370
FXUS61 KPHI 231759
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
159 PM EDT THU APR 23 2026
WHAT HAS CHANGED
NO SIGNIFICANT CHANGES.
KEY MESSAGES
1. WARM TEMPERATURES, LOW HUMIDITY AND BREEZY CONDITIONS WILL
CONTINUE TO BRING ELEVATED FIRE WEATHER CONCERNS FOR EASTERN
PENNSYLVANIA TODAY. FRIDAY WILL BE COOLER WITH LESS WIND AND HIGHER
HUMIDITY LEVELS COMPARED TO TODAY.
2. LOW PRESSURE WILL PASS THROUGH THE REGION THIS WEEKEND WITH
WIDESPREAD SHOWERS AND SEASONABLY CHILLY TEMPERATURES.
DISCUSSION
KEY MESSAGE 1...WARM TEMPERATURES, LOW HUMIDITY AND BREEZY
CONDITIONS WILL CONTINUE TO BRING ELEVATED FIRE WEATHER
CONCERNS FOR EASTERN PENNSYLVANIA TODAY. FRIDAY WILL BE COOLER
WITH LESS WIND AND HIGHER HUMIDITY LEVELS COMPARED TO TODAY.
HIGH PRESSURE CONTINUES TO DOMINATE OUR WEATHER THIS
AFTERNOON AS ONE HIGH CENTER SITS TO OUR NORTH OVER HUDSON BAY
WITH ANOTHER OFF THE SOUTHEAST COAST OVER THE WESTERN ATLANTIC.
IT WILL BE A BIT BREEZY OVER THE AREA THIS AFTERNOON HOWEVER AS
DIURNAL MIXING WILL ALLOW FOR SOME SLIGHTLY STRONGER WINDS TO
MIX DOWN. GENERALLY EXPECT NORTHWEST WINDS AROUND 10 TO 15
GUSTING 20 TO 25 MPH AT TIMES. HIGHS SHOULD BE MAINLY IN THE
MIDDLE TO UPPER 70S EXCEPT POSSIBLY REACHING 80 OVER PORTIONS OF
SE PA, INTERIOR SOUTHERN NJ, AND DELMARVA. COASTAL AREAS AS
WELL AS THE POCONOS WILL BE A BIT COOLER.
SURFACE DEW POINTS WILL MIX DOWN TO THE LOW 40S AND EVEN SOME 30S
WITH EFFICIENT MIXING THIS AFTERNOON. THIS RESULTS IN MINRH VALUES
FROM 25 TO 35 PERCENT AWAY FROM THE COASTS. GIVEN THIS, WE HAVE
COORDINATED WITH OUR FIRE WEATHER PARTNERS AND ISSUED A SPECIAL
WEATHER STATEMENT FOR EASTERN PA ZONES FOR FIRE WEATHER CONCERNS.
THIS IS IN EFFECT UNTIL 7 PM.
WINDS DIMINISH EARLY THIS EVENING WITH THE LOSS OF DAYTIME HEATING.
OTHERWISE, THE HIGH TO OUR NORTH ALONG WITH LOW PRESSURE EAST OF THE
CANADIAN MARITIMES WILL HELP DRIVE A BACKDOOR COLD FRONT SOUTHWARD
THROUGH THE AREA OVERNIGHT INTO EARLY FRIDAY. THIS WILL ALSO BRING
SOME INCREASING CLOUD COVER. FOR FRIDAY, EXPECT PARTLY TO MOSTLY
CLOUDY SKIES WITH LIGHT NE WINDS AND COOLER TEMPERATURES COMPARED TO
TODAY. HIGHS WILL BE MAINLY IN THE 60S TO AROUND 70 EXCEPT COOLER
NEAR THE COAST AND A BIT WARMER OVER OUR EASTERN MD COUNTIES IN
DELMARVA SINCE THIS WILL BE CLOSER TO THE FRONT. THE COOLER
TEMPERATURES WILL RESULT IN HUMIDITY LEVELS BEING HIGHER THAN TODAY
ALONG WITH LIGHTER WINDS SO WE DON'T EXPECT THERE TO BE FIRE WEATHER
CONCERNS.
KEY MESSAGE 2...LOW PRESSURE WILL PASS THROUGH THE REGION THIS
WEEKEND WITH WIDESPREAD SHOWERS AND SEASONABLY CHILLY TEMPERATURES.
HIGH PRESSURE WILL BE SETTLED OVER EASTERN CANADA, AND THE BASE OF
THIS HIGH WILL EXTEND DOWN INTO THE NORTHEAST. AS A RESULT, WINDS
WILL TAKE ON AN EASTERLY FLOW STARTING FRIDAY NIGHT, AND ONSHORE
FLOW WILL PERSIST THROUGH MOST OF THE WEEKEND. THIS WILL USHER A
CHILLY AIRMASS INTO THE REGION DUE TO OCEAN TEMPERATURES 50S. HIGH
TEMPERATURES SATURDAY AND SUNDAY WILL BE IN THE 50S WITH LOWS IN THE
40S.
LOW PRESSURE WILL ORGANIZE AND DEVELOP OVER THE GREAT LAKES FRIDAY
NIGHT AND WILL DIVE TOWARDS THE DELMARVA PENINSULA AND THE MID-
ATLANTIC ON SATURDAY BEFORE DEPARTING THROUGHOUT THE DAY SUNDAY.
SHOWERS DEVELOP SATURDAY NIGHT, AND THEN CONTINUES THROUGHOUT THE
DAY SATURDAY AND SATURDAY NIGHT. WILL KEEP CHANCE POPS FOR SUNDAY
MORNING AS THAT LOW DEPARTS.
THIS ALL SETS UP A RAW, BREEZY, WET WEEKEND.
RAINFALL TOTALS THIS WEEKEND, AT LEAST FROM FRIDAY NIGHT THROUGH
SATURDAY NIGHT, WILL RANGE FROM 1 TO 1.25 INCHES ACROSS THE SOUTHERN
POCONOS, NORTHERN NEW JERSEY, AND THE LEHIGH VALLEY, AND FROM 1/2 TO
1 INCH ACROSS THE DELAWARE VALLEY, INCLUDING PHILADELPHIA, SOUTHERN
NEW JERSEY, AND DELMARVA. WHILE THIS MAY BE UNPLEASANT, ESPECIALLY
SINCE IT WILL BE OVER THE WEEKEND, IT IS GOOD TO REMEMBER THAT THIS
IS A BENEFICIAL RAINFALL.
AVIATION /18Z THURSDAY THROUGH TUESDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
REST OF THIS AFTERNOON...VFR. NW WINDS AROUND 10 KNOTS GUSTING 15 TO
20 KNOTS AT TIMES. HIGH CONFIDENCE.
TONIGHT...VFR WITH MAINLY SOME HIGH CLOUDS. WINDS VEERING TO
NORTHEAST BY LATER THIS EVENING BUT DECREASING TO AROUND 5 KNOTS.
HIGH CONFIDENCE.
FRIDAY...VFR WITH SOME MID AND HIGH LEVEL CLOUDINESS AROUND AT
TIMES. WINDS GENERALLY NORTHEAST AROUND 5 TO 8 KNOTS EXPECT BECOMING
SOUTHEAST IN THE AFTERNOON FOR ACY AND MIV. MODERATE CONFIDENCE.
OUTLOOK...
FRIDAY NIGHT...SUB-VFR CONDS IN STRATUS AND SHRA DEVELOP LATE.
SATURDAY THROUGH SATURDAY NIGHT...SUB-VFR CONDS IN SHRA, PATCHY FOG,
AND LOW STRATUS.
SUNDAY...LINGERING SUB-VFR CONDS IN SHRA/STRATUS IN THE MORNING.
GRADUAL IMPROVEMENT LATE.
SUNDAY NIGHT THROUGH MONDAY NIGHT...VFR. NSW.
TUESDAY...SUB-VFR CONDS IN SHRA/STRATUS.
MARINE
SUB-SMALL CRAFT ADVISORY CONDITIONS THROUGH FRIDAY. WINDS WILL
GENERALLY BE AROUND 10 KNOTS OR LESS WITH SEAS GENERALLY 2 TO 4
FEET TODAY THROUGH FRIDAY.
OUTLOOK...
FRIDAY NIGHT...SUB-SCA CONDITIONS. VSBY RESTRICTIONS IN SHOWERS
DEVELOPING LATE.
SATURDAY THROUGH SUNDAY NIGHT...SCA CONDITIONS WILL DEVELOP ON
SATURDAY WITH 15 TO 20 KT WINDS WITH 25 TO 30 KT GUSTS AND SEAS 6 TO
8 FT. CANNOT RULE OUT A FEW BRIEF GALE FORCE GUSTS, MAINLY ON THE
NEW JERSEY OCEAN WATERS, SUNDAY AFTERNOON. VSBY RESTRICTIONS IN RAIN
AND FOG.
MONDAY THROUGH MONDAY NIGHT...SCA CONDITIONS, MOSTLY FOR 5 TO 6 FT
SEAS ON MONDAY, CONDITIONS SUBSIDE TO SUB-SCA CONDITIONS MONDAY
NIGHT.
TUESDAY...SUB-SCA CONDITIONS LIKELY.
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
DISCUSSION...FITZSIMMONS/MPS
AVIATION...FITZSIMMONS/MPS
MARINE...FITZSIMMONS/MPS
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page