FXUS61 KPHI 060840
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
340 AM EST SUN DEC 6 2009
.SYNOPSIS...
EARLY THIS MORNING, THE AREA OF LOW PRESSURE THAT BROUGHT
SATURDAY'S PRECIPITATION WAS MOVING FARTHER OUT OVER THE NORTH
ATLANTIC. MEANWHILE, HIGH PRESSURE WAS LOCATED OVER THE OHIO RIVER
VALLEY. THE HIGH WILL BUILD TO THE EAST AND ITS CENTER SHOULD PASS
OFF THE MIDDLE ATLANTIC COAST EARLY ON MONDAY MORNING. A DRY COLD
FRONT FROM THE WEST IS FORECAST TO ARRIVE ON MONDAY NIGHT. STRONG
LOW PRESSURE FROM THE SOUTHWEST IS EXPECTED TO PASS ACROSS THE
EASTERN GREAT LAKES REGION ON WEDNESDAY, WITH A SECONDARY LOW
DEVELOPING ALONG THE MIDDLE ATLANTIC COAST. HIGH PRESSURE IS
ANTICIPATED TO BUILD INTO OUR REGION FROM THE WEST FOR THURSDAY
AND FRIDAY, WITH ANOTHER COLD FRONT FOLLOWING ON SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AT 3:30 AM, THE SKY OVER OUR REGION WAS MAINLY CLEAR. THERE WERE
SOME LINGERING CLOUDS OVER PARTS OF THE POCONO REGION, THE LEHIGH
VALLEY AND NORTHWESTERN NEW JERSEY. THE WIND WAS FROM THE
NORTHWEST AND TEMPERATURES WERE MAINLY IN THE UPPER 20S AND LOWER
30S.
WITH TEMPERATURES NEAR OR BELOW THE FREEZING MARK, THERE WILL
CONTINUE TO BE SOME PATCHY ICE IN OUR REGION UNTIL A BIT AFTER
SUNRISE. AS A RESULT, WE WILL REISSUE THE SPECIAL WEATHER
STATEMENT AND WE WILL MAKE IT VALID UNTIL 9:00 AM.
AS HIGH PRESSURE CONTINUES TO BUILD INTO OUR REGION FROM THE
WEST, WE ARE EXPECTING A MOSTLY SUNNY SKY FOR TODAY WITH CHILLY
TEMPERATURES. AFTERNOON READINGS SHOULD BE MAINLY IN THE 30S AND
LOWER 40S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
THE UPPER FLOW WILL CONTINUE TO BE FROM THE WEST AND SOUTHWEST
FOR TONIGHT, MONDAY AND TUESDAY. AS A RESULT, WE SHOULD SEE A FAIR
AMOUNT OF MID AND HIGH LEVEL CLOUDINESS THROUGH THE PERIOD.
A WEAK UPPER LEVEL SHORT WAVE IS EXPECTED TO BE EJECTED OUT OF
THE SOUTHWEST AND IT SHOULD PASS OVER THE NORTHEASTERN STATES FROM
LATE MONDAY INTO MONDAY NIGHT. IT WILL LIKELY PULL A COLD FRONT
THROUGH OUR REGION ON MONDAY NIGHT. THE FRONT SHOULD HAVE LITTLE
MOISTURE ASSOCIATED WITH IT, SO WE WILL NOT BE FORECASTING ANY
PRECIPITATION WITH THE SYSTEM.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
FOR TUESDAY NIGHT, STRONG HIGH PRESSURE IS FORECAST TO BE LOCATED
OVER NEW ENGLAND AND EASTERN CANADA, WITH STRONG LOW PRESSURE
APPROACHING FROM THE WEST. PRECIPITATION IS EXPECTED TO SPREAD
INTO OUR REGION AT THAT TIME. WHILE TEMPERATURES ARE ANTICIPATED
TO FALL ON TUESDAY EVENING, THEY MAY BEGIN TO RISE LATE ON TUESDAY
NIGHT. NEVERTHELESS, WE COULD SEE MIXED PRECIPITATION FOR A TIME
ON TUESDAY NIGHT, ESPECIALLY IN EASTERN PENNSYLVANIA AND NORTHERN
NEW JERSEY.
BY EARLY WEDNESDAY MORNING, THE HIGH TO OUR NORTHEAST IS EXPECTED
TO START PULLING AWAY FROM OUR REGION. MEANWHILE, STRONG LOW
PRESSURE IS FORECAST TO BE PASSING NEAR CHICAGO WITH A SECONDARY
LOW DEVELOPING OVER EASTERN NORTH CAROLINA. IT LOOKS AS THOUGH
WEDNESDAY WILL BE ANOTHER WET DAY.
THE LOW SHOULD PUSH UP INTO EASTERN CANADA ON THURSDAY, ALLOWING
DRY AIR TO BUILD INTO OUR REGION FROM THE WEST FOR THURSDAY AND
FRIDAY.
ANOTHER COLD FRONT FROM THE WEST MAY BRING SOME RAIN AND SNOW
SHOWERS FOR SATURDAY.
&&
.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
HIGH PRESSURE WILL BUILD INTO THE AREA TODAY AND LINGER THROUGH
TONIGHT. THIS IS EXPECTED TO BRING VFR CONDITIONS OVERALL TO OUR
TERMINALS. A NORTHWEST WIND WILL BE AROUND 10 KNOTS TODAY, BUT
THIS WILL TEND TO DIMINISH TOWARD EVENING AS VERTICAL MIXING
BECOMES MUCH WEAKER AND ALSO A SHIFT TO THE WEST AND SOUTHWEST
OCCURS. THE WINDS OVERALL TONIGHT WILL BE UNDER 5 KNOTS. THE
FORECAST SOUNDINGS INDICATE SOME MOISTURE LINGERING AROUND 3,000
FEET FOR AWHILE TODAY, THEREFORE CARRIED FEW TO SCATTERED CLOUDS
AROUND 4,000 FEET. IT IS POSSIBLE THAT THE COVERAGE BECOMES MORE
FOR A TIME WITH PERHAPS SOME STRATOCUMULUS LOWER A LITTLE BIT. FOR
NOW, WE WILL CONTINUE WITH A VFR CLOUD DECK. AS THE HIGH PRESSURE
SYSTEM GRADUALLY BEGINS TO SLIDE TO OUR EAST LATER TONIGHT, SOME
MID TO HIGH LEVEL CLOUDS ARE EXPECTED TO MOVE INTO THE AREA.
OUTLOOK...
HIGH PRESSURE WILL CONTINUE TO SLIDE TO OUR EAST ON MONDAY, THEN
A WEAK FRONTAL BOUNDARY MAY MOVE THROUGH MONDAY NIGHT. AN INCREASE
IN CLOUDS IS EXPECTED WITH THIS /VFR AT THIS TIME/ WITH A RATHER
LOW CHANCE OF PRECIPITATION AS OF NOW. THE NEXT STORM SYSTEM, A
POTENTIALLY SIGNIFICANT ONE, IS FORECAST TO ARRIVE LATE TUESDAY
NIGHT AND CONTINUE WEDNESDAY. THIS MAY BRING A PERIOD OF HEAVIER
RAIN AND WINDY CONDITIONS, ALTHOUGH PERHAPS SOME SNOW OR MIXED
PRECIPITATION OCCURS AT THE ONSET AT KRDG, KABE AND KTTN. CLEARING
ARRIVES THURSDAY ALTHOUGH A GUSTY NORTHWESTERLY WIND WILL OCCUR IN
THE WAKE OF THE STORM.
&&
.MARINE...
HIGH PRESSURE TO OUR WEST WILL GRADUALLY BUILD OVER THE AREA
TODAY AND TONIGHT. DESPITE CAA FORECAST TO OCCUR THROUGH ABOUT THE
FIRST HALF OF TODAY, THE OVERALL WIND FIELD ABOVE THE SURFACE IS
EXPECTED TO DECREASE. NORTHWESTERLY WINDS HAVE BEEN STRUGGLING TO
REACH GALE FORCE DURING THE NIGHT AND WHILE THE FORECAST SOUNDINGS
SHOWED A FEW HOURS OF OPPORTUNITY, IT APPEARS THAT GALES WILL NO
LONGER OCCUR. AS A RESULT, WE WILL REPLACE THE GALE WARNING WITH A
SMALL CRAFT ADVISORY. BASED ON THE WIND FIELD IN THE FORECAST
SOUNDINGS, A DOWNWARD TREND IS EXPECTED AS SURFACE HIGH PRESSURE
BUILDS IN TODAY. WE WILL THEREFORE RUN THE ADVISORY ON THE BAY
UNTIL 15Z TODAY AND THE OCEAN WATERS UNTIL 21Z. THE ELEVATED SEAS
WILL SUBSIDE THROUGH THE DAY AS THE OFFSHORE FLOW HELPS TO PUSH
THE HIGHEST SETS FURTHER OFF THE COAST AND INVOKES A DOWNWARD
TREND. THE SEAS WERE RUNNING ABOVE WAVEWATCH, THEREFORE WE
INITIALIZED THE DATABASE WITH THE 06Z OBSERVATIONS AND THEN
LOWERED THE SEAS A BIT SLOWER THAN THE WAVEWATCH GUIDANCE.
HIGH PRESSURE THEN SLIDES TO OUR EAST DURING LATE TONIGHT AND MONDAY
WITH THE WINDS SHIFTING TO A SOUTHERLY DIRECTION. A WEAK FRONTAL
BOUNDARY LOOKS TO MOVE THROUGH MONDAY NIGHT WITH MAINLY JUST A WIND
SHIFT TO THE WEST AND NORTHWEST EXPECTED. THIS FEATURE LOOKS TO BE
ON THE WEAK SIDE, THEREFORE CONDITIONS ARE FORECAST TO REMAIN BELOW
ADVISORY CRITERIA. AS HIGH PRESSURE BUILDS INTO THE NORTHEAST LATE
TUESDAY, A POWERFUL STORM IS FORECAST TO DEVELOP IN THE CENTRAL
PLAINS. THIS STORM WILL INTENSIFY FURTHER AS IT TRACKS INTO THE
GREAT LAKES REGION WEDNESDAY THEN TO OUR NORTH WEDNESDAY NIGHT INTO
THURSDAY. THERE IS THE POTENTIAL FOR A SECONDARY SURFACE LOW TO
DEVELOP NEAR OUR COAST WEDNESDAY. THE WINDS ARE EXPECTED TO
INCREASE, ALTHOUGH IF THE SECONDARY LOW DOES INDEED DEVELOP AND IS
OVER OUR AREA, THE WINDS MAY BE LIGHTER FOR A TIME. OVERALL, WINDS
FROM THE EAST THEN SOUTHEAST ARE FORECAST TO INCREASE WEDNESDAY,
WITH AN EVENTUAL SHIFT TO THE SOUTH AND SOUTHWEST. THERE IS WARMER
AIR FORECAST TO SURGE NORTHWARD AHEAD OF THE SYSTEM, THEREFORE THAT
WOULD HINDER DEEPER VERTICAL MIXING. FOLLOWING THE FRONTAL PASSAGE
WEDNESDAY NIGHT, COLDER AIR ARRIVING WILL ALLOW DEEPER MIXING TO
OCCUR. WINDS ARE EXPECTED TO REACH ADVISORY LEVELS AND POSSIBLY EVEN
GALE FORCE THROUGH THURSDAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
ANZ450>455.
SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR ANZ430-
431.
&&
$$
SYNOPSIS...IOVINO
NEAR TERM...IOVINO
SHORT TERM...IOVINO
LONG TERM...IOVINO
AVIATION...GORSE
MARINE...GORSE
