977
FXUS61 KPHI 271718
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
118 PM EDT WED AUG 27 2025
SYNOPSIS
HIGH PRESSURE, CENTERED IN THE OHIO VALLEY THIS MORNING, WILL SLIDE
EASTWARD ACROSS THE MID-ATLANTIC LATER TODAY INTO TONIGHT BEFORE
SHIFTING OFFSHORE THURSDAY. A COLD FRONT THEN CROSSES OUR AREA LATER
THURSDAY NIGHT INTO FRIDAY, FOLLOWED BY HIGH PRESSURE OVER THE
WEEKEND. AN AREA OF LOW PRESSURE MAY DEVELOP OFF THE MID-ATLANTIC
COAST EARLY NEXT WEEK.
NEAR TERM /THROUGH THURSDAY/
HIGH PRESSURE REMAINS OUR DOMINANT WEATHER FEATURE THROUGH
TOMORROW. THERE IS A SURFACE TROUGH THAT IS OFF TO OUR
NORTHWEST CURRENTLY HELPING TO INITIATE THIS SHOWER ACTIVITY AND
IT WILL MOVE EAST THROUGH THE EVENING. AN ISOLATED SHOWER IS
POSSIBLE FOR OUR NW ZONES BUT THAT IS THE EXTENT OF IT.
OTHERWISE DRY WITH MINIMAL CLOUD COVER DUE TO THE HIGH PRESSURE
SYSTEM IN CONTROL. OVERNIGHT, WE STAY DRY AND MOSTLY CLEAR. LOWS
TONIGHT FALL INTO THE UPPER 40S TO UPPER 50S.
FOR TOMORROW, THERE IS STILL A LONGWAVE TROUGH IN THE UPPER-LEVELS
ACROSS THE NORTHEAST WITH A PIECE OF SHORTWAVE ENERGY MOVING THROUGH
THURSDAY. ALTHOUGH HIGH PRESSURE WILL BE IN CONTROL AT THE SURFACE,
THAT PIECE OF SHORTWAVE ENERGY COULD BE ENOUGH FOR SOME LIGHT
SPOTTY SHOWERS DURING THE DAY THURSDAY WITH SOME CLOUDS ALSO
PASSING THROUGH. OVERALL, NOT EXPECTING MUCH IN THE FORM OF RAIN
THROUGH THURSDAY EVENING. HIGHS ON THURSDAY ARE IN THE 70S.
SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/
AN UPPER-LEVEL TROUGH IS FORECAST TO AMPLIFY INTO THE NORTHEAST AND
MID-ATLANTIC REGIONS THURSDAY. A COLD FRONT APPROACHES FROM THE WEST
DURING THE DAY BEFORE ARRIVING THURSDAY NIGHT AS LOW PRESSURE TRACKS
TO OUR NORTH. A FEW SHOWERS MAY START TO ARRIVE BY LATER AT NIGHT
ACROSS THE WESTERN AREAS AS SOME MOISTURE RETURN CONTINUES AHEAD OF
THE COLD FRONT. OVERALL THOUGH, THE MOISTURE RETURN DOES NOT LOOK
ALL THAT ROBUST AND THE MAIN FORCING SLIDING BY TO OUR NORTH SHOULD
LIMIT THE AMOUNT OF SHOWERS STARTING TO ARRIVE FROM THE WEST.
TEMPERATURES ARE FORECAST TO BE ON THE COOLER SIDE (BELOW AVERAGE).
FOR FRIDAY, A STRONG UPPER-LEVEL TROUGH SWINGS ACROSS THE NORTHEAST
AND MID-ATLANTIC REGIONS. THE GUIDANCE IS IN GOOD AGREEMENT
REGARDING THE PRESENCE OF THIS TROUGH, WITH MOST OF THE GUIDANCE
SHOWING A CLOSED LOW EVOLVING NORTH OF LAKE ONTARIO. THIS TROUGH
WILL CONTINUE TO DRIVE A COLD FRONT ACROSS OUR AREA. THE TIMING MAY
BE FAST ENOUGH TO NOT OCCUR DURING PEAK HEATING AND THUS LIMITING
THE COVERAGE OF SHOWERS/THUNDER. IN ADDITION, THE MOISTURE RETURN IS
NOT ALL THAT ROBUST AND WITH THE STRONGER FORCING SLIDING BY TO OUR
NORTH, THE CHANCES FOR ANY SHOWERS/THUNDER IS ON THE LOW SIDE (20-30
PERCENT). TEMPERATURES MOSTLY BELOW AVERAGE, AND DEW POINTS INCREASE
AHEAD OF THE FRONT WELL INTO THE 50S BEFORE FALLING THROUGH THE 50S
AND INTO THE 40S AT NIGHT IN THE WAKE OF THE COLD FRONT.
LONG TERM /SATURDAY THROUGH TUESDAY/
SUMMARY...TEMPERATURES MOSTLY BELOW AVERAGE; MAY NEED TO WATCH FOR A
POSSIBLE COASTAL LOW EARLY NEXT WEEK.
SYNOPTIC OVERVIEW...A STRONG UPPER-LEVEL TROUGH IS FORECAST TO SWING
ACROSS THE NORTHEAST AND MID-ATLANTIC REGIONS SATURDAY. THIS SHOULD
BE IN THE FORM OF A CLOSED LOW AS IT PIVOTS ACROSS NEW ENGLAND, THEN
OPENS UP AS IT SHIFTS INTO THE CANADIAN MARITIMES THROUGH SUNDAY. A
TROUGH ALOFT THOUGH IS FORECAST TO EXTEND ACROSS OUR REGION INTO
EARLY NEXT WEEK. SOME GUIDANCE HAS SOME STRONGER ENERGY HANGING BACK
ACROSS THE OHIO VALLEY WHICH THEN POTENTIALLY RESULTS IN A CLOSED
LOW ACROSS THE MID-ATLANTIC MONDAY INTO TUESDAY. AT THE SURFACE, A
COLD FRONT IS FORECAST TO BE WELL OFFSHORE TO START SATURDAY WITH
HIGH PRESSURE BUILDING EASTWARD FROM THE MIDWEST AND GREAT LAKES.
THE HIGH SLIDES BY TO OUR NORTH DURING EARLY NEXT WEEK AS A LOW
PRESSURE SYSTEM MAY DEVELOP OFF THE MID-ATLANTIC COAST.
FOR SATURDAY AND SUNDAY....A STRONG UPPER-LEVEL TROUGH, AS A CLOSED
LOW OVER NEW ENGLAND, IS FORECAST TO WEAKEN AS IT SHIFTS MORE INTO
THE CANADIAN MARITIMES. THIS ALLOWS SURFACE HIGH PRESSURE CENTERED
FROM THE MIDWEST AND GREAT LAKES TO SHIFT EASTWARD SOME AND MORE
INTO OUR AREA. THE GUIDANCE OVERALL KEEPS A TROUGH ALOFT THOUGH
EXTENDED ACROSS OUR AREA AND BACK INTO THE OHIO VALLEY. OUR SENSIBLE
WEATHER LOOKS TO BE CONTROLLED MAINLY BY HIGH PRESSURE CENTERED TO
OUR NORTHWEST AND THEREFORE A DRY HOLIDAY WEEKEND IS MAINTAINED.
SOME OF THE GUIDANCE/ENSEMBLES SUGGEST THAT THE TAIL-END OF THE
TROUGH ALOFT STRENGTHENS AND STARTS TO CLOSE OFF DURING SUNDAY IN
THE VICINITY OF THE CENTRAL APPALACHIANS. AS THIS OCCURS, LOWERING
HEIGHTS RESULTS IN A LINGERING BAROCLINIC ZONE OFF THE SOUTHEAST
U.S. COAST TO START STRENGTHENING AND SURFACE LOW PRESSURE MAY BEGIN
TO DEVELOP. SOME HIGH LEVEL CLOUDS MAY THEN START TO ARRIVE IN OUR
AREA AS WE GO THROUGH SUNDAY. DAYTIME TEMPERATURES ARE FORECAST TO
BE IN THE 70S BOTH DAYS FOR MOST OF THE AREA, WITH LOWS MOSTLY IN
THE 50S.
FOR MONDAY AND TUESDAY...AS THE AFORMENTIONED TROUGH ALOFT BECOMES
POTENTIALLY A CLOSED LOW TO OUR SOUTHWEST INITIALLY, LOW PRESSURE
OFF THE MID-ATLANTIC COAST WOULD TEND TO TRACK TO THE NORTH OR
NORTHEAST. THIS COULD BRING SOME SHOWERS TO AT LEAST THE COASTAL
AREAS STARTING LATER MONDAY (LABOR DAY). THE EVOLUTION OF THIS
SYSTEM IS UNCERTAIN GIVEN THE SPREAD WITHIN THE MODEL GUIDANCE AND
ENSEMBLE DATA. THERE IS AT LEAST SOME SIGNAL THOUGH IN THE GUIDANCE
OF A COASTAL LOW TRACKING TO THE NORTH OR NORTHEAST DURING THIS TIME
FRAME, HOWEVER THE IMPACTS TO OUR AREA ARE MUCH LESS CERTAIN.
DESPITE IF SHOWERS OCCUR OR NOT, TEMPERATURES STILL LOOK TO BE NEAR
OR BELOW AVERAGE ACROSS THE REGION. GIVEN THE UNCERTAINTY ON WHETHER
A COASTAL LOW OCCURS OR NOT AND THE TRACK IF IT DOES DEVELOP,
CONTINUED TO RIDE WITH THE NATIONAL BLEND OF MODELS (NBM)
OUTPUT.
AVIATION /17Z WEDNESDAY THROUGH SUNDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
THROUGH 00Z...VFR WITH WNW WINDS AROUND 10 KNOTS; A FEW GUSTS
MAY REACH 20 KTS. HIGH CONFIDENCE.
TONIGHT...VFR WITH WNW WIND TAPERING TO 5 KTS OR LESS. WINDS
LOOK TO BECOME LIGHT AND VARIABLE FOR A PERIOD OVERNIGHT. HIGH
CONFIDENCE.
THURSDAY...VFR WITH A SW WIND AROUND 5-10 KNOTS. HIGH
CONFIDENCE.
OUTLOOK...
FRIDAY...A FEW SHOWERS OR A THUNDERSTORM POSSIBLE, OTHERWISE MAINLY
VFR.
SATURDAY AND SUNDAY...VFR.
MARINE
CONDITIONS ARE EXPECTED TO BE BELOW SMALL CRAFT ADVISORY LEVELS
THROUGH TONIGHT AS SEAS WILL BE AROUND 2 TO 3 FEET AND WNW
WINDS WILL BE AROUND 10 KNOTS WITH GUSTS AROUND 20 KNOTS. WINDS
DECREASE TO 5-10 KNOTS OVERNIGHT OUT OF THE WEST.
ON THURSDAY, SEAS REMAIN 2-3 FEET BUT THE WIND WILL PICK UP OUT
OF THE SOUTHWEST BY THE AFTERNOON AND CONTINUE INTO THURSDAY
NIGHT. WINDS WILL BE 10-15 KNOTS WITH GUSTS AROUND 20 KNOTS.
OUTLOOK...
FRIDAY THROUGH SUNDAY...THE CONDITIONS ARE ANTICIPATED TO BE
BELOW SMALL CRAFT ADVISORY CRITERIA.
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...GORSE
NEAR TERM...GUZZO
SHORT TERM...GORSE
LONG TERM...GORSE
AVIATION...GORSE/GUZZO
MARINE...GORSE/GUZZO
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