523
FXUS61 KCTP 291905
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
305 PM EDT Sun Jun 29 2025

.SYNOPSIS...
* Rain-free end of the last weekend of June for most with a
  stray shower or t-storm possible over the southern tier of CPA
* Stormy pattern resumes Monday-Tuesday with a renewed risk of
  strong to severe storms and locally heavy downpours
* Drier/less humid/more comfortable conditions are likely
  through midweek with high confidence of nice wx on the 4th

&&

.NEAR TERM /THROUGH TONIGHT/...
Airmass and cloud boundary continues to align very well with the
I-80 corridor this afternoon...

To the north of I-80: full sunshine and comfortable mid 50s Td
To the south of I-80: sct-bkn cu; very warm & sticky w/Td 65-75F

We still cannot rule out a stray thundershower near the MD line
through the late afternoon given plenty of moisture and CAPE.
Max temps remain on track to reach the 80-90F range from the
northern tier elevations to the south central valleys. Max heat
indices should reach the 90-95F range from the south central
Alleghenies through the middle and lower Susquehanna Valley.

Cu will fade as the sun sets with a mainly clear to partly
cloudy night ahead. There will be some fog in the valleys from
the predawn hours through daybreak Monday. Fog may be limited to
some extent by increasing mid and high clouds as WAA pattern
ramps up over the Ohio Valley downstream of 500mb trough moving
into the Upper Midwest.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
*Stormy End to June/Start of July moving into the 2H of 2025

A mid-level trough will amplify while traversing the Great
Lakes and Ohio Valley regions on Monday. A cold front will
accompany the Midwest mid-level trough and should reach western
PA by 12Z Tuesday.

In advance of the cold front, plenty of moisture/instability
will be present to support at least scattered thunderstorms by
peak heating. Given the presence of weak/modest vertical wind
shear, a few of the storms could become strong to locally
severe. Strong boundary-layer heating is fcst with 2000+ J/kg
of tall/thin SBCAPE) amid weak (<30kt) 0-6km deep layer wind
shear. This environment will support wet downburst potential
and a couple of damaging wind gusts are possible Monday
afternoon and evening. SPC has all of CPA in a level 1/5 MRGL
svr tstm risk for D2.

The aforementioned mid-level trough will shift east from the
Great Lakes to the Northeast on Tuesday. Moderate mid-level flow
will overspread much of the region. At the surface, a cold
front will move east across PA and will be the primary focus
for severe thunderstorm potential Tuesday afternoon/evening.

Stronger shear profiles will be present on D3 and this may
result in greater storm organization/intensity including the
potential for a few supercells capable of producing large hail
and damaging wind gusts. SPC will expand the level 1 MRGL svr
risk for D3, but we would not be surprised to see an future
upgrade to SLGT or level 2/5 given the more robust shear
profiles.

Max/min temps will be seasonably warm/muggy for late June and
early July in the 80-90/60-70F range to start the week. Temps
will cool off a bit on Tuesday/Tuesday night behind the front
over the north/west Alleghenies.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
* A much drier and more comfortable stretch of weather Wed-Sat
* High confidence in nice/dry weather on July 4th

There is growing confidence in a much drier and more comfortable
stretch of weather from midweek 7/2 into the first weekend of
July. Expanding on the drier/comfortable stretch, we are talking
specifically about: 1) very little to no rainfall forecast and
2) noticeably lower/reduced heat and humidity. A moisture-
starved cold front will provide the "best" chance of rain on
Thursday PM, but overall we expect the majority of the time to
be dry during the Wed-Sat period. Max/min temps will be close to
the historical average during the first week of July. There are
signals for heat and humidity to ramp upward by the end of next
weekend.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
Widespread VFR for the rest of today with sct-bkn cumulus over
the southern 3/4 of CPA airspace. VFR expected to continue into
tonight with some fog/low cloud restrictions possible during the
predawn/early morning hours Monday. Confidence is low on vis/cig
restrictions related to overnight fog and/or low clouds. Mid to
high level clouds may also limit the extent of valley fog. Sct
tstm impacts are likely Monday afternoon and evening and later
issuances may consider adding PROB30s to highlight the potential
for brief MVFR/IFR restrictions.

Outlook...

Mon-Tue...PM showers & t-storms likely; areas of fog & low
clouds overnight.

Wed...AM fog, then VFR.

Thu...Primarily VFR; stray PM shower/t-storm possible.

Fri...AM fog possible; otherwise VFR.

&&

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

&&

$$

SYNOPSIS...Steinbugl
NEAR TERM...Steinbugl
SHORT TERM...Steinbugl
LONG TERM...Steinbugl
AVIATION...Steinbugl