The passage of a warm front during the morning of July 20th provided a moist and unstable air mass.  A strong, progressive upper trough tracked southeastward from the Great Lakes, with an associated cold front crossing during the evening hours. Mixed-layer CAPE of up to 2500 J/kg, strong deep shear, and steep low and mid-level lapse rates were supportive of severe weather.  Widespread reports of wind damage were received, mainly to trees.  Some isolated urban flash flooding also occurred in Beaver and Allegheny Counties.

Flash Flood in MERCER, PENNSYLVANIA
From 20-JUL-23 20:10:00 to 20-JUL-23 22:15:00 (EST-5)
Location: HENLEIN
Flood cause: Heavy Rain
Property damage: 5.00K
Crop damage: 0.00K
Reported by: State Official

Water was reported to have entered a basement in Greenville.

Thunderstorm Wind in BEAVER, PENNSYLVANIA
From 20-JUL-23 20:32:00 to 20-JUL-23 20:32:00 (EST-5)
Location: WEST ALIQUIPPA
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: 911 Call Center

A few trees were reported to be down near Aliquippa.

Thunderstorm Wind in JEFFERSON, PENNSYLVANIA
From 20-JUL-23 20:33:00 to 20-JUL-23 20:33:00 (EST-5)
Location: BROCKWAY
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: State Official

Multiple trees were reported to be downed on Clay Plant Road, just outside the town of Brockway.

Thunderstorm Wind in BEAVER, PENNSYLVANIA
From 20-JUL-23 20:34:00 to 20-JUL-23 20:34:00 (EST-5)
Location: AMBRIDGE
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: State Official

Trees were reported to be down in the area of Ambridge.

Flash Flood in BEAVER, PENNSYLVANIA
From 20-JUL-23 21:15:00 to 21-JUL-23 00:30:00 (EST-5)
Location: SOUTH HGTS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

State Route 51 in South Heights was closed due to flooding.

Thunderstorm Wind in WESTMORELAND, PENNSYLVANIA
From 20-JUL-23 21:22:00 to 20-JUL-23 21:22:00 (EST-5)
Location: TRAFFORD
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Multiple trees were reported down along State Route 933 between Trafford and North Huntingdon Township.

Flash Flood in ALLEGHENY, PENNSYLVANIA
From 20-JUL-23 21:37:00 to 21-JUL-23 00:30:00 (EST-5)
Location: SHARPSBURG
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

The Washington Boulevard/Butler Street area near the Pittsburgh Zoo was reported to be flooded.

Thunderstorm Wind in WASHINGTON, PENNSYLVANIA
From 20-JUL-23 21:45:00 to 20-JUL-23 21:45:00 (EST-5)
Location: COURTNEY
Magnitude: 50.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Power lines were reported to be down in the area.

Flash Flood in BEAVER, PENNSYLVANIA
From 20-JUL-23 21:46:00 to 21-JUL-23 00:30:00 (EST-5)
Location: STOBO
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A foot and a half of water was reported to be on northbound State Route 51, just before Monaca Road.

Flash Flood in ALLEGHENY, PENNSYLVANIA
From 20-JUL-23 21:52:00 to 21-JUL-23 00:30:00 (EST-5)
Location: LONGVIEW
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

A road closure due to flooding occurred at the intersection of Grove Road and Village Lane.

Flash Flood in ALLEGHENY, PENNSYLVANIA
From 20-JUL-23 21:58:00 to 21-JUL-23 00:30:00 (EST-5)
Location: (AGC)ALLEGHENY CO AR
Flood cause: Heavy Rain
Property damage: 5.00K
Crop damage: 0.00K
Reported by: 911 Call Center

A flooded roadway in the area was reported to have several disabled vehicles on it, but no water rescues occurred.

Flash Flood in ALLEGHENY, PENNSYLVANIA
From 20-JUL-23 21:59:00 to 21-JUL-23 00:30:00 (EST-5)
Location: LIBERTY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

The eastbound Mansfield Bridge ramp was closed due to flooding.

Flash Flood in ALLEGHENY, PENNSYLVANIA
From 20-JUL-23 22:00:00 to 21-JUL-23 00:30:00 (EST-5)
Location: INGRAM
Flood cause: Heavy Rain
Property damage: 2.00K
Crop damage: 0.00K
Reported by: State Official

A vehicle was reported to be stuck in flood waters.

Flash Flood in ALLEGHENY, PENNSYLVANIA
From 20-JUL-23 22:01:00 to 21-JUL-23 00:30:00 (EST-5)
Location: PLEASANT HILLS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: State Official

The intersection of Clairton Boulevard and North Lewis Run Road was flooded.

Flash Flood in ALLEGHENY, PENNSYLVANIA
From 20-JUL-23 22:07:00 to 21-JUL-23 00:30:00 (EST-5)
Location: RIVERTON
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: State Official

Five vehicles were reported to be stuck in flood water on the ramp to the McKeesport-Duquesne Bridge, necessitating the activation of a swift water rescue team.

Thunderstorm Wind in JEFFERSON, PENNSYLVANIA
From 20-JUL-23 20:33:00 to 20-JUL-23 20:33:00 (EST-5)
Location: BROCKWAY
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: State Official

Multiple trees were downed on Clay Plant Road.

Thunderstorm Wind in MERCER, PENNSYLVANIA
From 20-JUL-23 18:33:00 to 20-JUL-23 18:33:00 (EST-5)
Location: SANDY LAKE
Magnitude: 50.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Trees were reported to be down in and around Sandy Lake.

Thunderstorm Wind in MERCER, PENNSYLVANIA
From 20-JUL-23 18:42:00 to 20-JUL-23 18:42:00 (EST-5)
Location: MAYSVILLE
Magnitude: 50.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Trees were blown down in and around West Salem Township.

Thunderstorm Wind in MERCER, PENNSYLVANIA
From 20-JUL-23 18:48:00 to 20-JUL-23 18:48:00 (EST-5)
Location: FARRELL
Magnitude: 50.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Trees were reported to be downed in and around Sharon.

Thunderstorm Wind in VENANGO, PENNSYLVANIA
From 20-JUL-23 18:51:00 to 20-JUL-23 18:51:00 (EST-5)
Location: OIL CITY
Magnitude: 50.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Public

Trees and wires were blown down.

Thunderstorm Wind in VENANGO, PENNSYLVANIA
From 20-JUL-23 18:53:00 to 20-JUL-23 18:53:00 (EST-5)
Location: BULLY HILL
Magnitude: 50.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Public

A tree was reported to be down.

Thunderstorm Wind in VENANGO, PENNSYLVANIA
From 20-JUL-23 18:57:00 to 20-JUL-23 18:57:00 (EST-5)
Location: CRANBERRY
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Public

Trees were reported down on Route 322.

Thunderstorm Wind in FOREST, PENNSYLVANIA
From 20-JUL-23 19:04:00 to 20-JUL-23 19:04:00 (EST-5)
Location: LYNCH
Magnitude: 50.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Public

In Jenks Township, a tree was reported down on Job Corps Road.

Thunderstorm Wind in MERCER, PENNSYLVANIA
From 20-JUL-23 19:18:00 to 20-JUL-23 19:18:00 (EST-5)
Location: GROVE CITY
Magnitude: 50.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: State Official

Numerous trees and power lines were reported to be blown down around Grove City.

Thunderstorm Wind in CLARION, PENNSYLVANIA
From 20-JUL-23 19:18:00 to 20-JUL-23 19:18:00 (EST-5)
Location: KNOX
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Public

A tree was blown down, blocking the westbound lane near Country Farm Supply.

Thunderstorm Wind in MERCER, PENNSYLVANIA
From 20-JUL-23 19:19:00 to 20-JUL-23 19:19:00 (EST-5)
Location: GROVE CITY
Magnitude: 50.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Numerous trees and power lines were downed in Pine Township.

Thunderstorm Wind in FOREST, PENNSYLVANIA
From 20-JUL-23 19:20:00 to 20-JUL-23 19:20:00 (EST-5)
Location: REDCLYTTE
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Public

On Greenwood Road, a tree was downed.

Thunderstorm Wind in CLARION, PENNSYLVANIA
From 20-JUL-23 19:22:00 to 20-JUL-23 19:22:00 (EST-5)
Location: CLARION
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Public

A tree was downed on to Route 68.

Thunderstorm Wind in MERCER, PENNSYLVANIA
From 20-JUL-23 19:22:00 to 20-JUL-23 19:22:00 (EST-5)
Location: GROVE CITY
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: 911 Call Center

A tree reportedly fell onto a vehicle, with the occupant suffering a minor injury.

Thunderstorm Wind in BUTLER, PENNSYLVANIA
From 20-JUL-23 19:22:00 to 20-JUL-23 19:22:00 (EST-5)
Location: HARRISVILLE
Magnitude: 50.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Multiple trees and power lines were reported down in the area.

Thunderstorm Wind in CLARION, PENNSYLVANIA
From 20-JUL-23 19:23:00 to 20-JUL-23 19:23:00 (EST-5)
Location: KNOX
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Public

Trees were blown down near Knox.

Thunderstorm Wind in CLARION, PENNSYLVANIA
From 20-JUL-23 19:24:00 to 20-JUL-23 19:24:00 (EST-5)
Location: CLARION PARKER ARPT
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Public

Trees were reported to be blown down in the area.

Thunderstorm Wind in CLARION, PENNSYLVANIA
From 20-JUL-23 19:24:00 to 20-JUL-23 19:24:00 (EST-5)
Location: CLARION PARKER ARPT
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Public

A tree was reported down near Route 322.

Thunderstorm Wind in BUTLER, PENNSYLVANIA
From 20-JUL-23 19:24:00 to 20-JUL-23 19:24:00 (EST-5)
Location: SLIPPERY ROCK
Magnitude: 50.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Multiple trees and power lines were reported down in the area.

Thunderstorm Wind in JEFFERSON, PENNSYLVANIA
From 20-JUL-23 19:32:00 to 20-JUL-23 19:32:00 (EST-5)
Location: SIGEL
Magnitude: 50.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Trees and power lines were reported down in the area.

Thunderstorm Wind in BUTLER, PENNSYLVANIA
From 20-JUL-23 19:32:00 to 20-JUL-23 19:32:00 (EST-5)
Location: BOYERS
Magnitude: 50.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Trees were reported down in the area.

Thunderstorm Wind in JEFFERSON, PENNSYLVANIA
From 20-JUL-23 19:36:00 to 20-JUL-23 19:36:00 (EST-5)
Location: BROOKVILLE
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: NWS Employee

Several trees on Main Street were blown down.

Thunderstorm Wind in JEFFERSON, PENNSYLVANIA
From 20-JUL-23 19:40:00 to 20-JUL-23 19:40:00 (EST-5)
Location: WARSAW
Magnitude: 50.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Trees and power lines were reported to be down in the area.

Thunderstorm Wind in JEFFERSON, PENNSYLVANIA
From 20-JUL-23 19:44:00 to 20-JUL-23 19:44:00 (EST-5)
Location: BROCKWAY
Magnitude: 50.00 EG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: State Official

In Brockway, trees and power lines were reported to be down.

Thunderstorm Wind in BUTLER, PENNSYLVANIA
From 20-JUL-23 19:48:00 to 20-JUL-23 19:48:00 (EST-5)
Location: MUDDY CREEK
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Trained Spotter

On the southbound lane of Route 8, a tree was reported to be down.

Thunderstorm Wind in BEAVER, PENNSYLVANIA
From 20-JUL-23 19:54:00 to 20-JUL-23 19:54:00 (EST-5)
Location: FOMBELL
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Trees were reported to be down in Franklin Township.

Hail in ARMSTRONG, PENNSYLVANIA
From 20-JUL-23 20:06:00 to 20-JUL-23 20:06:00 (EST-5)
Location: ATWOOD
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public