EF2 Tornado — Minnehaha, South Dakota

2019-09-10 · near South Sioux Falls, Minnehaha, South Dakota

Event narrative

Shortly after touchdown just southeast of O'Gorman High School, the tornado struck a multi-story apartment building and removed a majority of the roof. Numerous trees were uprooted in residential areas north of 41st Street as the tornado continued in a general southeast direction. The tornado crossed 41st Street into a more commercial district, causing significant structural damage to several businesses, including the removal of the roof from one strip mall and exterior walls from another building. After another quarter mile of travel to the southeast, the tornado destroyed an apartment building garage. The tornado lifted before reaching the corner of 49th Street and Western Avenue. Average path width was 50 yards. Property damage costs are rough estimates.

Wider weather episode

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.

View location on OpenStreetMap → (43.5160, -96.7611)

Source: NOAA Storm Events Database, event_id 857478. Narrative written by the NWS forecast office that issued the report.