An anomalously strong ridge centered across the Southeast brought record heat to the Upper Ohio Valley with the area in a zonal flow on the northern edge of the ridge. A weak frontal boundary extended from northern Indiana into western Pennsylvania.  Abundant moisture (1.75-2.00 PWAT), strong instability (SBCAPE 4000-5000 J/kg), moderate shear (40kts 0-6km), and a short wave just south of the boundary provided the ingredients for a long-tracked mesoscale convective system, classified by the Storm Prediction Center as a derecho, to track all the way from northern Indiana across eastern Ohio, southwestern Pennsylvania, northern WV, and western Maryland. As the MCS crossed the area, widespread wind damage was reported across areas primarily south and west of Pittsburgh. There were several reports of structural damage and damage led to a fatality when a barn collapsed in Muskingum county. Power outages were widespread with up to 130,000 outages reported immediately after the storms passage, most of which, were in Ohio. Muskingum and Guernsey counties sustained $712,000 and $500,000 in damages respectively. This also became on of the the costliest disasters to hit Ohio, right behind Hurricane Ike in 2008.

Hail in FAYETTE, PENNSYLVANIA
From 29-JUN-12 19:29:00 to 29-JUN-12 19:29:00 (EST-5)
Location: COLDBROOK
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm Wind in WASHINGTON, PENNSYLVANIA
From 29-JUN-12 18:38:00 to 29-JUN-12 18:38:00 (EST-5)
Location: WASHINGTON
Magnitude: 60.00 EG
Property damage: 2.50K
Crop damage: 0.00K
Reported by: Public

The public reported large branches broken.

Thunderstorm Wind in ALLEGHENY, PENNSYLVANIA
From 29-JUN-12 18:50:00 to 29-JUN-12 18:50:00 (EST-5)
Location: WHITEHALL
Magnitude: 60.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: State Official

State official reported trees down.

Thunderstorm Wind in GREENE, PENNSYLVANIA
From 29-JUN-12 18:50:00 to 29-JUN-12 18:50:00 (EST-5)
Location: RICES LNDG
Magnitude: 60.00 EG
Property damage: 2.50K
Crop damage: 0.00K
Reported by: Public

The public reported large trees blown down.

Thunderstorm Wind in ALLEGHENY, PENNSYLVANIA
From 29-JUN-12 18:51:00 to 29-JUN-12 18:51:00 (EST-5)
Location: BOGGS
Magnitude: 60.00 EG
Property damage: 2.50K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported trees down.

Thunderstorm Wind in ALLEGHENY, PENNSYLVANIA
From 29-JUN-12 19:00:00 to 29-JUN-12 19:00:00 (EST-5)
Location: WHITEHALL
Magnitude: 60.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency management stated that there are multiple reports of downed trees across the far southern portions of the county.

Thunderstorm Wind in WESTMORELAND, PENNSYLVANIA
From 29-JUN-12 19:05:00 to 29-JUN-12 19:05:00 (EST-5)
Location: WEST NEWTON
Magnitude: 60.00 EG
Property damage: 2.50K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported trees down on Route 20.

Thunderstorm Wind in FAYETTE, PENNSYLVANIA
From 29-JUN-12 19:17:00 to 29-JUN-12 19:17:00 (EST-5)
Location: LEITH
Magnitude: 60.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency management reported numerous trees and power lines down.

Thunderstorm Wind in FAYETTE, PENNSYLVANIA
From 29-JUN-12 19:21:00 to 29-JUN-12 19:21:00 (EST-5)
Location: BITNER
Magnitude: 60.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: State Official

State official reported numerous trees down county wide.

Thunderstorm Wind in WESTMORELAND, PENNSYLVANIA
From 29-JUN-12 19:25:00 to 29-JUN-12 19:25:00 (EST-5)
Location: GREENSBURG
Magnitude: 60.00 EG
Property damage: 2.50K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported trees down on Mount View Intersection off of Route 3.

Thunderstorm Wind in FAYETTE, PENNSYLVANIA
From 29-JUN-12 19:34:00 to 29-JUN-12 19:34:00 (EST-5)
Location: OHIOPYLE
Magnitude: 60.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency management reported numerous trees down.