Shortwave digging through an upper trough helped to develop two convective systems that crossed the upper Ohio Valley on the 10th. Moderate instability and shear provided for intensification of the second system over central and eastern Ohio but both produced scattered reports of wind damage. An EF-0 tornado was also confirmed in Beaver county, Pennsylvania that then continued into Butler county.

Tornado in BEAVER, PENNSYLVANIA
From 10-JUL-17 14:57:00 to 10-JUL-17 14:59:00 (EST-5)
Location: FOMBELL
Tornado F-scale: EF0
Property damage: 15.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

National Weather Service survey team confirmed a tornado near Fombell in Beaver County that continued into Lancaster Township in Butler County in Western Pennsylvania on Jul 10, 2017. A coherent, continuous swath of damage was discovered from near Bowers Lane/North Camp Run Road in Fombell east-northeastward to near the Strawberry Ridge Golf Course in Lancaster Township. Damage was universally to trees, consisting of snapped large limbs and trunk snappage or uproots of both healthy and unhealthy trees. At its most significant, the damage exhibited a rotationally-convergent debris pattern consistent with a weak tornado as it traversed a hillside through the golf course. Observers on the golf course at the time of this storm event reported tree debris being lofted and swirled cyclonically, which was consistent with the debris pattern noted by the survey team. Although not an accepted damage indicator, corn stalks just upstream from this location also were laid over and exhibited a swirl pattern. It should be noted that no structural damage was discovered at any point through the survey path. This lack of damage to structures enables the team to cap the storm's estimated wind speed. Farther to the northeast (at least as far as Eagle Mill Road and Whitestown Road), a coherent, discontinuous damage swath was noted, but lacked sufficient conclusive evidence to identify its origin. It is entirely possible that this damage was an extension of the tornado, but the debris was too sparse for any conclusions. The survey team has concluded that a brief, weak tornado occurred from near Bowers Lane through at least the Scott Ridge Road/McNulty Lane area. The damage was consistent with a tornado of peak wind speed of 60-70 mph, which yields a rating of EF0 on the Enhanced Fujita Scale.

Tornado in BUTLER, PENNSYLVANIA
From 10-JUL-17 14:59:00 to 10-JUL-17 15:01:00 (EST-5)
Location: MIDDLE LANCASTER
Tornado F-scale: EF0
Property damage: 15.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

National Weather Service survey team confirmed a tornado near Fombell in Beaver County that continued into Lancaster Township in Butler County in Western Pennsylvania on Jul 10, 2017. A coherent, continuous swath of damage was discovered from near Bowers Lane/North Camp Run Road in Fombell east-northeastward to near the Strawberry Ridge Golf Course in Lancaster Township. Damage was universally to trees, consisting of snapped large limbs and trunk snappage or uproots of both healthy and unhealthy trees. At its most significant, the damage exhibited a rotationally-convergent debris pattern consistent with a weak tornado as it traversed a hillside through the golf course. Observers on the golf course at the time of this storm event reported tree debris being lofted and swirled cyclonically, which was consistent with the debris pattern noted by the survey team. Although not an accepted damage indicator, corn stalks just upstream from this location also were laid over and exhibited a swirl pattern. It should be noted that no structural damage was discovered at any point through the survey path. This lack of damage to structures enables the team to cap the storm's estimated wind speed. Farther to the northeast (at least as far as Eagle Mill Road and Whitestown Road), a coherent, discontinuous damage swath was noted, but lacked sufficient conclusive evidence to identify its origin. It is entirely possible that this damage was an extension of the tornado, but the debris was too sparse for any conclusions. The survey team has concluded that a brief, weak tornado occurred from near Bowers Lane through at least the Scott Ridge Road/McNulty Lane area. The damage was consistent with a tornado of peak wind speed of 60-70 mph, which yields a rating of EF0 on the Enhanced Fujita Scale.

Thunderstorm Wind in BUTLER, PENNSYLVANIA
From 10-JUL-17 15:05:00 to 10-JUL-17 15:05:00 (EST-5)
Location: BUHLS
Magnitude: 50.00 EG
Property damage: 2.50K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reported several trees down on little creek and Hartmon Roads.

Thunderstorm Wind in BUTLER, PENNSYLVANIA
From 10-JUL-17 15:05:00 to 10-JUL-17 15:05:00 (EST-5)
Location: WHITESTOWN
Magnitude: 50.00 EG
Property damage: 2.50K
Crop damage: 0.00K
Reported by: NWS Storm Survey

National Weather Service storm survey discovered trees and limbs down along Rabbit Road.

Thunderstorm Wind in BUTLER, PENNSYLVANIA
From 10-JUL-17 15:05:00 to 10-JUL-17 15:05:00 (EST-5)
Location: MIDDLE LANCASTER
Magnitude: 50.00 EG
Property damage: 0.50K
Crop damage: 0.00K
Reported by: State Official

State official reported a tree down.

Thunderstorm Wind in BUTLER, PENNSYLVANIA
From 10-JUL-17 15:10:00 to 10-JUL-17 15:10:00 (EST-5)
Location: EVANS CITY
Magnitude: 50.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Social Media

Member of social media reported two trees down.

Thunderstorm Wind in ALLEGHENY, PENNSYLVANIA
From 10-JUL-17 15:30:00 to 10-JUL-17 15:30:00 (EST-5)
Location: CULMERVILLE ARPT
Magnitude: 50.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: NWS Employee

NWS Employee reported a 60-70 foot pine tree with a diameter of 20 feet was snapped a couple of feet off the ground.