217
FXUS61 KCTP 010445
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
1145 PM EST Sun Nov 30 2025

.SYNOPSIS...
* A brief period of lake effect snow will affect northwest PA
  tonight.
* A more widespread winter storm is expected Monday night and
  Tuesday.
* A strong cold front Thursday will bring lake effect snow and
  the coldest temps of the season thus far, in the single digits
  and low teens by Fri AM

&&

.NEAR TERM /THROUGH MONDAY/...
An additional inch or two of snow is possible in northwest PA
overnight in light lake effect snow. Surface ridging will result
in lowering inversion heights by later tonight, bringing an end
to the precipitation by sunrise on Monday. Temps overnight will
range from the upper teens in the north to the mid 20s in the
southern tier.

Monday will be dry with high pressure arriving and centering
overhead. Clouds will probably linger in the west with upslope
flow before high clouds move in later in the day on Monday. More
sunshine is expected east. Temps will be stuck below freezing in
the northern tier, but rise through the 30s most everywhere
else.

&&

.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
A fast moving upper trough will result in more widespread wintry
weather Monday Night into Tuesday. The system at this time
looks to be somewhat progressive with a lack of a strong area
of high pressure to slow its forward momentum. A band of snow
looks to arrive shortly after midnight in the NW mountains as
the right entrance region of a jet max forces ascent overtop
some modest 700 mb frontogenesis. The upper jet will strengthen
and extend southward through the first half of Tuesday,
supporting another area of ascent over the eastern half of PA.
At the same time, warm advection in the southeast will lead to
isentropic ascent and another area of heavy snow is possible
just north of the rain-snow line Tuesday morning. Though
accumulation rates may locally approach 1 inch per hour, the
limiting factor for snow totals will be longevity. At any given
location, most of the snow accumulation will occur in just a 6
hour window. Most likely forecast is 4-5 inches for the northern
2/3 of central PA, with higher amounts perhaps focused in the NW
and SE and a "shadow" through the middle, and lesser amounts in
the southern tier where rain/sleet/freezing rain may mix in.
Highest chance for locally 6 inches is somewhere between
Harrisburg and Williamsport and points east, maybe the higher
terrain of Schuylkill or Sullivan Counties. Precip tapers off
late Tuesday afternoon as RH quickly drops above the 700 mb
level.

From previous...
The latest Winter Storm Outlook highlights a 30-50% chance of
Warning criteria snowfall (6"+) in northeast PA, primarily east
of US-15. GEFS and ECENS probabilities of 6"+ also support the
30-50% probability in the Poconos, with an even higher
likelihood up through coastal New England. The ECENS suggests
the higher terrain farther south could also bear watching. Have
gone ahead and hoisted a Winter Storm Watch from Lycoming and
Sullivan Counties down through Northumberland and Schuylkill
Counties for Monday night into Tuesday evening. May certainly
need to expand this and want to reiterate that storm
intensity/track will weigh heavily on where future advisories
and/or warnings may be needed. Regardless, a plowable snowfall
is likely for almost all of central PA on the low end of the
spectrum. 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 border into south central PA and the lower
Susquehanna Valley. If mixing is a problem for anywhere in
central PA, it would probably be for locations southeast of
US-30 in York and Lancaster County. Continue to monitor the
forecast in the days ahead, especially if you have plans to
travel.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
High pressure builds in Wednesday with a reinforcing cold front
moving through Wednesday night into Thursday. This will likely
produce some light snow across the northern tier. Some
indication there could be some snow squalls with the front as it
pushes southeast on Thursday.

Thursday night and Friday look quite cold, with lows in the
single digits and teens while highs only make it into the 20s to
low 30s. Otherwise, temperatures will be fairly consistent for
the upcoming week and weekend, with highs in the 30s and lows in
the teens and 20s.

By next weekend, another storm system looks to affect the
Midwest and northeast US. Considerable uncertainty remains with
the low track of this system. A track northwest of PA would
lead to snow changing to a wintry mix and rain, while a track
southeast of PA could look pretty similar to Tuesday`s system
with primarily snow. Regardless, a prolonged stretch of cooler
than normal temperatures and an active storm track through the
northeast looks to continue into the first week (and more) of
December.

&&

.AVIATION /03Z MONDAY THROUGH FRIDAY/...
Generally MVFR to VFR across the area as a cold frontal
boundary crosses the area. There is little in the way of
precipitation with this front, but a west northwest wind does
increase to 15G25KT along and behind.

Scattered -SHSN will continue for the next few hours at KBFD as
nominal lake effect continues. This should diminish after
midnight but remain MVFR through the remainder of the period.

Confidence is high (>80%) of all other locations becoming VFR
after 01/12Z as weak high pressure builds in ahead of the next
storm system.

The next widespread snowfall system will arrive on Tuesday as a
coastal low develops and move up the coast of New England
Tuesday afternoon.

Outlook...

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

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

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
Winter Storm Watch from late Monday night through Tuesday
evening for PAZ041-042-046-051>053-058.

&&

$$

SYNOPSIS...Guseman/Colbert
NEAR TERM...Guseman/Colbert
SHORT TERM...Guseman/Colbert
LONG TERM...Guseman/Colbert
AVIATION...Bowen/Tyburski