614
FXUS61 KCTP 052209
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
509 PM EST Fri Dec 5 2025

.SYNOPSIS...
* Low, non-precipitating clouds will blanket the region through
  tonight leading to much higher, but still cold overnight lows
  tonight
* 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 /UNTIL 6 AM SATURDAY MORNING/...
North south axis of well-defined llvl streamline convergence is
in place across central PA and has resulted in quick nwd
advection of an extensive albeit shallow, stratus layer that
now covers practically the entire CWA (except for the NW corner
of Warren County) this mid afternoon hour.

Sunshine through 14-15Z today across the north (where single
digits temps above and below zero were recorded) allowed for a
quick rebound in temps into the teens to low 20s, while the temp
change was much less across the south where extensive cloud
cover was found for much of the night and all day today.

Some additional lowering of this cloud deck will occur through
the rest of this afternoon and tonight, that will eventually
intersect the highest ridges overnight. these shallow clouds may
be capable of producing some patchy freezing drizzle or snizzle
later today and tonight on the favored upslope portions of the
ridges - something to monitor going forward.

Temps across the Southern half of the state were mainly between
24-27 deg F. Readings in all locations will still rise about
another few to several deg with weak llvl warm advection from
the south.

The clouds will also trim the temp drop with mins fcst in the
upper teens (north) to low and mid 20s (south) - which will be
much warmer than this morning.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
Some fleeting sunshine possible Saturday, but dont bank on it in
most places, as the exit of the aforementioned widespread
stratus deck (resulting from development of a mean swrly llvl
flow) is quickly replaced by a dual layer of higher based
stratocu and thick layer of mid and high clouds.

The passage of a weak sfc trough will add a Southwesterly breeze
on Saturday, helping to push max temps closer to early December
climo with highs +5-10F warmer day/day in most locations.

Highs Sat afternoon will range from 30-35 across the Northern
Mtns to the low 40s in the Southern Valleys.

Lake effect snow trajectories marginally improve by Saturday
night over the NW mtns (generally Northern Warren and Mckean
Ctys) 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 2-3" across the NW mtns along and north of US-6.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
A cold but quiet start to next week will be followed by a
reinforcing cold weather pattern as we see the exit to the east
of the strong and persistent Swrly Subtropical Jet from the
Baja area to the Carolina Coast.

The large scale upper flow will become more amplified for the
middle to late week period with a persistent trough in the east
and ridging over the Rockies and Western States.

Several clippers migrating through and reinforcing the Eastern
U.S. trough will bring at least 2-3 opportunities for snow (and
possibly a little mixed precip across the south).

The next, best chance for wintry precip area-wide is
Wednesday/Wednesday night, as a vigorous clipper drops southeast
across the region. Model consensus points toward low-end
advisory category snow (3-4 inches) possible across the Nrn and
Western Mtns with an inch or so of accum in the Central Ridge
and Valley region associated with the several hour period of
warm advection snow in advance of the upper shortwave.

The second noteworthy precip event for next week will come
Friday as a similar shortwave (but with a much more southern
track) spreads some snow over primarily southern PA as a
northerly llvl flow with 850 mb temps in the -8 to -12C range
will ensure deep cold air in place for all snow.

Confidence remains high in below normal temperatures; Monday
night could be another frigid period with lows -5F to +15F by
daybreak Tuesday.

&&

.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
Not much change for the 00Z TAF set.

There could be isolated tiny snowflakes at times overnight,
some indication of this on the radar returns on the MD/PA
border as of 5 PM. MVFR to IFR CIGS across the entire area
as of 5 PM as well, not seeing much change in conditions
overnight. CIGS will trend to lower with time, before
improving later on Sat.

See earlier information below on the potential for very light
freezing drizzle with the lower CIGS over the higher terrain.

Earlier information below.

Widespread MVFR to low end VFR stratus covers all of the
Central PA the mid afternoon hour. Ceilings will lower to
IFR across most of central PA during the evening and overnight.

Once IFR ceilings develop, they will likely persist at BFD,
JST, and LNS through 12Z Sat. The other sites may see ceilings
rise to MVFR before sunrise Sat.

Some patchy light freezing drizzle is possible late today
through early Sat where cloud bases lower to within 500 feet or
so of the ground (which will occur mainly on the ridge tops).

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 brought
frigid temperatures to central Pennsylvania, the coldest of
this winter thus far. Multiple locations across the area
challenged (or broke) record low temperatures for 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...Lambert/Steinbugl
NEAR TERM...Lambert/Steinbugl
SHORT TERM...Lambert/Steinbugl/Banghoff
LONG TERM...Lambert/Steinbugl/Banghoff
AVIATION...Lambert/Martin/Bauco
CLIMATE...NPB