493
FXUS61 KPHI 100650
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
150 AM EST Mon Nov 10 2025

.SYNOPSIS...
Low pressure and its associated strong cold front moves through
the area and offshore overnight. 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 TODAY/...
No significant changes to the near term this morning. Another
light round of rainfall is slowly moving into the area but
should only bring minor accumulations. Temps will begin starting
to fall mainly into the 40s, with 30s in the Poconos behind the
frontal passage.

By Monday morning, the cold front will be located off the coast
and low pressure will be tracking up through New England. Any
remaining showers are expected to cease shortly after daybreak.
Cannot rule out an isolated flurry up across the Pocono Plateau
as some colder air filters in. As the day progress, the
deepening upper-level trough will begin to pivot into the region
delivering a shot of modified, arctic air. With cold air
advection increasing under cyclonic flow, this should support a
pretty hefty strato-cumulus cloud deck, resulting in mostly
cloudy to at times overcast skies. Thus, high temperatures are
expected to peak by mid-day with highs only in the mid 40s to
mid 50s. Northwest, post-frontal winds will increase as well,
occasionally gusting around 20-25 mph. This will result in wind
chill values falling into the 20s and 30s, especially by late
afternoon.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
A deepening upper-level trough will delivery a shot of modified
arctic air into the region, resulting in the coldest
temperatures so far this season Monday night through Tuesday.

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 near 15-25 mph 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 SUNDAY/...
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 /06Z MONDAY THROUGH FRIDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Tonight...Low confidence forecast. Generally VFR conditions will
prevail behind the initial rainfall. Some MVFR cigs/vis will
remain possible through 10z this morning before drier air
filters in before 12z. LGT/VRB winds, becoming W 4 to 8 kt by
05Z, then W 5 to 10 kt prior to 12Z.

Monday...MVFR conds are possible in the morning, lifting to VFR
late in the morning. W winds 5 to 10 kt, increasing to 10 to 15
kt with 20 to 25 kt gusts after 18Z. Moderate confidence.

Monday night...VFR. W to NW winds 10 to 15 kt with gusts up to
20 kt. High confidence.

Outlook...

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

Wednesday through Friday...VFR. Wind gusts 20-25 knots,
diminishing each night.

&&

.MARINE...
No marine hazards are in effect through tonight. A Small Craft
Advisory has been issued beginning at 1 PM Monday for both the
Atlantic Coastal Waters and Delaware Bay.

Through tonight, southerly winds around 10-15 kt will quickly
transition to a west-northwest wind in wake of a cold frontal
passage. Seas of 3-4 feet. Showers likely with perhaps and
isolated thunderstorm. Dense marine fog possible.

On Monday, west-northwest winds will increase to around 10-20
kt with gusts up to 25 kt possible during the afternoon. Seas of
3-5 feet. Outside of developing SCA conditions, fair weather is
expected.

Outlook...

Monday night...Small Craft Advisory in effect. Northwest winds
increasing to 20-30 kts and seas building to 3-5 feet.

Tuesday...Westerly winds increasing to 25-35 kts with gusts up
to 40 kts possible. Seas 4-7 feet. Gale Watch has been upgraded
to a Gale Warning for Tuesday through Tuesday evening.

Wednesday through Friday...Small Craft Advisory conditions
probable.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...Small Craft Advisory from 1 PM this afternoon to 6 AM EST
     Tuesday for ANZ430-431-450>455.
     Gale Warning from 6 AM to 8 PM EST Tuesday for ANZ430-431.
     Gale Warning from 6 AM Tuesday to midnight EST Tuesday night
     for ANZ450>455.

&&

$$

SYNOPSIS...Gorse/Staarmann
NEAR TERM...Deal/DeSilva/MPS
SHORT TERM...Gorse/Staarmann
LONG TERM...Gorse/Staarmann
AVIATION...Deal/DeSilva/Gorse/MPS/Staarmann
MARINE...DeSilva/Gorse/Staarmann