001
FXUS61 KPHI 062355
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
755 PM EDT THU AUG 6 2026
WHAT HAS CHANGED
THE HEAT ADVISORY FOR CARBON AND MONROE COUNTIES WILL BE ALLOWED
TO EXPIRE AT 8 PM. ALSO, UPDATED AVIATION SECTION FOR 00Z TAFS.
TIMING OF STORMS FRIDAY NIGHT HAS TRENDED SLIGHTLY LATER.
KEY MESSAGES
1. HOT AND VERY HUMID CONDITIONS ARE EXPECTED TO PERSIST
THROUGH TUESDAY OF NEXT WEEK. A HEAT ADVISORY IS IN EFFECT FOR
PORTIONS OF THE AREA.
2. THERE ARE DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH
SATURDAY, AS WELL AS MUCH OF NEXT WEEK. THERE IS AT LEAST A
MARGINAL RISK EACH DAY FOR LOCALIZED HEAVY RAINFALL LEADING TO
FLASH FLOODING AND LOCALLY DAMAGING WIND GUSTS WITH ANY STRONGER
THUNDERSTORMS THAT DEVELOP.
DISCUSSION
KEY MESSAGE 1...HOT AND VERY HUMID CONDITIONS ARE EXPECTED TO
PERSIST THROUGH TUESDAY OF NEXT WEEK. A HEAT ADVISORY IS IN
EFFECT FOR PORTIONS OF THE AREA.
A RELATIVELY STAGNANT SYNOPTIC PATTERN IS DEVELOPING ACROSS OUR
REGION. QUASI ZONAL MID AND UPPER LEVEL FLOW WILL BE IN PLACE
THROUGH THE MIDDLE OF NEXT WEEK AS BERMUDA HIGH PRESSURE
PERSISTS OFFSHORE. THIS WILL KEEP A STEADY STREAM OF VERY WARM
AND MOIST AIR IN PLACE ACROSS THE REGION THROUGH THE PERIOD.
A PROLONGED PERIOD OF HOT AND, MOST NOTABLY, VERY HUMID
CONDITIONS IS EXPECTED TO REMAIN IN PLACE FOR THE NEXT SEVERAL
DAYS. WE LOOK TO HAVE A WEAK COLD FRONTAL PASSAGE EARLY SUNDAY,
USHERING IN SLIGHTLY DRIER AIR. THIS WILL GIVE SOME SLIGHT
REPRIEVE FROM THE EXCESSIVE HUMIDITY, THOUGH HIGHS WILL STILL
BE IN THE UPPER 80S TO LOW 90S. MOISTURE ADVECTION WILL RETURN
AGAIN BY MONDAY THOUGH, AND HOT AND VERY HUMID CONDITIONS ARE
ANTICIPATED TO RETURN MONDAY THROUGH TUESDAY. A SOMEWHAT
STRONGER COLD FRONT LOOKS TO COME THROUGH LATE TUESDAY OR
WEDNESDAY, WHICH WILL HELP BREAK THE EXCESSIVE HEAT AND HUMIDITY
SOME.
A HEAT ADVISORY REMAINS IN EFFECT FOR PORTIONS OF EASTERN
PENNSYLVANIA, MUCH OF NEW JERSEY EXCEPT THE FAR SOUTHERN
COUNTIES, AS WELL AS NEW CASTLE COUNTY, DELWARE.
KEY MESSAGE 2...THERE ARE DAILY CHANCES FOR SHOWERS AND
THUNDERSTORMS THROUGH SATURDAY, AS WELL AS MUCH OF NEXT WEEK.
THERE IS AT LEAST A MARGINAL RISK EACH DAY FOR LOCALIZED HEAVY
RAINFALL LEADING TO FLASH FLOODING AND LOCALLY DAMAGING WIND
GUSTS WITH ANY STRONGER THUNDERSTORMS THAT DEVELOP.
DIURNALLY DRIVEN INSTABILITY WILL MOSTLY BE IN THE 1000-2000
J/KG EACH AFTERNOON THROUGH THE NEXT SEVERAL DAYS ALONG WITH
PWATS IN THE 1.5-2" RANGE. MEAN FLOW WILL BE PREDOMINANTLY
SOUTHWESTERLY AND RELATIVELY WEAK THROUGH SATURDAY. THIS WILL
SUPPORT A CONTINUED LOCALIZED HEAVY RAINFALL THREAT WITH
POTENTIAL FOR FLASH FLOODING, ALTHOUGH WATER LOADED DOWNDRAFTS
COULD CAUSE LOCALIZED WIND DAMAGE. AREAS WITH VERY SATURATED
GROUND FROM RECENT RAINS WILL BE MOST PRONE TO EXPERIENCING
TREES FALLING.
FOR THIS EVENING, THE MAIN LIMITING FACTOR IS THE LACK OF MID
LEVEL FORCING AND RELATIVELY WEAK LOW LEVEL CONVERGENCE. AS
SUCH, WHILE WE WILL CONTINUE TO SEE ISOLATED OR EVEN SCATTERED
SHOWER AND STORM DEVELOPMENT, NOT EXPECTING ANYTHING WIDESPREAD
OR PARTICULARLY LONG LIVED. THE MAIN THREATS WILL BE BRIEF HEAVY
DOWNPOURS AND GUSTY WINDS.
ON FRIDAY, A MID LEVEL SHORTWAVE TROUGH IS EXPECTED TO APPROACH
LATE IN THE DAY, PROVIDING MORE FORCING (AS COMPARED TO TODAY).
AS SUCH, STORM COVERAGE IS EXPECTED TO BE MORE WIDESPREAD, AND
STORMS SHOULD BE MORE ORGANIZED ALTHOUGH BULK SHEAR VALUES ARE
STILL RELATIVELY MODEST (UP TO 25 KT). ALL THAT BEING SAID,
CONTINUED CONCERN FOR HEAVY RAIN/FLASH FLOODING AND DAMAGING
WINDS. TO A LESSER EXTENT, THERE IS ALSO SOME RISK FOR HAIL,
GIVEN THE DEEP UNSTABLE LAYER.
DETAILS FOR SATURDAY'S CONVECTION REMAIN UNCLEAR, BUT WE COULD
CERTAINLY END UP WITH SOME POTENTIAL FOR FLASH FLOODING AND SEVERE
STORMS AGAIN. CURRENT INDICATIONS IN THE GUIDANCE SUPPORT A
LATER TIMING OF STORMS DURING THE EVENING OR EVEN OVERNIGHT
DEPENDING ON THE TIMING OF A WEAK COLD FRONT AND SHORTWAVE
TROUGH.
WE LOOK TO HAVE A WEAK COLD FRONTAL PASSAGE BY EARLY SUNDAY,
USHERING IN SLIGHTLY DRIER AIR. THIS COMBINED WITH SUBTLE
SUBSIDENCE ALOFT WILL HELP BRIEFLY LIMIT CONVECTION POTENTIAL ON
SUNDAY AND ALSO GIVE SOME SLIGHT REPRIEVE FROM THE EXCESSIVE
HUMIDITY, THOUGH HIGHS WILL STILL BE IN THE UPPER 80S TO LOW 90S.
MOISTURE AND FORCING ALOFT WILL RETURN BY MONDAY AS MEAN FLOW
SHIFTS MORE WESTERLY AND MID LEVEL FLOW INCREASES. THIS SHOULD
RESULT IN A GREATER SEVERE THUNDERSTORM THREAT COMPARED TO THIS
WEEK, AND PERHAPS SLIGHTLY LOWER FLASH FLOODING THREAT, BUT THE
DETAILS INTO THE PERIOD EARLY NEXT WEEK REMAIN UNCLEAR. LONG
STORY SHORT, MONDAY AND TUESDAY LOOK TO CONTINUE THE HOT AND
HUMID CONDITIONS AND DAILY THUNDERSTORM CHANCES.
A SOMEWHAT STRONGER COLD FRONT LOOKS TO COME THROUGH LATE
TUESDAY OR WEDNESDAY, WHICH WILL HELP BREAK THE EXCESSIVE HEAT
AND HUMIDITY SOME, BUT THE PATTERN ALOFT MAY STILL SUPPORT
DIURNALLY DRIVEN CONVECTION.
AVIATION /00Z FRIDAY THROUGH TUESDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
TONIGHT...PREVAILING VFR EXPECTED. ANY LINGERING SHOWER OR
THUNDERSTORM SHOULD CEASE BY 03Z. AFTER 06Z, SOME FOG
DEVELOPMENT IS POSSIBLE, ESPECIALLY AT KRDG, KABE, AND KTTN, BUT
CANNOT RULE OUT SOME PATCHY FOG AT SOME OTHER TERMINALS. WINDS
WILL GENERALLY SETTLE OUT OF THE SOUTHWEST AROUND 5 KT, BUT MAY
BECOME LIGHT AND VARIABLE AT TIMES. MODERATE CONFIDENCE AS A
WHOLE.
FRIDAY...VFR EXPECTED FOR MOST OF THE DAY. THERE WILL BE A
CHANCE FOR SHOWERS AND THUNDERSTORMS LATE IN THE DAY, PRIMARILY
AFTER 20-23Z FROM WEST TO EAST. OPTED TO CARRY VCTS IN SOME TAF
SITES WHERE APPLICABLE AT THIS TIME. SOUTHWEST WINDS GENERALLY
BETWEEN 5-10 KT, LOCALLY UP TO 15 KT. MODERATE-HIGH CONFIDENCE.
OUTLOOK...
FRIDAY NIGHT...PRIMARILY VFR EXPECTED, HOWEVER SUB-VFR
CONDITIONS ARE LIKELY AT TIMES WITH ANY SHOWERS OR THUNDERSTORMS
THAT LINGER INTO THE EVENING/OVERNIGHT.
SATURDAY-SATURDAY NIGHT...MOSTLY VFR EXCEPT LOWER CONDITIONS
POSSIBLE WITH AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS.
SUNDAY-SUNDAY NIGHT...VFR CONDITIONS EXPECTED.
MONDAY-TUESDAY...MOSTLY VFR EXCEPT LOWER CONDITIONS POSSIBLE WITH
AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS.
MARINE
WINDS AND SEAS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA
THROUGH FRIDAY.
OUTLOOK...
FRIDAY NIGHT...GUSTY AND ERRATIC WINDS ARE POSSIBLE IN THE
VICINITY OF ANY THUNDERSTORMS FRIDAY EVENING.
SATURDAY-TUESDAY...CONDITIONS EXPECTED TO REMAIN BELOW ADVISORY
LEVELS THROUGH TUESDAY OF NEXT WEEK.
RIP CURRENTS...
FOR FRIDAY...SOUTHWEST TO SOUTH WINDS AROUND 10 MPH WITH BREAKING
WAVES IN THE SURF ZONE OF 1 TO 3 FEET. A MEDIUM PERIOD EAST TO
SOUTHEAST SWELL CONTINUES (DOMINANT WAVE PERIOD OF 5-7 SECONDS).
OPTED TO GO WITH A LOW RISK FOR THE DEVELOPMENT OF DANGEROUS
RIP CURRENTS AT ALL BEACHES.
FOR SATURDAY...SOUTHWESTERLY WINDS CONTINUE AND SHOULD INCREASE
SOME TO 10-20 MPH. BREAKING WAVES IN THE SURF ZONE ARE FORECAST
TO INCREASE SOME, ESPECIALLY FOR THE JERSEY SHORE, AT 2 TO 4
FEET. GIVEN THE INCREASING SURF AND SOUTHERLY WINDS, WENT WITH A
MODERATE RISK FOR THE DEVELOPMENT OF DANGEROUS RIP CURRENTS FOR
THE JERSEY SHORE. BREAKING WAVES SHOULD BE A LITTLE LOWER STILL
FOR THE DELAWARE BEACHES, THEREFORE WENT WITH A LOW RISK FOR
THE DEVELOPMENT OF DANGEROUS RIP CURRENTS.
FOR SPECIFIC BEACH FORECASTS, VISIT WEATHER.GOV/BEACH/PHI
PHI WATCHES/WARNINGS/ADVISORIES
PA...HEAT ADVISORY UNTIL 8 PM EDT SATURDAY FOR PAZ070-071-102-104-
106.
HEAT ADVISORY UNTIL 8 PM EDT FRIDAY FOR PAZ060>062-101-103-105.
NJ...HEAT ADVISORY UNTIL 8 PM EDT SATURDAY FOR NJZ010-012>015-
017>020-027.
HEAT ADVISORY UNTIL 8 PM EDT FRIDAY FOR NJZ001-007>009.
DE...HEAT ADVISORY UNTIL 8 PM EDT SATURDAY FOR DEZ001.
MD...NONE.
MARINE...NONE.
DISCUSSION...DESILVA/JOHNSON/ROBERTSON/STAARMANN
AVIATION...DESILVA/JOHNSON/STAARMANN
MARINE...GORSE/JOHNSON/MPS/STAARMANN
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