A weak, low-amplitude shortwave crossed the region during the daylight hours.  Combined with sufficient instability, scattered thunderstorms were able to develop during the afternoon.  The strongest storms, and thus the bulk of the severe weather reports, occurred near and north of Pittsburgh, where synoptic support was maximized.
Sufficient mid-level shear allowed storms to organize into a line over time, with the period of strongest activity occurring from 3:30 PM to 7:00 PM.  Many reports of tree and power line damage were received.  One injury occurred near Howe in Jefferson County, where a tree fell on a moving vehicle, injuring the driver when the windshield shattered.

Thunderstorm Wind in CLARION, PENNSYLVANIA
From 17-AUG-19 15:58:00 to 17-AUG-19 15:58:00 (EST-5)
Location: HUEFNER
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: 911 Call Center

According to the county 911 call center, multiple trees and power lines were downed in Lucinda and Syndersburg.

Thunderstorm Wind in BUTLER, PENNSYLVANIA
From 17-AUG-19 16:22:00 to 17-AUG-19 16:22:00 (EST-5)
Location: GOFF
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: 911 Call Center

The county 911 call center stated that multiple trees and power lines were blown down around Boyers.

Thunderstorm Wind in JEFFERSON, PENNSYLVANIA
From 17-AUG-19 16:22:00 to 17-AUG-19 16:22:00 (EST-5)
Location: KAHLETOWN
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: State Official

County 911 officials stated that a tree fell on to a moving vehicle on Moore Bridge Road near Route 36.  The driver was injured by shattered glass from the tree hitting the car.

Thunderstorm Wind in JEFFERSON, PENNSYLVANIA
From 17-AUG-19 16:40:00 to 17-AUG-19 16:40:00 (EST-5)
Location: RED MILL
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: State Official

Multiple trees were blown down in Snyder and Washington Townships, according to the county 911 call center.

Thunderstorm Wind in ALLEGHENY, PENNSYLVANIA
From 17-AUG-19 18:04:00 to 17-AUG-19 18:04:00 (EST-5)
Location: CHERRY CITY
Magnitude: 50.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Emergency Manager

The county emergency manager reported that a telephone pole was blown down on to a car.

Thunderstorm Wind in BUTLER, PENNSYLVANIA
From 17-AUG-19 16:30:00 to 17-AUG-19 16:30:00 (EST-5)
Location: EAU CLAIRE
Magnitude: 50.00 EG
Property damage: 3.00K
Crop damage: 0.00K
Reported by: 911 Call Center

The county 911 call center reported that multiple trees and power lines were blown down in Eau Claire.

Thunderstorm Wind in ALLEGHENY, PENNSYLVANIA
From 17-AUG-19 18:05:00 to 17-AUG-19 18:05:00 (EST-5)
Location: CHERRY CITY
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

According to the county emergency manager, two partial building collapses occurred near the intersection of Butler and 48th Streets.

Thunderstorm Wind in ALLEGHENY, PENNSYLVANIA
From 17-AUG-19 18:05:00 to 17-AUG-19 18:05:00 (EST-5)
Location: CHERRY CITY
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

The county emergency manager reported that several trees were blown down in the Millvale, Reserve, and Lawrenceville areas.

Thunderstorm Wind in MERCER, PENNSYLVANIA
From 17-AUG-19 14:45:00 to 17-AUG-19 14:45:00 (EST-5)
Location: ORANGEVILLE
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Emergency Manager

The county emergency manager reported a tree and wires down on a structure.

Thunderstorm Wind in VENANGO, PENNSYLVANIA
From 17-AUG-19 14:55:00 to 17-AUG-19 14:55:00 (EST-5)
Location: GALLOWAY CITY
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: 911 Call Center

The county 911 call center reported that multiple trees were blown down between Cooperstown and Sugarcreek.

Hail in VENANGO, PENNSYLVANIA
From 17-AUG-19 14:48:00 to 17-AUG-19 14:48:00 (EST-5)
Location: COOPERSTOWN
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Thunderstorm Wind in ALLEGHENY, PENNSYLVANIA
From 17-AUG-19 18:16:00 to 17-AUG-19 18:16:00 (EST-5)
Location: MONTROSE HILL
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

The county emergency manager reported that several trees and power lines were blown down.

Thunderstorm Wind in MERCER, PENNSYLVANIA
From 17-AUG-19 15:00:00 to 17-AUG-19 15:00:00 (EST-5)
Location: TRANSFER
Magnitude: 50.00 EG
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Social Media

A social media user reported that multiple large trees were uprooted near Transfer.

Thunderstorm Wind in MERCER, PENNSYLVANIA
From 17-AUG-19 15:13:00 to 17-AUG-19 15:13:00 (EST-5)
Location: TRANSFER
Magnitude: 50.00 EG
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Emergency Manager

The county emergency manager reported that trees and power lines were blown down on to a house.

Thunderstorm Wind in MERCER, PENNSYLVANIA
From 17-AUG-19 15:13:00 to 17-AUG-19 15:13:00 (EST-5)
Location: NEW HAMBURG
Magnitude: 50.00 EG
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Trees and power lines were downed near McDowell Road, according to a local fire department.

Thunderstorm Wind in FOREST, PENNSYLVANIA
From 17-AUG-19 15:28:00 to 17-AUG-19 15:28:00 (EST-5)
Location: KIZER CORNERS
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

The county emergency manager reported that a tree fell on to a house on Barnes Road.

Thunderstorm Wind in FOREST, PENNSYLVANIA
From 17-AUG-19 15:41:00 to 17-AUG-19 15:41:00 (EST-5)
Location: KIZER CORNERS
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: State Official

Multiple trees were blown down in southern Green Township, according to county 911 officials.

Thunderstorm Wind in CLARION, PENNSYLVANIA
From 17-AUG-19 15:45:00 to 17-AUG-19 15:45:00 (EST-5)
Location: FRYBURG
Magnitude: 50.00 EG
Property damage: 3.00K
Crop damage: 0.00K
Reported by: 911 Call Center

The county 911 call center reported that Old Fryburg Road was briefly closed due to downed power lines and trees.

Thunderstorm Wind in CLARION, PENNSYLVANIA
From 17-AUG-19 15:45:00 to 17-AUG-19 15:45:00 (EST-5)
Location: TYLERSBURG
Magnitude: 50.00 EG
Property damage: 3.00K
Crop damage: 0.00K
Reported by: 911 Call Center

The county 911 call center reported that multiple trees and power lines were blown down in Tylersburg.

Thunderstorm Wind in CLARION, PENNSYLVANIA
From 17-AUG-19 15:50:00 to 17-AUG-19 15:50:00 (EST-5)
Location: LICKINGVILLE
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Sunny Road was closed briefly due to downed power lines and trees, according to county 911 officials.