Thunderstorm Wind in Sioux County, North Dakota

Thunderstorm wind gusts were estimated by a trained spotter.

Thunderstorms developed over southwest into south central North Dakota in an environment of very strong instability and elevated deep layer shear. The atmosphere remained capped until early in the evening when rapid thunderstorm development occurred. The initial severe storm produced a tornado near Selfridge in Sioux County, which broke power poles. Based on the damage done this this tornado was rated EF-1. Additional storms developed ahead of a frontal boundary, producing large hail and damaging winds. One storm over southern Morton County south of St. Anthony produced a four-inch diameter hailstone. In the town of St. Anthony, wind driven hail produced extensive damage to structures, with the siding shredded on some homes. Later in the evening, a storm passed over and to the south of Sterling in Burleigh County, producing 100 mph straight line winds which dislodged a large grain bin, broke or severely damaged 15 power poles, and significantly damaged a large sunflower field. The storm then moved towards Steele in Kidder County where it produced a tornado just to the east of town. The tornado crossed the path of a stopped train and knocked about 40 railroad cars off the tracks. An oats field was destroyed and several hardwood trees were snapped. This tornado was rated EF-1. Additional storms then continued through the evening producing hail over south central and parts of north central North Dakota before moving to the east and dissipating. Along with the severe weather, three male teenagers were struck by lighting to the north of Sterling in Burleigh County while returning to their vehicle after goose hunting. All three were injured and required medical attention at a hospital emergency room, but were able to quickly recover from their injuries.