994
FXUS61 KPHI 301924
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
324 PM EDT SUN AUG 30 2026
WHAT HAS CHANGED
THERE IS AN INCREASING THREAT OF SEVERE THUNDERSTORMS AND
POTENTIAL FLASH FLOODING DURING THE MIDDLE OF THE UPCOMING WEEK.
KEY MESSAGES
1. SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE ACROSS
PORTIONS OF EASTERN PENNSYLVANIA AND NEW JERSEY INTO TONIGHT.
TEMPERATURES WILL BE WARMER WITH INCREASING HUMIDITY AS WELL.
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. TEMPERATURES WILL BE WARMER WITH INCREASING
HUMIDITY AS WELL.
THIS AFTERNOON, THE HIGH PRESSURE THAT HAS BEEN DOMINATING OUR
WEATHER FOR THE PAST DAY HAS SHIFTED OFF THE MID-ATLANTIC COAST,
AND WILL CONTINUE TO SLIDE EASTWARD WITH TIME. WARM AND MOIST
SOUTHWESTERLY FLOW HAS COMMENCED ACROSS THE REGION, WITH
TEMPERATURES RISING INTO THE MID 70S TO UPPER 80S FROM NORTH TO
SOUTH. WIDESPREAD CLOUD COVER OVER THE NORTHERN HALF OF THE AREA
WILL CONTINUE TO LIMIT HEATING THIS AFTERNOON, BUT TEMPERATURES
MAY RISE A COUPLE MORE DEGREES INTO LATE THIS AFTERNOON ACROSS
SOUTHERN NJ AND DELMARVA.
THE ATMOSPHERE ACROSS PORTIONS OF SOUTHEASTERN PA AND SOUTHERN
NJ IS MODESTLY DESTABILIZING, WITH OBJECTIVE ANALYSIS INDICATING
AROUND 500 J/KG OF MLCAPE. SOME ADDITIONAL DESTABILIZATION IS
LIKELY THROUGH THE AFTERNOON, WITH AT LEAST POCKETS OF 1000 J/KG
EXPECTED. WITH MODEST FORCING OVERSPREADING THE REGION,
ISOLATED TO SCATTERED SHOWERS ARE DEVELOPING ACROSS PORTIONS OF
SOUTHEASTERN PA. THUS FAR, THIS ACTIVITY HAS MOSTLY STRUGGLED.
HOWEVER, SOME INCREASE IN STORM COVERAGE AND INTENSITY IS
EXPECTED AS WE HEAD TOWARD THE EVENING HOURS. 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 /19Z SUNDAY THROUGH FRIDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
REST OF TODAY...PRIMARILY VFR. ISOLATED TO SCATTERED SHOWERS
AND STORMS WILL BE POSSIBLE FOR RDG, ABE, AND THE I-95
TERMINALS. TRENDS THIS AFTERNOON SUGGEST THAT THE GREATEST
CHANCE FOR STORMS WILL BE ACROSS THE I-95 TERMINALS, BUT
COVERAGE SHOULD BE LIMITED. SOUTH-SOUTHWEST WINDS GENERALLY 5-10
KTS, THOUGH A FEW GUSTS 15-20 KTS WILL BE POSSIBLE. LOW
CONFIDENCE REGARDING POTENTIAL SHOWER AND STORM COVERAGE THIS
AFTERNOON.
TONIGHT...CEILINGS WILL ONCE AGAIN LOWER AFTER 04-06Z IN THE
WAKE OF THE AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS.
CURRENTLY FORECASTING MVFR CEILINGS FOR AT LEAST A FEW HOURS AT
ALL TERMINALS. SOUTH TO SOUTHWEST WINDS AROUND 5 KTS, BECOMING
LIGHT AND VARIABLE AFTER 06Z WITH CALM PERIODS POSSIBLE. LOW
CONFIDENCE IN THE EXTENT OF MVFR RESTRICTIONS.
MONDAY...MVFR CEILINGS IN THE MORNING SHOULD LIFT/SCATTER TO
VFR BY AROUND 15Z. 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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