967
FXUS61 KPHI 140120
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
920 PM EDT WED AUG 13 2025
SYNOPSIS
A SURFACE TROUGH WILL SLOWLY MOVE ACROSS OUR AREA TONIGHT,
AHEAD OF A COLD FRONT WHICH CROSSES ON THURSDAY. THE FRONT THEN
SETTLES JUST TO OUR SOUTH INTO FRIDAY BEFORE DISSIPATING BY
SATURDAY. HIGH PRESSURE ARRIVES FOR SATURDAY INTO SUNDAY, THEN A
COLD FRONT CROSSES OUR AREA LATE SUNDAY INTO MONDAY. HIGH
PRESSURE STARTS TO BUILD IN FROM THE NORTHWEST TUESDAY INTO
WEDNESDAY.
NEAR TERM /THROUGH THURSDAY/
THE FLOOD WATCH WAS CANCELED AT 9 PM. SHOWERS AND THUNDERSTORMS
WILL LINGER ACROSS DELMARVA AND SOUTHERN NEW JERSEY, AND SOME
ADDITIONAL SHOWERS ARE POSSIBLE ELSEWHERE. HOWEVER, NO
ADDITIONAL FLOODING OR SEVERE THUNDERSTORMS ARE EXPECTED THROUGH
THE OVERNIGHT PERIOD. PATCHY FOG IS POSSIBLE ONCE AGAIN. LOWS
TONIGHT WILL GENERALLY BE IN THE UPPER 60S TO LOW 70S UNDER
MOSTLY CLOUDY SKIES.
THE UPPER TROUGH/SURFACE FRONT LINGERS ACROSS OUR FORECAST AREA
THURSDAY WITH WIDELY SCATTER SHOWERS IN THE MORNING. CLOUDS
WILL BE ACROSS THE AREA FOR MUCH OF THE DAY, KEEPING TEMPS A FEW
DEGREES COOLER THAN RECENT DAYS. HIGHS WILL STILL MOSTLY BE 85
TO 90 MOST AREAS. THE BREAKS IN THE CLOUDS AND DAYTIME HEATING
WILL STILL ALLOW ENOUGH INSTABILITY TO DEVELOP TO CONTINUE WITH
TSTMS FOR THU. SEVERE WEATHER IS NOT ANTICIPATED BUT LOCALLY
HEAVY RAINS WILL OCCUR.
SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/
A WEAK COLD FRONT IS FORECAST TO SETTLE TO OUR SOUTH THURSDAY
NIGHT. ANY SHOWER OR THUNDERSTORM IN THE EVENING ARE EXPECTED TO
MOVE OUT OF THE AREA OR DISSIPATE, WITH AREAS SOUTH AND EAST OF
I-95 HAVING THE GREATER CHANCE GIVEN THE PROXIMITY OF THE
FRONT. SOME DRIER AIR ADVECTING IN FROM THE NORTH SHOULD BE
STRONG ENOUGH TO LOWER OUR DEW POINTS AT LEAST SOME, WITH THIS
MORE NOTABLE ACROSS OUR NORTHERN AREAS. THE AMOUNT OF DRYING AND
CLOUD COVER WILL DETERMINE IF ANY FOG DEVELOPS, ESPECIALLY AS
THE WINDS ARE ANTICIPATED TO BE RATHER LIGHT OR CALM THURSDAY
NIGHT. THE FOG POTENTIAL IS OF LOW CONFIDENCE GIVEN SOME DRYING
WORKING INTO FROM THE NORTH.
FOR FRIDAY, THE FLOW ALOFT BECOMES MORE ZONAL WITH SOME
LINGERING RIDGING INITIALLY ACROSS PARTS OF EASTERN CANADA AHEAD
OF AN UPPER- LEVEL TROUGH. THIS WILL SUPPORT SURFACE HIGH
PRESSURE SLIDING BY TO OUR NORTH. THIS SHOULD ASSIST IN PUSHING
THE WEAK COLD FRONT JUST TO OUR SOUTH BEFORE IT STARTS TO
DISSIPATE. WE HAVE MORE OF THE INFLUENCE OF THE SURFACE HIGH TO
OUR NORTH, HOWEVER THERE IS NO SIGNIFICANT PUSH OF COOLER AIR.
THE DEW POINTS ARE FORECAST TO COME DOWN A LITTLE, ESPECIALLY
ACROSS THE NORTHERN PORTION OF OUR AREA, WITH ENOUGH DRIER AIR
MIXING IN ESPECIALLY DURING THE DAYTIME HOURS. WHILE NOT MUCH OF
A FOCUSING MECHANISM LOOKS TO BE PRESENT TO INITIATE
CONVECTION, A FEW SHOWERS OR A THUNDERSTORM CANNOT BE RULED OUT
IN THE AFTERNOON AS THE AIR MASS WILL STILL BE RATHER WARM AND
HUMID. HIGH TEMPERATURES OUTSIDE OF THE COASTAL AREAS AND HIGHER
ELEVATIONS ARE FORECAST TO BE IN THE UPPER 80S TO 90 DEGREES.
AS WE GO THROUGH SATURDAY, OUR REGION IS FORECAST TO BE ON THE
NORTHEASTERN PART OF A STRONG WEST TO EAST MID/UPPER LEVEL
RIDGE. THE VERY WARM CONDITIONS ARE FORECAST TO CONTINUE WITH
DAYTIME HIGHS REACHING THE MID TO UPPER 80S (COOLER ALONG THE
COAST). WHILE THE DEW POINTS MAY COME DOWN SOME DURING PEAK
HEATING, IT WILL STILL BE ON THE HUMID SIDE. OTHER THAN AN
ISOLATED AFTERNOON TO EARLY EVENING SHOWER OR THUNDERSTORM
POSSIBLE, MAINLY NORTH AND WEST OF I-95.
LONG TERM /SUNDAY THROUGH WEDNESDAY/
SUMMARY...WARM/HOT AND HUMID CONDITIONS, THEN TURNING COOLER
AND LESS HUMID LATE TUESDAY AND ESPECIALLY WEDNESDAY. SOME LOW
CHANCES FOR SHOWERS AND THUNDERSTORMS.
SYNOPTIC OVERVIEW...A MID/UPPER LEVEL RIDGE MORE CENTERED NEAR
THE MID-MISSISSIPPI VALLEY IS FORECAST TO SHIFT WESTWARD SOME AS
AN UPPER-LEVEL TROUGH SLIDES ACROSS EASTERN CANADA. THIS TROUGH
WILL WEAKEN THE NORTHEASTERN PART OF THE RIDGE ACROSS THE MID-
ATLANTIC REGION SUNDAY AND BEYOND. AT THE SURFACE, A COLD FRONT
IS FORECAST TO CROSS OUR AREA LATE SUNDAY INTO MONDAY FOLLOWED
BY HIGH PRESSURE FROM THE NORTHWEST TUESDAY AND WEDNESDAY.
FOR SUNDAY...AN UPPER-LEVEL TROUGH MOVING ACROSS EASTERN CANADA
LOOKS TO PUSH A RIDGE SOUTH AND WESTWARD WITH TIME. THIS WILL
RESULT IN THE HEIGHTS LOWERING SOME ACROSS THE NORTHEAST INTO
THE NORTHERN MID-ATLANTIC. HOWEVER GIVEN THE STRONGEST PART OF
THE TROUGH IS WELL TO OUR NORTH OUR TEMPERATURES SHOULD NOT BE
IMPACTED MUCH. AS A RESULT, THE WARM TO HOT CONDITIONS ARE
FORECAST TO CONTINUE WITH DAYTIME HIGHS REACHING THE MID/UPPER
80S TO LOW 90S. THE DEW POINTS ARE FORECAST TO BE IN THE UPPER
60S TO LOW 70S FOR THE MAJORITY OF OUR AREA, THEREFORE THE
CONTINUATION OF THE HUMID CONDITIONS. DESPITE THE HUMID
CONDITIONS, THE HEAT INDICES ARE STILL FORECAST TO BE SAFELY
BELOW HEAT ADVISORY CRITERIA. A COLD FRONT ASSOCIATED WITH THE
UPPER-LEVEL TROUGH ARRIVES LATE SUNDAY. THE OVERALL FORCING WITH
THIS FRONT LOOKS TO BE ON THE WEAKER SIDE, THEREFORE THE
PROBABILITY OF CONVECTION IS ON THE LOW SIDE (20-30 PERCENT FOR
MOST OF THE AREA IN THE AFTERNOON AND EVENING).
FOR MONDAY AND TUESDAY...THE AFOREMENTIONED UPPER-LEVEL TROUGH,
WHILE THE STRONGEST PART REMAINS WELL TO OUR NORTH, AMPLIFIES A
LITTLE ACROSS THE NORTHEAST THROUGH TUESDAY. THIS WILL LOWER
THE HEIGHTS A LITTLE MORE, HOWEVER THE MODEL GUIDANCE OVERALL
HAS SLOWED THIS PROCESS SOME. THIS RESULTS IN THE VERY WARM AND
HUMID CONDITIONS CONTINUING, HOWEVER A LOWERING OF THE DEW
POINTS SHOULD OCCUR ESPECIALLY ON TUESDAY WHEN MORE OF THE HIGH
PRESSURE INFLUENCE FROM THE NORTHWEST STARTS TO BECOME MORE
PRONOUNCED. A WEAK COLD FRONT IS FORECAST TO BE SETTLING TO OUR
SOUTH, HOWEVER WITH THE PRESENCE OF SOME TROUGHING ALOFT A FEW
SHOWERS/THUNDERSTORMS CANNOT BE RULED OUT EACH AFTERNOON AND
EVENING. SOME COOLING STARTS TO TAKE PLACE, WITH HIGH
TEMPERATURES CLOSER TO AVERAGE ESPECIALLY ON TUESDAY.
FOR WEDNESDAY...A LARGE UPPER-LEVEL TROUGH ACROSS EASTERN
CANADA IS FORECAST TO AMPLIFY MORE ACROSS THE NORTHEAST AND
NORTHERN MID- ATLANTIC REGIONS. AS THIS OCCURS, SURFACE HIGH
PRESSURE WILL CONTINUE TO BUILD INTO OUR AREA FROM THE NORTH OR
NORTHWEST. THE PRESENCE OF THE TROUGH AND INCOMING CANADIAN HIGH
PRESSURE SHOULD RESULT IN A MUCH MORE NOTICEABLE AIR MASS
CHANGE. COOLER TEMPERATURES WITH DEW POINTS FORECAST TO DROP
THROUGH THE 60S, AND EVEN INTO THE UPPER 50S FOR SOME AREAS,
DURING THE DAY AND AT NIGHT. DESPITE THE GRADUAL DRIER AIR
ARRIVING, STILL CANNOT RULE OUT A FEW SHOWERS OR THUNDERSTORMS
WITHIN THE MORE CYCLONIC FLOW REGIME ESPECIALLY IF THE DRIER AIR
IS SLOWER TO ARRIVE. MADE NO CHANGES TO THE NBM GUIDANCE, WHICH
HAS POPS OF 20-30 PERCENT ACROSS THE AREA.
AVIATION /01Z THURSDAY THROUGH MONDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
TONIGHT...LINGERING SHRA/TSRA WILL TAPER OFF IN THE EVENING,
THOUGH MAY PERSIST AT KMIV/KACY FOR MOST OF THE NIGHT.
CONDITIONS WILL GRADUALLY LOWER FROM VFR EARLY IN THE EVENING TO
A MIX OF MVFR/IFR AFTER 05Z. POSSIBLE LIFR IN SOME SPOTS. WINDS
GENERALLY WILL BE LIGHT AND VARIABLE TO CALM. MODERATE-LOW
CONFIDENCE OVERALL.
THURSDAY...AREAS OF STRATUS/FOG TO START THE MORNING, THEN VFR
THEREAFTER. SOME SHRA/TSRA AROUND WITH LOCALLY BUT BRIEF SUB-
VFR CONDITIONS POSSIBLE IN THE AFTERNOON, SO HAVE CARRIED EITHER
VCSH OR VCTS AT ALL TERMINALS. NORTH-NORTHWEST WINDS BECOMING
VARIABLE AT TIMES. MODERATE CONFIDENCE.
OUTLOOK...
THURSDAY NIGHT...A FEW SHOWERS/THUNDERSTORMS POSSIBLE EARLY,
OTHERWISE MOSTLY VFR
FRIDAY AND SATURDAY...MAINLY VFR.
SUNDAY AND MONDAY...A FEW SHOWERS AND THUNDERSTORMS POSSIBLE
WITH BRIEF SUB-VFR CONDITIONS.
MARINE
SUB-SMALL CRAFT ADVISORY CONDITIONS THROUGH THURSDAY. SOUTH TO
SOUTHWEST WINDS GENERALLY 10 TO 15 KT WITH OCCASIONAL GUSTS UP
TO 20 KT. SEAS 2 TO 3 FEET.
LATE DAY AND EVENING SHOWERS AND THUNDERSTORMS WILL RESULT IN
VSBY RESTRICTIONS AND LOCALLY HIGHER WINDS AND SEAS.
OUTLOOK...
THURSDAY NIGHT THROUGH MONDAY...THE CONDITIONS ARE ANTICIPATED
TO BE BELOW SMALL CRAFT ADVISORY CRITERIA.
RIP CURRENTS...
FOR THURSDAY, WINDS WILL START OUT OF THE SOUTHWEST AND MOVE TO
BE MORE SOUTHEAST BY LATE DAY AT 5-10 MPH WITH A WAVE HEIGHT OF
1-2 FEET. THE PERIOD WILL BE 7-8 SECONDS. DUE TO THESE FACTORS,
A LOW RISK FOR THE DEVELOPMENT OF DANGEROUS RIP CURRENTS IS IN
PLACE FOR ALL OF THE JERSEY SHORE AND THE DELAWARE BEACHES.
FOR FRIDAY, WINDS WILL BE OUT OF THE NORTHEAST AT 5-10 MPH WITH
A WAVE HEIGHT OF GENERALLY 1-2 FEET. THE PERIOD WILL BE AROUND
8 SECONDS. DUE TO THESE FACTORS, A LOW RISK FOR THE DEVELOPMENT
OF DANGEROUS RIP CURRENTS IS IN PLACE FOR ALL OF THE JERSEY
SHORE AND THE DELAWARE BEACHES.
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
SYNOPSIS...GORSE
NEAR TERM...DEAL/DESILVA/MPS/STAARMANN
SHORT TERM...GORSE
LONG TERM...GORSE
AVIATION...DEAL/DESILVA/GORSE/MPS
MARINE...DEAL/DESILVA/GORSE/GUZZO/MPS
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