120
FXUS61 KCTP 251814
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
214 PM EDT Wed Jun 25 2025

.SYNOPSIS...
* Not as hot, but nearer normal temperatures for the end of the
  week and into next week. It will be increasingly unsettled
  starting today through the last weekend in June with daily
  chances for heavy downpours.

&&

.NEAR TERM /THROUGH TONIGHT/...
Early morning cluster of storms in the middle of an otherwise
clear sky slid right over Happy Valley. That has since died off
and even the clouds from it are dissipating. Diurnal cu should
be popping shortly.

As mentioned below, sct SHRA/TSRA still expected all over the
area. So, coverage is the main limiting factor with PoPs this
aftn and early evening. 100% certainty that it`ll rain, but a
range of 30-70% coverage across the area, with the more-
dense/likely locations for storms over the nrn mtns and Laurels.


All of these storms will be capable of making gusty wind, but
more so heavy rain. MRGL risk for both Severe TS and Excessive
Rain/Flash Flooding. But, the high PWAT (1.75"+) and slow storm
motion probably make it more of a FF threat today.

Prev...
One more very hot day is in store for locations east of the
Allegheny Front where high temperatures will be in the low to
mid 90s with heat index values exceeding 100 degrees. Heat
Advisories and Extreme Heat Warnings remain unchanged and will
continue through 8PM. Areas farther to the west will be a few
degrees cooler today than they have been in recent days as
cloud cover increases ahead of an approaching cold front.

A couple of showers have developed to our west this morning and
may drift into our far western counties, but the better chance
for rain will come during the afternoon as the cold front enters
the region from the north. With 0-6 km shear expected to
generally be less than 20 knots over much of the region, storms
will likely struggle to become organized. However, with most
guidance showing moderate instability in the 1500 to 2000 J/kg
range developing over the region and fairly steep low level
lapse rates, a few strong wind gusts will be possible with any
stronger storms. SPC has maintained the marginal risk of severe
thunderstorms for all of Central PA.

PWATs will exceed 1.75 inches this afternoon, which is well
above the 90th percentile for today according to SPC sounding
climatology, so heavy rainfall will be a concern, particularly
for locations that see repeated rounds of thunderstorms. The
storms will likely be slow moving with mean flow expected to be
generally less than 15 knots throughout the entire warm cloud
layer. WPC has included a marginal risk of excessive rainfall
to highlight this threat.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY/...
The pattern turns rather unsettled through late week as the
cold front becomes quasi stationary over the area.

Increasing low-level moisture under weak westerly flow
continues into Thursday. NBM PoPs increases into the 60-70 pct
range areawide Thu afternoon as the frontal boundary lingers
over the region and slightly better, deep-layer westerly shear
develops. Best chc for a few potent updrafts and a MRGL risk for
SVR appear to be limited to SCent PA where temps will top out
near 90F. Farther to the north, cloud cover should limit the
amount of instability available.

Chances for rain increase further on Friday across the NW but
drop slightly across the Susq Valley that will be in between the
departing warm front and next cold front approaching the Lower
Great Lakes.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Shortwave troughing across the Ohio Valley coupled with
placement in the warm sector and vicinity of a quasi-stationary
boundary will spell an active period of showers and storms
through the weekend. A cool front looks to approach central PA
on Saturday, thus the uptick in shower/storm chances then.
Passage of an upper trough axis and surface boundary may lead to
a mostly dry day on Sunday if drier air can settle into the
Commonwealth. Upper ridging building across the western Atlantic
into eastern Canada then looks to take place downstream of a
more potent shortwave trough digging across the Great Lakes
early next week. Shower/storm chances will subsequently increase
by Tuesday with temperatures continuing to remain near to
slightly above normal.


&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
Early morning convection that rolled through FIG-UNV-RVL has
dissipated. Already some tiny diurnal cu on the high ground of
the Laurels. Fcst for mainly VFR conds with sct (not prevailing)
MVFR/IFR inside any TSRA is still on track.

Prev...
Rain and thunderstorms return to the airspace this afternoon
with a cold front expected to push in to the northwest near 18Z.
Expect an increase in cloud coverage as the front approaches
tomorrow. Prob30 groups have been included for the most likely
timing of the arrival of showers. Low confidence is exactly
when and where storms will fire up, but restrictions should be
brief.

Overnight, fog is expected to develop across much of the region
in the wake of showers and storms today. Have introduced MVFR
and IFR visibility at most sites.

Outlook...

Wed...Mainly VFR with increasing chances of SHRA/TSRA and brief
MVFR Cigs and Vsbys after 18Z, especially north.

Thu-Sun...Increasing impacts from SHRA/TSRA. Less hot.

&&

.CLIMATE...
Ongoing extreme heat wave will record challenging max/min temps
early this week.

The following climate sites broke or tied their daily record
temperatures:

MONDAY JUNE 23, 2025
Altoona: Low of 72F broke the record of 71F set last year.
Altoona: High of 93F broke the record of 90F set in 1994.
Bradford: High of 89F broke the record of 86F set in 2013.
Harrisburg: High of 97F tied the record set in 1965. State
College: High of 92F the broke record of 91F set in 1966.
Williamsport: High of 97F the broke record of 94F set in 1923.

TUESDAY JUNE 24, 2025
Altoona: Low of 70F broke the record of 68F set in 1994.
Altoona: High of 93F broke the record of 91F set in 1966.
Bradford: High of 89F broke the record of 86F set in 2013.
Harrisburg: Low of 78F broke the record of 75F set in 2010.
Harrisburg: High of 98F tied the record set in 1966.
State College: Low of 74F broke the record of 70F set in 1948.

The following temperature record is in jeopardy of being tied
or broken on June 25th:
Harrisburg: Low of 75F in 1976

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 8 PM EDT this evening for PAZ019-025>028-
034-035-045-046-049>053-058.
Heat Advisory from 9 AM to 7 PM EDT Thursday for PAZ034>036-
063>065.
Extreme Heat Warning until 8 PM EDT this evening for PAZ036-
056-057-059-063>066.

&&

$$

SYNOPSIS...Lambert/Martin/Bauco
NEAR TERM...Dangelo/Bauco
SHORT TERM...Lambert/Bauco
LONG TERM...Guseman/Martin
AVIATION...Dangelo/Banghoff
CLIMATE...Banghoff