642
FXUS61 KCTP 051133
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
633 AM EST Fri Dec 5 2025

.SYNOPSIS...
* Cold Super Moonset ends of one the coldest nights on record
  for early December; max temps stay below freezing today
* Light snow accumulation likely over the western and central
  Alleghenies later Sunday through Sunday night
* Reinforcing cold weather pattern and clippers provide
  additional opportunities for snow next Tuesday-Friday

&&

.NEAR TERM /THROUGH TONIGHT/...
Baby, it`s cold outside. A perfect night and early morning for
the Cold Super moonset around 8:20 AM. Daily record low smashed
at KBFD down to -5F at 08 UTC with more room to the downside
with -8F dewpoint. A low temp below -5F would rank as the 3rd
coldest on record between Dec 1-5; below -7F would rank as the
2nd coldest. Several locations across the northwest 3/4 of CPA
will see min temps bottom very close to daily record lows. A
veil of mid/high clouds associated with a weak low sliding off
the Southeast coast is preventing the bottom from falling out on
min temps across the Lower Susquehanna Valley/areas near and SE
of I81; unless skies can clear - the record low at KMDT not be
tied or broken.

Primary stripe of snow - driven by a combo of low level fgen
forcing, isentropic upglide, and jet-induced lift to the
northwest of the aforementioned sfc low - stays south of the MD
line. So while most of CPA will start the day sunny and very
cold/frigid, look for cloud cover to expand northward by the
afternoon. Given the record to bitter cold start and increasing
clouds, max temps are fcst to remain below the freezing mark
(32F) which is actually a pretty rare occurrence this early in
the winter season.

Hires models and "goal-post" sounding profiles suggest that the
expanding and low cloud deck beneath a strong inversion may be
capable of producing some patchy freezing drizzle or snizzle
later today and tonight - something to monitor going forward.
The clouds may also add a few degrees to min temps currently
fcst in the 20-25F range (much warmer than this morning!)

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
Passage of weak sfc trough will add a SWly breeze on Saturday
helping to push max temps closer to early December climo with
highs +5-10F warmer day/day in most locations. Lake effect snow
trajectories marginally improve by Saturday night over the NW
mtns before lowering inversion heights and backing low level
winds keep light snow accums mainly confined to the I90 corridor.

Split/northern stream trough swings through on Sunday and likely
brings some light (lake/terrain enhanced) snow primarily to the
western and northern Alleghenies. NBM snow accum favors sub-
advisory level accumulation for most areas, with the best odds
for 1-3/2-4" across the NW mtns along and north of US-6.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
A cold but quiet start to next week will be followed by a
reinforcing cold weather pattern with clippers providing
at least 2-3 opportunities for snow. Confidence remains high in
below normal temperatures; Monday night could be another frigid
period with lows -5F to +15F by daybreak Tuesday.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
Current satellite shows stratus developing over southern PA.
These clouds will continue to expand northward through the
morning, eventually reaching all TAF sites. Ceilings will
initially drop to MVFR as these clouds move in, but most
guidance continues to indicate that further reductions to IFR
are likely across most of central PA during the evening and
overnight. Once IFR ceilings develop, they will likely persist
at BFD, JST, and LNS through the rest of the 12Z TAF period.
The other sites may see ceilings rise to MVFR before sunrise.

Model soundings show a fairly deep saturated layer below the
dendritic growth zone late this morning and during the
afternoon, which could support patchy freezing drizzle.
Confidence on this occurring remains too low to include in the
TAFs at this point.

Outlook...
Sat...Restrictions possible, chance of snow showers in the NW

Sun...A compact but more amplified upper level trough with a preceding
low level south to southwesterly wind max will likely bring a 4
to 6 hour period of mainly light snow with IFR vsbys and MVFR to
IFR CIGS (targeting mainly Central and Northern PA) late
Sunday/Sunday night.

Mon...Mainly VFR

Tue...Snow/restrictions possible mostly in the second half of
the day

&&

.CLIMATE...
Cold temperatures in the wake of the Arctic Front will bring
frigid temperatures to central Pennsylvania, the coldest of this
winter thus far. Multiple locations across the area will be
challenging record low temperatures on December 5th:

Location|Record
Harrisburg | 12 (1926)
Williamsport |   8 (1926)
Bradford | 0 (2007)**
Altoona | 13 (1966)*

** record broken
*  record tied

&&

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

&&

$$

SYNOPSIS...Steinbugl
NEAR TERM...Steinbugl
SHORT TERM...Steinbugl/Banghoff
LONG TERM...Steinbugl/Banghoff
AVIATION...Bauco
CLIMATE...NPB