(Radio Iowa) – A powerful series of storms swept over Iowa, Illinois, Indiana and Michigan late Monday afternoon and night, spinning off at least one tornado in Iowa and knocking out the power to nearly a half-million Midwesterners. The Weather Channel and several news outlets are calling the storms a derecho, but meteorologist Brooke Hagenhof, at the National Weather Service office in Johnston, says still it’s too early to say that. “The official determination for a derecho is made by the Storm Prediction Center, their national center down in Norman, Oklahoma,” Hagenhoff says. “Derechos have a very strict definition as far as how long they are and how wide that swath of wind damage is, so they will be going through the data today and determining whether this fits that description.”

A derecho, also called a land hurricane, is defined as a widespread, long-lived, straight-line wind storm that is associated with a fast-moving group of severe thunderstorms. This storm system appears to fit that definition, bringing exceptionally powerful winds to many areas of Iowa, including a report of 102-mile an hour gusts near New Vienna in Dubuque County. There are dozens of damage reports from central into eastern Iowa of toppled trees, downed power lines, and structural damage to homes, businesses and other buildings. The one confirmed tornado touched down in metro Des Moines.

“We did have the area that moved across portions of the metro from Urbandale into the Windsor Heights area across the Des Moines metro,” Hagenhoff says. “We’re also investigating some damage near Eldora, as well as a swath of wind gusts that went from near Pella towards Montezuma and just north of Oskaloosa.” A national report says the power was cut to more than 460-thousand customers in the region, including parts of Chicago. Iowa-based MidAmerican Energy reported 40-thousand customers without power at 11 last night, mostly in the Des Moines, Iowa City and Davenport areas.

80,000-bushel grain bin toppled in Luxemburg (Photo by Luxemburg Fire Dep’t)

A Des Moines T-V station reports the electricity may not be restored to all Urbandale residents until late tonight or early tomorrow. Many counties in northeast Iowa reported large hail, Benton County reported two-and-a-half inches of rainfall, and there was scattered flash flooding, including Highway 61 being underwater near Zwingle. Hagenhoff says the weather service is dispatching survey teams to several Iowa locations where the damage is concentrated. “We’re going to be working today to determine which of those were due to tornado damage and which was straight line winds with this complex of storms that moved across the state,” she says.

There are no serious injuries reported in Iowa, though one death is attributed to the storm. Reports say a woman in Indiana was killed when a tree fell on her home. The derecho that hit Iowa in August of 2020 had winds that peaked in the Cedar Rapids area around 140 miles an hour. The storm destroyed more than seven-million Iowa trees and caused some 11-billion dollars damage.