A slow moving frontal boundary crept southeastward through the mid-Atlantic during the day on August 12. A hot and humid air mass was in place along and ahead of the front, contributing to the development of strong instability. Lift associated with the front helped trigger convective development as early as near noontime in the unstable air mass. This event was notable for having almost zero wind shear present. Consequently, storms showed little organization, but the strong instability created an environment favorable for downbursts, with several thunderstorms producing pockets of wind damage.

Thunderstorm Wind in MONTGOMERY, PENNSYLVANIA
From 12-AUG-20 13:10:00 to 12-AUG-20 13:10:00 (EST-5)
Location: NORTH HILLS
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Wind gusts were estimated to 60 mph with multiple downed trees and limbs. Power lines were also downed with several traffic lights out. Time estimated from radar.

Thunderstorm Wind in CHESTER, PENNSYLVANIA
From 12-AUG-20 13:30:00 to 12-AUG-20 13:30:00 (EST-5)
Location: DOWNINGTOWN
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Trees and wires were downed near Country Club Dr at E Lancaster Ave near the Downingtown Country Club. Time estimated from radar.

Thunderstorm Wind in CHESTER, PENNSYLVANIA
From 12-AUG-20 13:31:00 to 12-AUG-20 13:31:00 (EST-5)
Location: WHITFORD
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

A downed tree partially blocked Boot Rd near Circle Dr. Time estimated from radar.

Thunderstorm Wind in CHESTER, PENNSYLVANIA
From 12-AUG-20 13:38:00 to 12-AUG-20 13:38:00 (EST-5)
Location: ROCK RUN
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Multiple reports of downed trees on and near Route 30 near Kings Hwy. Time estimated from radar.

Thunderstorm Wind in CHESTER, PENNSYLVANIA
From 12-AUG-20 14:33:00 to 12-AUG-20 14:33:00 (EST-5)
Location: TOUGHKENAMON
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Downed trees and wires blocked Church Rd at Polo Rd near Loch Nairn Golf Links. Time estimated from radar.

Thunderstorm Wind in CHESTER, PENNSYLVANIA
From 12-AUG-20 12:54:00 to 12-AUG-20 12:54:00 (EST-5)
Location: ROCKY HILL
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: County Official

Large tree limbs were downed on Dutton Mill Rd near Cratin Ln. Time estimated from radar.

Thunderstorm Wind in CHESTER, PENNSYLVANIA
From 12-AUG-20 13:38:00 to 12-AUG-20 13:38:00 (EST-5)
Location: DOWNINGTOWN MEML ARP
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Trees were downed onto wires on Bondsville Rd at E Fisherville Rd. Bondsville Rd was closed due to downed trees and was also flooded. Time estimated from radar.

Thunderstorm Wind in CHESTER, PENNSYLVANIA
From 12-AUG-20 13:54:00 to 12-AUG-20 13:54:00 (EST-5)
Location: EMBREEVILLE
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

A tree was downed into wires near the intersection of Brandywine Creek Rd and Green Valley Rd. Time estimated from radar.

Thunderstorm Wind in CHESTER, PENNSYLVANIA
From 12-AUG-20 14:24:00 to 12-AUG-20 14:24:00 (EST-5)
Location: TOUGHKENAMON
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

A tree was downed into wires near Church Rd and Third St. Time estimated from radar.

Thunderstorm Wind in CHESTER, PENNSYLVANIA
From 12-AUG-20 14:29:00 to 12-AUG-20 14:29:00 (EST-5)
Location: AVONDALE
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

A downed tree blocked Baltimore Pike. Time estimated from radar.