The thunderstorms on July 28 produced two damage-causing tornadoes in South Dakota, and a third in Iowa, according to the ...

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

The second tornado of the evening, rated EF-1, spawned approximately one mile east of Alvord, Iowa, or 11 miles northeast of Inwood. The tornado was not witnessed by storm chasers or law enforcement, ...