298
FXUS61 KCTP 220247
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
1047 PM EDT Tue Jul 21 2026

.WHAT HAS CHANGED...
* Severe and flooding threat for this evening has largely
  decreased across all of central Pennsylvania.
* Included the Marginal Risk for severe thunderstorms across SE
  PA tomorrow and outlook for the rest of the forecast period.

&&

.KEY MESSAGES...
1) Severe and flash flooding threat has largely diminished this
evening with no widespread hazardous weather expected tonight.

2) Outside of some strong-to-severe storms across Lancaster
County on Wednesday, generally tranquil weather expected through
the end of the work week.

&&

.DISCUSSION...
KEY MESSAGE 1: Severe and flash flooding threat has largely
diminished this evening with no widespread hazardous weather
expected tonight.

Current radar outlines a cluster of showers with some isolated
lightning strikes across northern Indiana County with scattered
showers behind this cluster that will continue to move into
Clearfield/Cambria counties over the next hour. Severe threat
has largely waned given stability across the region despite the
favorable shear parameters based on the most recent SPC
Mesoanalysis parameters. Flooding threat also remains fairly
low across the region with the only area of real concern given
the overall lack of widespread heavy rainfall this afternoon and
evening and a fall off of rainfall rates overall. Some potential
for fog formation across the higher elevations of western
Pennsylvania where heavy rainfall was observed today; however,
the signal is not super strong at this time with overall dew
point depressions still having a bit of ways to fall before fog
formation occurs tonight. If fog forms across higher elevations,
rapidly changing driving conditions could be present across
portions of the Allegheny Front into Wednesday morning.

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

KEY MESSAGE 2: Outside of some strong-to-severe storms across
Lancaster County on Wednesday, generally tranquil weather
expected through the end of the work week.

Surface cold front will continue to push eastward across central
Pennsylvania tomorrow morning and throughout the afternoon
hours, which will bring some potential for showers and storms to
Lancaster County during the late afternoon hours depending on
the speed of the cold frontal passage. More recent NBM guidance
has trended back on precipitation mentions across the region and
this is shown in the most recent forecast. If the cold front
trends slower, it appears there would be enough moisture and
potentially shear in place to bring a threat for marginally
strong-to-severe thunderstorms. It is of note that instability
will likely not be super sufficient for severe thunderstorms
given morning cloud cover in place across the region, which
could tamper the severe threat should the slower cold frontal
passage solution play out in real time.

Dry conditions prevail Wednesday evening and are generally
expected to continue through the Saturday evening based on most
recent NBM model guidance. Towards the latter half of the
weekend and into the beginning of next week, overall an
unsettled pattern appears to take hold of the region with
showers and chances of afternoon/evening thunderstorms progged
by NBM model guidance. Despite this, no large-scale signals for
severe weather at this time.

&&

.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
Current SHRA/TSRA stationed just west of BFD could continue to
maintain itself over the next hour or two before running into a
layer of more stable air and generally go onto a weakening
trend. Current forecast outlines no TSRA mentions throughout the
00Z TAF package; however, VCTS could be possible at BFD through
01Z. The bulk of lightning activity is expected to be south of
the airfield; however, so no mentions. SHRA mentions retained
further east at UNV/IPT where this complex could sustain itself
and bring lower ceilings/visibilities but generally not below
IFR thresholds. Secondary complex of SHRA is expected at MDT/LNS
brining SHRA and lower ceilings/visibilities with MVFR likely
the worst-case scenario at this time.

Overnight, HREF/GLAMP guidance outlines lower ceilings and
visibilities most likely across the western terminals (BFD/JST)
so have continued to outline this potential in the updated
forecast package. Elsewhere, guidance paints a more optimistic
picture for flying conditions compared to the 18Z TAF package,
likely due precipitation not being as widespread as originally
forecast. Some pockets of MVFR/IFR will be possible at UNV/IPT
as well; however, will mainly be based on precipitation reaching
the airfield and a slight decrease in winds so this remains a
lower confidence solution at this time. Gradual improvement of
the western airfields is expected after sunrise, with widespread
VFR conditions expected to prevail in the 14-16Z Wednesday
timeframe with high (~70-80%) confidence. These conditions are
likely (~80-90%) confidence to continue after prevailing through
the end of the 00Z TAF package.

Outlook...

Thu-Fri...Some potential for valley fog across NW PA Friday
morning; otherwise, VFR conditions expected.

Sat...Generally VFR conditions with low-end (< 20%) chance of an
afternoon shower/storm across SW PA.

Sun...Increasing chances of PM showers/storms, with some
restrictions possible.

&&

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

&&

$$

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