The latest shortwave in a series of such disturbances passed across the region during the afternoon of August 25th.  The Storm Prediction Center painted the Upper Ohio Valley with a risk for scattered severe storms. The storms began to develop in the lee of Lake Erie around midday.  The storms were able to take advantage of a frontal boundary sagging towards I-70. Shear and increasing instability favored multicells and short bowing segments initially.  Activity was eventually able to congeal into a linear MCS as it crossed the Mason-Dixon Line during the evening hours.
Most of the severe activity in southwest Pennsylvania occurred to the north and east of Pittsburgh, running from Butler County southeastward to Westemoreland County.  Many instances of tree damage were reported from thunderstorm wind gusts, with a few instances of minor structural damage.  Isolated large hail reports were also received.

Thunderstorm Wind in WESTMORELAND, PENNSYLVANIA
From 25-AUG-20 07:17:00 to 25-AUG-20 07:17:00 (EST-5)
Location: GRAPEVILLE
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Trees were reported to be blown down at a residence.

Thunderstorm Wind in WESTMORELAND, PENNSYLVANIA
From 25-AUG-20 07:25:00 to 25-AUG-20 07:25:00 (EST-5)
Location: GREENSBURG
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: 911 Call Center

A tree was reported to be down along Route 119 near the Country Farms garden center.

Thunderstorm Wind in ARMSTRONG, PENNSYLVANIA
From 25-AUG-20 13:01:00 to 25-AUG-20 13:01:00 (EST-5)
Location: WORTHINGTON
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Public

Trees and power lines were reported to be blown down in Worthington.

Hail in INDIANA, PENNSYLVANIA
From 25-AUG-20 13:47:00 to 25-AUG-20 13:47:00 (EST-5)
Location: ISELIN
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm Wind in INDIANA, PENNSYLVANIA
From 25-AUG-20 13:47:00 to 25-AUG-20 13:47:00 (EST-5)
Location: JACKSONVILLE
Magnitude: 50.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Social Media

Several trees were snapped and damage was done to a barn along Route 217 between Blairsville and Aultman.  Time of occurrence was estimated based on radar data.

Thunderstorm Wind in WESTMORELAND, PENNSYLVANIA
From 25-AUG-20 14:38:00 to 25-AUG-20 14:38:00 (EST-5)
Location: WILPEN
Magnitude: 50.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: 911 Call Center

A tree was reported down near the intersection of Wilpen Road and Ramsey Road.

Thunderstorm Wind in WESTMORELAND, PENNSYLVANIA
From 25-AUG-20 15:15:00 to 25-AUG-20 15:15:00 (EST-5)
Location: CRISP
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Trees and power lines were blown down in Cook Township off of Linn Run Road.

Thunderstorm Wind in WESTMORELAND, PENNSYLVANIA
From 25-AUG-20 15:29:00 to 25-AUG-20 15:29:00 (EST-5)
Location: STANDARD SHAFT
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Several trees were reported down in Mount Pleasant Township.

Thunderstorm Wind in WESTMORELAND, PENNSYLVANIA
From 25-AUG-20 07:40:00 to 25-AUG-20 07:40:00 (EST-5)
Location: KEFFER
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Power lines were reported to be blown down.

Thunderstorm Wind in BUTLER, PENNSYLVANIA
From 25-AUG-20 12:33:00 to 25-AUG-20 12:33:00 (EST-5)
Location: PETROLIA
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Trees and wires were reported to be blown down in Washington Township.

Thunderstorm Wind in BUTLER, PENNSYLVANIA
From 25-AUG-20 12:40:00 to 25-AUG-20 12:40:00 (EST-5)
Location: PETROLIA
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Trees and power lines were reported to be blown down.

Thunderstorm Wind in INDIANA, PENNSYLVANIA
From 25-AUG-20 13:52:00 to 25-AUG-20 13:52:00 (EST-5)
Location: GRAFTON
Magnitude: 50.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Public

Around 10 trees were downed at a residence, with additional trees down in the neighborhood.  Metal was also ripped off of a shed roof.

Thunderstorm Wind in WESTMORELAND, PENNSYLVANIA
From 25-AUG-20 14:03:00 to 25-AUG-20 14:03:00 (EST-5)
Location: BAIRDSTOWN
Magnitude: 50.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: 911 Call Center

A tree was reported to be blown down off of Deep Hollow Road.

Thunderstorm Wind in WESTMORELAND, PENNSYLVANIA
From 25-AUG-20 14:05:00 to 25-AUG-20 14:05:00 (EST-5)
Location: BAIRDSTOWN
Magnitude: 50.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: 911 Call Center

A tree was reported to be blown down on the 200 block of Garrigan Hill Road.

Thunderstorm Wind in WESTMORELAND, PENNSYLVANIA
From 25-AUG-20 16:08:00 to 25-AUG-20 16:08:00 (EST-5)
Location: SMITHTON
Magnitude: 50.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: 911 Call Center

A large tree was reported to be down on the 200 black of Porter Road in Rostraver Township.

Hail in BUTLER, PENNSYLVANIA
From 25-AUG-20 12:47:00 to 25-AUG-20 12:47:00 (EST-5)
Location: CHICORA
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm Wind in ARMSTRONG, PENNSYLVANIA
From 25-AUG-20 12:50:00 to 25-AUG-20 12:50:00 (EST-5)
Location: SHERRETT
Magnitude: 50.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Trees were reported to be blown down across many portions of northern Armstrong County.

Thunderstorm Wind in ARMSTRONG, PENNSYLVANIA
From 25-AUG-20 12:55:00 to 25-AUG-20 12:55:00 (EST-5)
Location: COWAN
Magnitude: 50.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Public

In Cowansville, large trees were reported to be blown down and split in half, with some laying on power lines.

Thunderstorm Wind in WESTMORELAND, PENNSYLVANIA
From 25-AUG-20 14:15:00 to 25-AUG-20 14:15:00 (EST-5)
Location: WEST FAIRFIELD
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: 911 Call Center

In Fairfield Township, multiple trees were reported to be blown down.

Thunderstorm Wind in WESTMORELAND, PENNSYLVANIA
From 25-AUG-20 14:16:00 to 25-AUG-20 14:16:00 (EST-5)
Location: MANNITTO HAVEN
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Trees were reported to be blown down on power lines in Derry Township near the intersection of Route 981 and Shortcut Road.

Thunderstorm Wind in BEAVER, PENNSYLVANIA
From 25-AUG-20 14:18:00 to 25-AUG-20 14:18:00 (EST-5)
Location: NEW SHEFFIELD
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Public

Several trees and power lines were reported to be blown down in and around Hopewell Township.