EF1 tornado in Lincoln County, South Dakota

Storm chaser video revealed a very brief tornado that moved southeast to northwest as it rotated around a much larger mesocyclone. The tornado tracked across Mount Hope Dairy, destroying one barn and damaging another before quickly lifting. Debris from the barns was scattered north of 290th Street in a southwest to northeast orientation. The tornado was rated EF1 with an estimated peak wind of 90 mph and an estimated average path width of 40 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.