169
FXUS61 KPHI 191124
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
624 AM EST Wed Nov 19 2025

.SYNOPSIS...
A weak area of low pressure quickly shifts to our east later this
morning, then high pressure builds in tonight and Thursday. A weak
cold front moves through during Friday, which then stalls near
Delmarva on westward. Low pressure along this front tracks near our
area Friday night into Saturday, then high pressure builds in for
Sunday. A cold front crosses our area later Monday followed by high
pressure gradually arriving during Tuesday.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of early this morning, an elongated area of low pressure extends
from Virginia south and west across Tennessee. Meanwhile in the
upper levels a fairly potent but quick moving shortwave moving in
from the west is centered more or less right over the CWA.
Precipitation is ongoing with most areas seeing rain except some
snow across portions of Carbon and Monroe Counties right near the
northern edge of the precip. As we go through this morning,
precipitation will taper off from west to east as the upper level
wave progresses east of the area. Before precip ends the rain/snow
line may make it a little farther south through roughly the I-80
corridor. Any accumulation though will be limited to a coating up to
an inch with these higher amounts occuring in the higher elevations
(areas mainly above 1200 ft or so). Once the precipitation ends,
there will still be a fair amount of moisture lingering across much
of the region within a light north to northeast wind, therefore the
cloud cover will struggle to break up. Some drier air across the
northern areas however during the afternoon may result in a bit more
sunshine trying to appear there while it stays mostly cloudy farther
south. High temperatures are forecast to be in the 40s to low 50s.

High pressure initially centered over the lower Great Lakes this
evening will drift eastward towards New England by early Thursday.
Meanwhile a frontal boundary will linger near Delmarva with some
weak impulses moving through aloft in the upper level flow. This
will tend to keep skies mostly cloudy however it should remain
mainly dry. The exception will be across Delmarva where there could
be some spotty drizzle. With the lingering front, overnight lows
will vary from the upper 20s over NE PA and NW NJ to the 35 to 40
degree range over Delmarva as well as SE PA and adjacent portions of
southern NJ.

&&

.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
A more zonal flow aloft is forecast to be in place across our region
through Thursday night. Surface high pressure across our area is
then forecast to become more centered to our northeast and east
later in the day and at night. A light northeasterly low-level flow
in place along with surface high pressure may keep quite a bit of
cloud cover in place, especially across the southern half of the
region. While some sprinkles cannot be ruled out across Delmarva,
the area should be precipitation-free.

A shortwave trough in the central to southern Plains through
Thursday night will assist in warm air advection increasing east and
northeastward with time. A front is forecast to be draped east to
west from lower Delmarva westward to surface low pressure in the
central Plains. Some associated overrunning precipitation associated
with this system and focused along the front is currently forecast
to remain well southwest of our area Thursday night. High
temperatures are forecast to be in the mid to upper 40s across the
northern areas to the low to mid 50s across the coastal plain. Low
temperatures Thursday night are forecast to be mostly in the
mid/upper 30s to low 40s across the region.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
Synoptic Overview...A closed low traversing much of eastern Canada
Friday into Saturday supports surface low pressure. An associated
cold front slides across our area during Friday, however it stalls
from about Delmarva westward to the Ohio Valley. An impulse within a
more zonal flow south of this closed low supports a weak surface low
along the front in the Tennessee Valley. This feature slides
eastward and shifts offshore during Saturday. A trough remains
across eastern to central Canada over the weekend, which then may
amplify across the Northeast during early next week.

For Friday and Saturday...Our region is forecast to be on the
southern periphery of a closed low in eastern Canada. A weak cold
front, associated with surface low pressure tied to this closed low,
is forecast to cross our area Friday with it then stalling in the
vicinity of Delmarva on westward. A ripple of energy with the more
zonal flow across the southern Plains to the southern Mid-Atlantic
supports low pressure along the tailend of the front. There are some
differences on how the model guidance handles this, with the GFS
ensembles all showing precipitation however some are weaker, faster,
farther south or farther north. Other guidance also shows this which
is partially due to surface high pressure centered over the Great
Lakes building southeastward some with time. Given the uncertainty
with the details/timing, did not deviate from the National Blend of
Models (NBM) which has chance PoPs north of Philadelphia with likely
PoPs south and east of there. Some milder air on Friday is followed
by some cooling Saturday, especially it more rain occurs or lasts
longer on Saturday.

For Sunday...A shortwave trough may slide across the Mid-Atlantic
during this time, however weak surface high pressure is currently
forecast to be across our region during the day before it shifts
south and east at night. As a result, a dry day is currently
expected with more sunshine returning.

For Monday and Tuesday...An upper-level trough across eastern to
central Canada may amplify eastward and across the Northeast. This
would support surface low pressure tracking well to our north,
however its cold front slides across our area later Monday. Some
guidance/ensembles are stronger with this upper-level trough and
also the cold front. If the stronger solutions end up being correct,
then rain chances would tend to increase and also Tuesday would
feature a stronger/gusty northwest wind. No changes from NBM during
this timeframe.

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Today...IFR conditions this morning improve to primarily MVFR
through the early to mid afternoon with VFR possible later in
the afternoon. Improvement from IFR to MVFR likely between
16z-19z but confidence remains low in when exactly conditions
improve. Rain tapering off west to east through the morning
hours. North/northeast winds 5-8 knots. Moderate confidence.

Tonight...Becoming mainly VFR through the evening except around
MIV and ACY where MVFR cigs could persist longer. Winds
generally north to northeast around 5 knots.

Outlook...

Thursday...VFR ceilings.

Friday and Saturday...A period of sub-VFR conditions and some rain
possible, especially Friday night into Saturday morning.

Sunday...Mostly VFR.

&&

.MARINE...
Marine conditions will remain below SCA criteria through
today and tonight. Winds continue to back to more of a north
and northeast direction this morning and will generally increase
to around 15 gusting to around 20 knots by later in the day.
These winds will diminish slightly tonight. Seas generally 2 to
3 feet today and tonight. Rain and mist this morning may result
in some reduced visibilities with precip ending by early this
afternoon.

Outlook...

Thursday through Sunday...The conditions are anticipated to be below
Small Craft Advisory criteria.

&&

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

&&

$$

SYNOPSIS...Gorse
NEAR TERM...Fitzsimmons
SHORT TERM...Gorse
LONG TERM...Gorse
AVIATION...Fitzsimmons/Gorse
MARINE...Fitzsimmons/Gorse