS...KLEIN

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