Thunderstorm Wind in Franklin County, Pennsylvania

A severe thunderstorm, producing estimated wind gusts near 70 mph, knocked down multiple trees near Rutledge Road in Mercersburg. This severe thunderstorm also produced damage to powerlines throughout Mercersburg.

Ample instability and modest shear ahead of an approaching cold front allowed for scattered convection to occur across the northern half of Pennsylvania during the early afternoon hours, producing isolated instances of tree and wire damage mainly along the Interstate 80 corridor of central Pennsylvania. Later in the evening hours, enhanced destabilization across the southern tier of Pennsylvania ahead of an approaching mesoscale convective system allowed for a long-track thunderstorm to traverse across the area, with widespread damage observed in a corridor of downdraft CAPE values approaching 1000 J/kg from Somerset County through Adams County, with sunset allowing for less destabilization further east. The most widespread damage was observed in Elk Lick Township and Addison Township in Somerset County, where straight-line wind damage brought down numerous trees and wires, with two people injured when their ATV collided with a large downed tree. Extensive damage was also observed in Salisbury (Somerset County) where a silo collapsed into a barn, completely destroying the barn.