067
FXUS61 KPHI 292247
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
647 PM EDT Mon Sep 29 2025

.SYNOPSIS...
High pressure is in control through Tuesday. A strong but
moisture-starved cold front moves through on Tuesday night
before an expansive area of high pressure moves in for the rest
of the week and the upcoming weekend.

&&

.NEAR TERM /THROUGH TUESDAY/...
Very large shield of high clouds has spread north of Imelda,
but otherwise, impacts for land areas are expected to be minimal
before it turns east and out-to-sea on Tuesday. Otherwise, weak
high pressure will remain in control through Tuesday, keeping
it warm and humid by late September standards. A few showers may
creep their way into parts of the Delmarva, most likely this
evening, but overall dry weather should prevail with a
relatively light northeast wind of 5-10 mph. Near the coastal
waters, this wind may become closer to 10-20 mph by later in the
day Tuesday. Lows tonight will be in the mid 50s to mid 60s,
warmest south/coast/urban areas, while highs Tuesday will be in
the mid 70s to low 80s, warmest eastern PA and central/northern
NJ where there should be a little more sun and a bit less marine
influence.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
Initially, a fairly complex upper-pattern will be in place
across the region as we find ourselves between a ridge to the
west over the Missouri Valley and Great Lakes regions, Humberto
and Imelda to the southeast over the open Atlantic, and the
polar jet across portions of northern New England. With time,
the ridge will expand eastward, eventually encompassing our area
on Thursday, as the other features continue to track away. At
the surface, a cold front will track southward through the
region Tuesday night, with strong high pressure building in from
the north.

With sufficient moisture in place and easterly flow, widespread
cloud cover is expected Tuesday night ahead of the cold front.
No precipitation is expected, however, and clouds should clear
from north to south with the frontal passage. Lows Tuesday night
look to be in the mid-upper 40s across the higher elevations of
eastern PA and far northern NJ, the low 50s across the
remainder of eastern PA and inland NJ, and in the upper 50s to
near 60 along the coast and in the Delmarva. Wednesday should
feature mostly clear skies with highs ranging from the upper 60s
to low 70s. Wednesday night will feel like fall, with
temperatures falling deep into the 40s across eastern PA and
northern NJ, and the upper 40s to near 50 elsewhere. The cooler
trend will continue on Thursday, with highs likely struggling to
climb out of the 60s across the entire area.

Aside from fair weather and cooler temperatures behind a cold
front, our area will be between the pair of tropical cyclones to
our southeast and strong high pressure building in from the
north. This setup will favor gusty winds along the coastal
strip. The gustiest period looks to be Tuesday night into
Wednesday, with gusts in the 30-40 mph range. As of right now,
it appears winds will fall short of wind advisory criteria, but
this is something that will need to be watched the next few
forecast cycles in case there is any upward trend to forecasted
winds.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
There will likely be very little change to the upper-pattern
through the extended period, with ridging remaining situated
over the eastern tier of the US. At the surface, high pressure
will remain centered over portions of the Mid-Atlantic and
northeast.

Tranquil weather is expected from Thursday night through
Monday, with skies ranging from partly to mostly clear.
Temperatures will remain below average Thursday night through
Friday night, though slowly moderating with time. By Saturday,
temperatures are expected to be mostly seasonable across the
area. Sunday into Monday look to continue the slow moderating
trend, with temperatures getting back to being slightly above
normal.

&&

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

Tonight...Mainly VFR except some mist possible around KACY
where we`ve indicated MVFR visbys overnight. East winds around
3-5 knots backing to more northeast than northerly overnight.
Moderate confidence.

Tuesday...VFR with northeast winds generally around 5-10 knots.
High confidence.


Outlook...

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

Wednesday night through Saturday...VFR. No significant weather.

&&

.MARINE...
Small Craft Advisory goes into effect this evening on the ocean
waters as seas start to build thanks to the influence of
Hurricane Humberto and Tropical Storm Imelda. While the SCA
continues as seas build further on Tuesday, winds should stay
below advisory levels through Tuesday. However, they will start
increasing notably towards day`s end.

Outlook...

Tuesday night through Wednesday...Confidence is increasing in a
period of gale force winds beginning Tuesday night and
continuing through much of the day Wednesday. Have issued a Gale
Warning for ocean zones south of Manasquan Inlet, where
frequent gusts of 35-40 kt are expected. Have maintained the SCA
north of Manasquan Inlet and for the Delaware Bay, where winds
are expected to peak in the 25- 30 kt range. Seas over the open
ocean could build to 7-11 feet.

Wednesday night through Thursday...SCA conditions are expected
to continue across all ocean zones, and at least the lower
Delaware Bay. While winds should decrease on Thursday, seas will
remain elevated, in the 5-7 foot range.

Thursday night...SCA conditions may linger on some waters,
primarily in the form of elevated seas.

Friday through Saturday...No marine headlines expected. Fair
weather.

Rip Currents...

For Tuesday, 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 30th. This will be the final day that rip
current statements will be issued.

&&

.TIDES/COASTAL FLOODING...
Strengthening northeast winds through later Tuesday into
Wednesday will lead to a piling up of water along the ocean
front, back bays, and the Delaware Bay. There is an increasing
potential that this will lead to widespread minor coastal
flooding for these areas with the Wednesday PM high tide cycle.
For areas along the tidal Delaware Bay, if any minor flooding
occurs it will be very spotty. No tidal flooding is expected
along the Chesapeake Bay for our eastern MD zones.

&&

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

&&

$$

SYNOPSIS...Hoeflich/RCM
NEAR TERM...RCM
SHORT TERM...Cooper
LONG TERM...Cooper
AVIATION...Cooper/Fitzsimmons/RCM
MARINE...Cooper/RCM
TIDES/COASTAL FLOODING...