Thunderstorm Wind in Ziebach County, South Dakota

Roof partially blown off of a barn at the Dupree Rodeo Arena. Tree branches and a few power poles were downed in the area.

Supercell thunderstorms developed over southeast Montana and merged into a line of severe thunderstorms as the moved across far southeast Montana and into northwest South Dakota. The storms produced widespread wind gusts of 50 to over 80 mph, with some areas within the line producing wind gusts of 80 to over 100 mph. Considerable damage was noted with the stronger wind gusts across portions of northwest South Dakota, especially southern Harding, northern Butte, northern and eastern Meade, and Haakon counties. The line of storms was classified as a derecho event as it tracked more than 250 miles across the region from southeast Montana to central South Dakota.