FXUS61 KPHI 261538
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1038 AM EST THU NOV 26 2009

.SYNOPSIS...
LOW PRESSURE WILL TRACK SLOWLY EASTWARD THROUGH THE GREAT LAKES 
REGION TONIGHT AND THURSDAY AS ANOTHER LOW PRESSURE SYSTEM ORGANIZES 
OFF THE EAST COAST. THESE SYSTEMS WILL MERGE ACROSS EASTERN NEW 
ENGLAND FRIDAY. A STRONG COLD FRONT IS FORECAST TO MOVE THROUGH OUR 
AREA FRIDAY MORNING. HIGH PRESSURE WILL BUILD IN FOR THE WEEKEND AND 
LAST INTO MONDAY. THE NEXT COLD FRONT WILL APPROACH FROM THE WEST BY 
MONDAY NIGHT.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
OUR REGION IS BETWEEN SYSTEMS TODAY WITH ONE OVER THE GREAT LAKES
AND OHIO VALLEY AND A SECONDARY STORM OFF THE NORTH CAROLINA
COAST. THERE IS NOT MUCH LOW-LEVEL FLOW AND WHAT IS PRESENT IS
FROM THE NORTHEAST AND EAST. A COMPARISON OF THE 00Z/12Z STERLING,
VIRGINIA RAOB INDICATES THAT THE DEPTH OF THE LOW-LEVEL MOISTURE
HAS DECREASED SOME. IT APPEARS THAT SOME SUBSIDENCE ON THE
NORTHWESTERN SIDE OF THE DEVELOPING LOW OFF THE NORTH CAROLINA
COAST HAS ALLOWED ENOUGH SINKING AIR TO ERODE THE LOW CLOUDS
ACROSS NORTHERN NEW JERSEY. THIS THINNING IS NEARLY LINED UP ALONG
THE WESTERN EDGE OF THE HIGHER LEVEL CLOUD SHIELD. ELSEWHERE,
PLENTY OF LOW CLOUDS CONTINUE, HOWEVER THERE ARE SIGNS OF IT
STARTING TO THIN IN SOME AREAS. THE AREAS OF FOG, SOME LOCALLY DENSE,
HAS BEEN LIFTING QUITE A BIT OVER THE LAST HOUR OR SO, THEREFORE
WE DID NOT CARRY ANY ADDITIONAL FOG PAST THE NOON HOUR. AS SOME
DRIER AIR GRADUALLY WORKS IN, WE ARE EXPECTING SOME ADDITIONAL
BREAKS IN THE CLOUDS TO OCCUR. THE HOURLY GRIDS WERE ADJUSTED
BASED ON TRENDS SO FAR THIS MORNING AND THE HIGH TEMPERATURES WERE
ADJUSTED SLIGHTLY IN SOME AREAS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
THE APPROACHING UPPER VORTICITY LOBE AND THE SFC LOWS ADVANCING
TOWARD THE AREA WILL BRING AN INCREASED CHANCE FOR RAIN TO THE
AREA TONIGHT. THE RAIN CHANCES WILL DECREASE FROM SOUTH TO NORTH
ON FRIDAY AS DRIER AND COLDER AIR ADVANCE OVER THE AREA. A COLD
FRONT WILL ADVANCE OVER THE AREA FRIDAY MORNING AND GUSTY WEST TO
NORTHWEST WINDS WILL DEVELOP OVER THE AREA. GUSTS AROUND OR OVER 30
MPH ARE EXPECTED. HIGH TEMPERATURES WILL GENERALLY BE IN THE 40S
BUT THE GUSTY WINDS WILL MAKE IT FEEL MUCH COLDER. OVER THE SOUTHERN
POCONOS ANY LINGERING RAIN SHOWERS MAY MIX WITH SOME SNOW SHOWERS
FRIDAY NIGHT. NO ACCUMULATIONS ARE EXPECTED ATTM. 

HIGH PRESSURE WILL BUILD IN LATER FRIDAY NIGHT AND SATURDAY. THIS
SHOULD PUT AN END TO ANY REMAINING PRECIPITATION ACROSS THE NORTH.
SKIES WILL CLEAR OUT FROM SOUTH TO NORTH AS THE DAY PROGRESSES.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AT THE UPPER LEVELS, A TROUGH IS FORECAST TO BE LIFTING TO OUR 
NORTHEAST ON SATURDAY EVENING. MEANWHILE, A RIDGE IS EXPECTED TO 
EXTEND FROM THE SOUTHEASTERN STATES UP OVER THE UPPER MISSISSIPPI 
RIVER VALLEY AT THAT TIME. THE RIDGE AXIS SHOULD DRIFT TO THE EAST, 
PASSING OVERHEAD ON SUNDAY AFTERNOON. WE ARE FORECAST TO BE ON THE 
NORTHERN EDGE OF SURFACE HIGH PRESSURE FROM SATURDAY NIGHT INTO 
EARLY MONDAY, WITH DRY WEATHER AND NEAR SEASONABLE TEMPERATURES 
ANTICIPATED.

AN UPPER LEVEL TROUGH IS EXPECTED TO DROP ACROSS THE GREAT LAKES AND 
THE NORTHEASTERN STATES DURING THE MONDAY AND TUESDAY TIME FRAME. IT 
SHOULD PUSH A COLD FRONT THROUGH OUR REGION LATE ON MONDAY NIGHT OR 
EARLY ON TUESDAY. AS A RESULT, WE HAVE MENTIONED A CHANCE FOR 
SHOWERS. TEMPERATURES MAY BE LOW ENOUGH FOR SOME SNOW FLAKES UP IN 
THE POCONOS AND IN FAR NORTHERN NEW JERSEY.

THE SURFACE COLD FRONT IS FORECAST TO STALL OFF THE COAST. 
MEANWHILE, ANOTHER UPPER RIDGE SHOULD BUILD UP FROM THE SOUTHWEST 
WITH ITS AXIS PASSING OVERHEAD ON WEDNESDAY. HIGH PRESSURE IS 
EXPECTED TO PASS TO OUR NORTH AT THAT TIME, BRINGING DRY WEATHER TO 
OUR NORTHERN COUNTIES FROM LATE TUESDAY INTO EARLY WEDNESDAY. WITH 
THE SURFACE FRONT NEARBY, WE WILL KEEP SLIGHT CHANCE OR LOW CHANCE 
POPS FOR OUR SOUTHERN COUNTIES.

AN UPPER TROUGH IS EXPECTED TO BEGIN APPROACHING FROM THE SOUTHWEST 
ON WEDNESDAY, ALONG WITH SURFACE LOW PRESSURE FROM THE SOUTHWEST AND 
SOUTH. AS A RESULT, WE HAVE INCLUDED CHANCE POPS FOR RAIN IN THE 
FORECAST.

&&

.AVIATION /16Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, 
KMIV, KACY AND SURROUNDING AREAS.

VSBYS AND CIGS HAVE SLOWLY BEEN IMPROVING THIS MORNING, BUT THERE IS 
STILL A RATHER LARGE AREA OF MVFR CIGS THAT WE BELIEVE WILL PERSIST 
INTO THE AFTERNOON.  

A COLD FRONT WILL MOVE THROUGH FROM THE NW TONIGHT AND BE FOLLOWED 
BY GUSTY NW WINDS. ALTHOUGH SOME PATCHY FOG COULD FORM THIS EVENING, 
ONCE THE FRONT MOVES THROUGH, VSBY WILL BECOME UNRESTRICTED. 
ALTHOUGH MVFR CIG MAY STILL LINGER WITH THE COLD AIR ADVECTION, ANY 
LINGERING CIGS SHOULD INCREASE TO VFR.

ON FRIDAY, GUSTY NW WINDS WILL DOMINATE WITH MVFR CIGS AND POSSIBLE 
SHOWERS. OVER THE HIGHER ELEVATIONS TO THE N OF RDG-ABE THERE MAY BE 
SNOW SHOWERS IN THE AFTN WITH MVFR VSBY. WINDS SHOULD BECOME 
SUSTAINED UP TO 20 KT WITH GUSTS UP TO 35 KT.

OUTLOOK...
HIGH PRESSURE SHOULD BUILD IN FROM THE WEST FOR SATURDAY, SUNDAY AND 
MONDAY. GUSTY WINDS SHOULD CONTINUE THROUGH FRIDAY NIGHT AND THEN 
DIMINISH DURING THE DAY SATURDAY.

&&

.MARINE...
SCA HAVE BEEN ISSUED FOR LATE TONIGHT AND GALE WARNINGS HAVE BEEN 
ISSUED FOR FRIDAY AND FRIDAY NIGHT. 

INITIALLY WE ARE IN A LIGHT WIND SITUATION WELL AHEAD OF THE COLD 
FRONT TODAY. HOWEVER, ONCE A COLD FRONT MOVES THROUGH FROM THE NW 
TONIGHT, WINDS WILL INCREASE DUE TO COLDER AIR ON WARMER WATERS AS 
WELL AS AN INCREASED GRADIENT. INITIALLY THE GRADIENT ONLY SUPPORTS 
WINDS TO 25 KT TONIGHT, BUT ON FRIDAY, THE GRADIENT SUPPORTS GUSTS 
TO 35-40 KT AND PERHAPS AS HIGH AS 45 KT FRIDAY NIGHT.

THE GALES MAY CONTINUE INTO SATURDAY. HOWEVER, THE GRADIENT SLOWLY 
RELAXES AND DUE TO THAT WINDS SHOULD DECREASE DURING SATURDAY AND 
ESPECIALLY SAT NIGHT. BY SUNDAY THE THE COLD AIR SHOULD HAVE MOVED 
AWAY AND A SW FLOW SHOULD BE OVER THE AREA ALLOWING THE WINDS TO 
DROP UNDER 25 KT. THESE WINDS ARE FORECAST TO CONTINUE THROUGH 
MONDAY.

ALSO, TIDES WILL BE WELL BELOW NORMAL WITH NEGATIVE DEPARTURES OF 1 
TO 2 FT ON THE OCEAN LATE FRIDAY NIGHT AND SATURDAY. HOWEVER, THESE 
DEPARTURES DO NOT APPEAR LARGE ENOUGH FOR ANY LOW WATER
ADVISORIES.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 6 AM EST 
     FRIDAY FOR ANZ430-431-450>455.
     GALE WARNING FROM 6 AM FRIDAY TO 6 AM EST SATURDAY FOR ANZ430-
     431-450>455.

&&

$$
SYNOPSIS...O'HARA
NEAR TERM...GORSE
SHORT TERM...O'HARA
LONG TERM...IOVINO
AVIATION...GIGI/STAUBER
MARINE...STAUBER