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Tuesday’s storm in Iowa shows not all derechos are created equal

2022 Iowa Derecho NWS Map
Tuesday's derecho storm system made its way from South Dakota through Iowa, terminating in Indiana.
National Weather Service of the Quad Cities
A derecho storm system made its way from South Dakota through Iowa, terminating in Indiana. This map was prepared by the National Weather Service of the Quad Cities and issued the afternoon of Tuesday, July 5.

This week's storm that blew through the state caused minor damage, reaching speeds of 60 to 70 miles per hour. Meteorologists said these large lateral storms "aren't that uncommon" in the Midwest.

Tuesday morning, the mayor of Cedar Rapids got word from Linn County Emergency Management. There was a storm brewing in South Dakota. The winds were strong and became rooted in the hot and humid air over the Great Plains region. It all but echoed a nightmare from 2020: the derecho.

Derechos are lines of thunderstorms spanning over 400 miles in length and 60 miles wide with winds of at least 60 miles per hour.

It was one of these strong lateral traveling systems that caused an estimated $11 billion in damages, toppled millions of trees and caused widespread power outages in August 2020. One of the hardest-hit areas was Cedar Rapids, which lost 65 percent of its tree canopy and left many residents without power for weeks.

Cedar Rapids Mayor Tiffany O’Donnell said the storm has changed the way she reacts to threatening weather.

“I think for those of us who grew up in Iowa, severe storms are really nothing new but those of us who lived through that derecho, we do… it gives us pause,” O’Donnell said. Everyone was noticeably—certainly at the city—on edge.”

While Tuesday’s storm system reached speeds of 100 mph in South Dakota, Iowa experienced winds of "just" 70 to 60 miles per hour – a far cry from 2020’s derecho that clocked a peak of 140 mph. There were reports of crop damage and power outages from Cedar Rapids to the Quad-Cities.

Peter Speck, a meteorologist at the National Weather Service in the Quad-Cities, told IPR News that while both storms fit the bill, derechos vary.

“Derechos aren't that uncommon across the Plains and Midwest. Though the magnitude of those has not really reached what we saw in Cedar Rapids in 2020, not all derechos are created equal,” Speck said. “It highly depends on the environments they’re going into.”

Zachary Oren Smith is a reporter covering Eastern Iowa