846
FXUS61 KPHI 142015
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
415 PM EDT Sun Sep 14 2025

.SYNOPSIS...
A weakening cold front approaches the region late tonight. High
pressure briefly builds in on Monday before weakening and shifting
northeast. Meanwhile, a coastal low which is expected to develop
off the coast of the Carolinas later tonight will gradually drift
northward, approaching our region Tuesday into Thursday before dissipating.
Late in the week, a cold front may approach the region.

&&

.NEAR TERM /THROUGH MONDAY/...
A weak, decaying cold front will wash out as it moves into the
region tonight. Thereafter, the local area will be caught
between two systems: high pressure centered near Hudson Bay
building south, and low pressure, both at the surface and aloft,
over the Southeast that will lift towards the Mid-Atlantic by
Monday afternoon.

In terms of sensible weather, a few sprinkles, perhaps a light
shower, is possible into this evening with the approach of that
cold front this evening. There is a good deal of low levels
moisture, especially for mid-September, with dew points in the
50s to low 60s, but there is little, if any, upper level support
for more widespread showers.

While some clouds may develop with that front, especially in
northern zones, those clouds will dissipate through the
overnight. Clouds associated with the low over the Southeast
will lift towards Delmarva and southern New Jersey. These clouds
should inhibit the development of fog, but where skies are
relatively clear, some patchy fog is possible. Not expecting
dense fog. Warm and muggy tonight with lows in the 50s to low
60s.

Clouds increase from south to north throughout the day Monday as
low pressure lifts towards the Carolina coast. Onshore flow
will keep temperatures generally in the 70s to low 80s, with the
coolest temperatures near the coasts. Muggy with dew points
rising into the lower 60s.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
The short term will contain mostly unsettled weather. A coastal
system will develop east of the Carolinas tonight/Monday. It
will meander in place Tue and into early Wed before weakening
and drifting northeast out to sea. The east/northeast flow on
the north side of the low will bring clouds and showers to the
area from late Monday night into Wednesday night. The chances
for rain will be greatest for S/E areas with Delmarva and
southern NJ having likely/low categorical pops. Areas N/W will
have chance pops these period. There could be a few tstms also
Tue night/Wed morning. Models are still somewhat inconsistent
with the details with the low, so overall the NBM solution was
used in the grids. QPF for the period could be around an inch
for southern Delaware and a quarter inch for the Delaware
Valley.

Winds will increase as the low deepens and moves closer to the
area, so winds of 15 to 25 mph with gusts around 30 mph will
develop for the shore areas starting overnight Monday.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
If you liked the weather for the present weekend, looks like more of
the same for next. Before that, however, we`ll have the last of the
coastal system affecting the area Thursday. We`ll have a chance for
showers (around 30%) for the morning and cloudiness at times. The
clouds diminish later Thursday leaving Fair skies for Thu night and
Friday.

Temperatures for Thursday will be seasonable with some cloudiness
and showers for the first part of the day. After that, well above
normal temps for Friday before the front arrives. During Fri, we
will have widespread max temps in the low/mid 80s across the region.
Then, the cooler air behind the front arrives, readings for Sat/Sun
will top out a few degrees below normal with 70s for NJ/PA and
Delmarva. Humidity levels will be moderate Friday but then low for
next weekend. Pleasant overnight temps mostly in the 50s Sat/Sun.

&&

.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY and surrounding areas.

Rest of today...VFR. E-NE winds 5 to 10 kt. High confidence.

Tonight...Prevailing VFR. There is the potential for some fog,
but confidence is quite low for sub-VFR conditions to develop.
NE winds less than 5 kt, becoming nearly calm at some terminals.

Monday...VFR. E winds 8 to 12 kt. High confidence.

Outlook...

Monday night and Tuesday...Prevailing VFR for most TAF sites.
MVFR or IFR possible (30-40% chance) with low clouds, and brief
visibility restrictions in rain showers.

Tuesday night through Thursday...40 to 70 % chance of periods
of MVFR or IFR conditions with rain showers.

Friday... VFR expected.

&&

.MARINE...
Sub-Small Craft Advisory conditions tonight through Monday. East
to northeast winds around 10 kt tonight, increasing to 10 to 15
kt with gusts up to 20 kt on Monday. Seas 2 to 3 feet tonight,
building to 3 to 4 feet on Monday.

Outlook...

Monday night... SCA flag issued for lower Delaware Bay and the
southern coastal waters as winds and seas increase ahead of the
approaching coastal low. Fair early then a chance for rains
after midnight for the southern NJ and DE waters.

Tuesday through Wednesday night... SCA flag will likely be
extended in time and area for this period. Showers and a few
tstms Tue night/Wed.

Thursday... Increasing chance (80% or higher) that winds and
seas will subside below SCA criteria before Thursday morning.

Rip Currents...

A LOW RISK OF RIP CURRENTS CONTINUES THROUGH THIS EVENING.

For Monday, the winds back to easterly at around 10 to 15 mph and
breaking waves increase to around 2 to 3 feet with a continuing
easterly swell around 8 seconds. Due to the winds becoming onshore
along with building wave heights the risk for dangerous rip currents
is expected to increase to a MODERATE risk for all of the New Jersey
Shore and Delaware Beaches.

For Tuesday, northeast winds further increase to around 15 to 20 mph
with breaking waves increasing to 3 to 5 feet. This will result in a
HIGH risk for the development of dangerous rip currents.

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

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...Small Craft Advisory from 6 PM Monday to 6 AM EDT Tuesday for
     ANZ431-452>455.

&&

$$

SYNOPSIS...Johnson
NEAR TERM...MPS
SHORT TERM...OHara
LONG TERM...OHara
AVIATION...MPS/OHara
MARINE...Fitzsimmons/MPS/OHara