948
FXUS61 KPHI 261833
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
233 PM EDT TUE AUG 26 2025
SYNOPSIS
HIGH PRESSURE CENTERED WELL TO OUR WEST THIS AFTERNOON WILL
SLIDE EASTWARD ACROSS THE MID-ATLANTIC ON WEDNESDAY BEFORE
SHIFTING OFFSHORE ON THURSDAY. A COLD FRONT THEN CROSSES OUR
AREA LATE THURSDAY NIGHT INTO FRIDAY, FOLLOWED BY HIGH PRESSURE
OVER THE WEEKEND INTO EARLY NEXT WEEK.
NEAR TERM /THROUGH WEDNESDAY/
AN EXPANSIVE AREA OF HIGH PRESSURE CENTERED WELL TO OUR WEST
OVER MISSOURI DOMINATES OUR WEATHER THIS AFTERNOON. THE RESULT
OF THIS HIGH AND A LOW PRESSURE SYSTEM OVER ATLANTIC CANADA
CONTINUES TO RESULT IN A GENERALLY WESTERLY FLOW THAT'S HELPED
BRING IN SOME COOLER TEMPERATURES RELATIVE TO AVERAGE FOR THIS
TIME OF YEAR. THE CAVEAT TO OUR OTHERWISE NICE DAY ACROSS THE
AREA IS THAT AN UPPER LEVEL TROUGH CONTINUES TO DOMINATE THE
EASTERN CONUS AND THERE IS ALSO A WEAK COLD FRONT CURRENTLY
MOVING THROUGH CENTRAL PA INTO UPSTATE NY. THIS WILL HELP BRING
SOME ISOLATED SHOWERS TO PORTIONS OF OUR EASTERN PA ZONES INTO
NW NJ LATER THIS AFTERNOON INTO EARLY THIS EVENING. THESE
SHOULD STAY WELL TO THE N/W OF THE URBAN CORRIDOR HOWEVER AND
AFFECT AREAS MAINLY FROM AROUND BERKS COUNTY NORTHEAST INTO
PORTIONS OF THE LEHIGH VALLEY INTO THE SOUTHERN POCONOS AND THEN
ON INTO NW NJ.
TONIGHT, CLOUDS WILL FADE OUT AS THE WEAK FRONT MOVES THROUGH
AND INSOLATION DIMINISHES, THOUGH UPPER TROUGHING WILL ACTUALLY
BE INCREASING. ANY SPOTTY SHOWERS MAINLY N AND W SHOULD
DISSIPATE, WITH LOWS ENDING UP IN THE HIGH 40S POCONOS, 50S MOST
EVERYWHERE ELSE, EXCEPT AROUND 60 IN THE URBAN CENTERS AND NEAR
TIDAL WATERS. AS WITH TODAY'S DAYTIME HIGHS, THESE WILL BE
SEVERAL DEGREES BELOW NORMAL, WITH MOST REGIONAL NORMALS
CURRENTLY IN THE LOW-MID 60S FOR LOWS.
FOR WEDNESDAY, HIGH PRESSURE WEAKENS AS IT MOVES EASTWARD
TOWARDS THE VIRGINIA COAST WHILE IN THE UPPER LEVELS TROUGHINESS
CONTINUES TO DOMINATE THE EAST. THE UPSHOT OF ALL THIS IS THAT
IT WILL BE ANOTHER DAY WITH TEMPERATURES SEVERAL DEGREES BELOW
AVERAGE ALONG WITH LOW HUMIDITY UNDER PARTLY TO MOSTLY SUNNY
SKIES. GENERALLY EXPECT HIGHS IN THE MIDDLE TO UPPER 70S (UPPER
60S TO AROUND 70 OVER THE POCONO PLATEAU).
SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/
AN UPPER-LEVEL TROUGH IS FORECAST TO REMAIN IN PLACE THROUGH
THURSDAY, ALTHOUGH THE INITIAL AXIS LIFTS TO OUR NORTHEAST WITH
A SECONDARY ONE APPROACHING FROM THE GREAT LAKES. SOME CLOUDS
SHOULD INCREASE AHEAD OF THIS NEXT TROUGH AXIS. A COLD FRONT
APPROACHES FROM THE WEST DURING THE DAY BEFORE ARRIVING THURSDAY
NIGHT AS LOW PRESSURE TRACKS TO OUR NORTH. SOME SHOWER ACTIVITY
MAY START TO ARRIVE LATER AT NIGHT AS SOME MOISTURE RETURN
OCCURS AHEAD OF THE COLD FRONT AS WINDS BACK TO SOUTHWESTERLY.
OVERALL THOUGH, THE MOISTURE RETURN DOES NOT LOOK ALL THAT
ROBUST. TEMPERATURES THROUGH THIS ENTIRE TIMEFRAME ARE FORECAST
TO BE ON THE COOLER SIDE (AT OR BELOW AVERAGE).
FOR FRIDAY, A STRONG UPPER-LEVEL TROUGH IS FORECAST TO SWING
ACROSS THE NORTHEAST AND MID-ATLANTIC REGIONS. THE GUIDANCE IS
IN GOOD AGREEMENT REGARDING THE PRESENCE OF THIS TROUGH, WITH
MOST OF THE GUIDANCE INCLUDING ENSEMBLES SHOWING A CLOSED LOW
EVOLVING NORTH OF LAKE ONTARIO. THIS TROUGH WILL DRIVE A COLD
FRONT ACROSS OUR AREA DURING FRIDAY. THE TIMING MAY BE FAST
ENOUGH TO NOT OCCUR DURING PEAK HEATING AND THUS LIMITING THE
POTENTIAL CONVECTIVE COVERAGE. IN ADDITION, MOISTURE RETURN
COULD BE MORE LIMITED AND THUS ALSO A MORE DRIER ENVIRONMENT FOR
STRONGER CONVECTION.
LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/
TO START THE PERIOD, THERE WILL BE A STRONG UPPER LEVEL TROUGH
WITH A CLOSED LOW AT 500MB CENTERED TO OUR NORTH. THIS FEATURE
LOOKS TO GENERALLY MOVE EASTWARD THROUGH THE COURSE OF THE
WEEKEND INTO EARLY NEXT WEEK WITH THE MAIN UNCERTAINTY REGARDING
JUST HOW QUICKLY THIS OCCURS. HOWEVER THIS DETAIL SHOULDN'T HAVE
A SIGNIFICANT IMPACT ON OUR FORECAST FOR THE MID ATLANTIC, AT
LEAST THROUGH MONDAY, AS SURFACE HIGH PRESSURE LOOKS TO DOMINATE
THROUGH THE LABOR DAY WEEKEND. THIS WILL BRING MAINLY DRY
WEATHER UNDER MAINLY CLEAR TO PARTLY CLOUDY SKIES WITH
TEMPERATURES GENERALLY RUNNING A LITTLE BELOW AVERAGE.
HEADING TOWARDS THE MIDDLE OF NEXT WEEK, UNCERTAINTY IN THE
FORECAST STARTS TO GROW AS SOME OF THE FORECAST MODELS HAVE
BEEN SUGGESTING A LOW MAY FORM OVER THE WESTERN ATLANTIC OFF THE
EAST COAST. HOWEVER AT THIS POINT OUR FORECAST CONTINUES TO
STAY WITH THE NBM (NATIONAL BLEND OF MODELS) WHICH INDICATES
LARGELY FAIR WEATHER CONTINUING NEXT TUESDAY WITH POPS AROUND 10
TO 15 PERCENT.
AVIATION /18Z TUESDAY THROUGH SUNDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
THROUGH TONIGHT...MAINLY VFR. SMALL CHANCE OF AN ISOLATED
SHOWER THROUGH EARLY THIS EVENING, MAINLY FOR KRDG/KABE, BUT
CONFIDENCE A LITTLE LOW TO ADD TO TAFS. WEST WINDS AROUND 5 TO
10 KNOTS, BECOMING NORTHWEST TONIGHT. MODERATE CONFIDENCE.
WEDNESDAY...VFR WITH NW WINDS AROUND 5 TO 10 KNOTS.
OUTLOOK...
WEDNESDAY NIGHT AND THURSDAY...VFR.
FRIDAY...SOME SHOWERS AND THUNDERSTORMS POSSIBLE, OTHERWISE
MAINLY VFR.
SATURDAY AND SUNDAY...VFR.
MARINE
CONDITIONS ARE EXPECTED TO BE BELOW SMALL CRAFT ADVISORY LEVELS
TODAY AND TONIGHT AS SEAS WILL BE AROUND 3 TO 4 FEET AND NW
WINDS SHIFTING TO SW THIS AFTERNOON WILL BE AROUND 10 KNOTS,
SHIFTING BACK NW TONIGHT.
THE CONDITIONS ARE FORECAST TO STAY BELOW SMALL CRAFT ADVISORY
LEVELS WEDNESDAY AS SEAS WILL BE AROUND 2 TO 4 FEET WITH NW TO
W/SW WINDS GENERALLY 10 TO 15 KNOTS OR LESS.
OUTLOOK...
THURSDAY THROUGH SUNDAY...SW WINDS COULD GUST TO AROUND 20 KNOTS
OR SO LATE THURSDAY INTO THURSDAY NIGHT BUT OTHERWISE THE
CONDITIONS ARE EXPECTED TO STAY BELOW SMALL CRAFT ADVISORY
LEVELS.
RIP CURRENTS...
FOR TODAY, NORTHWESTERLY WINDS 5-10 MPH IN THE MORNING WILL
BECOME SOUTHWESTERLY AROUND 10 MPH IN THE AFTERNOON. BREAKING
WAVE HEIGHTS 2-3 FEET. EAST-SOUTHEASTERLY SWELL AROUND 2-3 FEET
AT 7-9 SECONDS IN LENGTH. AS A RESULT, HAVE OPTED TO MAINTAIN A
MODERATE RISK FOR THE DEVELOPMENT OF DANGEROUS RIP CURRENTS AT
ALL BEACHES.
FOR WEDNESDAY, NORTHWESTERLY WINDS AROUND 5-10 MPH REMAIN
THROUGH MUCH OF THE DAY. BREAKING WAVE HEIGHTS WILL BE AROUND
1-2 FEET WITH A FEW 3 FOOT WAVES POSSIBLE NORTH. EASTERLY SWELL
WILL DIMINISH TO AROUND 1-2 FEET AROUND 7-9 SECONDS IN LENGTH.
GUIDANCE SUGGESTS MARGINALLY HIGHER SEAS AND SWELL FOR COASTAL
ATLANTIC AND NORTH, SO WENT WITH A MODERATE RISK FOR THIS REGION
WITH A LOW RISK FOR COASTAL CAPE MAY NJ AND SUSSEX DE.
FOR SPECIFIC BEACH FORECASTS, VISIT WEATHER.GOV/BEACH/PHI
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
SYNOPSIS...FITZSIMMONS/GORSE
NEAR TERM...FITZSIMMONS/RCM
SHORT TERM...FITZSIMMONS/GORSE
LONG TERM...FITZSIMMONS/GORSE
AVIATION...FITZSIMMONS/GORSE/RCM
MARINE...FITZSIMMONS/GORSE/RCM
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