The National Weather Service in Sioux Falls has confirmed a tornado in Lyon County, Iowa, that occurred during Monday's ...

While two derechos in less than two months is extremely unusual for South Dakota, experts say it's just that — a fluke.

Severe storms overnight in Iowa caused fallen trees and downed power lines. See storm damage reports from across the state.

Parts of Lincoln County were not as lucky as Sioux Falls, including what the Lincoln County Sheriff's Office called ...

Monday’s storm system produced two tornadoes in Gregory County and a third near Alvord, Iowa, in Lyon County, the National ...

The thunderstorm risk level went from enhanced to moderate for the area, with timing now pushed back to between 5 p.m. and 1 ...

The National Weather Service in Sioux Falls has confirmed a tornado in Lyon County, Iowa, that occurred during Monday's derecho event.

A dangerous derecho is expected to form in parts of the Northern Plains and Upper Midwest on Monday, with wind gusts over 75 ...

To be called a derecho, the thunderstorm-generated high winds and wind damage should cover a distance of at least 250 miles ...

Jeff Chapman, a meteorologist with the National Weather Service in Sioux Falls, said thunderstorms and strong winds between ...

Potent storms were hitting the northern U.S. on Monday, with a potential to turn into a derecho with hurricane-force winds.