Possible tornado devastates town as wind damages communities across eastern South Dakota

CASTLEWOOD, S.D. — The National Weather Service has sent teams to investigate storm damage from high winds here and to determine if a tornado was to blame for damage to the school, destruction of several homes, downed power lines and extensive tree damage.

The damaging winds in Castlewood, a farming town south of Watertown, were part of a wave of storms that swept eastern South Dakota and continued into Minnesota Thursday night, May 12.

The National Oceanic and Atmospheric Administration said the damage was caused by a derecho — a widespread, long-lasting wind storm — that swept across the northern Great Plains and Upper Midwest, and showed satellite imagery of the storm raking the region.

The winds that caused severe damage in Castlewood — Gov. Kristi Noem’s hometown — were “more than likely a tornado,” but three survey teams are on the ground assessing damage here and in other towns in northeastern South Dakota, including Watertown, said Kari Sleegel, a weather service meteorologist in Aberdeen.

The teams are taking photographs that will be analyzed to determine whether the damage was caused by a tornado, and, if so, to assess the strength of the tornado. Eyewitnesses described seeing a tornado, and video from a drone showed a swath of damage, Sleegel said.

Hail damage did not appear to be widespread, but there were reports of one-inch hail in Faulkton in northeast South Dakota, she said.

The highest recorded wind speed in South Dakota was 107 mph in Tripp, south of Mitchell, with a gust of 102 mph reported in Gary, about 45 miles southeast of Watertown, and 97 mph near Madison, according to the National Weather Service.

Multiple semi-trucks were blown over on Interstate 90 between Mitchell and the Minnesota border, and trucks also were toppled on Interstate 29 in southeastern South Dakota.

All of eastern South Dakota, from Chamberlain on the eastern bank of the Missouri River to the east, appeared to sustain high winds from the Thursday storms, said Philip Schumacher, a weather service meteorologist in Sioux Falls.

“We believe it’s all been straight-line winds in southeast South Dakota,” he said. “There’s been quite a bit of damage. We’re still assessing it.”

In Sioux Falls, “There was quite a bit of damage,” he said, including tree damage and roof damage.