-- Discussion containing changed information from previous version are highlighted. --
775
FXUS61 KCTP 261747
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
147 PM EDT Thu Jun 26 2025

.SYNOPSIS...
* Flash flood and severe t-storm risk increased this afternoon
  and evening over east central PA
* Breaking heat gives way to drenching downpours into the last
  weekend of June; unsettled pattern continues to start July

&&

.NEAR TERM /THROUGH TONIGHT/...
Several changes/updates in the near term:

1. [Flash] flood watch over east central PA: 3pm to midnight
Signals from the 00 and 12Z HREF continue to favor slow moving
storms along lee-side trough and backdoor frontal zone. Both
HREF and RRFS show pockets of elevated probabilities of >2"/hr
rainfall rates by mid-late afternoon into the evening. Despite
the lack of synoptic/kinematic support, the favorable
thermodynamic profile (1.75-2.00" PWs and max CAPEs 2000-3000
J/Kg) combined with the likelihood of slow cell motions with the
potential for repetitive convection along the aforementioned
boundaries are key drivers of the watch with point rain amounts
2-4" possible over a short duration. No change to the D1 SLGT
risk ERO from WPC.

2. SPC convective outlook upgrade from risk level 1 to 2 (SLGT)
Full sunshine this morning across south central into southeast
PA allowing temps to rise into the mid 80s to low 90s. While not
as extreme, hot/humid conditions will lead to scattered
thunderstorm development through the evening. Winds aloft are
weak, suggesting disorganized/pulse convective modes. However,
steep low-level lapse rates and moderate CAPE values will once
again result in a risk of locally damaging wind gusts.

Heat Advisory remains in effect until 7 PM EDT.

Showers will gradually fade into late tonight. There appears to
be an emerging signal for fog and low clouds overnight into
early Friday morning particularly across the eastern half of
the CWA with plenty of residual moisture and low level easterly
flow.

&&

.SHORT TERM /FRIDAY/...
Friday should be a bit cooler across central and eastern PA,
although another round or two of SHRA/TSRA is expected for the
aftn/eve.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
-- Changed Discussion --
The anomalous upper-level ridge that brought heat to much of
the eastern United States will continue to gradually be
suppressed to the south in the extended period, and long range
models suggest that it should be replaced by an upper level
trough over the northeastern United States by the middle of next
week.

As for sensible weather...the unsettled pattern will persist
into at least the first half of the upcoming weekend, with
SHRA/TSRA likely on Saturday, especially in the afternoon and
evening. Sunday looks like the better day of the weekend, with
a small area of high pressure building in, and keeping PoPs less
than 40 percent. An approaching cold front and upper trough
will bring more widespread SHRA/TSRA later Monday into Tuesday.
After that, we could be in for a welcome shot of cooler and
drier weather for the middle to later part of next week.
-- End Changed Discussion --

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
Main thing this morning is pockets of dense fog, especially
here at the office. Areas that did not get much rain have
less low clouds and fog. Expect conditions to improve by
13Z, given the strong June sun.

More information below.

Main change to the 06Z TAF package was to use VCSH more,
instead of thunder. Cold front near PA early today, but main
driving force will be lee side trough forming later this
afternoon, as low levels heat up east of the mtns. Anyway,
expect coverage to be less than yesterday.

Earlier discussion below.

Weak boundary dropping down from the north now will drape
itself over the state tonight and be stubborn to move out over
the next few days.

Overnight, fog is expected to develop across much of the region
in the wake of showers and storms today, mainly where it ended
up raining. The coverage will not be 100% of the area, and more
so in the valleys. Have kept MVFR and IFR visibility at most
sites for a few hrs late tonight. That should dissipate Thurs AM
after just an hour or two of sun. There could be a deck of
low/IFR clouds instead or in addition to any fog over the NW.

The high moisture lingers for the next few days, and little
change is expected to our pattern. Daily SHRA/TSRA, and any
could make some heavy rain or gusty winds.

Outlook...

Fri-Mon...Continued impacts from SHRA/TSRA, mainly in the aftns
and eves. Less hot.

&&

.CLIMATE...
Record for MDT today is 100 set in 1952, not expecting to
break that one.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
Flood Watch until midnight EDT tonight for PAZ028-037-041-042-
046-049>053-056>059-063>066.
Heat Advisory until 7 PM EDT this evening for PAZ034>036-
063>065.

&&

$$

SYNOPSIS...Steinbugl
NEAR TERM...Steinbugl
SHORT TERM...Lambert/Evanego
LONG TERM...Colbert
AVIATION...Martin/Bowen
CLIMATE...Banghoff