Latest Area Forecast Discussion for Central PA

Here is the latest Area Forecast Discussion for Central PA

This text statement is the latest forecast reasoning from the NWS in State College, PA

See the links at the bottom of the page for previous issuances/versions of the statement as well as our other text statements.

688
FXUS61 KCTP 170323
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
1023 PM EST Fri Jan 16 2026

.WHAT HAS CHANGED...
* Slight increase in expected snowfall totals for late tonight (and
primarily Saturday morning) with a Winter Weather Advisory
issued for much of the Lower Susq Valley and Western Poconos
for Sat Morning. The Winter Weather Advisory continues for the
NW Mtns of PA and part of the Laurel Highlands.

&&

.KEY MESSAGES...
1) Plowable snowfall tonight into Saturday with scattered heavy
snow showers and squalls Saturday afternoon, mainly across the
western half of the state.

2) An arctic blast Monday will produce little snowfall but lead
to dangerous, sub-zero wind chills Monday night and Tuesday.

3) Colder than normal temperatures continue through the end of
the month with storm chances every few days.

&&

.DISCUSSION...
KEY MESSAGE 1: Plowable snowfall tonight into Saturday with
heavy snow showers and squalls Saturday afternoon.

A couple shortwaves (favorable quadrants of an upper level jet
and nose of a low-level jet) rotating around the base and
eastern side of a prevailing eastern US trough will pair with
an approaching low pressure system traversing the Great Lakes to
produce multiple rounds of snow this weekend.

The first arrives overnight across western PA as warm advection
lift develops underneath the left exit region of a strong upper
jet. Southwesterly flow will direct most of the moisture into
the northwest mountains, though recent model runs have shown
steadier snow making it as far south as Cambria County and the
western ridges of Somerset County. These areas will likely see 2
to 4 inches of snow by daybreak.

During the day on Saturday, a couple reinforcing cold fronts
and building instability will generate scattered to numerous
snow showers and squalls. Storm motion drifting from southwest
to northeast means the best chance for snow squalls will be
generally west of the I-99 to US-15 corridor. High temperatures
in the affected area will rise to near or slightly above
freezing during the afternoon, but air temps will be below
freezing for most of the day. With breaks in the clouds
expected, road temperatures will likely rise above freezing,
with a risk of flash freeze possible with any stronger/more
persistent snow showers/squalls. Additional snowfall of an inch
or two through the day on Saturday increases confidence in
reaching advisory criteria in theses areas and we have issued a
Winter Weather Advisory which is in effect from 7 PM tonight
through 1 AM Sunday.

The forecast is a bit more complicated for eastern PA. Marginal
temperatures and less moisture content should help to limit
snowfall somewhat, but strong divergence associated with the
thermally direct right entrance region of a 150 knot upper
level jet (and band of enhanced 850-700 mb FGEN) will support
an area of moderate snow during the second half of Sat morning
into the early afternoon. Most of the latest high res model
runs support higher snowfall in the both the Lower Susquehanna
Valley and Western Poconos, with 1 to 3 inches of snow
expected. Slightly higher amounts are possible in the higher
terrain of Schuylkill (and perhaps even parts of Sullivan)
County. A Winter Weather Advisory may be needed across Sullivan
county if confidence in higher snowfall totals continues to
increase.

KEY MESSAGE 2: An arctic blast Monday will produce little
snowfall but lead to dangerous, sub-zero wind chills Monday
night and Tuesday.

A lull in the snow Sat night into Sunday night will be followed
by another, colder, cold front. 8H temps drop into the -20/-23C
range for Monday. Moisture will be lacking with the front, but
light snow may accompany it. In its wake, surface and steering
winds out of the southwest or west-southwest should keep lake
effect snow bands directed into New York with mainly dry
conditions in Pennsylvania. Min wind chills Monday night/Tuesday
morning range from 0F in the LSV to minus 20F over portions of
the Alleghenies. The current forecast would support a Cold
Weather Advisory in the Laurels and northern mountains
(approximately along, west, and north of the I-99/I-80 corridor)
and possible an Extreme Cold Warning in the Laurel Highlands.

Fcst highs in the + single digits to ~20F on Tuesday are 15 to
25 degrees below the historical average. A long duration period
of sub zero wind chills is likely from Monday night through
Tuesday night/AM Wednesday. Low-level flow becomes more westerly
by Wednesday, which will help to direct lake effect snow bands
back into northwest PA.

KEY MESSAGE 3: Colder than normal temperatures continue through
the end of the month with storm chances every few days.

A persistent west coast ridge and east coast trough pattern in
the upper levels will ensure the continuation of below normal
temperatures through the end of January. Periodic waves of low
pressure traversing the High Plains and Great Lakes mean we`ll
see frequent opportunities for precipitation. Most of the storm
systems appear weak and relatively disorganized at this point,
which would favor the highest snowfall totals occurring in the
typical upslope and lake effect snow regions of the Laurels and
northwest mountains through the end of January.

&&

.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
Gradually deteriorating conditions will occur overnight as large
scale lift increases from SW to NW across the Central and
Western PA airfields. IFR conditions will develop across all of
the western mtns shortly and continue overnight, while VFR
gradual transitions to MVFR CIGS very late tonight/Sat morning
over the Central Mtns and Susq Valley.

IFR Vsbys are likely for several hours across and to the east of
the I-81 corridor from KMDT to KAVP in -SN between 10-17Z Sat.

As warm air advection increases out ahead of the next cold
front this evening, LLWS concerns increase south to southwest
winds near 40 kts at 2000 ft.

The 00Z TAF package maintains longer durations of snow at the
western airfields (BFD/JST/AOO) while limiting longer durations
further east (UNV/IPT) with PROB30 groups in the area of most
concern for visibility restrictions in light snow.

Lower restrictions will be possible in snow squalls with gusty
WSW winds across the western terminals (BFD/JST/AOO/UNV) Sat
afternoon/evening.

Outlook...

Sun...Scattered light snow/restrictions possible (low forecast
confidence)

Mon-Wed...Light snow/IFR possible in the NW at times.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 1 AM EST Sunday for PAZ004>006-
010-011-017-024.
Winter Weather Advisory from 5 AM to noon EST Saturday for
PAZ057>059-065-066.

&&

$$

WHAT HAS CHANGED...Lambert
KEY MESSAGES...Lambert/Bauco
DISCUSSION...Lambert/Bauco
AVIATION...Lambert/NPB

Forecaster's
Discussion: