659
FXUS61 KPHI 302307
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
707 PM EDT SUN AUG 30 2026
WHAT HAS CHANGED
UPDATED AVIATION SECTION FOR 0Z TAFS. UPDATED FIRST KEY MESSAGE.
KEY MESSAGES
1. SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE ACROSS
PORTIONS OF EASTERN PENNSYLVANIA AND NEW JERSEY INTO TONIGHT.
2. HEAT AND HUMIDITY WILL BUILD INTO THE MIDDLE OF THE WEEK,
ALONG WITH DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS. THERE IS
AN INCREASING THREAT OF SEVERE THUNDERSTORMS AND POTENTIALLY
FLASH FLOODING DURING THE MIDDLE OF THE WEEK, NAMELY TUESDAY
THROUGH THURSDAY.
DISCUSSION
KEY MESSAGE 1...SCATTERED SHOWERS AND THUNDERSTORMS ARE
POSSIBLE ACROSS PORTIONS OF EASTERN PENNSYLVANIA AND NEW JERSEY
INTO TONIGHT.
THERE HAS BEEN SOME MODEST DESTABILIZATION THAT HAS OCCURRED
INTO THIS EVENING WITH ML CAPES AROUND 500-1500 ACROSS THE HEART
OF THE CWA. AND AS AN UPPER LEVEL DISTURBANCE PIVOTS THROUGH
FROM THE NORTH AND WEST, THIS MAY TRIGGER SOME SHOWERS AND
STORMS THIS EVENING INTO THE EARLY PART OF THE OVERNIGHT.
LOCALLY HEAVY RAINFALL IS POSSIBLE WITH THE STRONGEST STORMS.
SOME LOCALIZED FLOODING CAN'T BE RULED OUT ESPECIALLY IN AREAS
THAT HAVE RECEIVED SUBSTANTIAL RAINFALL RECENTLY. HOWEVER,
OVERALL THIS POTENTIAL IS EXPECTED TO REMAIN FAIRLY LIMITED. WPC
HAS PLACED EASTERN PA AND NJ UNDER A MARGINAL RISK (1 OF 4) FOR
EXCESSIVE RAINFALL TODAY. THE THREAT FOR SEVERE THUNDERSTORMS
IS LOW, THOUGH A FEW INSTANCES OF GUSTY WINDS OR SMALL HAIL WILL
BE POSSIBLE WITH THE STRONGEST STORMS.
SCATTERED SHOWERS MAY PERSIST WELL INTO THE OVERNIGHT HOURS AS
FORCING REMAINS ALOFT.
KEY MESSAGE 2...HEAT AND HUMIDITY WILL BUILD INTO THE MIDDLE OF
THE WEEK, ALONG WITH DAILY CHANCES FOR SHOWERS AND
THUNDERSTORMS. THERE IS AN INCREASING THREAT OF SEVERE
THUNDERSTORMS AND POTENTIALLY FLASH FLOODING DURING THE MIDDLE
OF THE WEEK, NAMELY TUESDAY THROUGH THURSDAY.
BROAD UPPER LEVEL RIDGING RETURNS TO THE EASTERN US EARLY NEXT
WEEK, BRINGING IN SURFACE HIGH PRESSURE ACROSS THE EASTERN US.
AFTERNOON HIGHS WILL CREEP BACK INTO THE MID 80S TO LOW 90S FOR
MOST AREAS, ABOUT 5 DEGREES ABOVE AVERAGE FOR EARLY SEPTEMBER.
DEWPOINTS WILL ALSO REMAIN IN THE UPPER 60S TO LOW 70S. THE
HOTTEST DAY LOOKS TO BE TUESDAY, WHEN HIGH TEMPERATURES COULD
GET INTO THE MID 90S ACROSS DELMARVA AND INTO THE PHILLY METRO.
RESULTING HEAT INDICES WILL BE WELL INTO THE 90S TO AROUND 100.
WE WILL CONTINUE TO KEEP AN EYE ON THE POTENTIAL FOR HEAT
ADVISORIES.
ONE OTHER ASPECT TO WATCH WITH THIS RIDGING PATTERN IS THE
POTENTIAL FOR THUNDERSTORMS TO ROTATE AROUND THE PERIPHERY OF
THE RIDGE AND THE POSITION OF A FRONTAL BOUNDARY DURING THE
MIDDLE OF THE WEEK. LATEST GUIDANCE SUGGESTS THAT MONDAY MAY BE
MOSTLY DRY, THOUGH ISOLATED STORMS CAN'T BE RULED OUT. GUIDANCE
CONTINUES TO COME INTO CONSENSUS THAT THE PATTERN WILL BE
SUPPORTIVE OF MULTIPLE ROUNDS OF THUNDERSTORMS, ESPECIALLY
DURING THE TUESDAY THROUGH THURSDAY TIME FRAME.
SPC HAS PLACED PORTIONS OF THE AREA IN A SLIGHT RISK (2 OF 5)
FOR SEVERE THUNDERSTORMS TUESDAY. WEDNESDAY AND THURSDAY ARE
ALSO HIGHLIGHTED WITH 15% PROBABILITIES FOR SEVERE
THUNDERSTORMS. THE NORTHWEST FLOW PATTERN THAT WILL BE IN PLACE
WILL BE SUPPORTIVE OF ALL SEVERE THREATS, INCLUDING DAMAGING
WINDS, LARGE HAIL, AND TORNADOES. THE THREAT FOR FLASH FLOODING
IS TYPICALLY LOWER WITH THESE PATTERNS, HOWEVER GIVEN MULTIPLE
DAYS WITH THE POTENTIAL FOR STORMS AND RECENT HEAVY RAINFALLS,
AT LEAST SOME RISK FOR FLASH FLOODING WILL EXIST. LONG STORY
SHORT, THE TUESDAY THROUGH THURSDAY PERIOD LOOKS VERY ACTIVE
WITH MULTIPLE ROUNDS OF THUNDERSTORMS ACROSS THE REGION, BUT
DETAILS REMAIN UNCLEAR. STAY TUNED FOR UPDATES ON THESE THREATS
OVER THE COMING DAYS.
BY FRIDAY, CURRENT MODEL CONSENSUS INDICATES THE FRONTAL
BOUNDARY WILL BE PUSHING SOUTH OF OUR REGION WITH CANADIAN HIGH
PRESSURE BUILDING ACROSS THE NORTHEAST. THIS SHOULD FAVOR AN END
TO SEVERE WEATHER AND FLASH FLOODING POTENTIAL.
AVIATION /00Z MONDAY THROUGH FRIDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
TONIGHT...A FEW SHOWERS AND STORMS ARE POSSIBLE THIS EVENING
INTO THE EARLY OVERNIGHT BUT THE CHANCES OF THESE AFFECTING TAF
SITES ARE GENERALLY PRETTY LOW. THE EXCEPTION IS A SLIGHTLY
HIGHER CHANCE AT TTN WHERE WE'VE INDICATED A TEMPO GROUP.
OTHERWISE, CIGS LOWER OVERNIGHT WITH SOME MARGINAL MVFR
CONDITIONS POSSIBLE NEAR DAWN AT PHL, PNE, MIV, AND ACY.
SOUTH TO SOUTHWEST WINDS AROUND 5 KTS, BECOMING LIGHT AND
VARIABLE AFTER 06Z WITH CALM PERIODS POSSIBLE. LOW CONFIDENCE IN
THE MVFR RESTRICTIONS.
MONDAY...SOME MVFR CEILINGS POSSIBLE IN THE EARLY MORNING SHOULD
QUICKLY LIFT/SCATTER TO VFR. NORTHEAST WINDS IN THE MORNING
AROUND 5 KT, SHIFTING TO A MORE SOUTHERLY DIRECTION DURING THE
AFTERNOON. THERE IS A LOW (GENERALLY LESS THAN 20%) CHANCE FOR
ISOLATED SHOWERS OR STORMS WHICH COULD CAUSE BRIEF RESTRICTIONS
IN THE AFTERNOON. MODERATE CONFIDENCE.
OUTLOOK...
MONDAY NIGHT THROUGH THURSDAY...RESTRICTIONS POSSIBLE IN
SHOWERS AND THUNDERSTORMS EACH DAY, MAINLY DURING THE AFTERNOON
TO EVENING HOURS.
FRIDAY...PRIMARILY VFR.
MARINE
NO PREVAILING MARINE HAZARDS EXPECTED. SOUTH-SOUTHWESTERLY
WINDS OF 10-15 KTS INTO THE FIRST PART OF TONIGHT, WITH WINDS
TURNING MORE WESTERLY AND DIMINISHING LATE. EAST TO EAST-
SOUTHEAST WINDS MONDAY AROUND 5-10 KTS. SEAS 2-3 FEET. SHOWERS
AND STORMS ARE POSSIBLE BEGINNING THIS EVENING. GENERALLY FAIR
WEATHER MONDAY.
OUTLOOK...
MONDAY NIGHT THROUGH FRIDAY...NO PREVAILING MARINE HAZARDS
EXPECTED. CHANCES FOR THUNDERSTORMS EACH DAY, MAINLY IN THE
AFTERNOON AND EVENING HOURS.
RIP CURRENTS...
FOR MONDAY, NORTH TO NORTHWEST WINDS IN THE MORNING WILL SHIFT TO
EAST IN THE AFTERNOON AROUND 5 MPH. BREAKING WAVE HEIGHTS AROUND 1
FOOT. A LIGHT SOUTHEASTERLY SWELL WITH A PERIOD AROUND 8 SECONDS
WILL REMAIN. THIS WILL CONTINUE TO LEAD TO A LOW RISK FOR THE
DEVELOPMENT OF DANGEROUS AND LIFE THREATENING RIP CURRENTS AT THE
JERSEY SHORE AND DELAWARE BEACHES.
FOR TUESDAY, SOUTH/SOUTHWEST WINDS WILL INCREASE SOME TO AROUND 10
TO 15 MPH BUT THEY LITTLE CHANGE IS EXPECTED SO WE'LL CONTINUE WITH
A LOW RISK FOR THE DEVELOPMENT OF DANGEROUS RIP CURRENTS AT THE
JERSEY SHORE AND DELAWARE BEACHES.
FOR SPECIFIC BEACH FORECASTS, VISIT WEATHER.GOV/BEACH/PHI
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
DISCUSSION...AS/WFO PHI
AVIATION...AS/WFO PHI
MARINE...AS/WFO PHI
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