437
FXUS61 KCTP 081211
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
711 AM EST Mon Dec 8 2025

.SYNOPSIS...
* Mostly cloudy and colder today; bitterly cold/frigid tonight
* Not as cold Tuesday; quick shot of snow in the NW mtns
* Windy with snow/rain mix followed by lake effect snow through
  midweek; additional snow accumulation possible Friday-Sunday

&&

.NEAR TERM /THROUGH TONIGHT/...
A cold northerly wind is sending arctic air southward to the MD
line early this morning as 1030mb high pressure builds across
the eastern Great Lakes. Despite brief clearing north of I80
after midnight, expect a partly to mostly cloudy and cold day
with mid and high clouds streaming northward in association
with a 500mb trough tracking eastward from the TN Valley to the
VA/NC coast.

Sub-freezing max temps (below 32F) today in the upper teens to
upper 20s are quite cold by early December standards or 15 to 20
degrees below the historical average. Hires model data shows
mid/high clouds peeling off to the northeast by tonight,
setting up favorable radiational cooling under the modified and
reoriented arctic sfc high channeling down the east-side of the
Allegheny Front/Blue Ridge by 12Z Tue. This will translate into
a bitter cold to frigid night across CPA with lows ranging from
5 below to 15 above or 15 to 25 degrees below climo. It should
be noted that some daily record lows could be within reach
particularly if the min temps prints on 12/8 (before midnight)
vs. 12/9 or after midnight. (See climate section for 12/8 and
12/9 record mins)

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
High pressure shifts east of the I95 corridor by Tuesday
afternoon yielding to lead/low amplitude northern stream mid
level shortwave disturbance moving swiftly across the eastern
Great Lakes. Blended model data continues to favor a quick shot
of light snow ~1" btwn 18Z Tue-06Z Wed with this feature over
the NW mtns which could impact the evening commute.

Meanwhile upstream, an intense mid-980s mb clipper low will be
racing through WI and into Michigan`s Mitten btwn 06-12Z Wed.
WAA out ahead of this anomalously deep Alberta clipper (one of
the strongest for this time of year by historical/climatological
MSLP standards) is expected to spread accumulating light to mdt
snow across the NW 1/2 of the CWA for the Wednesday morning
commute. By Wednesday afternoon, 24-hour snow totals are
projected to reach 2-4" in the NW mtns with C-1" fcst elsewhere
in areas along and north of I80. As the precip expands eastward
into Wednesday afternoon, marginal temperatures/thermal profiles
will favor a snow/rain mix or just plain rain from the central
ridges eastward into the mid and lower Susquehanna Valley.

As the storm tracks through the St. Lawrence River Valley
Wednesday night, much colder cyclonic/NWly flow will trigger
lake effect snows with minor snow accums over the typical NW PA
snow belts and favored upslope areas along the Allegheny Front
and Laurel Highlands. The other factor to account for with
this powerful clipper tracking to the north of CPA is the wind
field which should generate max gusts 30-40+ mph range.

36-48hr snowfall is generally 2-4/3-6" over the NW mtns with
odds of a pending winter headline better than 50/50. Lower snow
amounts (C-1/1-2") are fcst for locations along and northwest of
I99/US220.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
Lake effect snow and gusty NW winds continue on Thursday with
additional snow accums expected over the NW mtns and Laurel
Highlands.

The next winter wx system is progged to arrive later Friday into
Friday night, although models are showing some variance with
the evolution and track. More lake effect snow/snow showers
continue over the weekend with temperatures staying below the
historical average heading into mid-December.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
High pressure moving across Pennsylvania will keep VFR
conditions in place through the day, but a wave of low pressure
passing to our south will lead to increasing mid and high clouds
during the morning. Skies will clear out again during the
evening from northwest to southeast and winds will decrease to
less than 5 knots.

Low stratus should expand northward into southwestern PA after
06Z as low-level flow takes on more of a southerly component.
Most guidance suggests that this shouldn`t reach much farther
than JST and AOO, and ceilings likely remain VFR in the 3000 to
4000 foot range.

Outlook...

Tue-Fri...Restrictions possible with snow or mixed ptype,
especially across the northern half of Pennsylvania, as multiple
low pressure systems track through the northeastern US. Gusts
15-30 kts, and up to 40 kts in the Laurels late Wed.

&&

.CLIMATE...
Astronomical winter (solstice) begins at 10:03 a.m. on Sunday,
December 21st

Record lows for 12/8:
MDT  12 in 2002
IPT  3  in 1901
AOO  7  in 2005
BFD -2  in 1970

Record lows for 12/9:
MDT  7   in 1989
IPT  3   in 2002
AOO -3   in 1989
BFD -12  in 2002

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

SYNOPSIS...Steinbugl
NEAR TERM...Steinbugl
SHORT TERM...Steinbugl
LONG TERM...Steinbugl/Colbert
AVIATION...Bauco
CLIMATE...Steinbugl