257
FXUS61 KCTP 291930
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
230 PM EST Sat Nov 29 2025

.SYNOPSIS...
* A quick-hitting system will bring snow and/or snow squalls
  (north) and a wintry mix (south) tonight and Sunday. Freezing
  drizzle is possible in the Laurels.
* A brief period of lake effect snow may affect the far NW
  Sunday night.
* A more widespread/significant winter storm is possible on
  Tuesday.

&&

.NEAR TERM /UNTIL 1 AM SUNDAY MORNING/...
Not much to see for the evening hours. Despite clearing over the
SE half of the area, the NW half has lagged and is now being
overrun by the mid and high clouds which are moving in from the
west. Deepening low pressure to our west will slide into the
Great Lakes tonight. Warm advective precip/snow will approach by
midnight, but it will take some time to work down from aloft.
So, despite some radar echos this evening and early tonight, we
don`t expect anything to stick until close to midnight in Warren
Co, with some flurries starting about that time along the rest
of the western CWA border.

&&

.SHORT TERM /1 AM SUNDAY MORNING THROUGH MONDAY/...
One wave of light WAA snow will lift across the far NW early
tonight with a second and maybe third wave by sunrise. As the
moisture thickens up overnight, some snow may stick over the
rest of the Alleghenies. A worry has developed for freezing
drizzle to occur on the higher elevations of the Laurels. Model
soundings indicate a thick cloud layer of super-cooled liquid
water there before sunrise. Temps will be below freezing there
despite the thickening clouds. Without (many) snow crystals in
the cloud there, the more-likely precip type is freezing
drizzle. The forcing and upslope flow are poor and non-existent,
respectively. It is even more of a downslope flow, esp for
Cambria and Bedford. After confab with PBZ/LWX, we came to the
consensus that a WW.Y was necessary to highlight a light ice
accum on the highest elevations.

The moisture does inch upward slightly before a cold front
sweeps through the CWA from W to E during mid-day. The better
lift and instability will be over the NW, and they could get
above freezing just before the front arrives. Almost all other
locations will likely get to or above freezing, too. The
soundings look like snow N of a line from JST-UNV-IPT before
the front passes despite the above freezing air temps.
Therefore, there could be some heavier snow showers or even
squalls that could ice up the previously warmed roads/bridges.
Something to be aware of at this point. The highest risk for
SQWs would be over the Alleghenies where the SNSQ parameter
start to light up as we see some instability develop in the
"warm" sector. The vertical profiles look more like mix or rain
as you move farther south toward I-81, especially the later in
the day things arrive/occur. Maxes will be in the 40s S of I-80
and below 1500ft.

For now, only mentions of SNSQ will be in the NW third. FROPA
18Z BFD, 22Z IPT/AOO, 00Z at LNS. Wind will get gusty in the
unstable/mixed air, but should be under 30KTs. Some hilltops in
the west could get into the 30s. The flow behind the front goes
NWrly and still has some kick. So, that means...lake effect. The
time period where the NW flow will be confined to late Sun and
Sunday night coincident with a secondary cold front pushing thru
the NW. Moisture decreases and inversion lowers by sunrise
Monday. Monday should be bland/fair with high pressure arriving
and centering overhead. Clouds will probably linger in the W
very much like today (Sat) before high clouds move in later in
the day Mon.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Unsettled weather will continue into the first week of December
as cold air in the middle of the country sets up a strong
baroclinic zone over the eastern US. High pressure in the Plains
should keep cold air in place on the northern side of the
precipitation shield from a wave of low pressure progged to move
out of the Gulf. This system should move northeast around the
base of the aforementioned high pressure system, bringing
increasing moisture to the Mid-Atlantic Tuesday into Wednesday.

The system at this time looks to be somewhat progressive with
the lack of a strong area of high pressure to slow the advance
of the system. Despite the expected fast forward movement, a
deepening coastal low could still provide enough forcing
juxtaposed with favorable upper jet dynamics to produce
significant snowfall across the region. Snow looks to arrive
later Monday night and lift across the region during the day on
Monday, though confidence is still low on timing given the
spread in current guidance this far out. The eventual track and
intensity of the low will have big implications on observed
snowfall totals and the northward extent of any mix/rain
scenarios.

The latest WPC probabilities of 0.25" or greater liquid
equivalent snow/sleet paint medium probabilities (40-70%)
across most of the region, with slightly lower amounts expected
in northwest PA. The latest Winter Storm Outlook highlights a
30-50% chance of Warning criteria snowfall (5"+) in northeast
PA. GEFS and ECENS probabilities of 6"+ continue to outline
probabilities <30% with a higher likelihood in northeast PA up
through coastal New England. If confidence increases in higher
amounts, Watches may be needed in the next 24-48 hours. At this
time, though, a plowable snowfall seems like a reasonable bet
for most of the region. Guidance has remained consistent overall
for snowfall amounts with the last two runs, however some
uncertainty remains whether or not warm nosing above the surface
could limit snow across the PA/MD boarder. Continue to monitor
the forecast in the days ahead, especially if you have plans to
travel.

Later in the week, high pressure will regain control of our
weather. Prevailing upper troughing brings high confidence in
continued below normal temperatures and a chilly start to
December. Low temperatures in the teens or single digits are
possible and our active storm pattern appears likely to
continue.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
Mainly clear skies to end the afternoon in southern PA with
scattered low clouds hanging on across the north. KBFD remains
in MVFR with those low ceilings, but elsewhere is VFR and should
remain VFR through the early evening hours tonight. Snow will
begin to overspread the area from the northwest and western
mountains around 06Z tonight. The highest confidence in
reductions to flight conditions is at BFD/JST/AOO. IFR is likely
at BFD with the heaviest snow expected over that terminal.
Further south near JST and AOO snow is likely before
transitioning to a rain snow mix by mid morning. Precipitation
will take the longest to reach the southeast with MDT and LNS
holding the highest chances to remain VFR throughout this TAF
package.

Once this system clears out, Monday will be relatively dry with
low ceilings hanging on for MVFR to IFR flight categories
before the next snow storm is expected across all of central PA
Tuesday.

Outlook...

Sun...Light rain/wintry mix developing from west to east;
restrictions possible. Precip may turn to rain across the south
during the day.

Mon...Mixed/wintry precip likely early on. MVFR likely. IFR
possible.

Tue...Snow possible, before a possible mix later in the day
across the south. Restrictions possible.

Wed...Trending drier, lingering snow across NW PA.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from 3 AM to noon EST Sunday for
PAZ033.

&&

$$

SYNOPSIS...Dangelo
NEAR TERM...Dangelo
SHORT TERM...Dangelo
LONG TERM...Banghoff/Bowen
AVIATION...Bowen