597
FXUS61 KPHI 090736
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
236 AM EST Sun Nov 9 2025

.SYNOPSIS...
Low pressure and its associated strong cold front moves through late
today and especially tonight. High pressure centered near the Gulf
Coast begins to build in through Tuesday, before another cold front
crosses our area later Wednesday. High pressure then starts to
arrive later Thursday and remains nearby through the start of next
weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
Complex forecast in the near term as multiple areas of low
pressure move across the area, but fortunately they are all
pretty weak. Early this morning, expect dry conditions with
increasing clouds, but patchy mist/light fog may develop where
skies stay clearer longer. Temps bottoming in the 40s, except
near 50 coast and urban centers.

During the day today, one weak wave of low pressure will ride
northward along the coast, but its path has shifted a little
further east, and less confidence in widespread rainfall than
existed 24 hours ago. Still should get SOMETHING as it moves
just east of us, with best chances late morning south and
afternoon north, but probably not a washout of a day. With
warmer air arriving as well, expect temps to manage the 60s for
much of the region despite plenty of clouds and some showers,
though 50s more likely especially north of I-78. Could even be
a thunderstorm mainly across southern areas.

A break late this afternoon into this evening looks probable,
though timing it is a little more tricky. In any case, another
round of showers with the primary low and cold front should move
through overnight. Again a risk of a thunderstorm, mainly south,
but overall QPF thru tonight looks pretty meager, certainly
below a half inch and in fact, probably below a quarter inch for
much of the region. Lows dropping into the 40s, mostly...30s
Poconos, near 50 along the coast.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
A deepening upper-level trough will delivery a shot of modified
arctic air into the region. As cold air advection increases on
Monday under cyclonic flow, this should support a stratocumulus
cloud deck, resulting in more clouds than sun. Thus, high
temperatures on Monday are expected to peak by midday with highs
ranging from the mid 40s to low 50s.

The deep upper-level trough begins to move into the region on Monday
night with the trough axis located over the East Coast by Tuesday
morning. Some of the coldest air of the season, so far, arrives as
850 mb temperatures will be as cold as -10C to -12C. Despite partly
to mostly cloudy skies, low temperatures will be below freezing for
all on Monday night, except perhaps for areas along the immediate
coast. Wind chill values should fall into the teens and 20s. Some
guidance also indicates some snow showers, especially in the Poconos
and Lehigh Valley overnight. Looks like this is tied to lake-effect
upstream, so wouldn`t be surprised if some flurries survive the trip
with such strong flow at the surface and the trough overhead.
Temperatures on Tuesday will feel more like December than November,
with highs only in the low to mid 40s (30s in the higher terrain).
The other item of note, is that the Mid-Atlantic region will be
situated between strong low pressure over the Canadian Maritimes and
strong high pressure over northern Gulf coast. This results in a
tight pressure gradient over the area. West-northwest winds are
anticipated with wind gusts 30-40 mph before diminishing later in
the day and especially Tuesday night. The area will remain nestled
within the upper-level trough through the afternoon before departing
the region by Tuesday night. This will allow the airmass to moderate
aloft. So, while it will still be quite chilly, low temperatures for
Tuesday night will not be as cold compared to the night before.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Summary...Airmass moderates some before cooling some to start the
weekend. Any precipitation chances look rather limited as of now.

Synoptic Overview...Shortwave energy should maintain a trough from
the Great Lakes and the Northeast Wednesday and Thursday. This may
amplify across the northeast Friday into Saturday before shifting
eastward with some ridging approaching from the west into Saturday.
At the surface, a cold front crosses our area later Wednesday, then
high pressure gradually approaches from the west later Thursday
before settling more into our area Friday and Saturday.

For Wednesday and Thursday...While the main upper-level trough has
already departed, additional shortwave energy diving southeastward
from the Midwest and Great Lakes should maintain a trough into the
Northeast and Mid-Atlantic regions through Thursday. As this occurs,
surface high pressure centered across the Southeast U.S. will track
eastward. A notable breeze looks to be present for both Wednesday
and Thursday as a modest pressure gradient persists. A weak clipper
system will also track across eastern Canada on Wednesday, with a
weak cold front crossing our area later Wednesday. Overall, this
front looks to be moisture-starved. Aside of a stray shower up into
the higher terrain, much of the area should remain dry. Temperatures
will be warmer compared to earlier in the week, but largely will
remain a few degrees below average.

For Friday and Saturday...The Mid-Atlantic region looks to be
situated on the backside of the aformentioned upper-level trough as
it may initially amplify Friday, then move away by later Saturday.
High pressure still looks like it will be centered off to the west,
so cool temperatures continue into the start of next weekend. As of
now, it looks mainly dry given the arrival of surface high
pressure.

&&

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

Thru 12Z...Mostly VFR, though patchy mist may result in MVFR.
LGT/VRB to nearly calm winds. High confidence.

Today...VFR in the morning...then MVFR/IFR conds in stratus and
SHRA. Cannot rule out an isolated TSRA, especially around KMIV
and KACY. ESE winds 5-10 kt, becoming VRB by 00Z. Moderate
confidence.

Tonight...Cold front passes through with SHRA and MVFR/IFR
intervals. VRB winds 5 to 10 kt, becoming W-NW late. Low
confidence.

Outlook...

Monday...Areas of MVFR ceilings possible at times, otherwise VFR
ceilings. A 20 percent chance of a rain shower for some areas during
the day. West to west-northwest wind gusts up to 20 knots during the
afternoon.

Tuesday...VFR. West-northwest wind gusts 25-35 knots during the day,
diminishing some at night.

Wednesday and Thursday...VFR. Wind gusts 20-25 knots, diminishing
each night.

&&

.MARINE...
Sub SCA conditions through tonight. Winds and seas increase
some today into tonight and could get near SCA conditions at
times but confidence not high on this. There will also be some
showers and fog around today and tonight and even the risk of a
few thunderstorms.

Outlook...

Monday...Small Craft Advisory conditions developing, especially in
the afternoon and at night. A chance for some gale force wind gusts
to develop late Monday night.

Tuesday...Gale force wind gusts probable.

Wednesday and Thursday...Small Craft Advisory conditions probable.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...None.

&&

$$

SYNOPSIS...DeSilva/Gorse
NEAR TERM...RCM
SHORT TERM...DeSilva/Gorse
LONG TERM...DeSilva/Gorse
AVIATION...Gorse/RCM
MARINE...Gorse/RCM