952
FXUS61 KCTP 261058
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
658 AM EDT Sun Jul 26 2026

.WHAT HAS CHANGED...
Augmented wording for Sct TSRA with gusty winds across the Lower
and Middle Susq Valley this afternoon and early this evening.

&&

.KEY MESSAGES...
1) A few gusty thunderstorms possible across portions of the
Lower and Middle Susquehanna Valley this afternoon and evening.

2) Turning more humid and unsettled early in the upcoming week
with the highest probability for showers and thunderstorms
Monday afternoon and evening and again on Tuesday and Tuesday
night.

&&

.DISCUSSION...
KEY MESSAGE 1:  A few gusty thunderstorms possible across
portions of the Lower and Middle Susquehanna Valley this
afternoon and evening.

A weak upper level disturbance embedded in the NW flow aloft
will race SE and over a favorable zone of convergence along a
lee trough that will be situated across the Middle and Lower
Susq Valley this afternoon/early evening.

Surface dewpoints in the low to mid 60s convergence and the
passage of the left exit region of a 90 kt jet max over Ohio and
SW PA late this afternoon will provide the fuel and favorable
larger scale UVVEL for some pulse and small clusters of
strong to potentially svr multicell TSRA across the I-81 and RT
11/15 corridors in southern PA within a fairly narrow corridor
of sfc-based CAPE between 1000-1500 J/KG between 18Z-00Z
today/Monday. SPC has this relatively small portion of
our CWA in a MRGL Risk for SVR TSRA today.


KEY MESSAGE 2: Turning more humid and unsettled early in the
upcoming week with the highest probability for showers and
thunderstorms Monday afternoon and evening and again on Tuesday
and Tuesday night.

A warm front will be moving across western PA Monday
afternoon/evening, followed by a rather potent/digging mid/upper
level shortwave and surface low. This shortwave will help to
amplify a slow-moving upper trough over the Mid Atlantic Region
as we head into the midweek period.

Fcst dewpoints are not all that high for late July, and there
has been a slight downward trend with fcst dewpoints over the
last few days.

Main things supporting showers and storms is a deepening low,
and a large scale pattern that supports significant directional
and speed shear in advance of a quite anomalous 995-1000 mb sfc
low moving over or just north of PA on Tuesday. Hodographs
Tuesday have a broad loop, but winds in the lowest KM are fairly
light, so we`re leaning to the storm type being pulse, but with
0-2KM helicity values peaking around 150 M2/S2 Tuesday, we could
see some transient supercells over Central and Ern PA during
the afternoon.

Previous disc...

The timing of the favorable lift associated with the thermally
indirect, left front quad of the 80+ KT jet max moving across
the Ohio Valley, WVA and southern PA Tuesday afternoon and
evening will help to enhance a low level lee trough and
convection along it. Scattered strong to severe TSRA are likely
Tue afternoon and evening over at least the eastern half of the
CWA with a second line of TSRA likely along the cold front
across NW PA Tuesday afternoon.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
Current LIFR conditions at BFD are progged to continue through
13-15Z Sunday before prevailing VFR with widespread VFR
conditions likely (> 80%) to continue elsewhere through 00Z
Monday. The only real potential for sub-VFR conditions in this
timeframe would after 21Z with some potential for isolated
moderate SHRA/TSRA in the vicinity of IPT (40-60% probabilities)
and MDT (20-40% probabilities) through 03Z Monday. Have trimmed
back mentions at LNS compared to earlier packages due to some
hi-res solutions trending back on precipitation mentions at this
airfield, but there remains a non-zero chance in SHRA/TSRA
making a push towards this airfield, generally between 01-03Z
Monday if this is to occur. Main restrictions would be limited
to MVFR at all of these airfields, with IFR looking unlikely
within SHRA/TSRA for the majority.

After 06Z Monday, quite the range in guidance thus slightly
lower confidence in the TAF package. Recent GLAMP/NBM model
guidance stand out as fairly pessimistic guidance with respect
to low ceilings and visibilities. Looking at 10th percentile
members of the HREF guidance; however, outlines these
restrictions being limited to BFD/IPT and *potentially* MDT
which tracks with RAP model soundings that outline the most
plentiful low-level moisture. Given this, have went with a
forecast that trends closer to the RAP/HREF solutions at this
time. There does remain a fair amount of uncertainty this far
out; however, and more widespread rainfall would lean towards
the GLAMP/NBM solutions and will need to be monitored more
closely this afternoon/evening.

Outlook...

Mon...Restrictions likely in afternoon -SHRA/-TSRA. Patchy
overnight fog possible.

Tue...Restrictions likely with scattered -SHRA/-TSRA.

Wed-Thu...Restrictions possible as -SHRA/-TSRA becomes less
numerous. Patchy overnight fog possible.

&&

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

&&

$$

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