186
FXUS61 KCTP 162341
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
741 PM EDT Wed Sep 16 2026

.WHAT HAS CHANGED...
* Minor adjustments to precip probs (% chance), timing and
  dewpoints through Thursday

&&

.KEY MESSAGES...
1) Warmer and more humid conditions promote increasing odds for
rain Thursday

&&

.DISCUSSION...
KEY MESSAGE 1: Warmer and more humid conditions promote
increasing odds for rain Thursday

Showers of varying intensity did develop during the mid to late
afternoon in the unstable airmass along a Laurel mountains to
I-99 corridor. These showers are dissipating as they move out of
the best CAPE region and the sun sets. Patchy fog is possible
toward morning where these showers fell, but would dissipate
after sunrise.

A subtropical high aloft will persist over the southern Plains
and lower MS Valley through Thursday. Around the periphery of
the high and in response to a shortwave trough crossing ON/QC, a
surface cold front will move slowly south/southeastward from
the lower Great Lakes across Pennsylvania and adjacent states.
This baroclinic/frontal zone will provide a trigger for showers
and a few thunderstorm clusters through Thursday evening. The
threat for severe storms is low enough that SPC has not
introduced probabilities with the D2 update. WPC will maintain a
level 1 excessive rain risk over the west-cetentral Alleghenies
given high pwats and above normal rainfall over the past 7-10
days. While it`s very likely that most of central PA picks up
some rainfall by Thursday night, we do not anticipate a washout.


Another taste of Fall is on the way for the end of the week with
noticeably cooler and much drier/less humid air poised to return
behind the front (Td crashing into the 40s/50s). Expect a crisp
and cool overnight Friday/Saturday morning with some upper 30s
possible across the northern tier. Dry/fair wx conditions are
forecast to start the weekend and last through the day on
Saturday followed by periods of rain Saturday night through
early next week.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
Generally VFR conditions at each forecast airport through the
remainder of the evening hours; however, isolated -SHRA of
varying intensity are moving northwest to southeast over lower
central PA. This initial batch of -SHRA will dissipate as the
sun sets.

Areas that did see a shower today will have the likelihood
(>50%) for BR or FG toward sunrise lasting for a few hours. A
cold frontal boundary will cross the region on Thursday,
bringing a chance of -SHRA and MVFR ceilings and visibility. As
the front passes through during the late afternoon, winds will
shift to the northwest and precipitation will end.

Outlook...

Fri-Sat...valley fog in the morning; otherwise VFR.

Sat night-Monday...periods of rain and sub-VFR likely.

&&

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

&&

$$

WHAT HAS CHANGED...Steinbugl/Tyburski
KEY MESSAGES...Steinbugl
DISCUSSION...Steinbugl
AVIATION...Tyburski