FXUS61 KPHI 022034
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
334 PM EST WED DEC 2 2009
.SYNOPSIS...
LOW PRESSURE OVER THE TENNESSEE VALLEY WILL MOVE NORTHEAST ACROSS
THE OHIO VALLEY, REACHING NEW YORK STATE THURSDAY MORNING. THE
COLD FRONT ASSOCIATED WITH THE LOW WILL CROSS OUR AREA LATE TONIGHT.
THE LOW PRESSURE SYSTEM WILL CONTINUE RAPIDLY NORTHEASTWARD AND AWAY
FROM OUR REGION DURING THURSDAY. HIGH PRESSURE WILL GRADUALLY BUILD
IN FRIDAY AND FRIDAY NIGHT. AN AREA OF LOW PRESSURE IS THEN
EXPECTED TO DEVELOP OFF THE SOUTHEASTERN UNITED STATES COAST AND
TRACK OFF THE MID ATLANTIC COAST SATURDAY AND SATURDAY NIGHT. HIGH
PRESSURE WILL BEGIN PUSHING IN FROM THE WEST SUNDAY AND DOMINATE
OUR WEATHER THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS THE SURFACE LOW OVER THE TENNESSEE VALLEY MOVES NORTHEAST, THE
ACCOMPANYING RAIN SHIELD WILL MOVE ACROSS OUR AREA. RAIN IS CURRENTLY
MOVING INTO SOUTHERN AREAS AND WILL SPREAD ACROSS THE REGION DURING
THE LATE AFTERNOON AND EVENING HOURS. THE RAIN IS EXPECTED TO
BECOME HEAVY AT TIMES AND THERE COULD EVEN BE A FEW ISOLATED
THUNDERSTORMS. RAINFALL AMOUNTS OVERNIGHT SHOULD AVERAGE ONE HALF TO
ONE INCH WITH LOCALLY HIGHER AMOUNTS IN ANY CONVECTION. STRONG
UPPER AIR SUPPORT AND A TIGHT SURFACE PRESSURE GRADIENT WILL BRING
GUSTY SOUTHEAST WINDS IN OFF THE OCEAN OVERNIGHT. THE HIGH WINDS
WILL SPREAD FROM SOUTH TO NORTH EARLY TONIGHT. A WIND ADVISORY
WILL GO INTO EFFECT FOR OUR SOUTHERN COASTAL ZONES AT 8 PM AND OUR
NORTHERN COASTAL ZONES AT MIDNIGHT. THE ADVISORY WILL REMAIN IN
EFFECT UNTIL 6 AM. TEMPERATURES CURRENTLY IN THE MID 40S TO MID 50S
WILL RISE A FEW MORE DEGREES AND THEN REMAIN ALMOST STEADY
OVERNIGHT.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
WITH THE RAPID MOVEMENT OF THE LOW PRESSURE SYSTEM, THE HEAVIEST
RAIN WILL BE ENDING DURING THE EARLY MORNING HOURS. DRY AIR WRAPPING
AROUND THE BACK SIDE OF THE STORM WILL BE MOVING INTO OUR AREA
AROUND DAYBREAK. THE THREAT FOR MEASURABLE RAIN WILL BE OVER
THROUGHOUT THE REGION BY MID MORNING. WINDS WILL SWING AROUND TO
SOUTHWEST BY DAYBREAK AND THEN TO WEST TOWARD NOON. WILL STILL SEE
GUSTS TO 25 OR 30 MPH THROUGH MUCH OF THE DAY. THE GUSTINESS WILL
DROP OFF LATE IN THE DAY AND CONTINUE TO DIMINISH THURSDAY NIGHT.
AS THE DRY AIR PUSHES IN, SKIES WILL BEGIN TO CLEAR AND WE SHOULD
SEE PLENTY OF SUNSHINE FROM MID TO LATE MORNING ON. TEMPERATURES
WILL BE ON THE MILD SIDE THURSDAY WITH HIGHS IN THE MID 50S TO
MID 60S.HIGH PRESSURE PUSHING IN FROM THE WEST WILL BRING FAIR
WEATHER THURSDAY NIGHT THROUGH FRIDAY NIGHT. COLDER AIR WILL BEGIN
MOVING IN THURSDAY NIGHT. LOWS WILL DROP INTO THE 30S. HIGHS
FRIDAY IN THE 40S TO LOWER 50S. LOWS FRIDAY NIGHT WILL RANGE FROM
THE MID 20S TO THE MID 30S. CLOUDS MOVING IN FROM THE SOUTH WILL
ACTUALLY KEEP TEMPERATURES FROM DROPPING LOWER. THE CLOUDS WILL
BE RUNNING OUT AHEAD OF A DEVELOPING LOW PRESSURE SYSTEM OFF THE
SOUTHEAST COAST. THIS LOW WILL INTENSIFY AND MOVE NORTHEAST
SATURDAY. AT THIS TIME IT APPEARS THAT THE TRACK OF THE LOW WILL
BE FAR ENOUGH OFF THE COAST SO THAT OUR REGION WILL BE ON
THE NORTHWEST FRINGE. EVEN SO, MUCH OF OUR AREA WILL SEE SOME
PRECIPITATION SATURDAY. THE PRECIPITATION WILL BE IN THE FORM OF
INTERMITTENT RAIN OR SNOW, WITH THE HEAVIEST OVER OUR SOUTHERN
AND COASTAL SECTIONS WHERE TEMPERATURES WILL BE THE WARMEST.
TEMPERATURES THROUGHOUT MOST OF OUR REGION WILL REMAIN IN THE 30S
FOR MUCH OF SATURDAY. SO EVEN IF THE PRECIPITATION FALLS AS MOSTLY
SNOW, IT SHOULD BE RELATIVELY LIGHT AND IS NOT EXPECTED TO
ACCUMULATE ON ROADWAYS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
THE PERIOD BEGINS WITH THE DEPARTURE OF THE LOW WELL OFFSHORE AND
THE ARRIVAL OF SURFACE HIGH PRESSURE. THIS HIGH WILL DOMINATE OUR
WEATHER SUNDAY, WEAKEN A BIT ON MONDAY, AND REESTABLISH ITSELF ON
TUESDAY. WEDNESDAY LOOKS WET AT THE MOMENT AS SOME SOUTHERN JET
ENERGY REACHES THE MID-ATLANTIC COAST.
TEMPERATURES ARE EXPECTED TO BE IN THE NORMAL RANGE DURING THE
PERIOD. BUT BECAUSE NOVEMBER WAS AS WARM AS IT WAS (+3.8, 7TH
WARMEST ON RECORD), IT'S GOING TO FEEL COOL IF NOT COLD. HIGH
TEMPERATURES, FROM SUNDAY THROUGH WEDNESDAY ARE ONLY GOING TO
SETTLE IN THE 40S. PHILADELPHIA HAS ONLY HAD FOUR DAY THUS FAR THIS
FALL WHERE THE TEMPERATURE HASN'T HIT AT LEAST 50. LOWS ACROSS THE
REGION ARE GOING TO BE IN THE 20S AND 30S.
WITH THE COOLER/COLDER AIR, MIXED PRECIPITATION CAN BE EXPECTED
ACROSS PORTIONS OF THE CWA WITH BOTH THE SATURDAY SYSTEM AND THE
TUESDAY NIGHT/WEDNESDAY SYSTEM.
&&
.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
THE FOLLOWING
DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY
AND SURROUNDING AREAS.
VFR WEATHER STARTS OFF THE TAFS WITH MID CLOUDS ALL AREAS. HOWEVER,
CONDITIONS WILL CHANGE RAPIDLY AROUND AND JUST AFTER SUNSET AS WE
LOWER TO MVFR FOR A FEW HOURS AFTER 22Z AND THEN IFR AFTER 02Z AS
RAIN, HEAVY AT TIMES MOVES IN FROM THE S AND SW. WINDS ALOFT WILL BE
QUITE STRONG WITH SPEEDS AT 2K FT GOING UP TO 40-45 KT WHICH SHOULD
CAUSE SOME WIND SHEAR. ANY HEAVY SHOWERS OR PSBL TSTMS OVERNIGHT
COULD ALSO CAUSE STRONG SFC WINDS AS SOME OF THE STRONG WINDS FROM
ALOFT COULD MIX DOWN. HOWEVER, SINCE THEY ARE DIFFICULT TO FCST OR
TIME, I ONLY INCLUDED CB IN THE TAFS FOR NOW.
A WARM FRONT THEN MOVES THROUGH FROM THE S TOWARD MORNING AND THIS
WILL BE FOLLOWED QUICKLY BY A COLD FRONT FROM THE WEST. CIGS AND
VSBYS WILL IMPROVE RAPIDLY TO MVFR AROUND SUNRISE AND THEN TO VFR
2-3 HRS LATER ON THURSDAY. HOWEVER, WINDS WILL REMAIN GUSTY WITH
SUSTAINED SPEEDS AROUND 15 KT AND GUSTS TO 30 KT. WINDS SHOULD
DIMINISH SLOWLY DURING THURSDAY AFTERNOON.
OUTLOOK...
THE NEXT CHANCE FOR PRECIPITATION IS ON SATURDAY AS A LOW PRESSURE
SYSTEM IS EXPECTED TO MOVE EAST WELL OFF THE COAST.
&&
.MARINE...
GALE FORCE WIND GUSTS ARE EXPECTED TO DEVELOP BEFORE MIDNIGHT IN
RESPONSE TO THE RAPIDLY INTENSIFYING LOW PRESSURE COMING OUT TO THE
TENNESSEE VALLEY. THIS SLOW RACE TO NEW YORK STATE BY EARLY THURSDAY
ALLOWING A TRAILING COLD FRONT TO MOVE THROUGH THE AREA WATERS.
WINDS SHOULD GUST UP TO 45 KT LATE TONIGHT. THE GUSTY WINDS SHOULD
CONTINUE THURSDAY MORNING BEHIND THE COLD FRONT, BUT DIMINISH DURING
THE DAY AND DROP BELOW GALE DURING THE AFTERNOON AS THE GRADIENT
WEAKENS.
HIGH PRESSURE WILL THEN BUILD OVER THE AREA THURSDAY AFTERNOON
THROUGH THE WEEKEND. DUE TO THIS HIGH, WINDS SHOULD BECOME MORE
TRANQUIL AND DROP BELOW SCA FRIDAY. EVEN SO, A LOW PRESSURE
SYSTEM WILL ALSO MOVE BY TO THE EAST ON SATURDAY AND COULD BRING AN
INCREASE IN THE WINDS BEGINNING FRIDAY NIGHT AND THE CHANCE OF RAIN
AND/OR SNOW SHOWERS SAT AND SAT NIGHT. MORE TRANQUIL CONDITIONS
SHOULD DEVELOP SUNDAY AND MONDAY.
&&
.TIDES/COASTAL FLOODING...
WE HAVE CONTINUED THE COASTAL FLOOD ADVISORY FOR MINOR TIDAL
FLOODING. HOWEVER, DEPARTURES SHOULD ONLY BE UP TO 1 FT. THIS MEANS
THAT FLOODING IS NOT EXPECTED TO BE WIDESPREAD OR SEVERE. HOWEVER,
IN AREAS WHERE WE HAVE LOST BEACHES AND DUNES DUE TO PREVIOUS
STORMS, THERE COULD BE A BIT MORE OF AN EFFECT FROM THE TIDES. ONE
PIECE OF GOOD NEWS IS THAT THE WINDS SHOULD SHIFT TO SW JUST BEFORE
HIGH TIDE OCCURS AND MAY LESSEN THE DEPARTURE JUST BEFORE HIGH TIDE.
HIGH TIDE OCCURS ON THE OCEAN FRONT BETWEEN 7 AND 830 AM. ALSO HAVE
ISSUED IT FOR THE NJ SIDE OF THE DELAWARE BAY FOR THE EAST POINT
AREA WHERE THE HIGH TIDE IS BETWEEN 8 AND 9 AM.
GALE FORCE SE AND THEN S WINDS ON THE OCEAN SHOULD KICK UP THE SEAS
TONIGHT AND FOR THAT REASON THE PREVIOUS ISSUED SURF ADVISORY WILL
BE CONTINUED.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...WIND ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM EST THURSDAY FOR
NJZ014-026.
COASTAL FLOOD ADVISORY FROM 1 AM TO 10 AM EST THURSDAY FOR
NJZ014-021-023>026.
HIGH SURF ADVISORY FROM 1 AM TO 10 AM EST THURSDAY FOR NJZ021-
023>026.
WIND ADVISORY FROM 8 PM THIS EVENING TO 6 AM EST THURSDAY FOR
NJZ024-025.
DE...COASTAL FLOOD ADVISORY FROM 1 AM TO 10 AM EST THURSDAY FOR
DEZ003-004.
HIGH SURF ADVISORY FROM 1 AM TO 10 AM EST THURSDAY FOR DEZ004.
WIND ADVISORY FROM 8 PM THIS EVENING TO 6 AM EST THURSDAY FOR
DEZ004.
MD...NONE.
MARINE...GALE WARNING UNTIL 1 PM EST THURSDAY FOR ANZ430-431-450>455.
&&
$$
SYNOPSIS...RPW
NEAR TERM...RPW
SHORT TERM...RPW
LONG TERM...KRUZDLO
AVIATION...STAUBER
MARINE...STAUBER
TIDES/COASTAL FLOODING...STAUBER
