A warm front was draped across northern Pennsylvania and far northern New Jersey on July 12. South of the front, a very warm and unstable air mass was present. An approaching trough also helped spur the development of a weak wave of low pressure, which tracked along the front during the afternoon and evening hours. This helped add some forcing and shear to an already unstable air mass. The result was scattered to widespread thunderstorm development along and south of the front during the peak heating hours. Some of the storms became severe, with a number of instances of damaging wind across the region. This event was also better known for producing prolific flash flooding near the Delaware River just northeast of Philadelphia, along the Pennsylvania and New Jersey border. Storm coverage gradually decreased in the evening hours as heating and forcing were lost.

Thunderstorm Wind in BUCKS, PENNSYLVANIA
From 12-JUL-21 15:57:00 to 12-JUL-21 15:57:00 (EST-5)
Location: LANGHORNE
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Utility Company

A few reports of downed wires west of Levittown. Time estimated from radar.

Thunderstorm Wind in BUCKS, PENNSYLVANIA
From 12-JUL-21 16:08:00 to 12-JUL-21 16:08:00 (EST-5)
Location: LEVITTOWN
Magnitude: 55.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Utility Company

Wires were downed in several locations near Levittown. Time estimated from radar.

Thunderstorm Wind in BUCKS, PENNSYLVANIA
From 12-JUL-21 16:11:00 to 12-JUL-21 16:11:00 (EST-5)
Location: FAIRLESS HILLS
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Utility Company

Multiple reports of downed trees and wires in Fairless Hills, especially near Beaumont Rd. Time estimated from radar.

Thunderstorm Wind in BUCKS, PENNSYLVANIA
From 12-JUL-21 16:11:00 to 12-JUL-21 16:11:00 (EST-5)
Location: CROYDEN
Magnitude: 55.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Utility Company

Several reports of downed power lines in the Croydon and Bristol areas. Time estimated from radar.

Thunderstorm Wind in BUCKS, PENNSYLVANIA
From 12-JUL-21 16:11:00 to 12-JUL-21 16:11:00 (EST-5)
Location: MORRISVILLE
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Utility Company

Tree limbs and wires were downed near Bridge St. Time estimated from radar.

Thunderstorm Wind in BUCKS, PENNSYLVANIA
From 12-JUL-21 16:24:00 to 12-JUL-21 16:24:00 (EST-5)
Location: CORNWELLS HGTS
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Utility Company

Power lines were downed near State Rd. Time estimated from radar.

Thunderstorm Wind in PHILADELPHIA, PENNSYLVANIA
From 12-JUL-21 16:32:00 to 12-JUL-21 16:32:00 (EST-5)
Location: CRESCENTVILLE
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Utility Company

Wires were downed near Glendale St and Bristol St. Time estimated from radar.

Thunderstorm Wind in PHILADELPHIA, PENNSYLVANIA
From 12-JUL-21 16:09:00 to 12-JUL-21 16:09:00 (EST-5)
Location: TACONY
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Utility Company

Wires were downed near Frankford Ave. Time estimated from radar.

Thunderstorm Wind in PHILADELPHIA, PENNSYLVANIA
From 12-JUL-21 16:21:00 to 12-JUL-21 16:21:00 (EST-5)
Location: CRESCENTVILLE
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Utility Company

Wires were downed near Rosehill St. Time estimated from radar.

Thunderstorm Wind in PHILADELPHIA, PENNSYLVANIA
From 12-JUL-21 16:10:00 to 12-JUL-21 16:10:00 (EST-5)
Location: BYBERRY
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

A tree was downed on US-1 near Southampton Rd. Time estimated from radar.