896
FXUS61 KPHI 302334
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
734 PM EDT Tue Sep 30 2025

.SYNOPSIS...
A cold front will move through the region tonight, with strong
high pressure building south into the region and remaining in
place through the weekend and into early next week. Several
tropical systems over the western Atlantic ocean will remain
away from the Mid- Atlantic coast.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
Our area is currently under fairly weak flow aloft, with
Hurricanes Humberto and Imelda over the Western Atlantic basin
to our southeast, a ridge axis across central portions of the
country, and the polar jet dipping southward into far northern
New England. With time, the ridge over the central tier of the
US will expand eastward into the area, becoming the dominant
feature. At the surface, a cold front to the north of the area
will move through the region tonight. Strong high pressure
centered over portions of Ontario will expand southward into the
area thereafter.

Widespread cloudiness from Imelda`s cirrus shield is prevalent
across the area, though it is gradually beginning to thin. With
very limited moisture, the approaching cold front is not
expected to trigger any showers. However, it will aid in
continuing to clear skies and also bring notably cooler
temperatures with its passage. Lows tonight will generally range
from near 50 across eastern PA and northern NJ to the upper 50s
to near 60 across southern NJ and the Delmarva. Across the
higher elevations of the Poconos and far northern NJ,
temperatures should fall into the 40s. High temperatures on
Wednesday will be in the upper 60s to near 70 areawide, with
mostly clear skies.

With high pressure building to the north and the hurricanes to
our southeast, a tight pressure gradient will begin to take
shape across the area tonight and during the day on Wednesday.
It will be somewhat breezy across the entire area, with gusts to
around 25 mph possible beginning late tonight. Near the coast,
however, this pattern will favor wind gusts perhaps to near 40
mph. Winds should begin to taper off some by late afternoon or
early evening.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
Surface high pressure centered over southern Quebec on
Wednesday night will build south over New England on Thursday,
then towards New York City Thursday night and finally end up
over the Atlantic east of New Jersey on Friday. Aloft, an upper
level ridge centered over Indiana Wednesday night will shift
southeastward towards Cincinnati Thursday, towards West
Virginia Thursday night, and into Virginia Friday, weakening
gradually as it does so. There will be a couple of very weak
impulses passing over the ridge and into our region Thursday
into Friday, bringing some high clouds, but that`s all.
Otherwise, the cooler Canadian surface high will promote dry
weather with partly to mostly clear skies and temps just a bit
below normal. Radiational cooling versus advection will
determine what the coolest night is at various locales, with
sites that get coldest with advection (urban areas) more likely
to be coolest Wednesday night when we still have a breeze, but
areas which chill best with radiational cooling (rural locales)
likely to be coldest Thursday night. Patchy frost may occur in
the coldest spots of our northwestern zones (Poconos/NW NJ), but
otherwise, nothing to write home about as it will only be
slightly cooler than our coldest night so far this side of the
summer solstice, which was nearly a month ago. Highs will be on
the cooler side, with 60s in most areas Thursday and creeping up
a few degrees closer to 70 on Friday.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
Surface high pressure likely settles just southeast of our
region for Saturday, lingering Sunday and Monday before starting
to be pushed eastward Tuesday as surface fronts start to
approach from the west. Aloft, upper ridge will remain in
overall control Saturday, actually strengthen somewhat Sunday as
it relocates to near Cape Hatteras, then starts to weaken a bit
Monday and losing more strength to oncoming shortwaves to the
northwest on Tuesday.

Sensible weather-wise, this means mostly continued dry, with
the chance of rain only starting to creep back up from zero on
Tuesday. It also means partly to mostly clear skies with
gradually warming temps as the air mass continues moderating.
Highs rise slowly towards 80 through Monday, then level off due
to increasing clouds Tuesday, while lows will slowly return to
the 50s for most, with 60s in the warmer spots by Monday night.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas...

Tonight...VFR. Broken high clouds will scatter out from north
to south through 01-03Z. Northeast wind beginning around 8-12
kts and increasing to 10-15 kts. Gusts increasing after 06Z, up
to 20 knots for most terminals with 20-25 kt gusts possible at
KMIV and KACY. High confidence.

Wednesday...VFR. Northeast wind 10-15 kt with gusts around 20
kt for most terminals. For KMIV and KACY, northeast wind 15-20
kt with gusts 25-30 kt. Moderate confidence.

Outlook...

Wednesday night through Sunday...VFR with no significant
weather.

&&

.MARINE...
Confidence remains high in gale force winds in frequent gusts
continuing into Wednesday afternoon. All ocean zones now have a
Gale warning through 6 PM Wednesday. Gusts near 40 kt are
expected. For the Delaware Bay, gusts near 30 kt are anticipated
and a Small Craft Advisory is in place.

Seas across the ocean zones around 4-6 feet initially will grow
to 7- 11 feet during the day Wednesday.

Outlook...

Gales dwindle early Wednesday night, but SCA winds linger into
Thursday. For the ocean waters, SCA wave heights likely continue
through Friday. Sub-SCA conditions likely over the weekend.

Rip Currents...

A high risk of rip currents is likely to continue through the
remainder of the week. However, the surf program ends today. No
further surf forecasts or rip current statements will be issued
until May 2026.

&&

.TIDES/COASTAL FLOODING...
Strengthening northeast winds and long period swells arriving
from Humberto through Wednesday will lead to a piling up of
water along the Atlantic coast, back bays, and Delaware Bay.
Widespread minor coastal flooding will develop for these areas
with the Wednesday afternoon to evening high tide cycle. Minor
coastal flooding may linger within the back bays of Ocean and
Sussex Counties into Thursday. Spotty minor coastal flooding is
forecast for the tidal Delaware River.

A Coastal Flood Advisory is now in effect to highlight the
threat of minor coastal flooding from Ocean County and south and
Delaware Bay. We will continue to monitor the latest
observations for possible expansion of the advisory to the tidal
Delaware River.

Spotty minor coastal flooding is forecast to occur with the
Wednesday night and Thursday night high tides along the eastern
shore of Chesapeake Bay, however impacts are expected to be
limited enough to preclude and advisory at this time.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...Coastal Flood Advisory from 5 PM to 9 PM EDT Wednesday for
     NJZ016.
     Coastal Flood Advisory from 2 PM to 8 PM EDT Wednesday for
     NJZ020>027.
DE...Coastal Flood Advisory from 5 PM to 9 PM EDT Wednesday for
     DEZ001.
     Coastal Flood Advisory from 2 PM to 8 PM EDT Wednesday for
     DEZ002>004.
MD...None.
MARINE...Small Craft Advisory from 11 PM this evening to 6 PM EDT
     Wednesday for ANZ430.
     Small Craft Advisory until 6 PM EDT Thursday for ANZ431.
     Gale Warning until 6 PM EDT Wednesday for ANZ450>455.

&&

$$

SYNOPSIS...Cooper/RCM
NEAR TERM...AKL/Cooper
SHORT TERM...RCM
LONG TERM...RCM
AVIATION...AKL/Cooper/RCM
MARINE...AKL/Cooper/RCM
TIDES/COASTAL FLOODING...Staarmann