FXUS61 KPHI 081556
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1056 AM EST TUE DEC 8 2009

.SYNOPSIS...
HIGH PRESSURE IS MOVING AWAY AND WILL MAKE ROOM FOR THE
APPROACHING LOW PRESSURE IN THE MID WEST THAT WILL SPAWN A SMALLER
SECONDARY LOW OVER THE DELMARVA PENINSULA. BOTH LOWS WILL HEAD
OFF TO THE NORTHEAST LATER WEDNESDAY INTO WEDNESDAY NIGHT. COLD
HIGH PRESSURE WILL THEN MOVE IN FROM THE WEST AND DOMINATE OUR
WEATHER THURSDAY INTO SATURDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MONSTRER OF A STORM RACING ACROSS THE MID SECTION OF THE COUNTRY
WILL SPREAD PRECIPITATION TO US THIS EVENING. ATMOSPHERE CONTINUES
TO WARM UP IN AVANCE OF THE STORM. WE HAPPEN TO BE ONE OF THE FEW
SPOTS EAST OF THE MISSISSIPPI VALLEY WITH SOME SUN XCPT FOR NE
ENGLAND STATES. CLOUDS WILL CONTINUE TO INCREASE THROUGHOUT THE
DAY AS WE AWAIT THE MIXED PRECIP NORTH AND ALL RAIN SOUTH.
SPEAKING OF THE RAIN, WILL BE ISSUING A FLOOD WATCH FOR PROBABLY A
GOOD PART OF THE CWA AS PW'S ARE IN EXCESS OF 1.6 INCHES AND WE'RE
IN FOR A VERY JUICY OVERRUNNING STORM. THANK GOODNESS ITS EARLY
DECEMBER AND NOT JANUARY. IN ANY EVENT, THE RUSH HOUR ON WED WILL
BE VERY SLOPPY WITH THE RAIN AND THERE WILL BE PUDDLES TO DEAL WITH.
 

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
AS THE STORM TO OUR WEST HEADS TOWARD THE GREAT LAKES, A SECONDARY
LOW WILL BEGIN TO DEVELOP TONIGHT OVER THE MID ATLANTIC COASTAL
STATES. THE CIRCULATION AROUND THESE STORMS WILL BRING PLENTY OF
MOISTURE IN OFF THE ATLANTIC. PRECIPITATION IN THE FORM OF RAIN
WILL BEGIN TO SPREAD INTO OUR SOUTHERN AREAS DURING THE EVENING
HOURS. IT WILL THEN SURGE NORTHEAST ACROSS OUR AREA AND BY MIDNIGHT
OR SHORTLY THEREAFTER, SOME FORM OF PRECIPITATION WILL BE FALLING
THROUGHOUT. WITH LOW LEVEL COLD AIR IN PLACE, WE CAN EXPECT 
WINTRY PRECIPITATION IN OUR NORTHERN AREAS. SNOW AND SLEET COULD
FALL TO THE NORTH AND WEST OF A TRENTON TO PHILADELPHIA LINE. MILD
AIR WILL MOVE INTO OUR AREA OVERNIGHT, CAUSING THE WINTRY
PRECIPITATION TO CHANGE TO ALL RAIN. BUT IT WILL HAVE A TOUGH TIME
BRINGING TEMPERATURES ABOVE THE FREEZING MARK IN THE NORTH. FOR
THIS REASON, A WINTER WEATHER ADVISORY HAS BEEN ISSUED FOR THE
LEHIGH VALLEY AND POCONOS IN PENNSYLVANIA AND FOR THE THREE
NORTHERN COUNTIES IN NEW JERSEY. THE ADVISORY WILL BE IN EFFECT
FROM AROUND MIDNIGHT INTO WEDNESDAY MORNING. SNOW IS EXPECTED TO
ACCUMULATE 3 TO 5 INCHES IN THE POCONOS AND SUSSEX COUNTY NJ AND 2
TO 4 INCHES IN LEHIGH AND NORTHAMPTON COUNTIES IN PA AND IN WARREN
AND MORRIS COUNTIES IN NJ. SLEET AND FREEZING RAIN MAY ALSO FALL
FOR A TIME IN THESE AREAS. FARTHER SOUTH, ALL RAIN IS EXPECTED.
THE RAIN COULD BE HEAVY AT TIMES LATE TONIGHT INTO WEDNESDAY
MORNING, AVERAGING AROUND 1 1/2 INCHES. WE WILL HOLD OFF ON
ISSUING ANY FLOOD WATCHES AT THIS TIME. HIGH TEMPERATURES
WEDNESDAY WILL RANGE FROM THE UPPER 30S NORTH TO THE LOWER 60S
SOUTH.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
HIGH PRESSURE WILL BUILD IN FROM THE WEST THURSDAY AND WILL DOMINATE
OUR WEATHER INTO THE EARLY PART OF THE WEEKEND.

ANOTHER SYSTEM LOOKS TO DEVELOP OFF OF THE CAROLINA COAST LATE IN 
THE WEEK AND MOVE NORTHEASTWARD ON SATURDAY. PRECIPITATION CHANCES 
LOOK GREATEST IN THE SOUTHERN AND COASTAL AREAS AS THE SYSTEM 
REMAINS OFFSHORE. WITH TEMPERATURES FALLING INTO THE 20S AND 30S
ON SATURDAY NIGHT/SUNDAY MORNING, PRECIPITATION MAY BEGIN AS SNOW
BEFORE MIXING WITH RAIN ON SUNDAY MORNING. ALSO, A LOW WELL OFF TO
OUR NORTH MAY DRAG A COLD FRONT ACROSS THE REGION ON SUNDAY. THE
FRONT DOES NOT LOOK TO HAVE AS MUCH OF AN IMPACT AS THE COASTAL
LOW AT THIS TIME BUT UNCERTAINTY WITHIN THIS PERIOD REMAINS HIGH.
A RETURN TO HIGH PRESSURE IS THEN EXPECTED FOR THE START OF THE
WEEK.

&&

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

VFR CONDITIONS WILL CONTINUE TODAY IN THE WAKE OF A WEAK COLD FRONT 
THAT MOVED THROUGH THE REGION. SOME STRATOCU FROM CENTRAL PA 
CONTINUES TO TRY TO ADVECT EAST INTO THE AREA, HOWEVER, IT WAS 
DISSIPATING AS IT MOVED IN. HOWEVER, THE CLOUDS COULD GO BKN AROUND 
5 THSD FT BEFORE 10Z. AFTER WHICH DOWNSLOPE DRYING SHOULD KEEP IT TO 
THE WEST OF THE TAF SITES.

TONIGHT, LOW PRESSURE MOVES BY TO THE WEST WITH A WEAK SECONDARY LOW 
ON THE COAST. THIS WILL CAUSE CONDITIONS TO DETERIORATE RAPIDLY 
AROUND MIDNIGHT. SNOW SHOULD DEVELOP AT RDG/ABE AND RAIN/SNOW AT TTN 
WITH RAIN AT THE REST OF THE TAF SITES. CIG/VSBY ARE EXPECTED TO BE 
IFR BY 12Z WED. 

DURING WED MORNING...ALL TAF SITES WILL SEE PCPN CHANGE TO RAIN. 
HOWEVER, THERE IS THE POSSIBILITY OF SOME FREEZING RAIN AND SLEET TO 
THE N/W OF PHL.

WINDS SHOULD BE EAST OR SE TONIGHT AND COME AROUND TO S OR SE WED 
MORNING.

OUTLOOK...
WEDNESDAY AFTERNOON, CONDITIONS SHOULD IMPROVE TO MVFR AND THEN VFR 
AS DRY AIR MOVES IN FROM THE WEST ON GUSTY SW WINDS. VFR CONDITIONS 
ARE ANTICIPATED FOR THURSDAY THROUGH SATURDAY.

&&

.MARINE...
A WEAK COLD FRONT MOVED THROUGH THE AREA OVERNIGHT. WINDS BECOME NW 
AND GUSTED TO 25 KT AT TIMES. HOWEVER, THE GRADIENT WILL DECREASE 
TODAY AND 25 KT GUSTS ARE NOT ANTICIPATED. 

LOW PRESSURE WILL MOVE THROUGH THE OHIO VALLEY TO THE GREAT LAKES 
REGION TONIGHT AND WEDNESDAY. A WEAK SECONDARY LOW MAY FORM ON THE 
COAST. A COLD FRONT TRAILING FROM THE MAIN LOW WILL MOVE THROUGH THE 
REGION WED AFTERNOON. 

WINDS SHOULD BE TRANQUIL INTO EARLY THIS EVENING, AND THEN GRADUALLY 
PICK UP FROM THE E OR NE. SCA HAVE BEEN ISSUED FOR MOST OF TONIGHT. 
THE GRADIENT TIGHTENS QUITE A BIT LATE TONIGHT AND WEDNESDAY WITH 
VERY STRONG WINDS ALOFT. HOWEVER...AT THE WATER SURFACE, 
TEMPERATURES WILL BE WARMER THAN THE WATER, THEREBY LIMITING THE 
POTENTIAL FOR BRINGING THESE WINDS DOWN TO THE SURFACE. BUT, SINCE 
THE GRADIENT IS STRONG, GALES ARE STILL POSSIBLE AND A GALE WATCH 
HAS BEEN ISSUED BEGINNING EARLY WED MORNING. 

THERE MAY BE A LULL IN THE STRONG WINDS WED AFTN, BUT COLDER AIR 
SHOULD RETURN WED NIGHT WITH MORE POTENTIAL STRONG WINDS TO GALE 
FORCE.

THE GUSTY NW WINDS TO GALE FORCE MAY CONTINUE INTO FRI MORNING AND 
THEN LET UP FRI AFTN AS THE GRADIENT WEAKENS, BUT COLD AIR IS IN 
PLACE.

HIGH PRESSURE SHOULD PREVAIL FOR NEXT SATURDAY WITH MORE TRANQUIL 
CONDITIONS ANTICIPATED.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY FROM 1 AM TO 10 AM EST WEDNESDAY FOR 
     PAZ054-055.
     WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 7 AM EST 
     WEDNESDAY FOR PAZ061-062.
NJ...WINTER WEATHER ADVISORY FROM 1 AM TO 10 AM EST WEDNESDAY FOR 
     NJZ001.
     WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 7 AM EST 
     WEDNESDAY FOR NJZ007-008.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 3 AM EST 
     WEDNESDAY FOR ANZ430-431-450>455.
     GALE WARNING FROM 3 AM WEDNESDAY TO 6 AM EST THURSDAY FOR 
     ANZ431-450>455.
     GALE WATCH FROM LATE TONIGHT THROUGH LATE WEDNESDAY NIGHT FOR 
     ANZ430.

&&

$$
SYNOPSIS...EBERWINE/RPW
NEAR TERM...EBERWINE/RPW
SHORT TERM...RPW
LONG TERM...MEOLA
AVIATION...STAUBER
MARINE...STAUBER