Piscataway, New Jersey 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

576
FXUS61 KPHI 240919
AFDPHI

Area Forecast Discussion
National Weather Service Mount Holly NJ
419 AM EST Wed Dec 24 2025

.SYNOPSIS...
Weak high pressure will build into the region through tonight
before sliding offshore. A weak clipper system will slide
quickly through the area on Christmas Day, then high pressure
will build again into Friday morning. A low pressure system will
bring widespread wintry precipitation to the region late Friday
through Friday night. Another system will impact the region
late Sunday, followed by cold and dry high pressure into early
next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Drying out today with breezy northwest winds into the
afternoon. Seasonable temperatures expected.

Guidance continues to indicate potential for wind gusts near
40-50 mph across the Pocono Plateau and higher elevations of
northwest New Jersey developing through this morning. This will
be due to strong low level winds developing beneath an inversion
and the Bernoulli effect accelerating winds across the ridge
lines and mountain peaks, and significant wind gusts are not
expected outside of these areas. A Wind Advisory remains in
effect for Carbon and Monroe Counties through 1 PM today.
Elsewhere, gusts around 25-35 mph are forecast. The winds will
diminish through the afternoon, and become calm tonight.

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY/...
Mostly cloudy, but seasonable for Christmas Day with a chance
of sprinkles or flurries early. A winter storm is expected to
impact the region with widespread wintry precipitation starting
Friday into Friday night, however exact amounts and
precipitation types remain uncertain. Light wintry precipitation
could lingering into Saturday morning.

For Christmas Day: not great weather, but not bad either for
late December. A weak mid level shortwave trough will pass
through during the morning hours, which could produce some brief
sprinkles or flurries south of I-78. There`s only a 20-30%
chance of measurable precip, so most places will probably remain
dry. Skies will be mostly cloudy through the day, but
temperatures will be near normal with highs in the 40s for most.
Southwest winds 5-10 mph shifting northwest in the afternoon as
a cold front passes through.

For Christmas night: The cold front will usher in a colder and
drier airmass. Temperatures are expected to fall into the 10s
near and north of I-78, and into the low to mid 20s south of
I-78 by Friday morning. Skies will be partly cloudy. Winds
relatively light, so wind chill won`t be much of a factor.


For the Friday through Friday night winter storm: Bottom line
up front - We are near 100% confident that most of our area will
receive wintry precipitation of some variety, save for our
southern Delmarva zones. The biggest question marks remains the
QPF and precipitation type forecast. Thus, the exact amount of
snow, sleet, and ice that any given location will receive
remains uncertain at this time. Folks with travel plans from
Friday afternoon through Friday night should expect impacts to
their plans, as road conditions will likely deteriorate during
this time with snowy and/or icy roads. Meteorological forecast
details follow below.

An unusual and thus very challenging meteorological forecast
setup for the Friday through Friday night winter storm. A polar
jet ridge will be building into eastern Canada, which will
provide low level cold, dry air from Canadian high pressure
needed for wintry precipitation in our region. Meanwhile, a
subtropical trough will attempt to amplify as it slides just to
our southwest Friday night. This will push a low pressure system
from the lower Great Lakes and upper Ohio Valley region Friday
across the Appalachians Friday night and offshore of the Mid
Atlantic coast by Saturday morning. This setup will result in
widespread precipitation for our region (near 100% chance).
Temperatures will likely be near to well below freezing across
the area Friday night, which will support accumulating wintry
precipitation.

A warm nose around 750 mb will push eastward into the area from
the west as precipitation spreads into the region around midday
Friday or Friday afternoon, with its 0C+ temperatures reaching
as far east as the Lehigh Valley, Philly metro, and southern New
Jersey. East of this line (northern and central NJ),
precipitation will likely remain all or mostly all snow. Near
and west of this line may experience some snow initially on
Friday before changing to sleet, or perhaps some freezing rain
or plain rain depending on surface temperatures and timing. For
precipitation type along and west of this line, it appears sleet
will be most favorable for much of the event, as the melting
layer will be quite high in the atmosphere and have plenty of
well below freezing air and time to refreeze into sleet before
reaching the ground. Some freezing rain is certainly possible
for far western areas in the CWA (SE PA, Philly proper, northern
Delmarva), especially later in the event when low level
temperatures (850-925 mb) warm closer to or above freezing.

As for our current deterministic forecast totals, we stuck
closely with the NBM as uncertainty remains very high on the
exact amounts. QPF amounts range from around 0.5-0.75" in most
areas. Snowfall totals range from 1-3" in northern Delmarva, far
southern NJ, and SE PA to 4-7" in eastern PA and much of NJ.
These totals could end up lower in the transition zone (where
ever that ends up) and areas that experience mostly sleet. It`s
possible some areas get 1-2"+ of pure sleet. Ice amounts are as
much as 0.1-0.25" in portions of SE PA, but these could be too
high if mostly sleet occurs.

Probabilistic amounts likely paint a better picture at this
stage in the forecast. The chance of plowable snow/sleet (2" or
more) is around 50-70% for northern DE, far southern NJ, and
west of I-476 in PA. Elsewhere to the north and east (where
precip is likely all snow), probabilities increase substantially
to around 70-90%. The probability of 5" or more is around
60-70% from Burlington County and north in NJ and adjacent
counties in PA, then drop off precipitously as you go west and
south from there. The probability of 0.10" of ice or more is
around 30-60% in SE PA and northern DE.

So to make this long AFD short, there is nearly a 100% chance
of wintry precipitation that will likely cause travel issues
beginning during the day Friday through Friday night, and
potentially lingering into Saturday morning. A Winter Storm
Watch was considered with this update, but the probability of
warning level snow is not large enough in coverage at this point
for one. Watches may need to be considered in future updates
though.

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
The late Saturday and Saturday night period will be in between
systems. A slight chance of precipitation possible, but nothing
significant. Mostly cloudy skies and seasonable temperatures.

For late Sunday through early Monday, a much more mild and
mostly wet system is anticipated to impact the region with
widespread rainfall. Details remain unclear, but should be a
mostly beneficial rainfall will potential for some light wintry
precip during precip onset. Temperatures near normal

Monday will be a post frontal day with breezy and colder
conditions as Canadian high pressure builds into the area. Wind
gusts over 40 mph possible. Wind chills in the single digits
Monday night.

Colder and remaining blustery on Tuesday with highs near to
below freezing for most. Lows in the 10s to low 20s.

&&

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

Through 12Z...Mostly VFR aside from some transient BR at a
couple sites. West wind increasing and shifting northwest by
08-10Z with gusts up to 20 kt. LLWS is expected for KRDG and
KABE and the I-95 terminals with the arrival of the cold front.
Moderate confidence.

Today...VFR. Northwest wind 10-15 kts with gusts near 25 kts,
perhaps peak gusts as high as 35 kt for KRDG and KABE. The wind
will start to decrease after 18Z, with gusts ending by 22Z. High
confidence.

Tonight...VFR. Winds going calm, then settling out of the south
around 5 kts or less late. High confidence.

Outlook...

Thursday...Some brief MVFR conditions possible in low clouds.

Friday through Friday night...Restrictions developing in snow,
sleet, and freezing rain. Sleet may impact some terminals in the
region for several hours.

Saturday...Lingering restrictions and light precipitation
possible.

Sunday...Restrictions likely in low clouds and rain.

&&

.MARINE...
Small Craft Advisory conditions developing through this
afternoon in the wake of a cold front. Northwest wind gusts
30-35 kts and seas 3-5 feet. The threat for gale force wind
gusts has increased for areas north of Little Egg Inlet, so the
advisory was upgraded to a Gale Warning for these zones. Winds
and seas diminish tonight.

Outlook...

Thursday through Thursday Night...Advisory conditions possible
as another frontal system passes offshore. Wind gusts 20-25 kts
possible.

Friday...No marine hazards expected.

Friday night through Sunday...Advisory conditions possible
through this period as two systems impact the region. Widespread
wintry precip Friday through Friday night. Rain Sunday.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...Wind Advisory until 1 PM EST this afternoon for PAZ054-055.
NJ...None.
DE...None.
MD...None.
MARINE...Small Craft Advisory until 4 PM EST this afternoon for ANZ430-
     431-452>455.
     Gale Warning until 4 PM EST this afternoon for ANZ450-451.

&&

$$

SYNOPSIS...Staarmann
NEAR TERM...Staarmann
SHORT TERM...Staarmann
LONG TERM...Staarmann
AVIATION...Staarmann
MARINE...Staarmann