Scattered severe thunderstorms developed along a frontal boundary lying across northwest Pennsylvania.

Tornado in MERCER, PENNSYLVANIA
From 01-MAY-07 17:15:00 to 01-MAY-07 17:21:00 (EST-5)
Location: MERCER
Tornado F-scale: EF0
Property damage: 20.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

An EF0 tornado touched down about 1.5 miles north of Mercer, traveling southeast with a sporadic path of damage extending about 4 miles.  Estimated maximum winds were 75 MPH with a maximum path width of 100 yards. Most of the damage consisted of uprooted and snapped trees. One barn was destroyed and two trees fell onto mobile homes, causing significant damage.

Thunderstorm Wind in MERCER, PENNSYLVANIA
From 01-MAY-07 17:20:00 to 01-MAY-07 17:20:00 (EST-5)
Location: MERCER
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency Manager reported a downburst in Mercer. Two trailers were damaged, and several trees and wires were down. Damage was confined to just north and west of the city of Mercer.

Thunderstorm Wind in MERCER, PENNSYLVANIA
From 01-MAY-07 17:20:00 to 01-MAY-07 17:20:00 (EST-5)
Location: MERCER
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

An amateur radio operator reported trees down near state routes 19 and 58.

Hail in MERCER, PENNSYLVANIA
From 01-MAY-07 17:10:00 to 01-MAY-07 17:10:00 (EST-5)
Location: STONEBORO
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter reported quarter sized hail in Stonboro.

Hail in VENANGO, PENNSYLVANIA
From 01-MAY-07 17:15:00 to 01-MAY-07 17:15:00 (EST-5)
Location: FRANKLIN
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Police in Sugar Creek reported golf ball sized hail 2 miles northwest of Franklin.

Thunderstorm Wind in CLARION, PENNSYLVANIA
From 01-MAY-07 18:10:00 to 01-MAY-07 18:10:00 (EST-5)
Location: CLARION
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency Manager reported that there were numerous trees and power lines down in Monroe, Redbank, and Limestone Townships.

Hail in LAWRENCE, PENNSYLVANIA
From 01-MAY-07 16:35:00 to 01-MAY-07 16:35:00 (EST-5)
Location: NEW WILMINGTON
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A member of the public reported golf ball sized hail in New Wilmington.

Hail in MERCER, PENNSYLVANIA
From 01-MAY-07 16:35:00 to 01-MAY-07 16:35:00 (EST-5)
Location: MERCER
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A member of the public reported dime sized hail five miles southeast of Mercer.

Hail in BUTLER, PENNSYLVANIA
From 01-MAY-07 16:35:00 to 01-MAY-07 16:35:00 (EST-5)
Location: BUTLER
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Dime sized hail was reported by a member of the public in Butler.

Hail in VENANGO, PENNSYLVANIA
From 01-MAY-07 19:12:00 to 01-MAY-07 19:12:00 (EST-5)
Location: UTICA
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency Manager reported golf ball sized hail in Utica.

Thunderstorm Wind in CLARION, PENNSYLVANIA
From 01-MAY-07 18:20:00 to 01-MAY-07 18:20:00 (EST-5)
Location: CLARION
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency Manager reported that a house was damaged near Limestone and Redbank Township line.

Hail in LAWRENCE, PENNSYLVANIA
From 01-MAY-07 16:15:00 to 01-MAY-07 16:15:00 (EST-5)
Location: NEW WILMINGTON
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter reported nickel size hail in New Wilmington.