651
FXUS61 KPHI 070951
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
551 AM EDT WED OCT 7 2026
WHAT HAS CHANGED
UPDATED KEY MESSAGES FOR NEWLY NAMED TROPICAL STORM ISAIAS AND
AVIATION SECTION FOR 12Z TAFS.
KEY MESSAGES
1. A COOL AIR MASS IN PLACE IS BRINGING FROST TO PARTS OF THE
REGION EARLY THIS MORNING, PARTICULARLY ACROSS THE POCONOS AND
NORTHWESTERN NEW JERSEY.
2. TRANQUIL WEATHER WILL PREVAIL THIS WEEK CONTINUING INTO THE
WEEKEND WITH NO SIGNIFICANT WEATHER HAZARDS ANTICIPATED.
3. THE REMNANTS OF WHAT IS NOW TROPICAL STORM ISAIAS WILL
APPROACH THE AREA LATER THIS WEEKEND BRINGING CHANCES FOR RAIN
AS EARLY AS SUNDAY.
DISCUSSION
KEY MESSAGE 1...A COOL AIR MASS IN PLACE IS BRINGING FROST TO
PARTS OF THE REGION EARLY THIS MORNING, PARTICULARLY ACROSS THE
POCONOS AND NORTHWESTERN NEW JERSEY.
CANADIAN HIGH PRESSURE HAS BROUGHT A COOL AIRMASS TO THE AREA. THE
HIGH IS GRADUALLY BEGINNING TO SLIDE OFFSHORE THIS MORNING.
THIS SETUP HAS LEAD TO VERY GOOD RADIATIONAL COOLING CONDITIONS
EARLY THIS MORNING DUE TO THE MAINLY CLEAR SKY AND NEAR CALM
WIND UNDER THE CENTER OF THE HIGH. FOR THESE REASONS OUR
FORECAST CONTINUES TO UNDERCUT NBM TEMPS FOR MOST AREAS WITH THE
MENTION OF PATCHY FROST IN THE NORMALLY COOLER AREAS INCLUDING
INTERIOR SOUTHERN NJ. FARTHER NORTH, FROST IS MORE EXTENSIVE SO
WE CONTINUE WITH THE FROST ADVISORY FOR EARLY THIS MORNING FOR
OUR POCONO ZONES AND SUSSEX COUNTY NJ. THESE AREA HAVE THE BEST
CHANCES FOR TEMPERATURES RADIATING TO FREEZING, AND IN FACT KMPO
REACHED FREEZING ALREADY, MARKING THE END OF THE GROWING SEASON
AT LEAST IN THE COLDEST PORTIONS OF OUR REGION. WHETHER THAT
CAUSES US TO DECLARE ANY ENTIRE FORECAST ZONES AS HAVING ENDED
THE GROWING SEASON REMAINS TO BE SEEN, AS IT GENERALLY NEEDS TO
BE AT LEAST HALF THE ZONE AND THAT PART IS NOT YET CLEAR. SOME
COLDER LOCATIONS FARTHER SOUTH, PARTICULARLY ACROSS THE NJ PINE
BARRENS, ARE ALSO MAKING A RUN AT 32 EARLY THIS MORNING, BUT WE
HAVEN'T SEEN ANY OTHER MAJOR LOCATIONS REACH THERE JUST YET.
KEY MESSAGE 2...TRANQUIL WEATHER WILL PREVAIL THIS WEEK
CONTINUING INTO THE WEEKEND WITH NO SIGNIFICANT WEATHER HAZARDS
ANTICIPATED.
HIGH PRESSURE WILL BE IN CONTROL THROUGH MOST OF THE WEEK
RESULTING IN MOSTLY CLEAR/SUNNY SKIES. FOLLOWING THIS MORNING'S
CHILLY WEATHER TEMPERATURES WILL MODERATE LATER TODAY THROUGH
THURSDAY AS THE FLOW TURNS SOUTHWESTERLY AHEAD OF THE NEXT COLD
FRONT. IN FACT HIGHS BY THURSDAY AFTERNOON LOOK TO REACH THE
MIDDLE TO UPPER 70S FOR MOST OF THE AREA, PERHAPS EVEN TOUCHING
80, THOUGH LATEST NBM HAS NUDGED THE TEMPS DOWN A BIT. THE COLD
FRONT MOVES THROUGH BY LATE THURSDAY AS A DRY FRONT AND WILL BE
FOLLOWED BY HIGH PRESSURE RE- ESTABLISHING ITSELF OVER THE AREA
FOR FRIDAY THROUGH AT LEAST SATURDAY WITH SEASONABLE
TEMPERATURES.
KEY MESSAGE 3...THE REMNANTS OF WHAT IS NOW TROPICAL STORM
ISAIAS WILL APPROACH THE AREA LATER THIS WEEKEND BRINGING
CHANCES FOR RAIN AS EARLY AS SUNDAY.
HIGH PRESSURE SHIFTS OFFSHORE BY SUNDAY AS THE NEXT LOW
PRESSURE SYSTEM (WHAT IS NOW TROPICAL STORM ISAIAS) APPROACHES
FROM THE SOUTH AND WEST. THERE ARE SOME MODEL DIFFERENCES
REGARDING THIS SYSTEM AND ITS ARRIVAL TIME IN THE AREA. THE
LATEST ECMWF SLOWED DOWN A BIT COMPARED TO ITS EARLIER RUN,
WHILE THE GFS HAS SPED UP. IN ANY EVENT, THE SYSTEM SHOULD BE
FAIRLY PROGRESSIVE BUT WILL LIKELY HAVE SIGNIFICANT MOISTURE
WITH IT (PWATS POTENTIALLY REACHING A RATHER TROPICAL 2 INCHES)
SO THE RAIN COULD BE HEAVY AT TIMES WITH THE POTENTIAL FOR SOME
AREAS TO SEE 1-2 INCHES.
AVIATION /09Z WEDNESDAY THROUGH SUNDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
TODAY...VFR. SOUTH-SOUTHWEST WINDS AROUND 7-12 KT. HIGH
CONFIDENCE.
TONIGHT...VFR. SOUTH-SOUTHWEST WINDS AROUND 5 KTS MAY BECOME
LIGHT/VARIABLE LATE. HIGH CONFIDENCE.
THURSDAY...VFR. SOUTHWEST WINDS 5-10 KTS. HIGH CONFIDENCE.
OUTLOOK...
THURSDAY NIGHT THROUGH SATURDAY...VFR. NO SIGNIFICANT WEATHER
EXPECTED.
SUNDAY AND MONDAY...RESTRICTIONS POSSIBLE WITH THE REMNANTS OF
WHAT IS NOW TROPICAL STORM ISAIAS MOVING THROUGH, ACCOMPANIED
BY LOW STRATUS AND RAIN.
MARINE
TODAY INTO THURSDAY, WINDS WILL BE SOUTHWEST AND INCREASE TO
15-20 KT BY LATE DAY THROUGH EARLY THURSDAY. SOME GUSTS OF 20
TO 25 KT WILL BE POSSIBLE SO IT WILL BE AT LEAST CLOSE TO SMALL
CRAFT ADVISORY LEVELS. HOWEVER GIVEN THAT IT'S MARGINAL, WE ARE
HOLDING OFF ON ISSUING A SMALL CRAFT ADVISORY AT LEAST AT THIS
POINT.
OUTLOOK...
FRIDAY THROUGH SATURDAY...NO MARINE HAZARDS EXPECTED.
SUNDAY INTO MONDAY...SCA POSSIBLE AS THE REMNANTS OF WHAT IS
NOW TROPICAL STORM ISAIAS MOVES THROUGH THE REGION.
PHI WATCHES/WARNINGS/ADVISORIES
PA...FROST ADVISORY UNTIL 9 AM EDT THIS MORNING FOR PAZ054-055.
NJ...FROST ADVISORY UNTIL 9 AM EDT THIS MORNING FOR NJZ001.
DE...NONE.
MD...NONE.
MARINE...NONE.
DISCUSSION...FITZSIMMONS/RCM
AVIATION...DESILVA/FITZSIMMONS/RCM
MARINE...FITZSIMMONS/RCM
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