457
FXUS61 KPHI 112108
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
508 PM EDT TUE AUG 11 2026
WHAT HAS CHANGED
UPDATED KEY MESSAGE 3 AND THE RIP CURRENT SECTION.
KEY MESSAGES
1. DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS THIS AFTERNOON
AND WEDNESDAY. THERE IS A RISK FOR STRONG TO SEVERE THUNDERSTORMS,
AS WELL AS A MARGINAL RISK FOR LOCALIZED HEAVY RAINFALL LEADING
TO FLASH FLOODING.
2. HOT AND HUMID CONDITIONS WILL PERSIST INTO THE MIDDLE OF THE
WEEK, BUT HUMIDITY WILL NOT BE AS OPPRESSIVE AS RECENT DAYS.
3. THERE IS POTENTIAL FOR MINOR TIDAL FLOODING DURING THE EVENING
HIGH TIDES THIS WEEK ALONG THE ATLANTIC COAST, DELAWARE BAY, AND
TIDAL DELAWARE RIVER, ESPECIALLY ON TUESDAY AND WEDNESDAY.
DISCUSSION
KEY MESSAGE 1...DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS THIS
AFTERNOON AND WEDNESDAY. THERE IS A RISK FOR STRONG TO SEVERE THUNDERSTORMS,
AS WELL AS A MARGINAL RISK FOR LOCALIZED HEAVY RAINFALL LEADING TO
FLASH FLOODING.
A SURFACE COLD FRONT WILL GRADUALLY SAG SOUTHWARD ACROSS THE NORTHERN
TIER OF THE REGION THIS AFTERNOON INTO EVENING BEFORE STALLING AROUND
THE I-80 OR I-78 CORRIDORS COME WEDNESDAY. DURING THIS TIME, A FEW
UPPER LEVEL SHORTWAVE PULSES WILL RENDEZVOUS WITH THE SURFACE COLD
FRONT, BRINGING ROUNDS OF SHOWERS AND STORMS THROUGH WEDNESDAY MORNING.
THE FIRST ROUND OF STORMS THIS AFTERNOON AND EVENING WILL BE ACROSS
THE NORTHERN AREAS NEAR THE POCONOS AND POSSIBLY INTO THE LEHIGH
VALLEY. OTHER MORE SCATTERED ACTIVITY IS POSSIBLE ACROSS CENTRAL
NJ. THE UPPER VORT MAXS ARE DIFFICULT TO TRACK AND THE CAMS GUIDANCE
IS VERY INCONSISTENT, SO WE'LL CONTINUE WITH BLENDED GUIDANCE AS
WELL AS SATELLITE/RADAR TRENDS FOR OUR UPDATES. THAT SAID, INSTABILITY
ACROSS THE REGION DOES LOOK TO BE LIMITED TO THE 1000-2000 J/KG
RANGE WITH LIMITED DEEP LAYER SHEAR, WHICH WILL, THEREFORE, LIMIT
THE SEVERE WEATHER POTENTIAL TODAY. SPC HAS EXPANDED THE MARGINAL
RISK (LEVEL 1 OUT OF 5) FARTHER NORTHEAST NOW COVERING OUR
ENTIRE CWA. ALSO THE ENTIRE AREA REMAINS IN THE MARGINAL RISK
(LEVEL 1 OUT OF 4) FOR EXCESSIVE RAINFALL.
THE LATEST GUIDANCE NOW SUGGESTS A SECOND ROUND OF SHOWERS AND
PERHAPS SOME CONVECTIVE THUNDERSTORMS TO ARRIVE EARLY WEDNESDAY
MORNING WITH THE POTENTIAL FOR HEAVY DOWNPOURS DURING THE WEDNESDAY
MORNING RUSH HOUR. WHILE THERE REMAINS A FAIR AMOUNT OF UNCERTAINTY
WITH THIS SETUP IT APPEARS THAT THIS ROUND MAY BE A RESULT OF A
DECAYING UPSTREAM MCS FROM THE OHIO VALLEY. THIS SETUP REMAINS
HIGHLY UNCERTAIN AND FULLY DEPENDENT ON HOW THE VOLATILE SETUP
ACROSS THE OHIO VALLEY EVENTUALLY PANS OUT THROUGH THE OVERNIGHT
HOURS. AREAS THAT ARE FAVORED FOR HIGHER POPS AND HEAVY RAINS
WILL BE DELMARVA AND SOUTH NJ, POSSIBLY INTO PHILADELPHIA.
ADDITIONAL ROUNDS OF UPPER LEVEL SHORTWAVES LOOK TO RIDE ALONG THE
QUASI-STATIONARY BOUNDARY WHICH WILL SUPPORT ROUNDS OF CONVECTION
CONTINUING AT LEAST THROUGH WEDNESDAY NIGHT, AND POSSIBLY INTO
THURSDAY. THE FRONT LOOKS TO PUSH THROUGH BY LATE THURSDAY, AND
A MUCH DRIER AND COOLER AIRMASS WILL ARRIVE BY FRIDAY AND
SATURDAY AS A RESULT. THIS WILL BRING US A MORE PRONOUNCED BREAK
IN CONVECTIVE POTENTIAL AND MORE PLEASANT WEATHER CONDITIONS.
KEY MESSAGE 2...HOT AND HUMID CONDITIONS WILL PERSIST INTO THE
MIDDLE OF THE WEEK, BUT HUMIDITY WILL NOT BE AS OPPRESSIVE AS
RECENT DAYS.
A RELATIVELY STAGNANT SYNOPTIC PATTERN WILL REMAIN IN PLACE ACROSS
OUR REGION. QUASI ZONAL MID AND UPPER LEVEL FLOW WILL BE IN PLACE
THROUGH THE MIDDLE OF THE WEEK AS BERMUDA HIGH PRESSURE PERSISTS
OFFSHORE. THIS WILL KEEP A VERY WARM AND MOIST AIRMASS IN PLACE
ACROSS THE REGION THROUGH THE PERIOD.
HOT AND HUMID CONDITIONS WILL CONTINUE INTO THE MIDDLE OF THE
WEEK, ALTHOUGH SLIGHTLY LOWER TEMPERATURES AND DEWPOINTS WILL
ARRIVE FOR WEDNESDAY. DEWPOINTS ARE ANTICIPATED TO MIX OUT INTO
THE MID TO UPPER 60S AGAIN THIS AFTERNOON. THIS WILL GIVE SOME
SLIGHT REPRIEVE FROM THE EXCESSIVE HUMIDITY WE'VE EXPERIENCED IN
RECENT DAYS, THOUGH HIGHS WILL STILL BE IN THE UPPER 80S TO MID
90S. THE LOWER DEWPOINTS WILL RESULT IN MAXIMUM HEAT INDICES
MAINLY IN THE MID TO UPPER 90S, THOUGH COULD GET NEAR 100
DEGREES IN DELMARVA AND NEAR THE COAST IN NEW JERSEY. THEREFORE,
HOT AND HUMID, BUT NOT TO THE POINT WHERE ANY HEAT HEADLINES ARE
NEEDED.
BY FRIDAY AND SATURDAY WITH THE FRONT FINALLY HAVING PUSHED THROUGH,
A MUCH DRIER AND MORE COOLER AIRMASS WILL ARRIVE, WHICH WILL BRING
MUCH MORE PLEASANT WEATHER CONDITIONS. DEWPOINTS MAY DROP INTO THE
50S AGAIN FOR MANY AREAS WITH HIGHS FORECAST TO BE IN THE LOW TO
MID 80S. DEWPOINTS LOOK TO START REBOUNDING INTO THE 60S AGAIN
BY SUNDAY.
KEY MESSAGE 3...THERE IS POTENTIAL FOR MINOR TIDAL FLOODING
DURING THE EVENING HIGH TIDES THIS WEEK ALONG THE ATLANTIC
COAST, DELAWARE BAY, AND TIDAL DELAWARE RIVER, ESPECIALLY ON
TUESDAY AND WEDNESDAY.
AS WE APPROACH THE NEW MOON TOMORROW, ASTRONOMICAL TIDES FOR
THE EVENING HIGH TIDE CYCLES WILL INCREASE TO AROUND A HALF FOOT
BELOW MINOR FLOOD STAGE IN MANY AREAS THIS WEEK ALONG THE
ATLANTIC COASTS OF NEW JERSEY AND DELWARE, DELAWARE BAY, AND THE
TIDAL DELAWARE RIVER. WITH TIDE DEPARTURES RUNNING AROUND A
HALF FOOT ABOVE AVERAGE, THIS WILL RAISE A THREAT OF MINOR FLOOD
STAGE BEING REACHED FOR THESE AREAS.
WE WILL CONTINUE TO MONITOR THE TIDE DEPARTURES IN THE COMING
TOTAL WATER LEVEL FORECASTS. COASTAL FLOOD ADVISORIES HAVE BEEN
ISSUED FOR AREAS ALONG THE DELAWARE BAY FOR THIS EVENING'S HIGH
TIDE ALONG WITH A NEW SET OF COASTAL FLOOD ADVISORIES FOR
TOMORROW EVENING'S HIGH TIDE CYCLE. AT LEAST SPOTTY MINOR TIDAL
FLOODING SHOULD BE ANTICIPATED AROUND THE TIMES OF THE EVENING
HIGH TIDES THIS WEEK WITH THE POTENTIAL FOR ADDITIONAL
ADVISORIES DEPENDING ON THE TIDAL DEPARTURES. THE HIGHEST
ASTRONOMICAL TIDES WILL OCCUR TOMORROW, THOUGH TODAY'S TIDES
ARE OF SIMILAR HEIGHT. THE THREAT OF MINOR TIDAL FLOODING MAY
LINGER THROUGH THURSDAY OR FRIDAY AS WELL.
TIDAL FLOODING IS NOT CURRENTLY FORECAST FOR THE EASTERN SHORE
OF THE CHESAPEAKE BAY.
AVIATION /20Z TUESDAY THROUGH SUNDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
UNTIL 00Z... VFR MOST SITES BUT A COUPLE POP-UP SHOWERS OR A
TSTM COULD AFFECT THE N/W MOST COUNTIES. WE DECIDED TO RETAIN
THE PROB30 FOR KRDG/KABE TO COVER THIS. WINDS HAVE RETURNED WEST
TO SOUTHWEST AROUND 10 KNOTS AND SHOULD REMAIN THERE INTO THE
EVENING.
TONIGHT...VFR GIVE WAY TO MVFR RESTRICTIONS WITH SHOWERS AND
THUNDERSTORMS ARRIVING DURING THE OVERNIGHT HOURS, AROUND
06-09Z, MAINLY ACROSS THE SOUTHERN TERMINALS. LOW/MEDIUM
CONFID.
WEDNESDAY... MORNING MVFR ACROSS THE SOUTHERN AREAS KILG/KMIV/KACY
WITH VFR RETURNING. MORE SCATTERED SHOWERS/TSTMS FOR THE AFTERNOON.
MEDIUM CONFID OVERALL.
OUTLOOK...
WEDNESDAY NIGHT...PREVAILING VFR. RESTRICTIONS POSSIBLE WITH
AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS.
THURSDAY THRU SATURDAY...MOSTLY VFR. NO SIGNIFICANT WEATHER
EXPECTED.
SUNDAY...VFR EARLY THEN SCATTERED SHOWERS/TSTMS WITH
RESTRICTIONS POSSIBLE.
MARINE
NO PREVAILING MARINE HAZARDS EXPECTED THROUGH WEDNESDAY.
OUTLOOK...
WEDNESDAY NIGHT THROUGH FRIDAY...NO PREVAILING MARINE HAZARDS
EXPECTED. THUNDERSTORMS POSSIBLE EACH AFTERNOON AND EVENING.
SATURDAY...NO MARINE HEADLINES ARE ANTICIPATED.
RIP CURRENTS...
FOR WEDNESDAY...LIGHT WINDS AROUND 5 TO 10 MPH WILL GRADUALLY
TURN FROM NORTHWESTERLY IN THE MORNING TO SOUTHEASTERLY IN THE
LATE AFTERNOON. BREAKING WAVE HEIGHTS WILL REMAIN AROUND 2 FEET
OR LESS WITH A SOUTHERLY 1 FOOT SWELL AROUND 5 TO 7 SECONDS.
WITH LITTLE CHANGES IN OVERALL CONDITIONS, WILL CONTINUE WITH A
LOW RISK FOR DANGEROUS RIP CURRENTS AT ALL BEACHES.
FOR THURSDAY...A SOUTHWESTERLY WIND AROUND 5 TO 10 MPH.
BREAKING WAVE HEIGHTS WILL REMAIN AROUND 2 FEET OR LESS WITH A
SOUTHEASTERLY 1 FOOT SWELL AROUND 6 TO 8 SECONDS. DUE TO THESE
CONDITIONS THERE IS A LOW RISK FOR DANGEROUS RIP CURRENTS AT
ALL BEACHES.
FOR SPECIFIC BEACH FORECASTS, VISIT WEATHER.GOV/BEACH/PHI
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...COASTAL FLOOD ADVISORY FROM 9 PM THIS EVENING TO 2 AM EDT
WEDNESDAY FOR NJZ016.
COASTAL FLOOD ADVISORY FROM 10 PM WEDNESDAY TO 2 AM EDT
THURSDAY FOR NJZ016.
COASTAL FLOOD ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR NJZ021-
023-024.
COASTAL FLOOD ADVISORY FROM 7 PM WEDNESDAY TO 1 AM EDT
THURSDAY FOR NJZ021-023-024.
DE...COASTAL FLOOD ADVISORY FROM 9 PM THIS EVENING TO 2 AM EDT
WEDNESDAY FOR DEZ001.
COASTAL FLOOD ADVISORY FROM 10 PM WEDNESDAY TO 2 AM EDT
THURSDAY FOR DEZ001.
COASTAL FLOOD ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR
DEZ002>004.
COASTAL FLOOD ADVISORY FROM 7 PM WEDNESDAY TO 1 AM EDT
THURSDAY FOR DEZ002>004.
MD...NONE.
MARINE...NONE.
DISCUSSION...GUZZO/MJL
AVIATION...MJL
MARINE...GUZZO/MJL
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