217
FXUS61 KPHI 081804
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
204 PM EDT THU OCT 8 2026
WHAT HAS CHANGED
ALL SECTIONS REFRESHED BUT NO MAJOR CHANGES TO THE FORECAST.
KEY MESSAGES
1. TRANQUIL, DRY WEATHER WILL PREVAIL THROUGH SATURDAY WITH NO
SIGNIFICANT WEATHER HAZARDS ANTICIPATED.
2. THE REMNANTS OF WHAT IS NOW HURRICANE ISAIAS WILL APPROACH THE
AREA LATE THIS WEEKEND BRINGING RAIN BACK TO THE REGION SUNDAY INTO
SUNDAY NIGHT.
DISCUSSION
KEY MESSAGE 1...TRANQUIL, DRY WEATHER WILL PREVAIL THROUGH SATURDAY
WITH NO SIGNIFICANT WEATHER HAZARDS ANTICIPATED.
A DIFFUSE COLD FRONT WILL MAKE ITS WAY OFFSHORE THROUGH EARLY THIS
EVENING. IN ITS WAKE, HIGH PRESSURE WILL BUILD IN TONIGHT THROUGH
FRIDAY BRINGING CONTINUING MAINLY CLEAR SKIES WITH DRY WEATHER. LOWS
TONIGHT LOOK TO GENERALLY GET DOWN INTO THE 40S FOR MOST AREAS
EXCEPT LOW 50S FOR THE WILMINGTON THROUGH PHILADELPHIA URBAN
CORRIDOR, DELMARVA, AND COASTAL NJ. THIS WILL BE FOLLOWED BY HIGHS
FRIDAY GENERALLY IN THE LOW TO MID 70S SO NOT TOO FAR OFF FROM
AVERAGE FOR THIS TIME OF YEAR. EXPECT THAT BY LATE IN THE DAY THERE
MAY BE SOME HIGH, THIN CIRRUS OVER PORTIONS OF DELMARVA AND SOUTHERN
NJ BUT IT WILL OTHERWISE BE A MAINLY SUNNY DAY.
FRIDAY EVENING, THE CENTER OF HIGH PRESSURE WILL BE CENTERED RIGHT
OVER THE AREA BUT WILL THEN START TO GRADUALLY RETREAT EAST AND
NORTHEASTWARD TOWARDS NEW ENGLAND HEADING INTO SATURDAY. EXPECT
INCREASING MID AND HIGH LEVEL CLOUDINESS THROUGH THE DAY SATURDAY AS
MOISTURE STARTS TO STREAM NORTHWARD IN THE UPPER LEVELS. HOWEVER IT
REMAINS DRY THROUGH THE DAY. MOST AREAS WILL SEE HIGHS SIMILAR TO
FRIDAY HOWEVER THE WINDS WILL BE COMING AROUND TO EASTERLY ON THE
SOUTH SIDE OF THE HIGH TO OUR NORTH SO THIS WILL KEEP IT A BIT
COOLER NEAR THE COAST.
KEY MESSAGE 2...THE REMNANTS OF WHAT IS NOW HURRICANE ISAIAS WILL
APPROACH THE AREA LATE THIS WEEKEND BRINGING RAIN BACK TO THE REGION
SUNDAY INTO SUNDAY NIGHT.
THE PRIMARY FORECAST CONCERN FOR THE LATTER PART OF THIS WEEKEND
INTO EARLY NEXT WEEK WILL BE THE REMNANTS OF WHAT IS CURRENTLY
HURRICANE ISAIAS IN THE GULF. IT IS EXPECTED TO INTENSIFY FURTHER
BEFORE MAKING LANDFALL SOMEWHERE ALONG THE NORTHERN GULF COAST
FRIDAY NIGHT AS IT BEGINS INTERACTING WITH AN UPPER TROUGH. FROM
THERE, IT IS EXPECTED TO UNDERGO EXTRATROPICAL TRANSITION AND
CONTINUE NORTHWARD TOWARDS PORTIONS OF THE OHIO VALLEY THROUGH
SATURDAY NIGHT, AND THEN NORTHEASTWARD IN THE DIRECTION OF OUR AREA
ON SUNDAY.
SOME TIMING DISCREPANCIES OF SEVERAL HOURS REMAIN AMONGST MODEL
GUIDANCE THIS AFTERNOON, BUT THERE IS STRONG AGREEMENT THAT THE
REMNANTS OF ISAIAS WILL BRING SOME IMPACTS TO THE REGION BEGINNING
DURING THE DAY SUNDAY AND PERHAPS LINGERING INTO EARLY MONDAY.
AT THIS POINT IN TIME, IT APPEARS THAT WIDESPREAD RAIN WILL BE
THE PRIMARY IMPACT. IT SHOULD BE NOTED THAT PWATS ARE MODELED TO
BE IN THE 1.5- 2+ INCH RANGE, SO SOME PERIODS OF HEAVY RAINFALL
WILL BE POSSIBLE. OUR CURRENT FORECAST IS FOR .50 TO 1.00
INCHES OF RAINFALL WITH THE SYSTEM THROUGH EARLY SUNDAY EVENING
BUT WITH MORE RAIN FALLING SUNDAY NIGHT INTO EARLY MONDAY, STORM
TOTALS IN THE 1.0 TO 2.0 INCH RANGE WILL BE QUITE POSSIBLE.
IT'S EVEN STILL POSSIBLE SOME AREAS COULD SEE OVER 2.0 INCHES
BUT CONFIDENCE REGARDING THIS IS LOW. WPC HAS PLACED MOST OF THE
REGION IN A MARGINAL RISK (1 OF 4) EXCESSIVE RAINFALL OUTLOOK
FOR SUNDAY MEANING AT LEAST ISOLATED INSTANCES OF FLOODING WILL
BE POSSIBLE. WE WILL CONTINUE TO MONITOR TRENDS OVER THE COMING
DAYS.
AVIATION /18Z THURSDAY THROUGH TUESDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
REST OF TODAY...VFR. WEST-NORTHWEST TO NORTHWEST WINDS OF 10-15
KT WITH GUSTS TO 20-25 KT. HIGH CONFIDENCE.
TONIGHT...VFR. WEST-NORTHWEST TO NORTHWEST WINDS GENERALLY 5 KT
OR LESS. HIGH CONFIDENCE.
FRIDAY...VFR. WEST-NORTHWEST WINDS AROUND 10 KT. SOME HIGHER
GUSTS ARE LIKELY, BUT HAVE LEFT OUT OF THE TAFS FOR NOW. HIGH
CONFIDENCE.
OUTLOOK...
FRIDAY NIGHT THROUGH SATURDAY NIGHT...VFR. NO SIGNIFICANT
WEATHER.
SUNDAY THROUGH MONDAY...SUB-VFR CONDITIONS ARE LIKELY IN RAIN
AND LOW CLOUDS.
MONDAY NIGHT THROUGH TUESDAY...PRIMARILY VFR. ISOLATED SHOWERS
ARE POSSIBLE TUESDAY AFTERNOON, WHICH COULD LEAD TO BRIEF
PERIODS OF SUB-VFR CONDITIONS.
MARINE
WESTERLY WINDS OF 10-20 KNOTS THIS AFTERNOON DIMINISHING TO AROUND 5-
10 KNOTS BY LATER THIS EVENING INTO THE OVERNIGHT. WINDS CONTINUE
MAINLY OUT OF THE WEST FOR FRIDAY AT AROUND 5-10 KNOTS. SEAS 2-3
FEET THIS AFTERNOON DIMINISHING TO AROUND 1-2 FEET BY LATER TONIGHT
THROUGH FRIDAY.
SOUTHWEST WINDS OF 10-20 KTS WILL SHIFT TO WESTERLY IN WAKE OF A
COLD FRONT TODAY, BEFORE BEGINNING TO DIMINISH BY THIS EVENING. SEAS
2 TO 4 FEET. FAIR WEATHER.
OUTLOOK...
FRIDAY NIGHT THROUGH SATURDAY NIGHT...NO MARINE HEADLINES CURRENTLY
ANTICIPATED WITH WINDS UNDER 25 KTS AND SEAS BELOW 5 FEET.
SUNDAY THROUGH MONDAY...ADVISORY CONDITIONS ARE POSSIBLE WITH WIND
GUSTS IN EXCESS OF 25 KTS AND SEAS IN EXCESS OF 5 FEET AS THE
REMNANTS OF HURRICANE ISAIAS MOVE THROUGH. VISIBILITY RESTRICTIONS
ARE POSSIBLE IN RAIN AND PERHAPS SPRAY.
TUESDAY...CONDITIONS RETURN TO BELOW SMALL CRAFT ADVISORY
LEVELS WITH WEST TO SOUTHWEST WINDS AROUND 10-15 KNOTS AND SEAS
2-4 FEET.
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
DISCUSSION...FITZSIMMONS/RCM
AVIATION...COOPER
MARINE...FITZSIMMONS
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