EF0 tornado in McCook County, South Dakota

A storm chaser witnessed a tornado develop around 2 miles northeast of Bridgewater. The tornado formed one-half mile south of 263rd Street just west of 437th Avenue. The tornado tracked northeast across open fields for around 3 minutes before it crossed 263rd Street around one-third mile west of 438th Avenue where metal roof panels were ripped off a barn. The tornado continued northeast for a couple more minutes before lifting just west of 438th Avenue. The tornado was rated EF0 with an estimated peak wind of 70 mph and an average estimated path width of 50 yards.

A trough lifted through the western High Plains as a weak convergence boundary drifted eastward into southeast South Dakota during the late afternoon. Near the boundary, a diurnally destabilized air mass focused convective development in a fairly weak shear environment across the lower James River Valley. Thunderstorms largely produced large hail up to ping-pong ball size during periods of stronger updrafts within the storm clusters. Shear concentrated in lower levels and storm interactions combined to produce several brief tornadoes in southeast South Dakota. Slow moving storms also produced spotty heavy rainfall, some of which that fell on areas that received heavy rainfall west of Sioux Falls in the previous night.