Harrisburg, Pennsylvania 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

549
FXUS61 KCTP 131901
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
201 PM EST Tue Jan 13 2026

.WHAT HAS CHANGED...
* Increased snowfall totals over northwest PA with lake effect
  snow Wednesday afternoon through Thursday night.
* Winter Weather Advisory issued for Warren County from 11 am
  Wednesday through 1 AM Friday.

&&

.KEY MESSAGES...
1) Milder today and Wednesday.

2) Low pressure tracking just to the north and west of
the area should bring some elevation wet snow and valley rain across
much of the area Wednesday into early Thursday, turning to snow
in the valleys from northwest to southeast Wednesday night and
early Thursday with a possible flash freeze of wet or slushy
surfaces. Cold temps Thursday keeps the precip all snow.

3) Active weather continues through the weekend and into the
beginning of next week with multiple chances for snow. Turning
colder.

&&

.DISCUSSION...
KEY MESSAGE 1...

Warm advection with a minor wave aloft tonight will keep temps
mild (over freezing everywhere but parts of northern PA).
Without much moisture to work with and low PoPs, we`ll not have
much worry for p-type tonight with a few rain or wet snow moving
across the northern mtns. Maxes will be in the upper 40s over
all of the S on Tues and SE on Wed.

KEY MESSAGE 2...

A sharp cold front moving through the western part of the state
late Wed and across Central and Eastern PA Wed night interacts
with fairly limited moisture. The forcing isn`t focused until
mid-day Wed, first over the west as deepening uvvel associated
with the thermally direct branch/right entrance region of a 130
kt upper level jet slides overhead.

Temps should stay plenty mild for the SErn half of the area to
be rain Wed/Wed evening. Temps over the NW have trended slightly
cooler and may even support a mix of rain and snow at the onset
of precipitation before changing completely to snow by late
afternoon. As temps get colder Wed evening/night, the lingering
precip in the east should turn to snow as it ends. Major models
all have precip ending (well) before sunrise Thurs in the
central and eastern zones.

Northwest flow behind the front will support lake effect and
upslope snow through the day on Thursday. Recent model runs are
beginning to show a Lake Huron connection developing, resulting
in slightly higher expected snowfall amounts downwind of Lake
Erie. We have issued a Winter Weather Advisory for Warren County
where 2 to 4 inches of snow is expected, with locally higher
amounts possible across the northwestern third of the county.
While the wind direction will be favorable for upslope snow
showers in the Laurel Highlands, model soundings suggest that
moisture in the DGZ will be limited. Snowfall amounts for much
of Cambria and Somerset counties will likely be less than 2
inches, though slightly higher amounts are possible on the
western ridges of Somerset County.

KEY MESSAGE 3...

Moderate uncertainty exists in the pattern for Sat-Sun, mainly
in the timing of a series of waves from the west. Long wave
trough moving across the nrn plains and Great Lakes will drive
the bus. But, the details are tough to pinpoint at this range. A
final burst of arctic air is possible and best timing on that
right now would be Sat night or Sun. SNSQs possible as that
would move through with a sharp/quick/deep drop in temps. Wind
chills could also near Cold Weather Advisory criteria

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
High confidence in widespread VFR flying today through this
evening. LLWS expected at all terminals, beginning near BFD
this afternoon and early this evening nearer LNS. Should see
this threat subside overnight as winds within 2000 feet of the
deck diminish.

Expect lowering/deteriorating ceilings Wednesday as light rain
mixes with and changes to snow Wednesday night. A blustery
west/northwest wind will ensue for Thursday.

Outlook...

Thu...MVFR/IFR snow showers persisting across the western and
northern airspace; windy with sfc gusts 25-35kt from 280-310.
Winds decrease Thursday night.

Fri...Snow and IFR most likely over the NW airspace. Breezy
with gusts from 180 degrees 15-25kt.

Sat/Sun...Light snow/IFR possible.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from 11 AM Wednesday to 1 AM EST
Friday for PAZ004.

&&

$$

WHAT HAS CHANGED...Bauco
KEY MESSAGES...Lambert/Bauco
DISCUSSION...Lambert/Bauco
AVIATION...Guseman/Steinbugl