EF2 tornado in Lincoln County, South Dakota

A tornado touched down around one quarter mile east of the intersection of Interstates 29 and 229, near the intersection of 69th Street and Tallgrass Avenue. The tornado tracked east-northeast for a quarter mile before it struck a building under construction, causing extensive damage to concrete and metal framing, and tossed a construction truck 200 yards into a tree. The tornado then damaged the Avera Heart and Behavioral Hospital Complex, where cars were displaced up to 100 feet and most windows were broken along with roof and facade damage to the hospital buildings. Eight people were injured by flying glass on the hospital complex. The tornado lifted about 400 yards to the east of the hospital. Average path width was estimated at 40 yards. Property damage costs are rough estimates.

A frontal boundary provided focus for convective development across south central South Dakota during the very late afternoon and early evening as a strong impulse moved in the southwest flow aloft. Initial discrete cells produced spotty hail and damaging wind, with MLCAPE values around 1500-2000 J/kg and 45-55 knots of deep-layer shear. As cells spread eastward and developed into a line, the increase in low-level jet during the evening quickly increased the 0-3 km shear to 35-40 knots. Three QLCS tornadoes occurred within the city limits of Sioux Falls. In addition to the tornadoes, widespread wind damage to trees and spottier damage to residences were reported across much of the city. A total of nine people were injured in the storms around Sioux Falls. Repeated cells resulted in flash flooding by later evening and into the overnight hours.