218
FXUS61 KPHI 270602
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
200 AM EDT WED AUG 27 2025
SYNOPSIS
HIGH PRESSURE WILL SLIDE EASTWARD ACROSS THE MID-ATLANTIC TODAY
BEFORE SHIFTING OFFSHORE 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 TONIGHT/
HIGH PRESSURE OVER THE OHIO VALLEY WILL BUILD EASTWARD THROUGH
THE NEXT 24 HOURS, ENDING UP ACROSS THE MID-ATLANTIC BY LATE
TONIGHT. ALOFT, UPPER TROUGH CURRENTLY OVERHEAD, CENTERED JUST
TO OUR WEST PRESENTLY, WILL SLIDE EAST AND START LIFTING OUT BY
THIS AFTERNOON, A PROCESS WHICH WILL CONTINUE TONIGHT. THUS,
OVERALL EXPECT A RELATIVELY TRANQUIL DAY, WITH LESS CHANCE OF
SPOTTY SHOWERS COMPARED TO YESTERDAY, THOUGH INSTABILITY
ASSOCIATED WITH THE LINGERING UPPER TROUGH MAY STILL SPAWN
SOMETHING, MOST LIKELY OVER THE POCONOS OR FAR NW NJ. OTHERWISE,
SOME HIGH CLOUDS THIS MORNING WILL GIVE WAY TO JUST SOME SPOTTY
CUMULUS LATER ON TODAY, WITH A BIT OF A BREEZY NORTHWEST WIND IN
THE WAKE OF YESTERDAY'S REINFORCING COLD FRONT. HIGHS IN MOST OF
THE AREA WILL FAIL TO REACH 80, A RARE EVENT ON WHAT OTHERWISE
SHOULD BE A MOSTLY SUNNY AND DRY LATE AUGUST DAY.
HIGH PRESSURE NEARBY WILL PROMOTE LIGHT WINDS, CLEAR SKIES AND
GOOD RADIATIONAL COOLING TONIGHT. THUS, EXPECT THE COOLEST NIGHT
OF THE MONTH ACROSS THE REGION, WITH 40S IN THE COLDEST SPOTS,
MOST OTHER LOCALES IN THE 50S, AND MAYBE A FEW 60S IN THE
ABSOLUTELY WARMEST URBAN AREAS AND NEAR THE IMMEDIATE COAST.
THAT SAID, IT LOOKS LIKE WE WON'T REACH RECORDS, WHICH ARE AT
LEAST 5 DEGREES BELOW THE CURRENT FORECAST.
SHORT TERM /THURSDAY 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 /06Z WEDNESDAY THROUGH SUNDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
THRU 12Z...VFR. PATCHY FOG WITH LOWER VSBYS POSSIBLE KRDG.
NORTHWEST WINDS AROUND 5 TO 10 KNOTS. HIGH CONFIDENCE.
TODAY...VFR WITH WNW WINDS AROUND 10 KNOTS; A FEW GUSTS MAY
REACH 20 KTS IN THE MIDDAY AND AFTERNOON. HIGH CONFIDENCE.
TONIGHT...VFR WITH WNW WINDS TAPERING TO 5 KTS OR LESS. HIGH
CONFIDENCE.
OUTLOOK...
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
THRU TONIGHT AS SEAS WILL BE AROUND 2 TO 3 FEET AND WNW WINDS
WILL BE AROUND 10 KNOTS WITH A FEW GUSTS UP TO 20 KTS.
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 AROUND 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 THURSDAY, WINDS SHIFT SOUTHERLY BUT REMAIN AROUND 10 MPH
THROUGH MUCH OF THE DAY. BREAKING WAVE HEIGHTS WILL REMAIN
AROUND 1-2 FEET WITH A FEW 3 FOOT WAVES POSSIBLE NORTH. EASTERLY
SWELL WILL REMAIN AROUND 1-2 FEET AROUND 7-9 SECONDS IN LENGTH.
GUIDANCE STILL SUGGESTS MARGINALLY HIGHER SEAS AND SWELL FOR
COASTAL ATLANTIC AND NORTH, SO AGAIN 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/RCM
NEAR TERM...FITZSIMMONS/RCM
SHORT TERM...FITZSIMMONS/GORSE
LONG TERM...FITZSIMMONS/GORSE
AVIATION...FITZSIMMONS/GORSE/RCM
MARINE...FITZSIMMONS/GORSE/RCM
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