560
FXUS61 KCTP 092239
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
539 PM EST Tue Dec 9 2025

.SYNOPSIS...
* Light snow ends in NW PA; round 2 on the way Wednesday morning
* Windy with wet snow and mixed precipitation Wednesday followed
  by lake effect/upslope snow showers through Thursday night
* Periods of snow and below normal temperatures Friday through
  the weekend

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
A quick shot of light snow across the NW mtns will end early
this evening. Elsewhere, expect cloudy skies with steady/flat
to slowly rising (non-diurnal) temps overnight as WAA ramps up
ahead of fast moving/intense clipper low racing eastward from
southwest MN to lower MI by 12Z Wednesday. Min temps occur early
tonight in the low to mid 20s.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
The strong WAA downstream from the clipper low will overrun a
retreating cold antecedent airmass, creating broadening plume of
precip, falling primarily as wet snow across the NW Alleghenies
during the predawn hours impacting the morning commute.
HREF/RRFS model signals suggest a brief period of zr/sleet is
possible along the southeast edge of the precip shield near the
I81 corridor (strongest ice signal is over Schuylkill County).
Later shifts can assess potential for SPS or short-fused winter
wx advisory (low confidence, but non-zero prob of ice glaze).

No significant changes to expected snowfall totals with max
amounts 2-5" over the northern tier/Route 6 corridor. Local max
~6" may be found in the higher terrain in Sullivan County. Snow
rates are projected to be in the 0.50-1 in/hr range in the NW
mtns during the 5-10AM window before shifting eastward across
north central PA toward the Poconos.

Intermittent snow/rain in the valleys along I99/US220 corridor
from Blair/Centre County east along I80/US220 should result in a
slushy coating to 1 inch. There is a scenario where wetbulb
effects help to lock in colder air for a longer duration over
the central ridge/valley region, which may result in a bit more
snow than currently fcst. Temps are expected to rise above the
freezing mark particularly along and southeast of I99/I80
corridor by the afternoon. Temps could stay a few degrees colder
in the northern tier, but road snow will likely become more
limited after midday given the marginal air/road temps.

We expanded the winter wx advisory to include the Laurel
Highlands in coordination with PBZ/LWX. Rain to snow transition
occurring over the course of the day on Wednesday will be
followed by an extended period of orographically enhanced snow
showers with blustery winds through Wednesday night as the
strong storm tracks northeast through the St. Lawrence River
Valley. We could foresee the advisory being extended for the NW
mtns where additional LES accums are expected into Thursday.

Winds increase tomorrow with frequent gusts in the 25-35 mph
range; locally higher gusts up to 40 mph on the Laurel
Highlands. Given the wet character of the snow early on
Wednesday, blowing and drifting impacts are not a concern at
least initially. However, as temps fall into Wednesday night,
expect the character of the snow to become drier or more fluffy
which increases the potential for blowing and drifting over the
higher terrain Wednesday evening through Wednesday night. Wet
surfaces and slush areas will be prone to refreezing and icy
spots overnight Wednesday into early Thursday morning.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Late afternoon update.

Pattern supports fast moving weaker systems, mainly to the north
and south. Wide swings in guidance at times, given the large
scale pattern.

For the next system, the highest chance for snow later Friday
is mainly south of our area again.

Pattern supports an abnormally cold period.

Earlier discussion below.

Lake effect snow showers and gusty northwesterly winds
continue on Thursday with additional snow accums expected over
the northwestern mountains and Laurel Highlands. A few long
fetch bands or locally heavy snow showers/squalls are possible
on Thursday and could extend as far southeast as I81.

Winter weather/periods of snow continue from Friday through the
weekend and into early next week with a series of upper troughs
and clippers followed by reinforced cold NW flow and lake
effect/upslope snow showers. Temperatures remain below the
historical average heading into mid-December.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
Some very light snow and MVFR CIG at BFD earlier, but most of
the snow on the radar returns earlier was aloft, given the very
dry air at low levels. Not a lot of change for the 00Z package.
Main change was to add a line for late afternoon for frontal
passage, tapering of the snow, and wind shift.

More information below.

MVFR ceilings will expand east tonight, likely arriving at JST,
AOO, IPT, and UNV within a couple hours of sunrise. A clipper
system system will bring periods of light to moderate snow to
the region on Wednesday morning and into the afternoon, initially
moving into BFD in the 06-09Z timeframe. Precipitation will be
much lighter south of UNV and east of AOO, but a mix of rain,
snow, and perhaps freezing rain is possible at MDT and LNS
during the late morning and early afternoon.

LLWS will also become a factor tonight into Wednesday as a 45-60
knot west-southwesterly LLJ moves into western PA after 00Z
Wednesday. Behind the cold front Wed evening into Thu, winds
will turn out of the west and increase with sfc gusts 15-35 kts
(highest in the Laurels).

Outlook...

Wed night-Thu...Snow showers continue, mainly N/W PA. Windy.

Fri-Sun...Additional rounds of light snow possible with multiple
clipper systems.

&&

.CLIMATE...
Bradford, PA had two records in one night! Their temp of -4F
just before midnight EST on 12/8 broke the previous record of -2F
set in 1970.

As the temp continued falling through the night, they tied the
12/9 record low of -12F at 618 AM EST. This tied the record set
in 2002.

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

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from 1 AM to 10 PM EST Wednesday for
PAZ004>006-010>012-017-018.
Winter Weather Advisory from 10 AM Wednesday to 10 AM EST
Thursday for PAZ024-033.
Winter Weather Advisory from 3 AM to 10 PM EST Wednesday for
PAZ037-041-042.

&&

$$

SYNOPSIS...Steinbugl
NEAR TERM...Steinbugl
SHORT TERM...Steinbugl
LONG TERM...Lambert/Steinbugl/Martin
AVIATION...Martin/Colbert
CLIMATE...Martin/Colbert