542
FXUS61 KPHI 041908
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
208 PM EST TUE NOV 4 2025
SYNOPSIS
HIGH PRESSURE RETURNS FOR TODAY AND TOMORROW BEFORE ANOTHER
COLD FRONT MOVES THROUGH WEDNESDAY NIGHT. HIGH PRESSURE BUILDS
BACK IN FOR THURSDAY AND FRIDAY AHEAD OF A SEQUENCE OF QUICK-
MOVING LOW PRESSURE SYSTEMS THAT IMPACT THE REGION OVER THE
WEEKEND AND INTO EARLY NEXT WEEK.
NEAR TERM /THROUGH WEDNESDAY NIGHT/
A BREEZY AND SEASONABLE AFTERNOON CONTINUES AT THIS HOUR AS THE AREA
REMAINS SITUATED BETWEEN A STRONG AREA OF LOW PRESSURE OVER ATLANTIC
CANADA AND HIGH PRESSURE BUILDING IN TO OUR SOUTH AND WEST. OVERALL,
SKIES CONTINUE TO BE MAINLY SUNNY WITH JUST SOME HIGH CLOUDS
AFFECTING PARTS OF DELMARVA.
AS WE GO INTO TONIGHT, WINDS DIMINISH FAIRLY QUICKLY THIS EVENING
BOTH DUE TO THE LOSS OF HEATING/MIXING AS WELL AS A RELAXING
PRESSURE GRADIENT. HIGH PRESSURE WILL BE SITUATED TO OUR SOUTH WITH
THE NORTHERN EXTENT OF THIS RIDGE EXTENDING INTO THE MID ATLANTIC BY
LATER TONIGHT. THIS WILL LEAD TO FAIRLY GOOD CONDITIONS FOR
RADIATIONAL COOLING ALTHOUGH THE AIRMASS IS NOT PARTICULARLY COLD.
AS A RESULT, GENERALLY EXPECT LOWS RANGING FROM THE LOW TO MID 30S
NORTH WITH UPPER 30S TO AROUND 40 SOUTH.
FOR WEDNESDAY, HIGH PRESSURE WILL MOVE OFF THE COAST TO OUR SOUTH AS
THE NEXT AREA OF LOW PRESSURE APPROACHES FROM THE WEST. THIS WILL
LEAD TO WARMER TEMPERATURES WITH INCREASING SOUTHWEST WINDS THROUGH
THE DAY. GENERALLY EXPECT HIGHS IN THE 60S FOR MOST AREAS WITH THE
POTENTIAL FOR SW WINDS TO GUST 20 TO 30 MPH BY LATE DAY.
THINGS GET MORE INTERESTING FOR WEDNESDAY NIGHT AS DEEPENING LOW
PRESSURE PASSES BY TO OUR NORTH EN ROUTE FROM LAKE ONTARIO
TOWARDS NEW ENGLAND. THERE WILL ALSO BE A NEW AREA OF HIGH
PRESSURE BUILDING INTO THE MIDWESTERN STATES BY LATER AT NIGHT
IN THIS SYSTEM'S WAKE. THE UPSHOT OF ALL THIS IS THAT THE
PRESSURE GRADIENT WILL REALLY INCREASE, ESPECIALLY FOLLOWING THE
PASSAGE OF A COLD FRONT THAT WILL MOVE THROUGH DURING THE LATE
EVENING INTO THE OVERNIGHT. A COUPLE THINGS TO NOTE WITH
THIS...1) ALONG THE FRONT THERE COULD BE SOME LOW TOPPED
CONVECTION THAT BRINGS VERY STRONG WINDS ALOFT DOWN TO THE
SURFACE. WINDS ARE PROGGED TO BE UP TO 50 KNOTS IN THE LOWEST
FEW THOUSAND FEET SO EVEN THOUGH ANY PRECIP WOULD LIKELY JUST BE
SHOWERS (THUNDER UNLIKELY) IT COULD STILL BRING WIND GUSTS OF
50 TO 60 MPH DOWN TO THE SURFACE. THE BEST CHANCES FOR THIS
WOULD BE AROUND THE LATE EVENING MAINLY OVER OUR NE PA INTO NW
NJ ZONES. 2) FOLLOWING THE PASSAGE OF THE COLD FRONT THERE WILL
BE SHARP PRESSURE RISES ALONG WITH A STRONG PRESSURE GRADIENT.
LOW LEVEL LAPSE RATES WILL ALSO BE FAIRLY STEEP WITH WINDS AT
THE TOP OF THE BOUNDARY LAYER OF 50+ KNOTS. AS A RESULT OF ALL
THIS, EXPECT A PERIOD OF VERY STRONG NW WINDS FOLLOWING THE
PASSAGE OF THE FRONT AROUND THE LATE EVENING INTO THE OVERNIGHT.
WIND GUSTS OF 45 TO 60 MPH WILL BE POSSIBLE WITH THE STRONGEST
WINDS LIKELY EXTENDING FROM AROUND BERKS COUNTY EAST AND
NORTHEAST THROUGH THE LEHIGH VALLEY AND THEN INTO NORTHERN NJ.
WE'VE ISSUED A HIGH WIND WATCH 6 PM WED TO 6 AM THU TO COVER
THIS THREAT AND IT BASICALLY ENCOMPASSES THE NORTHERN 40 PERCENT
OF THE CWA...NOT GETTING DOWN TO THE I-95 CORRIDOR. THESE AREAS
UNDER THE WATCH HAVE THE BEST CHANCE OF SEEING DAMAGING WIND
GUSTS UP TO 60 MPH BUT CAN'T RULE OUT AREAS EVEN SOUTH OF HERE
SEEING WIND GUSTS OF 45 TO 55+ MPH. EXPECT THE STRONGEST OF THE
WINDS OVER ROUGHLY A 6 TO 9 HOUR PERIOD AND THEY SHOULD BE
STARTING TO DIMINISH BY THURSDAY MORNING. EXPECT LOWS GENERALLY
RANGING FROM THE MID 30S NORTH TO THE MID 40S SOUTH.
SHORT TERM /THURSDAY THROUGH FRIDAY/
ON THURSDAY, A WEAK HIGH PRESSURE SYSTEM BUILDS IN FROM THE
WEST DURING THE DAY AND SETTLES OVERHEAD THURSDAY NIGHT. THIS
HIGH PRESSURE SYSTEM ALLOWS FOR A MOSTLY SUNNY DAY THURSDAY AND
OUR WINDS DECREASE. HIGHS ON THURSDAY ARE IN THE MID 40S TO
UPPER 50S AS WE GET THAT COLD AIR ADVECTION FILTERING IN BEHIND
WEDNESDAY NIGHT'S COLD FRONT. BY THURSDAY NIGHT, OUR WINDS TURN
LIGHT TO CALM WITH A MOSTLY TO PARTLY CLEAR SKY. OUR LOWS END UP
IN THE UPPER 20S TO UPPER 30S FOR MANY. THIS WILL LIKELY RESULT
IN AT LEAST FROST (AND POTENTIALLY SOME FREEZE) HEADLINES FOR
AREAS WHERE THE GROWING SEASON REMAINS ACTIVE.
FRIDAY IS THE BEGINNING OF A MORE ACTIVE PATTERN. ANOTHER LOW
PRESSURE SYSTEM MOVES INTO THE NORTHEAST FROM THE GREAT LAKES
REGION. THIS SYSTEM DRAGS A WARM FRONT THROUGH THE AREA FRIDAY
WHICH ALLOWS FOR WARM AIR ADVECTION INTO THE REGION WITH MORE OF
A SOUTHERLY WIND. HIGHS ON FRIDAY REACH THE MID 50S TO MID 60S.
DURING THE DAY FRIDAY LOOKS TO BE DRY WITH THE BULK OF THE
PRECIP HOLDING OFF UNTIL FRIDAY NIGHT WITH THE COLD FRONT. AS
OUR SYSTEM MOVES INTO THE NORTHEAST, WE DO SEE A TIGHTENING
PRESSURE GRADIENT THAT LOOKS TO LEAD TO WIND GUSTS CURRENTLY IN
THE 20-30 MPH RANGE.
LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/
OVERNIGHT FRIDAY, THE COLD FRONT ASSOCIATED WITH THE LOW
PRESSURE SYSTEM MOVES THROUGH. FOR FRIDAY NIGHT, POPS ARE
GENERALLY 60-80% AS THE COLD FRONT MOVES THROUGH AND WE STAY
BREEZY WITH WIND GUSTS 20- 30 MPH OVERNIGHT. LOWS FRIDAY NIGHT
ARE IN THE MID 40S TO MID 50S. WE TREND DRIER THROUGH THE DAY
SATURDAY AND INTO SATURDAY NIGHT. HIGHS ON SATURDAY REACH THE
MID 50S TO UPPER 60S.
OUR NEXT SYSTEM LOOKS TO ARRIVE DURING THE SUNDAY INTO MONDAY
TIMEFRAME. THERE IS STILL UNCERTAINTY IN THE TRACK AND INTENSITY
OF THIS LOW PRESSURE SYSTEM GIVEN THIS BEING TOWARDS THE END OF
THE LONG TERM PERIOD. THERE ARE SLIGHT CHANCE TO CHANCE POPS
(30-50%) SUNDAY INTO SUNDAY NIGHT ACROSS THE AREA. WE THEN TREND
DRIER THROUGH THE DAY MONDAY WITH SOME LINGERING SHOWERS
POSSIBLE. IT ALSO TURNS NOTABLY COLDER BY SUNDAY NIGHT AND
CONTINUES INTO THE BEGINNING OF NEXT WEEK AS WE SEE WELL BELOW
NORMAL TEMPERATURES.
AVIATION /19Z TUESDAY THROUGH SUNDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
THIS AFTERNOON...VFR WITH A FEW CIRRUS CLOUDS. WNW WINDS AROUND 10-
15 KTS WITH GUSTS NEAR 20-25 KTS CONTINUING. WINDS WILL DIMINISH
AFTER 21Z. HIGH CONFIDENCE.
TONIGHT...WESTERLY WINDS NEAR 5-10 KTS EARLY WILL DIMINISH TO 5 KTS
OR LESS (LOCALLY CALM) FAVORING A SOUTH TO SOUTHWEST DIRECTION AFTER
05Z. HIGH CONFIDENCE.
WEDNESDAY...CONTINUING VFR WITH SW WINDS INCREASING TO AROUND 10 TO
15 GUSTING 20 TO 25 KNOTS BY LATE DAY. EVEN STRONGER NW WINDS WILL
THEN OCCUR AT NIGHT FOLLOWING THE PASSAGE OF A COLD FRONT WITH GUSTS
OF 40 TO 45 KNOTS POSSIBLE. MODERATE CONFIDENCE.
OUTLOOK...
THURSDAY THROUGH FRIDAY...MAINLY VFR. GUSTY WINDS FOR THURSDAY.
FRIDAY NIGHT THROUGH SATURDAY...SUB-VFR CONDITIONS POSSIBLE
WITH SHOWERS LIKELY.
MARINE
A SMALL CRAFT ADVISORY REMAINS IN EFFECT BUT THIS ENDS EARLY THIS
EVENING AS THE WINDS DIMINISH. WINDS THEN RAMP UP AGAIN BY WEDNESDAY
AFTERNOON AND BY WEDNESDAY NIGHT THERE WILL BE THE POTENTIAL FOR
STORM FORCE WIND GUSTS OVER OUR NORTHERN OCEAN ZONES (450, 451) WITH
GALES FARTHER SOUTH. SEAS INCREASE TO AROUND 6 TO 8 FEET. ALSO,
THE STRONG OFFSHORE WINDS ARE EXPECTED TO LEAD TO ABNORMALLY LOW WATER
LEVELS FOR THE LOW TIDES WEDNESDAY NIGHT INTO THURSDAY MORNING.
THIS CAN LEAD TO HAZARDOUS NAVIGATING CONDITIONS NEAR THE COAST.
OUTLOOK...
THURSDAY NIGHT...NO MARINE HEADLINES EXPECTED.
FRIDAY THROUGH SATURDAY...SCA CONDITIONS LIKELY. WIND GUSTS UP
TO 30 KT WITH SEAS UP TO 6-8 FEET.
PHI WATCHES/WARNINGS/ADVISORIES
PA...HIGH WIND WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
MORNING FOR PAZ054-055-060>062-103-105.
NJ...HIGH WIND WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
MORNING FOR NJZ001-007>010.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR ANZ430-
431.
GALE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY MORNING FOR
ANZ430-431.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR
ANZ450>455.
STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY MORNING
FOR ANZ450-451.
GALE WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING
FOR ANZ452>455.
SYNOPSIS...DESILVA/GUZZO
NEAR TERM...FITZSIMMONS
SHORT TERM...GUZZO
LONG TERM...GUZZO
AVIATION...FITZSIMMONS/GUZZO/STAARMANN
MARINE...FITZSIMMONS/GUZZO/STAARMANN
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