405
FXUS61 KPHI 072010
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
410 PM EDT FRI AUG 7 2026
WHAT HAS CHANGED
UPDATED KEY MESSAGE 1 AND 2.
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 THROUGH TOMORROW.
2. THERE ARE DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH
TOMORROW, AS WELL AS PORTIONS 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 THROUGH TOMORROW.
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 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 TOMORROW, AS WELL AS PORTIONS 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.
A SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED UNTIL 9 PM THIS EVENING
FOR OUR WHOLE FORECAST AREA. MLCAPE THIS AFTERNOON HAS REACHED NEAR
OR OVER 3000 J/KG WITH SOME FAVORABLE LAPSE RATES. HOWEVER, SHEAR
REMAINS AROUND 20-30 KT. THE PRIMARY RISK IS DAMAGING WIND GUSTS
WITH ANY SEVERE THUNDERSTORMS. THERE REMAINS A SLIGHT (LEVEL 2 OUT
OF 5) RISK FOR AREAS NEAR AND NORTHWEST OF THE I-95 CORRIDOR. THE
REMAINDER OF THE AREA IS UNDER A MARGINAL (LEVEL 1 OUT OF 5) RISK
FOR SEVERE THUNDERSTORMS. ANOTHER CONCERN IS THE HEAVY RAINFALL
POTENTIAL. THERE IS A SLIGHT (LEVEL 2 OUT OF 4) FOR EXCESSIVE
RAINFALL FOR AREAS NEAR AND NW OF I-95 CORRIDOR. THE REMAINDER OF
THE AREA IS UNDER A MARGINAL (LEVEL 1 OUT OF 4) RISK FOR EXCESSIVE
RAINFALL. PWATS OF 2 INCHES OR GREATER TODAY ALONG WITH A WARM CLOUD
LAYER PROCESS SHOWCASES THE HEAVY RAINFALL RISK. GIVEN THESE
CONDITIONS, RAINFALL RATES OF 2-3 INCHES PER HOUR ARE POSSIBLE.
ON SATURDAY, THE EXTENT OF THE CONVECTION REMAINS MORE UNCLEAR. THE
CURRENT GUIDANCE SHOWS ISOLATED CONVECTION DEVELOPING DURING THE
LATER AFTERNOON INTO THE EVENING HOURS. PWATS LOOK SLIGHTLY LOWER
THAN TODAY, AND MEAN FLOW IS A BIT MORE WESTERLY THAN SOUTHWESTERLY,
BUT OVERALL THE THERMODYNAMICS APPEAR SIMILAR. THERE WILL BE LESS
FORCING, SO THE COVERAGE IS MORE ISOLATED COMPARED TO TODAY. WE
REMAIN IN A MARGINAL (LEVEL 1 OUT OF 4) RISK FOR EXCESSIVE RAINFALL
FROM WPC. IN TERMS OF THE SEVERE WEATHER POTENTIAL, SPC HAS ADDED A
MARGINAL (LEVEL 1 OUT OF 5) RISK FOR ISOLATED SEVERE THUNDERSTORMS
FOR MOST OF OUR AREA WITH THE PRIMARY HAZARD BEING DAMAGING WIND
GUSTS.
WE LOOK TO HAVE A WEAK COLD FRONTAL PASSAGE BY SUNDAY, USHERING IN
SLIGHTLY DRIER AIR. THIS COMBINED WITH SUBTLE SUBSIDENCE ALOFT WILL
HELP BRIEFLY LIMIT CONVECTION POTENTIAL ON SUNDAY. 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 /20Z FRIDAY THROUGH WEDNESDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
THIS AFTERNOON...VFR EXPECTED FOR MOST OF THE DAY. SCATTERED
SHOWERS AND THUNDERSTORMS WILL DEVELOP LATE IN THE DAY,
PRIMARILY AFTER 20-23Z FROM WEST TO EAST. SOUTHWEST WINDS
GENERALLY BETWEEN 5-10 KTS, LOCALLY UP TO 15 KTS. ,
TONIGHT...PRIMARILY VFR EXPECTED, HOWEVER RESTRICTIONS ARE
POSSIBLE AT TIMES PRIOR TO 04Z WITH ANY SHOWERS OR
THUNDERSTORMS. PATCHY FOG POSSIBLE LATE. MODERATE CONFIDENCE
OVERALL.
SATURDAY...VFR. SCATTERED AFTERNOON THUNDERSTORMS WITH MVFR
CONDITIONS.
OUTLOOK...
SATURDAY NIGHT...MOSTLY VFR EXCEPT LOWER CONDITIONS POSSIBLE
WITH EVENING SHOWERS AND THUNDERSTORMS.
SUNDAY-SUNDAY NIGHT...VFR CONDITIONS EXPECTED.
MONDAY-TUESDAY...MOSTLY VFR EXCEPT LOWER CONDITIONS POSSIBLE
WITH AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS.
WEDNESDAY...VFR.
MARINE
NO PREVAILING MARINE HAZARDS ARE EXPECTED THROUGH SATURDAY.
SOUTHWESTERLY WINDS INCREASING TO 15-20 KTS WITH SEAS OF 2-4
FEET. A LINE OF SHOWERS AND THUNDERSTORMS MAY MOVE OFFSHORE LATE
IN THE EVENING, WITH GUSTS OF 30-40 KTS AND LOCALLY HIGHER SEAS
POSSIBLE. ON SATURDAY, SEAS REMAIN AT 2-4 FEET WITH A
SOUTHWESTERLY WIND AROUND 15-20 KT.
OUTLOOK...
SUNDAY THROUGH WEDNESDAY...NO PREVAILING MARINE HAZARDS EXPECTED.
THUNDERSTORMS POSSIBLE SATURDAY NIGHT AND TUESDAY NIGHT.
RIP CURRENTS...
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 MUCH OF 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 AND COASTAL MONMOUTH
COUNTY, THEREFORE WENT WITH A LOW RISK FOR THE DEVELOPMENT OF
DANGEROUS RIP CURRENTS.
FOR SUNDAY...SIMILAR CONDITIONS SUNDAY AS SATURDAY. SOUTHWESTERLY
WINDS CONTINUE AROUND 10-20 MPH. BREAKING WAVES IN THE SURF
ZONE ARE FORECAST TO REMAIN 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 AND COASTAL MONMOUTH COUNTY, 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 PAZ070-071-101>106.
HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR PAZ060>062.
NJ...HEAT ADVISORY UNTIL 8 PM EDT SATURDAY FOR NJZ008>010-012>015-
017>020-027.
HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR NJZ001-007.
DE...HEAT ADVISORY UNTIL 8 PM EDT SATURDAY FOR DEZ001.
MD...NONE.
MARINE...NONE.
DISCUSSION...GUZZO/STAARMANN
AVIATION...FRANKLIN/STAARMANN
MARINE...GORSE/GUZZO/STAARMANN
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