302
FXUS61 KPHI 010846
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
346 AM EST Mon Dec 1 2025

.SYNOPSIS...
High pressure will pass through the region today and offshore
tonight. Low pressure will develop over the Southeast tonight before
tracking northeast towards our area Tuesday into Tuesday night,
bringing widespread precipitation to the area. High pressure and
below normal temperatures return for the middle of the week. Another
cold front will track through the region Thursday night, with high
pressure building back in thereafter. Another system may impact the
region Friday night into the weekend.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A brief period of tranquil weather is on tap for today with high
pressure in control. The high is quickly transit from west to
east, currently centered over the Great Lakes but will become
centered over the region by late this afternoon into the
evening.

Skies have largely cleared with the high beginning to build in
and the preceding cold front now well offshore, though there is
some lingering stratus over the Appalachia that is edging into
the higher terrain areas in the northwest portion of the region.
Winds have dropped off to around 10 mph, though a few gusts to
around 20 mph remain possible early this morning. These gusts
may become a bit more frequent during the mid-morning hours
after sunrise. Otherwise, lows this morning will be in the
upper 20s to near 30 degrees across the entire area.

The daytime hours today will remain mostly clear, though some
increase in high clouds may come during the afternoon hours
ahead of the next system. Lingering gusty northwest winds in
the morning will diminish by the afternoon as the high moves
overhead and the pressure gradient relaxes. High temperatures
will be near freezing in the Poconos, in the upper 30s to lower
40s for eastern PA and much of NJ, and mid 40s for the Delmarva
into far southern NJ.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
The main story for the short term will be the strengthening low
pressure system moving northeast Monday night and off the coast into
Tuesday, which will bring widespread precipitation to the region,
including the first accumulating snowfall to portions of the area.
There will be a low developing over the southeastern US and our high
pressure system will retreat off to the northeast tonight. This low
will make its closest approach to the area Tuesday afternoon, and
begin departing to the northeast by Tuesday night.

In terms of the details with this system, there have been no
significant changes have been made to the forecast or messaging for
Tuesday. There are chance to likely PoPs (40-60%) starting late
Monday night, with the highest PoPs (90-100%) being during the
daytime Tuesday. There continues to be a trend toward a somewhat
faster solution in the deterministic guidance. If this trend holds,
it could have implications on initial precip type into the I-95
corridor with a little more snow possible. The precipitation will
end from west to east pretty quickly by Tuesday evening into Tuesday
night as the low moves off to the northeast.

For the precipitation accumulation, QPF remains fairly steady around
0.75-1.25" across the board, greatest across the coastal plain and
least farther inland north of I-78. Due to the earlier trend in
precip onset, there is the potential for light snow or perhaps some
sleet initially for the I-95 corridor and south, perhaps as far
south as northeastern Maryland, central and northern Delaware, and
portions of interior southern New Jersey. This initial light snow
could result in minimal accumulation (a dusting less than 1"), and
would not last long as the low draws closer to the area changing the
precip to rain. Again, any snowfall occuring this far south will be
dependent on exactly how quickly the precip moves into the area. A
slower/later onset would probably mean mostly all rain along and
southeast of I-95.

Through the day Tuesday, the onshore flow and warm marine influence
with the surface low drawing near will impact the temperature
profiles. By daybreak Tuesday, the rain/snow line should be near or
perhaps just NW of the I-95 corridor. As the warmer air continues to
filter in, the rain/snow line is expected to lift quickly northward
to near or even north of the I-78 corridor and northwestern New
Jersey by Tuesday afternoon. For perspective on this, high
temperatures on Tuesday are near freezing in the Poconos, mid 30s
northwest of the fall line, near 40 degrees along the I-95 corridor,
and in the mid 40s to near 50 degrees in Delmarva and along the
coastal areas. Although areas may start as snow, it does not appear
that it will last for much of the area. The southern Poconos have
the best potential at an all snow event from this system, but even
they could see some mixing with sleet or rain Tuesday afternoon.

As for snowfall accumulation, the forecast has remained largely the
same as the previous update. The probability for plowable snow (2"
or more) remains high (60-90%) in the Poconos and areas along and
north of I-78. As you head well south and east of I-78, the
potential for plowable snow quickly decreases to near 0% for the I-
95 corridor. Our latest forecast includes snowfall amounts less than
1" for the immediate I-95 corridor, 1-3" for areas just northwest of
there, and in the 3-5" range for the I-78 corridor and NW NJ. Higher
elevations (especially 1,500 feet and higher) in NW NJ and across
the Pocono Plateau have potential for snowfall in the 4-8" range.

The Winter Storm Watch remains in effect for the southern Poconos
and Sussex County NJ, where probability for warning criteria
snowfall (6" or greater) remains a little too low (40-60%) to
justify a warning upgrade just yet. If QPF trends a little lighter,
the storm continues to speed up, or if more mixing occurs, warning
level snowfall may not occur for the watch area.

A Winter Weather Advisory was issued for the counties on the
periphery of the watch area, including much of northern NJ and the I-
78 corridor and down into the far northwestern reaches of the Philly
metro. These are the areas most likely to experience a troublesome
Tuesday morning commute, with snowfall in the 1-5" range. Along the
southern-most fringe of the advisory area, probability for reaching
the 2-3" criteria is lower (40-60%). However, this will be the first
snowfall of the season, which is expected to occur during the
Tuesday morning rush hour commute. Thus, impacts may be more
significant than usual, even if observed snowfall amounts end up
closer to the 1-2" range.

Outside of the Poconos and perhaps the higher elevations in NW NJ,
the snow that falls will then be melting through the day with the
change to all rain and warm air moving further inland. During the
transition period from snow to rain, some sleet is possible briefly.
In terms of freezing rain, the overall threat looks minimal given
the current set up. The areas that see all rain or a change to rain
will have a good soaking all-day type of rain. A few precipitation
and/or snowfall records could be challenged. See the Climate section
below for more details on the records.

Once the low departs Tuesday night, a high pressure system will
build in from the southwest. This will lead to drier conditions
through Tuesday night. Lows Tuesday night are in the 20s for most,
which may lead to some black ice issues where any slushy snow melt
refreezes on roadways (especially north of I-78).

For Wednesday, the high pressure system will be in place, which
keeps us dry and mostly sunny with below normal temperatures
continuing. High temperatures will be in the mid 30s to low 40s. W-
NW winds 5-10 mph. Lows in the 20s again Wednesday night, with
clouds beginning to increase late in the night.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
In the long term period, we stay active with our weather pattern. A
cold front looks to cross the area Thursday into Thursday night. As
the cold front passes through, there is the potential for some snow
showers, especially near/north of I-78. The main factor with this
cold front will be the notably colder airmass in its wake. Thursday
night looks increasingly likely to be the coldest night so far this
season, with widespread low temperatures in the teens for most, and
even single digits for the higher terrain. Wind chill values
Thursday night will be in the single digits to mid-teens. By
Friday, highs are in the upper 20s to upper 30s for most areas.
Beyond that, our next system looks to arrive late Friday into
the weekend, bringing potential for another round of widespread
precipitation, including wintry precipitation. However, details
on this system remain very unclear at the moment.

&&

.AVIATION /08Z MONDAY THROUGH FRIDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Early this morning...VFR. West-northwest winds behind a cold
front around 10 kts with gusts upwards of 20 kts. High
confidence.

Today...VFR with an increase in high clouds late in the day.
Northwest winds around 10 kt with gusts up to 20 kt in the
morning, before diminishing to around 5-10 kt in the afternoon.
High confidence.

Tonight...Primarily VFR. Chance (20-40%) of MVFR conditions
after 09Z as rain and snow begin to move in. East-northeast
winds around 5 knots or less. Moderate confidence.

Outlook...

Tuesday through Tuesday night...IFR restrictions expected in low
clouds and precipitation during the daytime Tuesday. Snow changing
to rain at RDG/ABE. For the I-95 terminals, precipitation may begin
as snow for a couple hours before a change to rain. All rain for
MIV/ACY. Conditions should improve by late Tuesday night, though
gusty NW winds will be possible.

Wednesday...VFR. No significant weather.

Thursday...VFR. Gusty WNW winds possible.

Friday...Mainly VFR for Friday. Restrictions possible heading
towards Friday night with a chance (40-60%) of rain/snow.

&&

.MARINE...
A Small Craft Advisory is in effect for the Delaware Bay until 6
AM Monday and for the Atlantic Coastal Waters until 9 AM Monday.

Early this morning, winds are northwesterly around 20-25 kt
with frequent gusts near 30 kt for all ocean zones and the
Delaware Bay. Seas over the ocean are around 5 feet, but are
expected to decrease to around 4 feet by sunrise.

Wind will then begin to diminish by mid-morning today, falling
below 25 kt and with seas less than 5 feet. No marine hazards
are anticipated beyond the current SCA through tonight.

Outlook...

Tuesday through Wednesday...Advisory conditions with east winds
increasing to near 25-30 kts and then becoming northwest Tuesday
night into Wednesday. The potential for wind gusts near 35 knots has
decreased some, but will leave the Gale Watch in effect as
previously issued for now. Winds look to diminish through the day
Wednesday. Seas 5-7 feet, also diminishing through the day
Wednesday.

Thursday through Thursday night...SCA conditions likely
Thursday afternoon into early Thursday night as NW winds
increase to near 25-30 kts and seas 4-6 feet.

Friday through Friday night...No marine hazards anticipated. Rain
likely developing at night.

&&

.CLIMATE...
Widespread moderate to heavy precipitation is expected on
Tuesday, December 2nd. A few daily precipitation and/or snowfall
records could be challenged. Records for our climate sites are
listed below:

Record Precipitation (Rainfall)
                       December 2
Site                  Record/Year
Allentown (ABE)        0.86"/1934
AC Airport (ACY)       1.03"/1996
AC Marina (55N)        1.18"/1929
Georgetown (GED)       1.11"/1974
Mount Pocono (MPO)     3.56"/1996
Philadelphia (PHL)     1.48"/1986
Reading (RDG)          1.29"/1981
Trenton (TTN)          2.13"/1986
Wilmington (ILG)       1.27"/1991

Record Snowfall
                       December 2
Site                  Record/Year
Allentown (ABE)         3.6"/1952
AC Airport (ACY)           T/2019*
Philadelphia (PHL)      2.0"/1903
Reading (RDG)           6.0"/1929
Trenton (TTN)           3.0"/1903
Wilmington (ILG)        1.0"/1952

*Multiple years with a Trace.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Winter Weather Advisory from 4 AM to 1 PM EST Tuesday for
     PAZ060>062.
     Winter Weather Advisory from 4 AM to 10 AM EST Tuesday for
     PAZ101-103-105.
     Winter Storm Watch from late tonight through Tuesday evening
     for PAZ054-055.
NJ...Winter Storm Watch from late tonight through Tuesday evening
     for NJZ001.
     Winter Weather Advisory from 4 AM to 1 PM EST Tuesday for
     NJZ007-008.
     Winter Weather Advisory from 4 AM to 10 AM EST Tuesday for
     NJZ009.
DE...None.
MD...None.
MARINE...Small Craft Advisory until 6 AM EST early this morning for
     ANZ430-431.
     Small Craft Advisory until 9 AM EST this morning for
     ANZ450>455.
     Gale Watch from Tuesday afternoon through late Tuesday night
     for ANZ450>455.

&&

$$

SYNOPSIS...Guzzo/Staarmann
NEAR TERM...AKL
SHORT TERM...Guzzo/Staarmann
LONG TERM...AKL/Guzzo/Staarmann
AVIATION...AKL/Staarmann
MARINE...AKL/Staarmann
CLIMATE...WFO PHI