Thunderstorm Wind in Carroll County, Maryland

Thousands of trees, branches and wires blew down near Union Mills. Numerous trees blew down along MD-97 Littlestown Pike, including several large trees near Mayberry Road. Dozens of roads in the area were blocked by storm debris for several days. Several barns were destroyed. Several homes suffered minor roof, shingle and siding damage.

A strong cold front, driven by an unusually strong upper-level trough and wind shear, interacted with a hot, humid, and unstable airmass over the Mid-Atlantic. This pattern resulted in the formation of lines of thunderstorms and several supercells. The most widespread and significant wind damage was noted over northern Maryland, although pockets of considerable wind damage were noted over portions of northwestern Virginia and eastern West Virginia. Somewhat atypical for the Mid-Atlantic is late summer was the number of large hail reports, with multiple instances of giant hail noted.