A deep upper trough and low pressure moving across the Ohio Valley pushed warm and humid air northward ahead of a cold front moving east with the surface low. Severe thunderstorms were widespread across eastern Ohio, western Pennsylvania, northern West Virginia, and Garrett county Maryland. Significant flash flooding occurred over eastern Allegheny and western Westmoreland counties in Pennsylvania with estimated damage of 18 million dollars to public infrastructure and private buildings.

Thunderstorm Wind in ALLEGHENY, PENNSYLVANIA
From 17-JUN-09 19:15:00 to 17-JUN-09 19:15:00 (EST-5)
Location: CRAFTON
Magnitude: 52.00 EG
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter reported an estimated wind gust to 60 MPH on Mount Washington.

Thunderstorm Wind in VENANGO, PENNSYLVANIA
From 17-JUN-09 19:00:00 to 17-JUN-09 19:00:00 (EST-5)
Location: FRANKLIN
Magnitude: 50.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law enforcement reported trees down near Franklin.

Flash Flood in FAYETTE, PENNSYLVANIA
From 17-JUN-09 22:15:00 to 18-JUN-09 01:30:00 (EST-5)
Location: BOWEST JCT
Flood cause: Heavy Rain
Property damage: 250.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency management reported roads and homes flooded throughout Dunbar Township due to flash flooding.

Hail in ALLEGHENY, PENNSYLVANIA
From 17-JUN-09 17:47:00 to 17-JUN-09 17:47:00 (EST-5)
Location: CRAFTON
Magnitude: 0.88 
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in WESTMORELAND, PENNSYLVANIA
From 17-JUN-09 19:15:00 to 17-JUN-09 19:15:00 (EST-5)
Location: GREENSBURG
Magnitude: 1.00 
Crop damage: 0.00K
Reported by: Amateur Radio

Hail in WESTMORELAND, PENNSYLVANIA
From 17-JUN-09 19:20:00 to 17-JUN-09 19:20:00 (EST-5)
Location: LOYALHANNA
Magnitude: 0.75 
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in FAYETTE, PENNSYLVANIA
From 17-JUN-09 20:20:00 to 17-JUN-09 20:20:00 (EST-5)
Location: MOYER
Magnitude: 1.00 
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in VENANGO, PENNSYLVANIA
From 17-JUN-09 16:45:00 to 17-JUN-09 16:45:00 (EST-5)
Location: EMLENTON STATION
Magnitude: 50.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law enforcement reported trees down in Emlenton.

Thunderstorm Wind in FAYETTE, PENNSYLVANIA
From 17-JUN-09 21:30:00 to 17-JUN-09 21:30:00 (EST-5)
Location: VANDERBILT
Magnitude: 50.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law enforcement reported trees down northwest of Dunbar.

Flash Flood in BEAVER, PENNSYLVANIA
From 17-JUN-09 20:20:00 to 17-JUN-09 22:15:00 (EST-5)
Location: WEST ALIQUIPPA
Flood cause: Heavy Rain
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency management reported Kennedy BLVD and Franklin AVE in Aliquippa closed due to flash flooding.

Flash Flood in WESTMORELAND, PENNSYLVANIA
From 17-JUN-09 19:22:00 to 18-JUN-09 00:30:00 (EST-5)
Location: MURRYSVILLE
Flood cause: Heavy Rain
Property damage: 9.00M
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency management reported widespread flash flooding across much of western amd central Westmorland county from Murrysville to Greensburg and Mount Pleasant. At least 1,192 buildings were affected, with 136 having major damage and 11 buildings destroyed. Damages were estimated to be around 9 million dollars. Most major roadways had flooding and some were closed well after the water receded to clear debris. The hardest hit areas from Murrysville to Greensburg had rainfall of over 4 inches in 3 hours.

Flash Flood in BEAVER, PENNSYLVANIA
From 17-JUN-09 20:20:00 to 17-JUN-09 22:15:00 (EST-5)
Location: INDEPENDENCE
Flood cause: Heavy Rain
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency management reported Independence RD closed due to flash flooding.

Flash Flood in BEAVER, PENNSYLVANIA
From 17-JUN-09 20:20:00 to 17-JUN-09 22:15:00 (EST-5)
Location: SOUTH HGTS
Flood cause: Heavy Rain
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency management reported 4TH Street near Route 65 closed due to flash flooding.

Thunderstorm Wind in BEAVER, PENNSYLVANIA
From 17-JUN-09 17:30:00 to 17-JUN-09 17:30:00 (EST-5)
Location: WEST ALIQUIPPA
Magnitude: 50.00 EG
Property damage: 75.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law enforcement reported trees and power lines down in Beaver.

Thunderstorm Wind in WESTMORELAND, PENNSYLVANIA
From 17-JUN-09 19:15:00 to 17-JUN-09 19:15:00 (EST-5)
Location: GREENSBURG
Magnitude: 50.00 EG
Property damage: 75.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Amateur radio reported trees down in Greensburg.

Hail in WESTMORELAND, PENNSYLVANIA
From 17-JUN-09 20:20:00 to 17-JUN-09 20:20:00 (EST-5)
Location: KECKSBURG
Magnitude: 1.00 
Crop damage: 0.00K
Reported by: Trained Spotter

Flash Flood in ALLEGHENY, PENNSYLVANIA
From 17-JUN-09 19:30:00 to 18-JUN-09 01:30:00 (EST-5)
Location: OPTION
Flood cause: Heavy Rain
Property damage: 9.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency management reported flash flooding over Allegheny county from the eastern sections of downtown Pittsburgh to Monroeville and areas to the Westmoreland county line. 29 people were trapped in cars, and Emergency Medical Services crews rescued 14 of them. 70 to 80 people were evacuated from about 30 homes in the hardest hit Turtle Creek area. 3 to 4 inches of rain fell across the area in about 3 hours. Allegheny county reported 1,658 buildings were damaged due to flash flooding. Most major roadways were flooded with several closed for hours to remove debris. The estimated damage to both public infrastructure and private buildings is estimated between 8 and 10 million dollars.