742
FXUS61 KCTP 212326
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
626 PM EST Fri Nov 21 2025

.SYNOPSIS...
* Mostly cloudy skies remain in place through Saturday morning
  with a period of light rain lasting about 6 hours late today
  and tonight and focused mainly over the southern half to two
  thirds of Pennsylvania
* Decreasing clouds on Saturday will precede a drying and
  warming trend with more sunshine Sunday and Monday.
* Mild pattern with rain prior to Thanksgiving turns
  decidedly colder with temperatures below average by
  next weekend

&&

.NEAR TERM /THROUGH SATURDAY/...
Still stuck in overcast skies today with cool temperatures,
albeit several degrees warmer than yesterday. Temperatures
continue to underperform thanks to the persistent cloud cover,
with highs this afternoon ranging from the low 40s in the north
to low 50s closer to the Mason-Dixon line.

Two fairly weak upper-level short waves in the Northern and
Southern streams will move across the NE US and Ohio
Valley/Central Appalachians - out of phase - today and tonight. The
northern shortwave will be in the lead supporting a few
scattered light showers along and ahead of its associated weak
cold front this evening. The southern stream wave will have the
greatest impact on our CWA precip-wise (mainly over the
southern half to two thirds of PA) as an approx 5-8 hour period
of weak to moderate uvvel linked to the thermally indirect,
left exit region of an upper level jet late today and tonight.
Forecast rainfall from AOB 0.10 inch near the I-80 corridor to
between 2 and 3 tenths of an inch near and south of the PA
Turnpike looks good at this point. Many locations across the
northern mountains could escape the next 24 hours with very
little or no measurable rainfall.

Overnight, cooler and drier air will begin to pour into northern
PA in the wake of a cold front. Some pockets of mixed precip may
be possible on the northern edge of the precip by early
Saturday morning with any overrunning precipitation north of
US-6, but the southward suppression of QPF would render this
precipitation type uncertainty a moot point. Lows Saturday
morning will be near freezing in northwest PA while clouds/rain
keep temperatures in the mid 40s along and south of I-76.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY/...
A somewhat zonal pattern will settle in for the weekend with
the southern branch of the jet stream extending from northern
Mexico ENE across the Gulf Coast States as a slow moving Upper
Low drifts across northern Baja California. Several pieces of
energy diving SE from NW Canada, combined with a potent upper
level trough crashing into the Wash/Oregon Coast, will amplify
the flow across N American and the mean trough over the NE U.S.
Saturday night into early next week.

In our neck of the woods, surface ridging will support a drying
trend over the weekend behind the cold frontal passage. An upper
level trough pivoting through the Great Lakes may deliver some
rain/snow showers to the northern tier on Sunday. On balance,
it should be a quiet weekend with temps remaining close to the
historical average. We`ll see much more sunshine later Saturday
through Monday, which will be a welcome change. Sunday morning
is the coldest morning of the week ahead, with partly cloudy
skies supporting lows in the 20s.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
A reinforcing shot of cold air will push south across PA late
Sunday/Sunday night as a rather compact but potent shortwave
moves SE from the Glakes. A brief shower of rain (south) and a
few rain/snow showers (North) could occur with this frontal
boundary.

The 2 aforementioned storms (the upper troughs over Nrn Mexico
and the NW U.S.) will move to the NE/E respectively and merge
across the Nrn Plains states as 500 mb heights/flow at that
level back about 30-45 deg to a more swrly direction across the
NE US and Ohio/Tennessee Valleys. This storm system will
eventually move through the eastern US toward the middle of next
week. While the exact timing remains uncertain (typical
fast/low biases evident in the GFS/ECMWF), a period of rain
appears most likely in the Tuesday or Wednesday time frame ahead
of the next split stream system tracking eastward from the
Central U.S. Temperatures will be mild as the main slug of
moisture moves through, with rain as the predominant
precipitation type. Colder air wrapping around the system could
produce some snow showers in the northwest mountains late in the
week, but travel plans before thanksgiving should not be
impacted significantly. Thereafter, ensemble model data
continues to advertise a pattern shift toward colder/below
average temperatures after Thanksgiving.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
MVFR to IFR conditions expected to prevail through current TAF
period. Rain spreads across the southern 3/4 of the airspace
between 02-05Z; KBFD is likely just a bit far north to get wet.
However a prob30 has been added due to current radar trends. Rain
ends from NW to SE between 10-15Z with a drier flow from
300-330 degrees signaling a return to MVFR and VFR conditions by
Saturday afternoon as clouds lift and scatter out.

Outlook...

Sat...Improvement to VFR at most terminals. Fog may return
Saturday night.

Sun...Breezy with rain/snow showers possible northern tier.

Mon...VFR.

Tue...Breezy with periods of rain.

Wed...Breezy with rain/snow showers possible NW.

&&

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

&&

$$

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