Severe Thunderstorm Warning 39, NWS Pittsburgh, PA

Area Forecast Discussion
National Weather Service Pittsburgh PA
451 PM EDT Sun Mar 22 2026

.WHAT HAS CHANGED...
Confidence in occurrence and timing of severe storms remain
similar to the prior update. Mesoscale guidance may slightly
favor the highest chance of hail/wind impacts in western
Pennsylvania.

&&

.KEY MESSAGES...
1) Severe thunderstorms expected late today. Primary threat
remains hail (1.5" to 2.5" possible), and damaging wind (up to
60mph). Most likely timing for impacts is 3pm to 10pm. Rain and
marginal excessive rainfall concerns increase overnight.

2) Quiet weather through Thursday. Storm chances increase late
Thursday into early Friday.

&&

.DISCUSSION...
KEY MESSAGE 1...

.. 430 PM Update ..

Initial convection has struggled to develop deeply with slight
capping at around 500mb as evidenced by the 18Z sounding. This
has precluded widespread severe thus far, through we continue to
expect instances to become more numerous into this evening as
wet-bulbing from convection saturates and destabilizes the mid-
levels. This has prompted the issuance/continuation of Severe
Thunderstorm Watch #72.

While high-end hail main be curtailed by a failure to see many
discrete supercells, large hail remains possible (1" to 2")
within some storms both along and behind the cold front.
Although, areas behind the cold front may not see as much of a
wind threat with stabilization at the low levels. Wind and hail
threats exist in tandem ahead of the front.

.. Previous Discussion ..

The environment today remains primed for severe weather area-
wide. The main uncertainty will be the coverage of storms, tied
to uncertainties in initiation with plentiful low-level dry
air.

First, we will address the environment. The 12Z sounding showed
a rather atypical setup for the northeast. Dry air near the
surface has allowed for a rather deep mixed layer up to 600mb.
This is commonly referred to as an inverted-V setup. +6 hr. SPC
RAP mesoanalysis suggests that with diurnal heating into the
day today, some decent instability generation remains possible
(1000+ J/kg MLCAPE, 1500 to 2000 J/kg SB/MU CAPE), though we will
have to monitor cirrus blow-off from initial development as a
mode of potentially limiting additional instability generation.
Shear is bountiful, with effective/sfc-6km values reaching or
even exceeding 60 kts. Given this setup, one would expect the
potential to achieve strong storms. Supercell composites poke
above 4, with no inhibition. Given these environmental
ingredients, the primary risk early will be hail, which will
transition more to wind later tonight.

Initial development is still favored along a cold front between
the 2pm to 5pm hours in northwest PA, given the forecast push of
dewpoints back into the 50s. If dewpoints do not increase as
forecast, initiation may be challenged initially. Given that
mid- level flow is mostly boundary perpendicular, these cells
may remain discrete initially. Given the environment, high-
based supercells are possible. While traditionally, supercells
are favorable for tornadoes, high-based storms would not with
initial cloud bases as high as 5kft to 10kft. As mentioned
above, the initial threat would be large hail (1.5" to 2.5"
possible), though wind is also possible given the 60kts of shear
and up to 600 to 800 DCAPE.

Once initiation has established, there will likely be little to
limit a continued hail/wind threat as storms mature and persist
across the center of the forecast area. CAMs have latched on to
the idea that the best chance of storms will fall across
southwest PA at this time (4pm to 8pm) with the best shear
pushing the boundary strongest. For the latter end of this
period, there may be some congealing of discrete elements as
storms are expected to slowly transition to more of a wind
threat after sunset whilst pushing into northern West Virginia
(6pm to 10pm), as the presence of linear, shear-driven segments
increases.

Overnight, a marginal risk for excessive rainfall persists, with
any flooding most likely south of Pittsburgh as convection
congeals and potentially slows, becoming more boundary-parallel.
OHRFC FFG maintains 1" to 1.5" per hour rates to be concerning,
along with 1.5" to 2.0" in 3hrs, with HREF max alluding these
thresholds may be attained in isolated instances, but would be
reliant on multiple round of convection. Should the cold front
be progressive enough, flooding would likely not occur.

KEY MESSAGE 2...
Behind the cold front, temperatures tumble, with highs as much
as 10F to 20F below normal Monday. With northwest flow over the
lakes again, we would not be surprised to see lake effect
showers (or even snow showers in the coldest scenarios).
Temperatures climb warmer and back above normal by Wednesday
with mostly dry conditions.

By Thursday afternoon, temperatures may be as warm as 10F to
20F above normal again with gusty daytime wind and increasing
chances or rain as the next system approached from the northwest
late-day. This may bring the next chance of storms and severe,
although this will largely depend on arrival time (earlier
means higher chances of impacts).

&&

.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
VFR conditions are in place as of 18Z, with mainly mid and high
clouds at this moment in advance of a cold front, which crosses
during the late afternoon and the evening. Southwest wind gusts
of up to 25 knots should continue in advance.

Convective initiation is trending slower now, with the first
showers and thunderstorm more likely to appear after 20Z. More
widespread activity is forecast to develop ahead of the
boundary from 22Z on as it sinks through the region. All
terminals are expected to be impacted to some degree. Have used
2 hour TEMPO groups to try the most likely time of arrival.
Storms will be strong to perhaps severe in some cases. Due to
dry low-level air, ceilings with the main line of storms should
remain VFR. However, expect IFR to perhaps brief LIFR
visibility in downpours. Variable wind gusts to 40 knots or so
are possible at any terminal, but are a little less so at
FKL/DUJ, and thus these gusts have not been included in the
TEMPO groups at those terminals. Do not be surprised if hail is
observed at one or two area airports - and it could be fairly
large.

Behind the front this evening, ceilings should crash
through low MVFR to IFR in most cases as low-level moisture
lingers. A wind shift to northwest will occur behind the boundary,
with some gusts of 15 to 20 knots lingering. A few
thunderstorms may linger in the post-frontal environment, but
light rain/drizzle and low ceilings should dominate through most
of the night. Most of the precipitation should end late tonight
or near sunrise. Slow improvement back to MVFR ceilings is
forecast towards the tail end of the TAF period.

Outlook...
Mostly VFR returns Monday afternoon through Wednesday under
building high pressure. The next notable chance of restrictions
may arrive by Thursday with the next cold front.

&&

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

&&

DISCUSSION...Milcarek
AVIATION...CL

Hazardous Weather Outlook
National Weather Service Pittsburgh PA
1235 PM EDT Sun Mar 22 2026

OHZ039>041-049-050-058-059-068-069-PAZ013>016-020>022-029-031-
073>078-WVZ001>004-012-021-509-510-231645-
Tuscarawas-Carroll-Columbiana-Harrison-Jefferson OH-Guernsey-Belmont-
Noble-Monroe-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-
1235 PM EDT Sun Mar 22 2026

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

.DAY ONE...This afternoon and tonight.

There is a Enhanced (level 3 of 5) risk of severe thunderstorms this
afternoon and evening. Large hail and damaging wind gusts are the
primary threats, with the stronger storms potentially producing hail
of baseball size.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to Standard Operating Procedures.

OHZ048-057-PAZ007>009-WVZ511>514-231645-
Coshocton-Muskingum-Mercer-Venango-Forest-Preston-Eastern Preston-
Western Tucker-Eastern Tucker-
1235 PM EDT Sun Mar 22 2026

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

.DAY ONE...This afternoon and tonight.

There is a Slight (level 2 of 5) risk of severe thunderstorms this
afternoon and evening. Large hail and damaging wind gusts are the
primary threats, with the stronger storms potentially producing hail
of golf ball size.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to Standard Operating Procedures.

Milcarek

Preliminary Local Storm Report
National Weather Service Pittsburgh PA
509 PM EDT Sun Mar 22 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0502 PM     Hail             2 SW Clarion            41.19N 79.40W
03/22/2026  E1.50 Inch       Clarion            PA   Public

            Report from mPING: Ping Pong Ball (1.50
            in.).

&&

Preliminary Local Storm Report
National Weather Service Pittsburgh PA
529 PM EDT Sun Mar 22 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0502 PM     Hail             Clarion                 41.21N 79.38W
03/22/2026  M1.00 Inch       Clarion            PA   Public

            Public reported 1 inch hail in Clarion, PA.

&&

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Preliminary Local Storm Report
National Weather Service Pittsburgh PA
620 PM EDT Sun Mar 22 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0500 PM     Hail             Strattanville           41.20N 79.33W
03/22/2026  E1.25 Inch       Clarion            PA   Public

&&

SKH

Preliminary Local Storm Report
National Weather Service Pittsburgh PA
638 PM EDT Sun Mar 22 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0637 PM     Hail             Cambridge               40.03N 81.58W
03/22/2026  E0.50 Inch       Guernsey           OH   Public

&&

SKH

Preliminary Local Storm Report
National Weather Service Pittsburgh PA
639 PM EDT Sun Mar 22 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0625 PM     Hail             New Concord             40.00N 81.74W
03/22/2026  E1.00 Inch       Muskingum          OH   Public

&&

SKH