303
FXUS61 KPHI 112336
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
636 PM EST MON NOV 11 2024
SYNOPSIS
A COLD FRONT WILL PASS OFFSHORE OVERNIGHT USHERING IN COOL AND
DRY HIGH PRESSURE IN ITS WAKE. THE HIGH PRESSURE WILL RETREAT ON
THURSDAY GIVING WAY TO A WEAK SYSTEM AND LOW CHANCES FOR LIGHT
SHOWERS. HIGH PRESSURE WILL THEN SETTLE INTO THE OHIO VALLEY
INTO THE WEEKEND LEADING TO MORE DRY WEATHER AND MODERATING
TEMPERATURES.
NEAR TERM /THROUGH TUESDAY/
THIS EVENING THE UPPER TROUGH AXIS SWINGS THROUGH WITH A
SECONDARY COLD FRONT MOVING THROUGH OVERNIGHT. HOWEVER, WITH
LIMITED MOISTURE AVAILABLE ALOFT, THIS FRONT WILL BE MOSTLY DRY
AS IT PASSES, THOUGH AN ISOLATED SHOWER CAN'T BE RULED OUT IN
THE POCONOS. ALSO, A MODEST PRESSURE GRADIENT DEVELOPS IN ITS
WAKE SO WINDS ARE EXPECTED TO INCREASE AS THEY SHIFT TO THE
NORTHWEST OVERNIGHT. SKIES SHOULD REMAIN CLEAR I-95 SOUTH AND
EAST, WITH SOME COLD ADVECTION STRATOCUMULUS DEVELOPING NORTH
AND WEST. LOWS TONIGHT WILL MOSTLY BE IN THE UPPER 30S TO MID
40S.
MOSTLY SUNNY SKIES AND GUSTY NORTHWESTERLY BREEZES WILL
CONTINUE INTO TUESDAY AS THE PRESSURE GRADIENT REMAINS TIGHT AS
HIGH PRESSURE BUILDS OVER THE GREAT LAKES. WIND GUSTS MAY GUST
AS HIGH AS 30-35 MPH DURING THE AFTERNOON AIDED BY DIURNAL
MIXING. BY THIS TIME, COLD AIR ADVECTION WILL BE WELL UNDERWAY,
SO HIGHS ON TUESDAY ARE ONLY EXPECTED TO TOP OUT IN THE 50S (40S
NORTH AND WEST). SEE DETAILS BELOW REGARDING FIRE WEATHER RISK
FOR TUESDAY.
SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/
THE SHORT TERM PERIOD THROUGH THE MIDDLE OF THE WEEK WILL
FEATURE BUILDING AND THEN RETREATING UPPER LEVEL AND SURFACE
RIDGING. THE SURFACE HIGH WILL GRADUALLY PASS WELL TO OUR NORTH
ACROSS SOUTHEAST CANADA THROUGH THIS PERIOD, LOCKING IN BELOW
NORMAL TEMPERATURES AND A VERY DRY AIRMASS IN PLACE.
THE STRONG GRADIENT WIND FROM THE DAYTIME TUESDAY WILL WEAKEN
CONSIDERABLY OVERNIGHT, WITH NORTH WINDS BECOMING 5 MPH OR LESS.
COLD ADVECTION AND DEWPOINTS PLUNGING TO NEAR 20 DEGREES WILL
SUPPORT LOW TEMPERATURES IN THE MID 20S UNDER CLEAR SKIES. THE
AIR WILL LIKELY BE TOO DRY FOR FROST FORMATION THOUGH.
BELOW NORMAL TEMPERATURES WILL PERSIST WEDNESDAY THROUGH
THURSDAY WITH HIGHS FROM THE UPPER 40S IN THE HIGHER ELEVATIONS
TO LOW TO MID 50S ELSEWHERE. EXPECT SIMILAR LOW TEMPERATURES
WEDNESDAY NIGHT AS TUESDAY NIGHT, ALTHOUGH INCREASING CLOUD
COVER OVERNIGHT SHOULD RESULT IN TEMPERATURES BOTTOMING OUT A
COULD DEGREES WARMER.
A DECAYING TROUGH AXIS AND ASSOCIATED SURFACE SYSTEM WILL MOVE
TOWARD THE REGION BY THURSDAY AFTERNOON. A FEW SHOWERS OR
SPRINKLES ARE POSSIBLE. FOLLOWING 3 DAYS OF SUNSHINE, THURSDAY
WILL BE MOSTLY CLOUDY TO EVEN OVERCAST.
LONG TERM /THURSDAY NIGHT THROUGH MONDAY/
A DECAYING TROUGH AND ASSOCIATED SURFACE LOW WILL MOVE TOWARD
THE AREA ON THURSDAY, WITH THE SURFACE LOW PASSING TO OUR SOUTH
THURSDAY NIGHT. GUIDANCE STILL SUPPORTS THIS SYSTEM BRING A FEW
LIGHT SHOWERS OR SPRINKLES INTO OUR AREA, ESPECIALLY NEAR AND
SOUTHWEST OF THE PHILLY METRO FROM LATE AFTERNOON THURSDAY AND
THROUGH THE EVENING. ANY MEASURABLE RAINFALL WITH THIS ACTIVITY
WILL BE VERY MINIMAL, LIKELY LESS THAN 0.10" AT MOST. NOT MUCH
TO WRITE HOME ABOUT, BUT WE'LL CERTAINLY TAKE ANYTHING WE CAN
GET WITH THE ONGOING SEVERE TO EXTREME DROUGHT. LOWS THURSDAY
NIGHT WILL BE MOSTLY IN THE MID 30S TO NEAR 40 DEGREES UNDER
CLOUDY SKIES WITH LIGHT WINDS. THE AREAS COLD ENOUGH FOR FROZEN
PRECIP ARE LEAST LIKELY TO GET ANYTHING AT ALL.
AS THE WEAK SYSTEM DEPARTS INTO FRIDAY, HIGH PRESSURE WILL
BEGIN TO RETURN FROM THE WEST. A LACK OF STRONG COLD ADVECTION
SHOULD SUPPORT BREEZY AND DRY DAYS WITH MODERATING TEMPERATURES.
EXPECT HIGH TEMPERATURES IN THE MID 50S TO MID 60S AND LOWS
NEAR 40 DEGREES WITH MOSTLY SUNNY/CLEAR SKIES.
AVIATION /00Z TUESDAY THROUGH SATURDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
TONIGHT...VFR. WEST WINDS AROUND 5-10 KT THIS EVENING SHIFTING
TO NORTHWEST AROUND 10-15 KT OVERNIGHT. HIGH CONFIDENCE.
TUESDAY...VFR/SKC. NORTHWEST WINDS AROUND 10-20 KT WITH GUSTS
UPWARDS OF 25-30 KT. HIGH CONFIDENCE.
OUTLOOK...
TUESDAY NIGHT THROUGH SATURDAY...PREVAILING VFR CONDITIONS AND
WINDS NO MORE THAN 10-15 KTS. SOME RESTRICTIONS POSSIBLE LATE
THURSDAY INTO THURSDAY NIGHT WITH LOW CEILINGS AND A FEW SHOWERS
POSSIBLE.
MARINE
A SMALL CRAFT ADVISORY IS IN EFFECT FOR BOTH THE ATLANTIC OCEAN
COASTAL WATERS AND THE DELAWARE BAY BEGINNING AT MIDNIGHT
TONIGHT THROUGH TUESDAY.
WESTERLY WINDS AROUND 10-15 KT TONIGHT WILL RAMP UP FOLLOWING A
SECONDARY COLD FRONTAL PASSAGE. NORTHWEST WINDS OF 20-25 KT
OCCASIONALLY GUSTING UPWARDS OF 30 KT POSSIBLE ON TUESDAY. SEAS
OF 2-4 FEET EARLY TONIGHT BUILDING TO 4-6 FEET ON TUESDAY.
OUTLOOK...
TUESDAY NIGHT THROUGH SATURDAY...SMALL CRAFT ADVISORY
CONDITIONS PERSISTING THROUGH ABOUT MIDNIGHT TUESDAY NIGHT ON
DELAWARE BAY WITH NORTHWEST WINDS 10-20 KTS AND GUSTS UP TO 25
KTS. ADVISORY CONDITIONS PERSISTING OVERNIGHT INTO WEDNESDAY DUE
TO WIND GUSTS NEAR 25 KTS AND SEAS LINGERING NEAR 5 FEET.
BEYOND WEDNESDAY, CONDITIONS ARE CURRENTLY FORECAST TO REMAIN
LARGELY BELOW ADVISORY CRITERIA. FAIR WEATHER WITH A FEW SHOWERS
POSSIBLE THURSDAY NIGHT.
FIRE WEATHER
DESPITE RECENT RAINFALL AND RH'S INCREASING TONIGHT A SECONDARY
COLD FRONT WILL CAUSE ANOTHER PERIOD OF GUSTY WINDS AND DRY
CONDITIONS THROUGH MID-WEEK, ESPECIALLY ON TUESDAY.
FOR TUESDAY, MINRH VALUES ARE FORECAST TO FALL AS LOW AS 30-40%
WITH GUSTY NORTHWEST WINDS AROUND 30-35 MPH - LOCALLY UP TO 40
MPH IN THE HIGHER TERRAIN. UPON DISCUSSION WITH OUR FIRE WEATHER
PARTNERS, HAVE ISSUED A SPECIAL WEATHER STATEMENT FOR MD, NJ
AND DE FOR TUESDAY.
FOR WEDNESDAY, DRY CONDITIONS ARE EXPECTED TO CONTINUE. WINDS
WILL GENERALLY BE NEAR 5-10 MPH. THE LOWEST RH WILL OCCUR ON
WEDNESDAY, WITH WIDESPREAD MINIMUM VALUES IN THE 20-30% RANGE.
ANY RAINFALL THAT OCCURS WITH SOME SHOWERS ON THURSDAY WILL BE
VERY MINIMAL AT BEST. RH THURSDAY NEAR 35-50%.
LOOKING FARTHER AHEAD, RH VALUES REMAIN IN THE 30-40% RANGE FOR
FRIDAY AND INTO THE WEEKEND ALONG WITH SOME BREEZY CONDITIONS.
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 1 AM EST
WEDNESDAY FOR ANZ430-431.
SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM EST
WEDNESDAY FOR ANZ450>455.
SYNOPSIS...STAARMANN
NEAR TERM...DESILVA/RCM
SHORT TERM...STAARMANN
LONG TERM...STAARMANN
AVIATION...DESILVA/RCM/STAARMANN
MARINE...DESILVA/RCM/STAARMANN
FIRE WEATHER...DESILVA/RCM
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page