FXUS61 KPHI 291803
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
103 PM EST SUN NOV 29 2009

.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVER THE REGION TODAY AND TONIGHT BRINGING
FAIR WEATHER. A COLD FRONT WILL APPROACH FROM THE WEST MONDAY MORNING
AND BRING A PERIOD OF RAIN INTO MONDAY NIGHT. THE FRONT WILL MOVE OFF
THE COAST BY TUESDAY MORNING AS ANOTHER HIGH PRESSURE MOVES OVER THE
AREA. TWO SYSTEMS WILL APPROACH FROM THE NORTH AND SOUTH DURING THE
DAY WEDNESDAY AND BRING A PERIOD OF WET AND WINDY WEATHER WEDNESDAY
NIGHT INTO THURSDAY NIGHT.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
VERY NICE DAY IN STORE WITH LIGHT WINDS, PLENTY OF SUNSHINE AND
TEMPERATURES RUNNING A BIT ABOVE NORMAL. AIRCRAFT SOUNDINGS FROM
BETWEEN 8 AND 9 AM EST SHOWED THE INVERSION WAS SURFACE BASED, AND
12Z NAM H925 TEMPERATURE PROGS SHOWED THAT OUR TEMPERATURES WOULD
RISE CONSIDERABLY IF WE BROKE IT. WE HAVEN'T QUITE GONE FOR THE MID
TO UPPER 60S THAT WOULD OCCUR OVER OUR SOUTHERN ZONES IF THAT DOES
HAPPEN, BUT WE HAVE RAISED TEMPS TO INDICATE THAT MORE THAN THE
SOUTHERN HALF OF THE AREA SHOULD REACH 60 WITH THE FAR SOUTHERN
ZONES APPROACHING THE MID 60S. 

ENJOY THE DAY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
MOST OF OUR MAJOR CLIMATE SITES ABOVE NORMAL HAS BEEN THE RULE
WITH PERHAPS ONLY 3 OR 4 DAYS THE ENTIRE MONTH OF NOV BELOW
NORMAL. AS WE GET TO THE END OF THE SHORT TERM WE'LL SEE
TEMPERATURES FALL BELOW AS WE ENTER DECEMBER. THE UPPER ATMOSPHERE
IS GOING TO UNDERGO MAJOR CHANGES THIS WEEK AS WE BEGIN TO SEE THE
CUSTOMARY SPLIT FLOW DEVELOP HIGH ABOVE IN THE JET STREAM. THE
UPPER FLOW OVERHEAD TODAY IN THE EAST IS WEST TO EAST BUT A CLOSED
LOW OVER THE SOUTHWEST AND A DIGGING TROUGH OVER THE UPPER PLAINS
WILL CHANGE OUR NICE WEATHER TO A CLOUDY AND WET DAYS.

IN THE SHORT TIME INTO TONIGHT, THE TROUGH DIGGING INTO THE
NORTHERN PLAINS HAS PUSHED TO THE EASTERN GREAT LAKES AND HAS
TAPPED SOME MOISTURE SPINNING AROUND THE SOUTHWEST LOW. THE
SURFACE REFLECTION WILL BE A LOW OVER LAKE HURON WITH A TRAILING
COLD FRONT DOWN TO TEXAS. AFTER CLOUDING UP TONIGHT AND
TEMPERATURES IN THE MID 30S NORTH TO MID 40S SOUTH...RAIN WILL
SPREAD WEST TO EAST DURING THE DAY MONDAY WITH SOME BRIEFLY
MODERATE TO HEAVY BURSTS. THE FRONT IS MOVING RATHER QUICKLY AND
THE MEASURABLE MOISTURE SHOULD BE EAST OF THE AREA BEFORE THE
TEMPERATURES TUMBLE TOO FAST BEHIND THE FRONT. HOWEVER, THERE MAY
BE A TRANSITION PERIOD WHEN THE LIQUID CHANGES OVER TO A WET SNOWY
MIX OVERNIGHT MONDAY INTO MID MORNING TUESDAY. THE MIXTURE COULD
EVEN MAKE IT AS FAR SOUTH AS THE NORTHWEST SUBURBS OF PHILADELPHIA
AND ALL LIGHT SNOW FROM THERE INTO THE POCONOS AND NORTHWEST NEW
JERSEY. TEMPERATURES MONDAY NIGHT WILL DROP INTO THE MID 20S IN
THE POCONOS AND MID 30S TO THE COASTAL PLAINS OF DELAWARE AND NJ.
HIGHS FOR TUESDAY WILL BE IN THE UPPER 30S TO LOWER 50S. TUESDAY
WILL ALSO BE A BREEZY TO WINDY DAY AS COOL AIR POURS IN BEHIND THE
FRONT.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
WITH THE SURFACE FRONT AND UPPER TROUGH THROUGH WE BRIEFLY RETURN
TO A ZONAL FLOW OVER US AS SURFACE HIGH SLIDES ACROSS THE AREA.
MEANWHILE, THE DEEP LOW IN THE SOUTHWEST HAS MOVE INTO SOUTHERN
TEXAS AND ANOTHER STRONG SHORT WAVE IS APPROACHING LAKE SUPERIOR. 
TIME TO PAY ATTENTION TO THE FORECAST AS WE GET CLOSER TO THE 3RD
AND THE FULL MOON ON THE 4TH. THE COMPUTER MODELS ARE ADVERTISING
A VERY WET SYSTEM WEDNESDAY NIGHT AND THURSDAY. HIGH PRESSURE
MOVES OFF THE COAST WEDNESDAY THEN THE SOUTHERN LOW REACHED THE
GULF COAST OR THE FLORIDA PANHANDLE WHILE A LOW IS CRUISING OVER
THE GREAT LAKES. MEANWHILE THE NORTHERN BRANCH OF THE SPLIT FLOW
IN THE UPPER ATMOSPHERE WILL DIG DOWN INTO THE CENTRAL PLAINS AND
NOT ONLY TAP THE MOISTURE FROM THE GULF BUT ALSO PROVIDE AN AVENUE
FOR THE SOUTHERN LOW TO TRACK UP ALONG THE APPALACHIANS WITH THE
SURFACE LOW APPROACHING SOUTHERN DELAWARE AND NEW JERSEY. THAT
SEEMS TO BE THE CONSENSUS OF A FEW MODELS. THE QPF OR RAINFALL
AMOUNTS FROM THIS SYSTEM WILL BE HEAVY WEDNESDAY NIGHT AND
THURSDAY THEN THE STORM MOVES QUICKLY TO THE NORTHEAST AND
OFFSHORE BY THURSDAY EVENING. 

OF PARTICULAR CONCERN WITH THIS SCENARIO IS WHAT CONTRIBUTION THERE
WILL BE FROM THE GUSTY ONSHORE WINDS AND FROM THE LOW PRESSURE
MOVING OVER THE COASTAL REGION. THE ASTRONOMICAL HEIGHTS DUE TO
THE PERIGEAN TIDE AND FULL MOON ARE ALREADY COMPENSATED FOR IN THE
NORMAL TIDAL PREDICTION FROM THE NOS VALUES. THE CONDITION OF THE
BEACHES SINCE THE VETERANS DAY STORM ARE STILL AS THEY WERE AFTER
THE SERIOUS EROSION THAT OCCURRED. A COUPLE OF FEET RISE IN THE
TIDE COULD CAUSE SOME ADDITIONAL EROSION. 

ONCE THE SYSTEM IS THROUGH THE TEMPERATURES FALL BELOW NORMAL AS
THE DEEP TROUGH SETTLES OVER THE NORTHEAST WITH SOME RESIDUAL
MOISTURE FOR FRIDAY INTO FRIDAY NIGHT WHICH WILL BE RAIN OR SNOW
SHOWERS IN SOME OF OUR FAR NORTHERN ZONES. HIGH PRESSURE BUILDS
OVER THE REGION LATE FRIDAY AND IT SHOULD LAST INTO THE WEEKEND.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, 
KMIV, KACY AND SURROUNDING AREAS.

AN AREA OF HIGH PRESSURE TO OUR SOUTH WILL CONTINUE TO SLIDE 
EASTWARD THROUGH TONIGHT. A WEAK AREA OF LOW PRESSURE ACROSS THE 
GREAT LAKES REGION WILL TRACK TO NEW ENGLAND TONIGHT AND MONDAY. 
THIS WILL PULL A COLD FRONT INTO AND THROUGH OUR AREA ON MONDAY. 
AHEAD OF THIS FRONT, A SOUTHWEST FLOW WILL INCREASE ABOVE THE 
SURFACE AND THIS WILL TEND TO ALLOW THE SURFACE WINDS TO HOLD UP 
SOME AT MOST TERMINALS TONIGHT. AS MOISTURE IS ON THE INCREASE, 
CLOUDS WILL ALSO BE INCREASING DURING TONIGHT AND THESE WILL 
GRADUALLY LOWER AS WELL. IT APPEARS THAT VFR CONDITIONS WILL 
CONTINUE THROUGH TONIGHT, THEN AS THE MOISTURE DEEPENS FURTHER THE 
CEILINGS WILL BEGIN TO LOWER DURING MONDAY MORNING. WE ARE EXPECTING 
THIS TO OCCUR AFTER SUNRISE WITH CEILINGS EVENTUALLY GETTING TO 
MVFR. WE DECIDED NOT TO GO ANY LOWER WITH THE CEILINGS AT THIS TIME 
AS CONFIDENCE IS NOT AS HIGH REGARDING THE RAIN INTENSITY, WHICH MAY 
END UP DRIVING ANY LOWER CEILINGS GIVEN THE EXPECTED WIND DIRECTION. 
A BAND OF RAIN IS EXPECTED TO OCCUR WITH AND BEHIND THE FRONT AND WE 
STEPPED THE VISIBILITIES DOWN TO MVFR THROUGH THE MORNING INTO THE 
EARLY AFTERNOON. IF SOME HEAVIER RAIN OCCURS, THE LOCAL VISIBILITY 
MAY LOWER EVEN MORE FOR MOSTLY A BRIEF TIME. 

THE LIGHT SOUTHWEST SURFACE WINDS WILL TEND TO SHIFT TO THE WEST AND 
NORTHWEST DURING MONDAY AS THE FRONT MOVES THROUGH. WE ARE NOT 
ANTICIPATING GUSTS AHEAD OF THE FRONT, HOWEVER AS COLDER AIR 
ARRIVES BEHIND THE FRONT, SOME GUSTS WILL BE POSSIBLE AND WE WENT 
WITH 20 KNOTS FOR NOW. 

OUTLOOK...
AS THE THE COLD FRONT SLIDES EASTWARD, THE RAIN WILL TAPER OFF FROM 
WEST TO EAST MONDAY AFTERNOON AND EVENING. HIGH PRESSURE THEN BUILDS 
INTO THE OHIO VALLEY MONDAY NIGHT, HOWEVER A NORTHWEST WIND 
/POSSIBLY GUSTY AT TIMES/ WILL CONTINUE. THESE WINDS LOOK TO 
DIMINISH TUESDAY AS HIGH PRESSURE GRADUALLY SETTLES ACROSS THE AREA. 
DURING WEDNESDAY, THE HIGH PRESSURE SYSTEM WILL BE SHIFTING TO OUR 
EAST ALLOWING THE WINDS TO BECOME SOUTHERLY. A POTENTIALLY STRONG 
AND MOISTURE LADEN STORM SYSTEM THEN ARRIVES LATE WEDNESDAY AND 
THURSDAY FROM THE SOUTHWEST. IN ADDITION TO THE POSSIBLE LOWER 
CEILINGS AND VISIBILITIES, GUSTY WINDS MAY OCCUR AS WELL WEDNESDAY 
NIGHT AND THURSDAY. THIS STORM MOVES AWAY THURSDAY NIGHT WITH A 
GUSTY NORTHWEST WIND IN ITS WAKE.

&&

.MARINE...
A NICE DAY IS IN STORE ACROSS THE AREA WATERS TODAY AS HIGH
PRESSURE REMAINS OVER THE SERN CONUS. BY TONIGHT, AN AREA OF LOW
PRESSURE WILL MOVE FROM NR THE GRTLKS TO NEW ENG, AND THE TRAILING
CDFNT WILL CROSS THE WATERS ON MONDAY. SWLY WIND WILL INCREASE
AHEAD OF THE CDFNT AND COULD APPROACH SCA RANGE, BUT WAA SHUD
PRECLUDE TOO MUCH ON THE SEAS AT THIS POINT. THE BEST SHOT AT SCA
WOULD BE MONDAY LATE MORNING THROUGH THE AFTN, AND THINGS SEEM
MARGINAL FOR NOW, SO WILL NOT RAISE ANY FLAGS WITH THE MORNING
PACKAGE. THE CDFNT THEN CROSSES THE AREA, BRINGING RAIN AND HIGH
PRESSURE BUILDS BACK OVER THE REGION FROM MONDAY NIGHT THROUGH
MIDWEEK.

THEN, A STRONGER STORM IS EXPECTED TO MOVE OUT OF THE SERN STATES 
AND TRACK NORTHEASTWARD, ALONG OR JUST E OF THE APPALACHIANS.  THE 
MODELS ARE IN VERY GOOD AGREEMENT WITH MOST OF THE FEATURES OF THIS 
STORM BUT THERE ARE SOME DECENT DIFFS WITH REGARD TO THE PATH, 
ESPECIALLY WHETHER ITS ONSHORE OR OFFSHORE.  WE'RE TALKING A GAME OF 
INCHES HERE AND THE SCENARIO WILL CONTINUED TO BE MONITORED.  THERE 
WILL CERTAINLY BE SOME MARINE IMPACTS THOUGH, BUT JUST WHERE AND TO 
WHAT EXTENT REMAINS TO BE SEEN.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...EBERWINE
NEAR TERM...DELISI/EBERWINE
SHORT TERM...EBERWINE
LONG TERM...ROBERTSON
AVIATION...GORSE
MARINE...NIERENBERG