051
FXUS61 KPHI 300722
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
322 AM EDT Tue Sep 30 2025

.SYNOPSIS...
High pressure over the area departs later today. A cold front
moves through the region tonight, and then broad high pressure
builds down from eastern Canada through the weekend. Several
tropical systems over the western Atlantic ocean will remain
away from the Mid- Atlantic coast.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
High pressure retreats to the south today ahead of an
approaching cold front. The cirrus shield from distant Tropical
Storm Imelda should keep things mostly cloudy today albeit dry.
Even with mostly cloudy skies, temperatures get into the upper
70s/low 80s.

Cold front comes approaches tonight and will usher in a fall-
like airmass. Not much moisture to work with, and the front may
even wash out by the time it gets through our region, so not
expecting any precipitation. We begin to feel the effects of the
Canadian airmass tonight as lows dip into the mid to upper 40s
in the Poconos and northern NJ, with 50s elsewhere. With the
front not getting through the southern half of the area until
late, some spots in far south Jersey and Delmarva could stay
above 60.

High pressure begins to nudge in from the north on Wednesday,
with a cool airmass overhead. There will be a notable northeast
breeze as a tight pressure gradient sets up with the incoming
high and two tropical systems exiting stage right in the
Atlantic. Winds near the coast could gust near 40 MPH at times,
with lesser gusts the further inland you go. While skies are
mostly sunny, temperatures only get into the upper 60s/low 70s.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
Broad high pressure will be centered over eastern Canada
Wednesday and will build down into the Northeast on Thursday
with the center of the high over the Gulf of Maine and around
Cape Cod by Thursday afternoon. Meanwhile, what are currently
Hurricane Humberto and Tropical Storm Imelda will be well east
of the Southeast coast and will depart. This will allow the
northeast pressure gradient over the area to relax Wednesday
night and Thursday, and winds along the coast will gradually
diminish during this time. High pressure remains in control
through Thursday night.

Skies will be clear Wednesday night and mostly sunny on
Thursday. Clouds begin to increase Thursday night.

Temperatures will be several degrees below the seasonal
averages during this time. Lows Wednesday night will range from
the low to mid 40s in the southern Poconos, northern New Jersey,
and Lehigh Valley, and in the upper 40s to low 50s for southern
New Jersey, the Delaware Valley, and Delmarva. Lows will be in
the mid to upper 50s along the coasts due to the proximity of
the warmer ocean waters. Highs on Thursday will be in the mid
and upper 60s. Lows Thursday night will be similar to Wedensday
night. There is the potential for radiational cooling away from
the coasts and away from the urban areas especially Thursday
night resulting in cooler temperatures. Not expecting
temperatures to be cold enough to support frost development.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
High pressure over eastern New England and the Gulf of Maine
builds south and will be centered over the western Atlantic
ocean off the Mid-Atlantic coast during this time. Return flow
sets up behind the high, and this will allow a warmer air mass
to return to the area for the weekend and start of the new week.

Temperatures return to seasonal averages Friday, and then will
be several degrees above normal from Saturday through Monday,
with highs around 80 in most areas during this time.

&&

.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas...

Rest of Tonight (through 12z)...VFR. North/northeast winds 3 to
5 kt. High confidence.

Today...VFR. Northeast winds around 10 kt. High confidence.

Tonight...VFR. Northeast winds 5-10 kt, with wind gusts 20-25
kt expected at KACY. High confidence.

Outlook...

Wednesday...VFR. Wind gusts could approach 30 kt for KMIV and
KACY.

Wednesday night through Sunday...VFR. NSW.

&&

.MARINE...
A Small Craft Advisory is in effect for all ocean zones as seas
build through the day due to distant swells from Hurricane
Humberto and Tropical Storm Imelda. Sub-SCA conditions are
expected on Delaware Bay.

For tonight and Wednesday, a Gale Warning is in effect for
ocean zones south of Manasquan Inlet as winds increase, with
gusts up to 40 kt expected out of the northeast. Winds north of
Manasquan Inlet will be a bit lighter, hovering around 30 kt,
also out of the northeast. For Delaware Bay, a Small Craft
Advisory is up for the lower bay beginning at 6 PM and upper bay
at 11 PM. Wind gusts near the mouth of the bay could get above
30 kt at times, but primarily expecting northeasterly winds
25-30 kt. Seas tonight and tomorrow of 7 to 11 feet are
expected.

Outlook...

Wednesday night through Thursday...SCA conditions are expected
to continue across all ocean zones, and lower Delaware Bay.
Northeast winds will range from 15 to 20 kt with 25 to 30 kt
gusts, and winds diminish throughout the day Thursday. Seas
remain elevated at 5 to 7 feet.

Thursday night...SCA may have to continue on the ocean for
elevated seas exceeding 5 feet, which will subside through the
night.

Friday through Saturday...Sub-SCA conditions on the waters with
fair weather.

Rip Currents...

Today, the long period swells associated with the tropical
systems to our south will continue to build and this will result
in a HIGH risk for the threat of dangerous rip currents at all
beaches. Generally expect rough surf conditions as wave heights
in the surf zone look to be around 3 to 6 feet. Increasing
onshore winds of 10-20+ MPH are expected. The Rip Current
Statement remains in effect for Tuesday.

For specific beach forecasts, visit weather.gov/beach/phi

A high risk of rip currents is likely to continue through the
remainder of the week. However, the surf program and SRF product
ends on September 30. This will be the final day that rip
current statements will be issued.

&&

.TIDES/COASTAL FLOODING...
Strengthening northeast winds through later today into
Wednesday will lead to a piling up of water along the ocean
front, back bays, and the Delaware Bay. Widespread minor coastal
flooding will develop for these areas with the Wednesday
afternoon and evening high tide cycle. Tidal flooding is not
expected along the Chesapeake Bay for the eastern MD zones.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...High Risk for Rip Currents from 8 AM EDT this morning through this
     evening for NJZ014-024>026.
DE...High Risk for Rip Currents from 8 AM EDT this morning through this
     evening for DEZ004.
MD...None.
MARINE...Small Craft Advisory from 11 PM this evening to 6 PM EDT
     Wednesday for ANZ430.
     Small Craft Advisory from 6 PM this evening to 6 PM EDT
     Thursday for ANZ431.
     Small Craft Advisory until 6 PM EDT Thursday for ANZ450.
     Small Craft Advisory until 6 PM EDT this evening for
     ANZ451>455.
     Gale Warning from 6 PM this evening to 6 PM EDT Wednesday for
     ANZ451>455.

&&

$$

SYNOPSIS...MPS
NEAR TERM...Hoeflich
SHORT TERM...MPS
LONG TERM...MPS
AVIATION...Hoeflich/MPS
MARINE...Hoeflich/MPS
TIDES/COASTAL FLOODING...MPS