Northwest Pennsylvania was within the warm sector during the morning of the 11th through early evening of the 13th as the region remained along the northwestern flank of the Bermuda-Azores subtropical high pressure ridge. Simultaneously, a very slow-moving cold front approached northwest Pennsylvania from the Upper Midwest as multiple surface lows moved northeastward along the front. Ahead of the front, three distinct rounds of severe thunderstorms with damaging wind gusts affected northwest Pennsylvania during the early evening hours of the 11th, 12th, and 13th, respectively. These storms utilized weak to strong MUCAPE, moderate to strong DCAPE, and primarily moderate effective bulk shear.

Thunderstorm Wind in CRAWFORD, PENNSYLVANIA
From 12-AUG-21 16:49:00 to 12-AUG-21 16:49:00 (EST-5)
Location: CONNEAUT LAKE
Magnitude: 55.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Numerous trees downed in Conneaut Lake. One home was damaged and a mobile home was damaged severely.

Thunderstorm Wind in CRAWFORD, PENNSYLVANIA
From 13-AUG-21 18:10:00 to 13-AUG-21 18:10:00 (EST-5)
Location: PENNLINE
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Two trees downed along PA-198, just east of the OH/PA line. Damage occurred between Pierpont, OH and Conneautville, PA.

Thunderstorm Wind in CRAWFORD, PENNSYLVANIA
From 11-AUG-21 17:32:00 to 11-AUG-21 17:32:00 (EST-5)
Location: CONNEAUT LAKE
Magnitude: 60.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Numerous trees and power lines down in Conneaut Lake.

Thunderstorm Wind in CRAWFORD, PENNSYLVANIA
From 11-AUG-21 17:39:00 to 11-AUG-21 17:39:00 (EST-5)
Location: MEADVILLE
Magnitude: 60.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Numerous trees and power lines downed in Vernon Township, about four-miles WSW of Meadville.

Thunderstorm Wind in CRAWFORD, PENNSYLVANIA
From 11-AUG-21 17:51:00 to 11-AUG-21 17:51:00 (EST-5)
Location: COCHRANTON
Magnitude: 60.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Numerous trees downed in Cochranton.

Thunderstorm Wind in CRAWFORD, PENNSYLVANIA
From 11-AUG-21 17:40:00 to 11-AUG-21 17:40:00 (EST-5)
Location: DRAKES MILLS
Magnitude: 52.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Estimated peak gust of 60 mph from QLCS about two-miles SSE of Edinboro. Several eight-inch diameter trees were snapped.

Thunderstorm Wind in CRAWFORD, PENNSYLVANIA
From 11-AUG-21 17:33:00 to 11-AUG-21 17:33:00 (EST-5)
Location: CONNEAUT LAKE PARK
Magnitude: 65.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Probable downburst damaged a boat and two docks along the northeastern shore of Conneaut Lake, about 1.5-miles NNE of the town of Conneaut Lake. The same residential property had a window blown-out and its porch was damaged by downed tree branches.

Thunderstorm Wind in ERIE, PENNSYLVANIA
From 11-AUG-21 17:10:00 to 11-AUG-21 17:10:00 (EST-5)
Location: WEST SPRINGFIELD
Magnitude: 55.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Trees damaged in West Springfield.

Hail in CRAWFORD, PENNSYLVANIA
From 12-AUG-21 16:14:00 to 12-AUG-21 16:14:00 (EST-5)
Location: HYDETOWN
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Golf ball-size hail in Hydetown. Size estimated from photo.

Hail in CRAWFORD, PENNSYLVANIA
From 12-AUG-21 16:18:00 to 12-AUG-21 16:18:00 (EST-5)
Location: TITUSVILLE
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Golf ball-size hail two-miles NNE of Titusville. Size estimated from photo.

Thunderstorm Wind in CRAWFORD, PENNSYLVANIA
From 12-AUG-21 16:28:00 to 12-AUG-21 16:28:00 (EST-5)
Location: HARMONSBURG
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Tree fell onto house in Harmonsburg.