Lyon County, Iowa — It has now been confirmed that during the midst of Monday’s (7/28/2025) derecho in northwest Iowa — which is a line of severe thunderstorms producing strong straight-line winds — two tornadoes were kicked up in Lyon County.
Meteorologist Jeff Chapman with the National Weather Service’s Sioux Falls office tells us that about 9:30 p.m. on Monday night, an EF1 tornado struck the area about two miles east of Alvord. He says it was rated an EF1 for some damage that it had done to some farm out buildings along its track. They estimated it had winds of 110 miles per hour.
The second tornado, just a short distance away, didn’t get a rating — or you could say it got a rating of “EFU” says Chapman — the “U” standing for “unknown. He says they couldn’t give it an EF rating because, other than the track that it left in a cornfield, it did not impact any other objects in order to be able to get an actual rating.
There was a tornado warning issued for Lyon County for the EF1 tornado at 9:30 p.m. on Monday.
KIWA Staff Photo
