Severe Thunderstorm Warning 151, NWS Pittsburgh, PA

Area Forecast Discussion
National Weather Service Pittsburgh PA
157 PM EDT Sat Jun 20 2026

.WHAT HAS CHANGED...
Increased coverage of passing showers and thunderstorms this
afternoon. A Marginal Risk of severe weather has been introduced
for Monday. High confidence still on soaking rainfall on Monday.

&&

.KEY MESSAGES...
1) Scattered showers and storms Saturday afternoon

2) More widespread rain chances return Sunday night and Monday.
There is high confidence in a soaking rainfall, but low
confidence in the threat of flooding.

&&

.DISCUSSION...
KEY MESSAGE 1...
Expect troughing to linger across the area today. This coupled
with strong surface heating, will allow scattered showers and
thunderstorms to develop across the area today. Surface
parameters suggest with a 500 to 750 J/KG SB CAPE and 500 J/KG
DCAPE, some sub severe wind gusts seem more likely. In fact,
model soundings suggest a 40 mph wind gust at best for this
afternoon. In addition, heavy downpours are not likely to occur
either as PWATs from mesoanalysis shows values of 0.8 to 0.9.

Conditions today will favor a more diurnal trend for convection
today. Thus, showers and thunderstorms are expected to dissipate
and come to an end by sunset or just after.

KEY MESSAGE 2...
The mid-level ridge axis reaches the CWA around 00Z Monday,
after which moisture surges northeastward into our region ahead
of a surface low which will be riding up the Ohio Valley.
Precipitable water likely surges into the 1.7 to 1.8 inch range
by Monday, which reaches the 90th to 95th percentile of
climatology. This, coupled with an east-west oriented warm
front across the region, suggests rounds of moderate to heavy
showers and thunderstorms are likely during the Sunday night to
Monday period.

The NBM probs for rainfall show greater than 80% for 1 inch of
rainfall from Sunday morning through Monday morning. The probs
for 1.5 inches have gone down a bit from the previous run with
roughly 40% to 50% with 2 inches showing 20% to 30%. This slight
decrease due to the slightly southern track aligns with the
slight being pulled out of the area and thus the area is only
expected to be under a marginal outlook for Monday. It will
depend on training storms and how much rain falls in a short
period of time to be concerned for a potential flood threat.

The other impact for Monday will be a severe potential as a
Marginal outlook was introduced for wind gusts. As the boundary
sags south, the afternoon heating may be enough to spawn a few
strong thunderstorms with the potential for damaging winds.
However, morning showers and cloud cover could sabotage the
amount of instability.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
Scattered showers and a few thunderstorms have begun to develop
across the region due to the weak shortwave passage. Cloud tops
will struggle to cool below -10C to -15C given relatively weak
buoyancy, so any lightning activity should remain fairly
isolated with the highest confidence of this and precipitation
coverage at FKL and DUJ. TEMPOs for TSRA were used here, while
other terminals to the south have PROB30s for SHRA with low
confidence in rain-induced restrictions. Any activity should end
by sunset as the shortwave departs, with a VFR evening.

Some gusts of around 20 knots out the west during this
afternoon. Localized areas of fog or lower stratus may develop
Sunday morning as winds calm and clouds clear. Currently,
MGW/LBE and FKL/DUJ have the best chance for this, however,
they were omitted from the TAFs due to low confidence in its
occurrence.

During the day on Sunday, skies will remain SCT through early
afternoon when BKN ceilings move in ahead of the incoming
system. CIG/VIS restrictions are likely Sunday night into
Monday.

Outlook...
Probabilities favor overnight Sunday into Monday for widespread
showers (low probability thunderstorms) resulting in MVFR/IFR
restrictions as a deeper trough/surface low combo travels
through the Ohio River Valley region.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...None.
OH...None.
WV...None.

&&

DISCUSSION...Shallenberger
AVIATION...CL/Lupo

Hazardous Weather Outlook
National Weather Service Pittsburgh PA
1226 PM EDT Sat Jun 20 2026

OHZ039>041-048>050-057>059-068-069-PAZ007>009-013>016-020>022-029-
031-073>078-WVZ001>004-012-021-509>514-211630-
Tuscarawas-Carroll-Columbiana-Coshocton-Harrison-Jefferson OH-
Muskingum-Guernsey-Belmont-Noble-Monroe-Mercer-Venango-Forest-
Lawrence-Butler-Clarion-Jefferson PA-Beaver-Allegheny-Armstrong-
Washington-Greene-Westmoreland-Higher Elevations of Westmoreland-
Fayette-Higher Elevations of Fayette-Indiana-
Higher Elevations of Indiana-Hancock-Brooke-Ohio-Marshall-Wetzel-
Marion-Monongalia-
Ridges of Eastern Monongalia and Northwestern Preston-Preston-
Eastern Preston-Western Tucker-Eastern Tucker-
1226 PM EDT Sat Jun 20 2026

This Hazardous Weather Outlook is for east central Ohio, western
Pennsylvania, and northern West Virginia.

.DAY ONE...This afternoon and tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

Numerous showers and thunderstorms, some of them with heavy
rainfall, are expected Sunday night into Monday night. There is the
potential for isolated flooding issues, particularly in urban and
poor drainage areas. If the risk of more widespread flooding
increases, a Flood Watch may be necessary.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

Shallenberger