Warm, moist advection during the morning and early afternoon hours of the 10th led to humid and very warm conditions.  Mean-layer CAPE of around 2000 J/kg, highest over eastern Ohio, illustrated the very unstable conditions.  A few discrete thunderstorm cells were able to form over southwest PA initially, with a few hail and wind damage reports.  However, the bulk of the severe weather was the result of the passage of a negatively-tilted upper trough and a strong cold front, which crossed during the late afternoon and evening hours. Bulk shear of 40 to 50 knots and the cold front allowed for the development of a quasi-linear convective system, resulting in widespread reports of wind damage.  Gusts of 70-80 MPH were estimated in some cases, leading to numerous reports of damage to trees and power lines, as well as mostly minor structural damage to roofing and shingles. Mesovortices in the QLCS also led to the development and confirmation of three tornadoes in the NWS Pittsburgh forecast area. The strongest was in Beaver County PA, with EF1 damage observed.

Thunderstorm Wind in ALLEGHENY, PENNSYLVANIA
From 10-JUN-20 20:50:00 to 10-JUN-20 20:50:00 (EST-5)
Location: THORNBURGH
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: County Official

Five large trees were uprooted.

Thunderstorm Wind in LAWRENCE, PENNSYLVANIA
From 10-JUN-20 20:45:00 to 10-JUN-20 20:45:00 (EST-5)
Location: BESSEMER GWIN ARPT
Magnitude: 50.00 EG
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Three large trees were reported to be blown down along Mt Air Road.

Thunderstorm Wind in BUTLER, PENNSYLVANIA
From 10-JUN-20 21:09:00 to 10-JUN-20 21:09:00 (EST-5)
Location: HOMEACRE
Magnitude: 50.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Public

Numerous trees were reported to be blown down on Euclid Road.

Thunderstorm Wind in LAWRENCE, PENNSYLVANIA
From 10-JUN-20 20:52:00 to 10-JUN-20 20:52:00 (EST-5)
Location: NEW CASTLE
Magnitude: 50.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Numerous trees and power lines were reported down in the area of New Castle.

Thunderstorm Wind in LAWRENCE, PENNSYLVANIA
From 10-JUN-20 20:53:00 to 10-JUN-20 20:53:00 (EST-5)
Location: WALMO
Magnitude: 50.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: 911 Call Center

A roof was blown off of a house, and trees and wires were also reported to be down.

Thunderstorm Wind in ALLEGHENY, PENNSYLVANIA
From 10-JUN-20 21:04:00 to 10-JUN-20 21:04:00 (EST-5)
Location: BRENTWOOD
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Several instances of downed trees and power lines were reported.

Thunderstorm Wind in BUTLER, PENNSYLVANIA
From 10-JUN-20 21:11:00 to 10-JUN-20 21:11:00 (EST-5)
Location: EUCLID
Magnitude: 50.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: County Official

Numerous downed and uprooted trees were reported in Clay Township.

Thunderstorm Wind in MERCER, PENNSYLVANIA
From 10-JUN-20 21:12:00 to 10-JUN-20 21:12:00 (EST-5)
Location: GROVE CITY ARPT
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Public

Trees were reported to be blown down on Old Ash Road.

Thunderstorm Wind in VENANGO, PENNSYLVANIA
From 10-JUN-20 21:27:00 to 10-JUN-20 21:27:00 (EST-5)
Location: PEARL
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Department of Highways

Several instances of downed trees and wires were noted near Grove City.

Thunderstorm Wind in GREENE, PENNSYLVANIA
From 10-JUN-20 21:32:00 to 10-JUN-20 21:32:00 (EST-5)
Location: CARMICHAELS
Magnitude: 50.00 EG
Property damage: 3.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Three large trees were reported to be blown down near County Route 1035.

Thunderstorm Wind in GREENE, PENNSYLVANIA
From 10-JUN-20 21:34:00 to 10-JUN-20 21:34:00 (EST-5)
Location: FORDYCE
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Along Dutch Run Road, large trees were reported to be downed by wind.

Thunderstorm Wind in VENANGO, PENNSYLVANIA
From 10-JUN-20 21:32:00 to 10-JUN-20 21:32:00 (EST-5)
Location: UTICA
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Large trees were downed by wind on Georgetown Road.

Thunderstorm Wind in BEAVER, PENNSYLVANIA
From 10-JUN-20 20:36:00 to 10-JUN-20 20:36:00 (EST-5)
Location: DAWSON RIDGE
Magnitude: 50.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Widespread downed trees were reported on a property on Edgewood Drive.  67 snapped trees and 12 uprooted trees were counted.

Tornado in BEAVER, PENNSYLVANIA
From 10-JUN-20 20:31:00 to 10-JUN-20 20:43:00 (EST-5)
Location: FAIRVIEW
Tornado F-scale: EF1
Crop damage: 0.00K
Reported by: NWS Storm Survey

The damage started in the vicinity of Tuscarawas road then moved northeast to where five power poles were snapped near the Shop N' Save plaza. This is where the
strongest damage was observed of the entire track, with an estimated peak wind speed of 105-110 MPH. For the remainder of the track, hardwood and softwood trees were used to estimate wind speed.
The tornado continued northeast and caused uprooted hardwood and
softwood trees through Brady's Run Park. A lull in damage was
observed given limited access around Interstate 376 south of the
Brighton exit. Damage picked up again in Daughtery township where
at least 40 to 50 hardwood trees were snapped or uprooted. One
tree that was uprooted left a six foot crater in the ground. The
last damage was recorded just northeast of Klein Road.

Thunderstorm Wind in LAWRENCE, PENNSYLVANIA
From 10-JUN-20 20:29:00 to 10-JUN-20 20:40:00 (EST-5)
Location: BESSEMER GWIN ARPT
Magnitude: 70.00 EG
Reported by: NWS Storm Survey

This path was evaluated owing to the presence of a radar-depicted
mesovortex track. Damage along this extensive track was the most
considerable examined today, with abundant tree destruction in the
form of uprooted or snapped hardwood trunks, widespread snapped
large limbs and occasional fascia and shingle damage to single-
family residences. A tree was blown onto an occupied vehicle east
of Rogers, OH early in the swath before wind speed appeared to
increase considerably. Elsewhere along the path, several
outbuildings suffered roofing damage, including a barn in Lawrence
County, where a portion of the roofing structure was removed and
transported downwind among other local damage. Damage to power
poles along the swath appears tied to trees falling on power
lines.
Damage was concentrated in several areas, including the western
and northern sections of East Palestine, the area near Howell
Road/Route 14 area and areas adjacent to the Pennsylvania Turnpike
in Little Beaver and North Beaver Townships of Lawrence County,
PA.
Ultimately this damage was deemed to be non-tornadic but of
considerable intensity. The swath generally paralleled the radar-
depicted mesovortex on its southeast flank, but featured
considerable width and a modestly divergent pattern atypical of
mesovortex tornadoes. Nevertheless, the wind speed along this
swath was of comparable intensity to many tornadoes and over a
broader area, leading to the widespread damage observed.
At its peak over this roughly 11 mile swath examined, damage was
consistent with speed up to 80 mph at times. A vast majority of
the damage examined was consistent with wind of around 70 mph.
It is entirely probable that severe wind continued northeast of
the swath evaluated today, but a coherent swath was no longer
noted, and the radar-depicted mesovortex dissipated hereafter.

Thunderstorm Wind in ARMSTRONG, PENNSYLVANIA
From 10-JUN-20 17:32:00 to 10-JUN-20 17:32:00 (EST-5)
Location: ALADDIN
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Numerous trees were reported to be blown down across the area.

Thunderstorm Wind in FAYETTE, PENNSYLVANIA
From 10-JUN-20 17:30:00 to 10-JUN-20 17:30:00 (EST-5)
Location: FAYETTE CITY
Magnitude: 50.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Multiple trees and power lines were downed across the area.

Thunderstorm Wind in WASHINGTON, PENNSYLVANIA
From 10-JUN-20 17:34:00 to 10-JUN-20 17:34:00 (EST-5)
Location: DONORA
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Siding was reported to be ripped off of a building.

Hail in WESTMORELAND, PENNSYLVANIA
From 10-JUN-20 17:34:00 to 10-JUN-20 17:34:00 (EST-5)
Location: WEBSTER
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in GREENE, PENNSYLVANIA
From 10-JUN-20 21:35:00 to 10-JUN-20 21:35:00 (EST-5)
Location: GARARDS FT
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Two large trees were downed off of Roberts Run Road.

Thunderstorm Wind in ALLEGHENY, PENNSYLVANIA
From 10-JUN-20 17:47:00 to 10-JUN-20 17:47:00 (EST-5)
Location: BLAINE HILL
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Public

It was reported that multiple trees were uprooted.

Thunderstorm Wind in ALLEGHENY, PENNSYLVANIA
From 10-JUN-20 17:48:00 to 10-JUN-20 17:48:00 (EST-5)
Location: BUENA VISTA
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Public

Several trees were reported to be blown down on Butler's Golf Course.

Thunderstorm Wind in ALLEGHENY, PENNSYLVANIA
From 10-JUN-20 17:49:00 to 10-JUN-20 17:49:00 (EST-5)
Location: BOSTON
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Public

Numerous trees were blown down in the area around Osceola Drive.

Thunderstorm Wind in BEAVER, PENNSYLVANIA
From 10-JUN-20 20:34:00 to 10-JUN-20 20:34:00 (EST-5)
Location: DAWSON RIDGE
Magnitude: 50.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: State Official

Multiple trees and power lines were downed, and transformers were damaged, across the county.