Altoona, Pennsylvania 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

689
FXUS61 KCTP 250859
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
359 AM EST Thu Dec 25 2025

.SYNOPSIS...
* Mostly cloudy and relatively mild for Christmas Day
* Impactful post-Christmas snow and ice Friday-Friday night
* Rain Sunday then turning colder and windy with lake effect
  snow to start next week

&&

.NEAR TERM /THROUGH TONIGHT/...
Compact shortwave diving southeast from the Ohio Valley into
West Virginia is supporting a cluster of rain tracking across
far southwest PA at 08-09Z. Some of this rain could clip the
Laurel Highlands prior to 12Z/7AM.

MRMS radar also shows returns tracking southeast across the mid
Susquehanna Valley, but sfc obs indicate that precip is not
reaching the ground which is likely due to dry air near the sfc.

The weather looks largely benign for the rest of Christmas Day
with mostly cloudy skies, WNW breeze and max temps +5-10F above
the historical average in the 35-50F range.

Sfc ridge axis extending south from 1030mb high centered over
Quebec migrates through CPA tonight - bringing some clearing
and colder min temps in the 15-25F range. The sfc ridge and
shallow 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.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...

.WHAT HAS CHANGED...

On balance, not much with this cycle. There has been a slight
shift to the north/northeast with the WAA which nudged
QPF/snow/ice amounts a tad lower. The NAM was a notable
leader?/outlier? with this trend. No changes to winter storm
watch headline, although the 12Z start time may be too early
with regard to onset of wintry precip with hires data indicating
an arrival time closer to 18Z/1PM (later shifts can adjust as
needed).

500mb shortwave will push through northern Lower MI with its
sfc reflection over IL/IN/OH and the 850mb low moving through
BUF around 00Z Sat. The sfc low will weaken as it reaches
western PA Friday evening, getting too far behind the mid-level
shortwave, and ultimately pivoting to the south/east and jumping
into the Atlantic by 12Z Sat.

Strong warm air advection, isentropic lift, and healthy mid-to-
upper level ascent will send anomalous moisture plume into a
cold and dry boundary layer (sub-freezing wet bulb temperatures
at the surface). This will allow for potential significant
freezing rain over the southwest 1/3 of the CWA. The best and
most consistent ZR signal (40-60% probs of at least 0.25" icing)
remains over the Laurel Highlands and NW Alleghenies.

Looking into the interior and eastern portions of the CWA where
the cold layer is gradually deeper with northeast extent, a
snow/sleet to sleet/zr transition is forecast. Model output
continues to flash a moderate to heavy sleet signal (0.5-1.0")
over this area which essentially encompasses the central 1/3 of
the CWA. Precip should stay snow the longest over the far
north/eastern periphery of the CWA with up to 4-5" fcst in the
eastern portions of Sullivan/Columbia/Schuylkill Cos (heavier
amounts reduced and shifted to the east).

As we have seen with the 25/00Z model cycle, there remains
ongoing fluctuations in the forecast track which could result in
additional changes to snow/ice amounts. That being said, we
still have high confidence in an impactful post-Christmas
winter wx event causing hazardous travel conditions/slippery
roads.

Some freezing drizzle/drizzle could linger into Saturday morning
with low clouds trapped under the subsidence inversion.
Conditions dry out by Saturday afternoon, but cloudy skies (low
clouds) should be persistent into Saturday night.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
Precip returns on Sunday as WAA ramps up in advance of
deepening sfc low tracking into lower MI. Freezing rain is
possible on the front-edge of the precip as it catches up to the
retreating/shallow cold dome.

A strong cold front plows southeastward across the region on
Monday. A rain/snow transition may occur along the front with
falling temperatures Monday afternoon. Windy conditions are
expected behind the front Monday afternoon through Monday night
with gusts over 40 mph possible. A blustery NW flow will also
generate several inches of lake enhanced snow over the NW mtns
early next week. Min wind chills Monday night into Tuesday
morning are fcst in the -5 to 10F range. Below normal temps are
projected Tuesday and Wednesday.

&&

.AVIATION /07Z THURSDAY THROUGH MONDAY/...
Clouds are continuing to build in over the area, but everywhere
should remain VFR through the night. High res models indicate
an area of -SHRA passing northwest to southeast over
southwestern PA later tonight. Just made mention of VCSH in KJST
and KAOO as this feature looks to stay generally west with only
a <20% chance of affecting those airfields.

As this system passes our area in morning, winds will shift
more to the northwest and becoming gusty. Some lower clouds will
be possible at BFD and JST, as winds shift to the northwest.
MVFR has been mentioned for these two sites with low confidence.
There remains a slight chance for IFR ceilings (<20%).

For Friday, warm advection will bring the potential for snow,
sleet, and freezing rain to central PA. The system will be
messy, but confidence is increasing on significant ice
especially over the western airfields. Some improvement for
Saturday, but a strong cold front on Sunday will bring more
adverse weather to the area.

Outlook...

Fri...Snow developing, then a mix of sleet and freezing rain.

Sat...Spotty precipitation tapering off.

Sun...Rain with -FZRA possible across higher elevations early,
then becoming windy. Restrictions possible.

Mon...Windy and colder with snow showers across the mountains.

&&

.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...Steinbugl
AVIATION...Bowen/Tyburski