401
FXUS61 KCTP 301010
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
610 AM EDT Mon Jun 30 2025

.SYNOPSIS...
* Stormy pattern resumes today and tomorrow with a renewed risk
  of strong to severe storms and locally heavy downpours
* Drier/less humid/more comfortable conditions are likely from
  mid to late week with high confidence of nice weather on
  Independence Day

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Patchy valley fog not a significant concern this morning given
mid-high clouds over central PA. Healthy moisture return will
continue this morning with precipitable water values currently
breaching the 1.5 inch mark across south central PA as a warm
front surges north.

This influx of moisture will occur downstream of an amplifying
mid-upper trough moving into the Upper Midwest and western
Great Lakes. Numerous showers and thunderstorms are expected
beginning early this afternoon and lasting through this evening
as shortwave energy supplies large scale forcing for ascent.
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 expected with 2000+ J/kg of tall/thin
SBCAPE) amid relatively weak effective shear values of 25-30
knots. This environment will support the potential for wet
downbursts and damaging wind gusts.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
Storms will continue into this evening with cold pools taking
over and bringing an end to the widespread shower activity after
dark. Given the refuel of surface water from Monday`s rain and
sultry conditions tonight, expect fog tonight into Tuesday
morning, especially where low clouds can break.

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, including placing central PA
in the right entrance region of an upper-level jet. At the
surface, a cool 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 Tuesday 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. Storms should eventually congeal into a
more solid line as the front makes closer approach, maintaining
a damaging wind threat into the Lower Susquehanna Valley.

Drier air will begin advecting into central PA late Tuesday into
Tuesday night with dewpoints dropping well into the 60s.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
* Expect a drier and more comfortable stretch of weather for
  Wed-Sat.
* Increasing confidence in nice/dry weather on July 4th.

There is growing confidence in a drier and more comfortable
stretch of weather from midweek into the first weekend of July.
Expanding on the drier/comfortable stretch, we are talking
specifically about: 1) little to no rainfall and 2) noticeably
lower heat and humidity.

A moisture-starved cold front will provide the "best" chance of
rain 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 the weekend.

&&

.AVIATION /10Z MONDAY THROUGH FRIDAY/...
Lone shower in south central PA died shortly after Midnight.
However the edge of the higher dewpts not much further south
and also to our west, once one gets into OH.

NAM shows showers and storms will try to work in from both
the southeast and west toward mid to late aft. Highest chc
of thunder will be mainly west of a BFD, JST line.

Did not make any big changes to the earlier TAF fcst.

CIGS likely to be rather high with showers and storms this
afternoon, but would would lower down by mid to late evening.

Earlier discussion below.

Predominantly VFR conds are expected to continue overnight,
although there is low confidence that some spots could see the
development of fog/low clouds during the predawn hours. High
and mid level clouds may help to limit fog development.

Scattered SHRA/TSRA impacts are expected Monday afternoon and
evening, and have added a PROB30 group to several TAF sites Mon
aftn/eve to highlight the potential for brief 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...Guseman/Steinbugl/Bowen
NEAR TERM...Guseman/Steinbugl/Bowen
SHORT TERM...Guseman/Steinbugl
LONG TERM...Steinbugl/Evanego
AVIATION...Martin/Evanego