858
FXUS61 KPHI 310850
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
350 AM EST Fri Jan 31 2025

.SYNOPSIS...
Low pressure quickly moves across the Middle Atlantic region
today. High pressure follows for the start of the weekend. A
warm front crosses thru Sunday night followed by another cold
front Monday night. Another low and front may arrive for the
middle of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Rain is overspreading the region this morning. Forecast seems
to be working out nicely. A Winter Weather Advisory is in effect
through 9 AM for Carbon, Monroe, Northampton, and Lehigh County
in PA and Warren, Morris, and Sussex County in NJ. Temperatures
within these counties are around 27-32 currently and with rain
moving in at this hour, a period of freezing rain appears
increasingly likely, with ice accretion up to a tenth of an inch
possible. This could impact the morning commute, with some
slick spots likely especially for untreated surfaces.

By 9 AM, the entire region should be above freezing as a warm
front moves through. Periods of rain are anticipated for today
as an area of low pressure moves in from the west. Just a dreary
day to close out the week. Rainfall amounts have come down a
bit with this update, especially up north. Thinking areas north
of Philadelphia will end up with a quarter to half an inch with
locations from Philadelphia on south expected to end up between
0.5" and 1". Just a much needed beneficial rain. Temperatures
will surge into the 40s and 50s.

For tonight, the area of low pressure moves overhead and
offshore with showers gradually moving out as the night goes on.
Cold air advection sets up in the wake of the surface low, and
with some lingering moisture, a few rain/snow showers are
possible in the Poconos later tonight, but no accumulation is
expected. Temperatures fall pretty quickly as the night goes on,
with lows anywhere from the 20s up north in the Poconos, to low
40s in lower Delmarva. For the most part though, temperatures
will get down into the low to mid 30s.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
Low pressure should clear the region early Saturday morning,
though a few models hold precip back across southern NJ and the
Delmarva into the morning, so held some slight chances POPS
across this area for a few hours. Otherwise, clearing and breezy
with more seasonable temps returning...not a bad first day of
February overall.

High pressure building in from the northwest brings a chilly
night, and with clouds now looking slower to build in ahead of
the next warm front, temps should slide into the teens for most
areas north of PHL, with low 20s for most further south. Low
teens in the Poconos.

Warm front approaches with increasing clouds Sunday morning,
then some light snow may overspread northern areas in the
afternoon and evening. Not expecting much, but a light coating
is within the realm of possibility mainly north of I-78. Some
guidance also hinting at a little freezing rain potential which
would make sense given its a warm front, but for now left out of
the forecast. Highs Sunday still fairly seasonable.

Temps warm above normal starting Sunday night as the warm front
lifts north. Most areas stay in the 30s overnight, and the far
south of Delaware may actually not drop below 40. Upper 20s
still in the far north, but again, this is notably above normal.
Any lingering snow early should end before midnight.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
Strong southwest flow behind the Sunday night warm front and
ahead of the next cold front will help bring the warmest weather
of the year to the region for Monday. Much of the area should
crack 50, with southern Delaware/eastern shore of MD likely
cracking 60. Only far NW NJ and the Poconos should fail to reach
the 50 mark. It will be breezy but expect some sun as well.

Cold front slides across the region Monday night, bringing us
back closer to reality for Tuesday, but temps should still be
on the relatively mild side Monday night, with lows similar to
what`s expected Sunday night. Even Tuesday, temps should remain
on the plus side of normal, but 5-10 below Monday`s readings.
That should still be enough to bring most areas into the 40s and
southern Delmarva into the 50s.

Next system then brings some chance of precip by Wednesday, with
enough cold air present by then to produce potential wintry mix
across our northern areas. Right now, however, not sure precip
comes in fast enough to make use of the colder air, so just have
some chance POPs. Highs 30s north, 40s south.

With low pressure passing to the northwest, expect a warm front
to lift northward for Thursday, bringing much of the area back
to the 50s and far southern NJ and much of the Delmarva into the
lower 60s. However, unlike Monday, this likely is accompanied by
some wet weather, though it may only be scattered showers part
of the day.

&&

.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.

Through 12z...VFR lowering to MVFR after 09Z. Southerly winds
around 5 kt. A 40 to 45 kt LLJ will pass over the region, so
kept LLWS at 2000 ft in KRDG/KABE/KTTN/KPNE/KPHL/KILG until
12z-13z. A brief period of FZRA possible at KABE until 11z.
Moderate confidence.

Today...Conditions continue to drop through the morning down to
IFR/LIFR with periods of rain. S-Sw winds 5 to 10 kt. Another
period of 35-45 kt winds is likely aloft at 2000 feet this
afternoon, so added LLWS at all TAF sites. Low to moderate
confidence in timing and extent of restrictions.

Tonight...IFR/LIFR for most of the night. SW winds 5 to 10 kt,
becoming NW late. Low confidence.

Outlook...
Saturday through Tuesday...VFR overall with little if any
chance of precipitation.

&&

.MARINE...
A Small Craft Advisory is in effect beginning at 9 AM for ocean
zones south of Cape May, beginning at 11 AM for ocean zones
from Cape May to Manasquan Inlet, and beginning at 4 PM for
ocean zones north of Manasquan Inlet. The SCA goes through
tonight as 4-6 foot seas are expected with periods of wind
gusts around 25 kt out of the south/southwest.

Sub-SCA conditions expected on Delaware Bay with
south/southwest winds around 10-20 kt.

Outlook...
Saturday...Small Craft Advisory conditions will prevail on the
ocean waters with northwesterly winds gusting up to 30 kts and
seas up to 7 ft. Lighter winds should prevail over the bay.

Sunday through Tuesday...No widespread significant marine
headlines anticipated, though occasional marginal SCA winds are
possible Saturday evening and Monday/Monday night.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Winter Weather Advisory until 9 AM EST this morning for PAZ054-
     055-061-062.
NJ...Winter Weather Advisory until 9 AM EST this morning for NJZ001-
     007-008.
DE...None.
MD...None.
MARINE...Small Craft Advisory from 4 PM this afternoon to 6 PM EST
     Saturday for ANZ450.
     Small Craft Advisory from 11 AM this morning to 6 PM EST
     Saturday for ANZ451>453.
     Small Craft Advisory from 9 AM this morning to 6 PM EST
     Saturday for ANZ454-455.

&&

$$

SYNOPSIS...Hoeflich/RCM
NEAR TERM...Hoeflich
SHORT TERM...RCM
LONG TERM...RCM
AVIATION...Hoeflich/RCM
MARINE...Hoeflich/RCM