989
FXUS61 KCTP 172257
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
557 PM EST Wed Dec 17 2025

.SYNOPSIS...
* Areas of freezing fog tonight into early Thursday morning
* Widespread rain Thursday evening into early Friday morning
  followed by falling temperatures and lake effect snow Friday
* Strong winds Thursday night through Friday and again Sunday

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
Gusty winds over the western and central Alleghenies this
afternoon will diminish this evening into tonight as a sfc
ridge slides over CPA. Model guidance continues to indicate
areas of radiational [freezing] fog developing overnight under
partly cloudy skies with light/variable wind and min temps in
the 20s. The freezing fog could result in slick spots into
early Thursday morning.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
With warm air advection strengthening the existing temperature
inversion Thursday morning, any fog and low stratus may be slow
to dissipate. An increasingly moist SSE low level flow would
favor low cloud cover expanding to the east of the Allegheny
Front holding highs close to 40F.

Very strong 55-65kt LLJ will drive widespread rain ahead of a
sharp cold front Thursday evening/night into early Friday
morning (00-12Z Thu). Rainfall totals are 0.50-1.00" for most
with locally higher amounts >1" likely over the eastern
periphery of the CWA particularly where orographic enhancement
will be maximized. Recent runs of the RRFS suggest the potential
for a shallow, strongly forced cold frontal rain band feature
to sweep through btwn 06-12Z Fri and would not rule out sporadic
ltg flashes and rumbles of thunder within the convective line
and/or with elevated pre-frontal convective elements.

Temperatures will be non-diurnal (steady to rising) Thursday
night. A persistent flow of colder air behind the front will
continue the non-diurnal (falling) trend on Friday.

A tightening pressure gradient and sfc pressure rises within
broad CAA regime will deliver strong gusty winds on Friday. Max
gusts in the 35-45 mph range are probable with higher gusts
exceeding advisory level criteria certainly within reach. Odds
for a NPW headline are better than 50/50 and we considered a
CWA-wide headline for this cycle; however will allow the next
1-2 shifts to further assess and collaborate. We will continue
to highlight the high wind threat in the HWO. The strongest wind
gusts are most likely on Friday, however can`t rule out some
locally higher gusts on the ridgetops Thursday night given the
magnitude of LLJ (albeit with greater low level stability).

Short duration Lake effect snow accums in the 1-3" range are
likely across the NW mtns Friday-Friday night.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Arrival of sfc high ends LES by early Saturday. Model data
continues to show a strong cold frontal passage with quick shot
of arctic air Sunday-Sunday night along with gusty winds and
lake effect snow. SNSQ risk should also be monitored.

The cold air retreats through early next week, setting up a
possible overrunning mixed precip event for Tuesday. The weather
for Christmas Eve looks fair and seasonable with no major travel
impacts expected at this time.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
Some more input as of late afternoon.

Added a group for low CIGS late Thursday afternoon, as
the southeast flow brings in lower clouds. Most likely
spots to see this is LNS, MDT, and perhaps IPT, Locations
to the west may not have lower CIGS before 00Z Friday,
will be close, for now did include them as well.

More information below.

Not a lot of change for the 00Z TAF packege.

Some lower CIGS across the north, at spots like BFD. Will be
keeping an eye on how far south the lower CIGS go, but for
now will keep the packace close to what was issued on the
18Z TAF package. Main push with the cold front mainly to the
north, as our upper level height fields really fall off with
this front.

Still expect most of Thursday to be dry with VFR conditions.
Showers later in the day.

Earlier discussion below.

Current satellite indicated clearing across much of the area,
with the bulk of cloud cover expected to be limited to BFD
through 00Z. Current observations across northwest Pennsylvania
outline low- level (~2500ft AGL) ceilings, which are progged to
enter BFD in the 18-19Z Wed timeframe. This cloud deck will
continue to gradually drift southeast; however, limited impacts
at other central Pennsylvania terminals at this time based on a
consensus of HREF/GLAMP model guidance.

The presence of high pressure overnight will bring some
potential for fog/low ceiling formation across much of central
Pennsylvania. Recent HREF probabilities outline the eastern
terminals (UNV/IPT/MDT/LNS) as the most probable to experience
MVFR-to-IFR restrictions in the 06Z-12Z Thursday timeframe with
lower probabilities across the western terminals for sub-VFR
conditions. LIFR conditions will be possible, where fog manages
to form overnight.

Increasing confidence in VFR conditions after 12-15Z Thursday,
with some signals in recent model guidance in clearing
conditions. Winds will be on the increase later Thursday, with
increasing LLWS concerns after 14Z Thursday; however, would like
to see another cycle of model guidance to increase confidence.

Outlook...

Fri...Gusty W wind (40+ kts possible). MVFR w/SCT SHSN at
JST/BFD. Mainly VFR elsewhere.

Sat-Sun...MVFR-IFR BFD in SCT -SHSN. VFR cigs favored
elsewhere.

Mon...Trending drier with VFR favored. Snow enters W PA late
evening with restrictions possible.

&&

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

&&

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

&&

$$

SYNOPSIS...Steinbugl
NEAR TERM...Steinbugl
SHORT TERM...Steinbugl
LONG TERM...Steinbugl
AVIATION...Martin/NPB
CLIMATE...Steinbugl