528
FXUS61 KCTP 031845
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
245 PM EDT Thu Sep 3 2026

.WHAT HAS CHANGED...
* Convection timing narrowed.

&&

.KEY MESSAGES...
1) Showers and thunderstorms into tonight can hold heavy rain
and damaging winds. A small chance of tornadoes and hail also
exists. Additional storms possible Friday.

2) Dry weather returns on Saturday and lasts through the
weekend.

&&

.DISCUSSION...

KEY MESSAGE 1: Showers and thunderstorms into tonight can hold
heavy rain and damaging winds. A small chance of tornadoes and
hail also exists. Additional storms possible Friday.

Weak wave crossing LE has been touching off a few TSRA farther
to the west. However, the shallow cu and higher stability
overhead indicate that it`s influence to cause new storms
locally will be low. However, the high humidity and slight
convergence over nrn tier counties will help a couple of tall
cells to build up before 22Z. The main show is shortly
afterward, though. Much stronger short wave trough is moving
through lower MI and should drive a complex of storms through
most/all of the CWA this evening. Arrival in the NW should be
around 22Z and exit to the east of the CWA will be in the
02-03Z range. The strong dynamics and initial curve to the
hodographs in the NW may generate a few supercells. Then, the
vertical wind profile becomes more W-E/linear. That should
result in a more clustered or linear mode, ripe for a bow echo.
70-75F dewpoints and PWAT near 2" this evening (highest S) will
make heavy rain a possibility, too. The risk for flooding still
exists, especially because of the very wet ground due to the
past 36-48hr rainfall. However, the faster the storm motions
are, the lower a risk it could be. The problem this evening is
as it has been - multiple/repeated storm cores moving over the
same spots. Will keep on with the FF Watch thru midnight. Timing
should encompass all of the threat.

Heat index numbers haven`t quite built to the point expected
yet, likely due to the delayed onset of sunshine. But, we`ll
keep the advisory in place until 8 PM as the temps could jump
another 5-6F before it starts to cool off over the S now that
they have nearly full sunshine.

The cool air that the storms this evening generate will help to
nudge a cold front off to our S tonight. But, not very far
south of PA. It won`t take much forcing to fire up SCT-NMRS
storms on Friday. PoPs may be a little high for Fri-Fri night,
but we`ll follow the recent trend toward a wetter forecast.
These will stay closer to the MD border, but isold storms will
form as far as the NY border. SPC outlook has been consitently
worse (SLGT) for the Laurels on Fri.

   -------------------------------------------------------

KEY MESSAGE 2: Dry weather returns on Saturday and lasts
through the weekend.

Upper low over New England will close even more and drop a
little to the south as cooler air slides into NY/PA. The cold
front finally gets far enough to our south to keep all the
SHRA/TSRA off to our south on Sat. Other than some morning
valley fog, the wx will be really nice for the holiday weekend.
Highs mainly in the 70s and lows 45-55F both Sat night and Sun
night. Upper ridge inches to the east from the central states
into mid-week. Quiet weather stretch will be welcomed by many.
Next chc precip isn`t until Wed-Thurs.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
SKC now. We will see the high clouds invade over the next few
hours. A weak wave is touching off a couple of TSRA that are
crossing Lower Ontario and Lake Erie. While those cells
themselves may not be able to survive into central PA, the
forcing could pop some tall cells over the nrn tier before 6 PM.
However, it will be a stronger short wave trough back over lower
MI that is already lit up with deep convection that will make
our main weather troubles for this evening and early tonight. A
line or bow of storms is possible this evening (arriving around 22Z
W and 01-02Z E). Strong wind gusts and very heavy rain are
possible. Outside of the convection, VFR should rule until
after 02-03Z when the SHRA/TSRA move away. Some fog is possible
(30%) over any of the terminals, but only if the wind goes light
again. The wrly wind overnight could make some low stratus over
the wrn ridges. Have mentioned it for the time being. But, not
confident (50%) of LIFR cigs there.

Cooler air in behind the main slug of storms will settle
southward, but not very far south of PA. But, it won`t take much
forcing to fire up SCT-NMRS storms on Friday. These will stay
closer to the MD border, but isold storms will form as far as
the NY border. Will hold off on mentions of daytime convection
until the next (00Z) package as most/all should wait until
after 18Z.


Outlook...

Sat-Tues...VFR favored; morning fog possible.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
Flood Watch until midnight EDT tonight for PAZ004>006-010>012-
017>019-024>028-033>037-041-042-045-046-049>053-056>059-
063>066.
Heat Advisory until 8 PM EDT this evening for PAZ026>028-035-
036-056-057-059-063>066.

&&

$$

WHAT HAS CHANGED...Dangelo
KEY MESSAGES...Dangelo
DISCUSSION...Dangelo
AVIATION...Dangelo