766
FXUS61 KCTP 180353
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
1053 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/...
Model guidance indicates areas of radiational [freezing] fog
developing overnight under fair skies with light/variable wind
and min temps in the 20s. As of 03z, already seeing patchy fog
begin to form across the NW mtns. Any freezing fog could result
in slick spots on untreated surfaces 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 clouds may be slow
to dissipate. An increasingly moist SSE low level flow should
favor low cloud cover expanding to the east of the Allegheny
Front holding highs in the low to mid 40s.

Very strong 55-65kt LLJ will drive widespread rain ahead of a
sharp cold front Thursday evening into early Friday morning.
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 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, before colder air begins to advect into the western
highlands towards daybreak. 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
shift to further assess and collaborate. We 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.

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 /03Z THURSDAY THROUGH MONDAY/...
Mid evening update.

An interesting evening so far.

Winds at MDT went calm, then got gusty last hour, resulting
in the temperature jumping up there.

On the other end, BFD went calm with fog and low CIGS.

Another interesting feature on radar, just north of the
office. Perhaps what remains of the cold front that was
located to the north of the area earlier.

Anyway, more in the fog and even some lower CIGS may
form overnight, as temperatures drop to below the dewpoints.
However, dewpoints may fall as well, given the very dry air
not very far above the ground.

In addition, LLWS across the far west, BFD and JST, later
tonight into Thursday.

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.

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

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/Evanego
NEAR TERM...Steinbugl/Evanego
SHORT TERM...Steinbugl/Evanego
LONG TERM...Steinbugl/Evanego
AVIATION...Martin
CLIMATE...Steinbugl