600
FXUS61 KCTP 132317
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
717 PM EDT Thu Aug 13 2026

.WHAT HAS CHANGED...
Bumped fog probabilities slightly later into tomorrow morning,
other than that, few major changes at this time. Added small
chc POPS next few hours.

&&

.KEY MESSAGES...
1) Generally quiet pattern statewide looks to persist through
Saturday with any precipitation chances confined to the
southern tier of the state.

2) Sunday brings a return to wet conditions with showers and
thunderstorm chances returning.

&&

.DISCUSSION...
KEY MESSAGE 1: Generally quiet pattern statewide looks to
persist through Saturday with most precipitation chances
confined to the southern tier of the state.

Added low end POPS to central zones for a few hours, based
on current radar.

More information below.

Showers on the decrease early this evenig.

The upper level jet streak is anticipated to traverse through
Ontario and into New England, passing over New York/Northern
Pennsylvania. As the right entrance region passes over
Pennsylvania, it will interact with a remnant MCV from
convection that is currently ongoing in the Midwest. This ascent
should allow for another round of clouds some shower
development in the southern tier of the state later tomorrow.

Main timing looks to be from the late morning to mid-afternoon.
The ascent may allow for some spotty afternoon showers
elsewhere, but dry air filtering in from the north should keep
things fairly isolated.

As these features pass through and drier air filters in from the
north, skies should start clearing Friday evening into Saturday.
This will make for some relatively less humid conditions to
begin the weekend with any isolated rain chances looking to
remain in the southwest.

KEY MESSAGE 2: Sunday brings a return to wet conditions with
showers and thunderstorm chances returning.

A low pressure system moving through Canada will allow a stalled
frontal boundary to move through Pennsylvania as a warm front
on Sunday. This will bring a moist airmass, with PWATs possibly
exceeding 2" into Pennsylvania. With a secondary low likely
forming closer to Pennsylvania at the intersection of the warm
front and a trailing cold front, this will invigorate
development of showers and thunderstorms. With a cold front
draping across Pennsylvania Sunday night, multiple rounds of
showers/thunderstorms may be possible into the night.

As it stands right now, ensemble guidance has the northern tier
of Pennsylvania targeted for highest rain probabilities and
totals. Exact timing of this activity and how fast/slow the
cold front moves through will likely become clearer as we
approach Sunday. With such high PWATs and potential for multiple
rounds/training activity, flooding potential will need to be
watched. Should the cold front stall/move slower, activity may
linger into Monday morning. After that passage, the start of
next week is showing signs of high pressure moving over the
region.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
Line of showers along a slight convergence boundary have popped
up just north of KIPT. These showers will continue to make a run
at KIPT over the next few hours. Thus far no ltg, but we`ve
mentioned vcts as the showers are getting taller here in the
hottest part of the day. Some other showers may pop up back
along the same boundary more to the west and eventually drift
toward KUNV later the aftn or very early evening. Have only made
mentions for now with TEMPOs. With larger-scale subsidence, the
skies should mostly clear tonight. This should help form some
fog with radiational cooling down close to the dewpoints. Expect
this to remain confined to the valleys, but anywhere that does
get wet today could also have a little light fog. Did go for IFR
conditions for a couple of hours at KBFD, where conditions may
improve before morning. Have put the fog mention into KIPT, as
well, and also the normal FL003 cloud deck that can occur there
through the post-sunrise hours.

Friday looks dry with any morning fog burning away to leave a
VFR day with light wind over most of the area. But, there will
be some showers/thunderstorms try to sneak into JST and maybe
AOO in the evening. Have not mentioned any precip at those
sights before 18Z.

Outlook...

Sat...AM fog possible, then VFR. Warm front moves in and
SHRA/TSRA likely W Sat night.

Sun...Restrictions possible in showers/thunderstorms.

Mon...CFROPA by Monday morning. SHRA/TSRA ending Mon AM. Mainly
VFR for most of the day.

&&

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

&&

$$

WHAT HAS CHANGED...Martin/Lambrech
KEY MESSAGES...Martin/Lambrech
DISCUSSION...Lambert/Martin/Lambrech
AVIATION...Dangelo