Harrisburg, Pennsylvania 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

325
FXUS61 KCTP 241113
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
613 AM EST Wed Dec 24 2025

.SYNOPSIS...
* Breezy early today with sun and clouds; dry for holiday travel
* Impactful post-Christmas snow and ice Friday and Friday night
* Another round of mixed precip Sunday then sharply colder with
  blustery winds and lake effect snow to start next week

&&

.NEAR TERM /THROUGH TONIGHT/...
Breezy start to Christmas Eve with partly to mostly cloudy
skies. High pressure migrates over CPA this afternoon providing
a dry day for holiday travel.

Clouds increase tonight in response to low amplitude shortwave
diving southeast from southern Lake Michigan into the Central
Appalachians. Hires model data continues to indicate the
potential for spotty/light mixed precip to reach the forecast
area in the 06-12Z Thu timeframe. Highest odds/POPs are focused
over the western and southern periphery of the CWA with dominant
ptypes either light rain/drizzle or freezing rain/drizzle.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
The weather looks largely benign for the rest of Christmas Day
with cloudy skies, WNW breeze and max temps +5-10F above the
historical average. High pressure ridge drifts over CPA Thursday
night bringing some clearing and colder min temps in the 15-25F
range. The sfc ridge and cold air wedge channels down the east
side of the Appalachians by Friday morning - setting the stage
for a classic CAD "overrunning" post-Christmas wintry mix event.

Strong warm air advection, isentropic lift, and healthy mid-to-
upper level ascent (ahead of sfc low tracking from IA/IL border
eastward to western PA btwn 12-24Z Friday) will send anomalous
moisture plume into a cold and dry boundary layer (sub-freezing
wet bulb temperatures at the surface). This will allow for an
icy mix of sleet/freezing rain over the southwest 1/3 of the
CWA. The best ice signal >0.25" is over the Laurel Highlands.
Farther to the northeast where cold layer is gradually deeper,
snow/sleet/zr transition is forecast. A deep cold layer below
the elevated warm nose could favor the majority of precip
falling as sleet over the interior central ridge and valley
region where WPC WWD shows a broad area of 0.50"+ of sleet
accumulation. Precip should stay snow the longest over the
northeast periphery of the CWA with perhaps up to 4-6" in the
eastern portions of Tioga/Sullivan/Columbia/Schuylkill Cos.

There remains ongoing fluctuations in the forecast track which
could result in additional changes to which areas see the most
snow and ice. That being said, we have high confidence in an
impactful post-Christmas winter wx event. We issued a winter
storm watch for the entire CWA with an emphasis on hazardous
travel impacts; the best odds (highest confidence) to reach
warning criteria are over the Laurels due to significant ice
accretion with WSSI-P showing >50% odds for minor impacts over
the remainder of the CWA.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
Some spotty freezing drizzle/drizzle could linger into Saturday
morning with low clouds trapped under inversion. The weekend
warmup has been tempered due to persistent low clouds Saturday
and rainfall now projected on Sunday. If precip arrives early
Sunday, there is a chance it could be freezing rain. Periods of
rain are expected Sunday afternoon into Sunday evening before a
sharp arctic cold front plows southeastward across the region
Sunday night. An arctic blast is now forecast for early next
week with strong gusty winds, lake effect snow and +/- single
digit wind chills.

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
Northwesterly winds at the surface are keeping a thin deck of
low clouds over the western airfields of BFD and JST. Any
remaining MVFR ceilings over the area should quickly mix out
after sunrise and skies should become mainly clear over the
region through the day today. Dry conditions and VFR will
prevail for the 12Z TAF package. Winds gusting out of the
northwest at 25-30kts should gradually slacken throughout the
morning and become more calm by 18Z.

Clouds will begin building in again overnight tonight ahead of a
system expected to arrive after Christmas Day. Friday is looking
more likely for a high impact winter storm event to affect all
airfields with snow and ice probable.

Outlook...

Thu...Scattered rain showers, some FZRA possible mainly central
and SW PA. Restrictions possible.

Fri-Sat AM...Widespread -SN developing, possibly changing to
sleet or a brief period of -FZRA late Friday. Restrictions
probable.

Sat PM-Sun...Rain with -FZRA possible across higher elevations.
Restrictions possible.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
Winter Storm Watch from Friday morning through Saturday
morning for PAZ004>006-010>012-017>019-024>028-033>037-041-042-
045-046-049>053-056>059-063>066.

&&

$$

SYNOPSIS...Steinbugl
NEAR TERM...Steinbugl
SHORT TERM...Steinbugl
LONG TERM...Lambert/Steinbugl
AVIATION...Bowen