Lancaster, Pennsylvania 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

755
FXUS61 KCTP 060552
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
1252 AM EST Sat Dec 6 2025

.SYNOPSIS...
* Light snow accumulation likely over the western and central
  Alleghenies later Sat and again 24 hrs later
* Reinforcing shots of cold weather and clippers provide
  additional opportunities for snow throughout the next 7+ days
  for the northwestern half of PA.

&&

.NEAR TERM /UNTIL 8 AM THIS MORNING/...
CLouds have done the job of keeping temps up from last night.
But, they also are hanging down low enough to touch the highest
ridge tops where temps are (well) below freezing. We have heard
reports of FZDZ in the Laurels just to the east of Somerset Co,
and we`ve been carrying mentions of patchy FZDZ for a while.
We`ve tried to highlight the not-widespread threat of icy
patches via an SPS (special wx statement). We will keep an eye
on developments thru the night, but it is not expected to get
worse than patchy icy spots.

&&

.SHORT TERM /8 AM THIS MORNING THROUGH SUNDAY NIGHT/...
Have tried to bring more continuity to the PoPs for Sat and Sat
night. Expect -SHSN over the wrn mtns as a very weak upper short
wave trough passes through. Some breaks in the clouds are
possible Sat and again Sun, but many layers of clouds are
expected to make it tough to find them. Some clearing is
possible for the SE half Sat night.

Prev...
Some fleeting sunshine possible Saturday, but don`t 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 /06Z SATURDAY THROUGH WEDNESDAY/...
MVFR or lower ceilings are expected at all airfields through the
rest of the night, with BFD and JST having the best chance of
seeing IFR ceilings. Patchy freezing drizzle will remain
possible across west-central PA as the clouds thicken.
Southwesterly flow develops after sunrise ahead of an
approaching shortwave trough and ceilings will rise through the
morning. VFR conditions are expected for the afternoon at all
TAF sites except BFD.

Ceilings gradually lower to MVFR once again west of UNV during
the afternoon as the shortwave wave moves through the region.
A few upslope snow showers could impact JST during the evening
as flow becomes more west-northwesterly. Scattered lake effect
snow showers will also develop off of Lake Erie and could
approach BFD Saturday night, though most of the high resolution
guidance keeps most of the snow to the north and west. VFR
conditions will continue farther to the east.


Outlook...
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-Wed...Restrictions possible with snow, especially across the
northern half of Pennsylvania, as multiple low pressure systems
pass over or just north of the region.

&&

.CLIMATE...
A couple of record lows were set this morning (12/5/2025).

Location     | Actual low (thru 5 PM) | Record (YEAR)
------------   ----------------------   --------------
Harrisburg   |         21             |   12 (1926)
Williamsport |         10             |    8 (1926)
Bradford     |         -8 **          |    0 (2007) **
Altoona      |         12 **          |   13 (1966) **
Johnstown    |          8             |    3 (1966)

                 ** record broken

&&

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

&&

$$

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