Thunderstorm Wind in Sanborn County, South Dakota

Numerous tree and limb damage was reported across Woonsocket. An empty grain bin had the sides blown in and an empty grain truck was blown over. Significant damage was done to several businesses in town with severe wall and/or roof damage to numerous buildings. A survey of direction and extent of damage from drone footage revealed this was the result of severe downburst winds.

In response to a subtle short-wave aloft, a cluster of thunderstorms moved along the North Dakota-South Dakota border during the early morning hours of July 20, and then slowly expanded to the south as it pushed east. By early afternoon, northern portions of the cluster weakened, while southern portions intensified as it encountered an environment of higher instability and shear. Damaging wind gusts developed across Jerauld and Sanborn Counties with estimated wind gusts up to 90 mph. The town of Woonsocket, South Dakota was particularity hard hit, with significant tree and structural damage across the city. A National Weather Service survey of drone images determined the damage to be a result of severe downburst winds.