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Tuesday’s storm qualified as a derecho — what does that mean?
‘Not all derechos are created equal,’ says meteorologist

Jul. 6, 2022 6:42 pm, Updated: Jul. 7, 2022 11:28 am
The storm complex that trudged through South Dakota, Iowa and parts of Minnesota and Illinois on Tuesday met all the criteria for a derecho — but its treacherous journey fell far short of the devastation that unfolded during the infamous 2020 natural disaster.
That’s because “not all derechos are created equal,” said Rich Kinney, a warning coordination meteorologist for the National Weather Service bureau in the Quad Cities.
“Obviously, folks in the Cedar Rapids area are going to be very sensitive when they hear the word ‘derecho’ because of August 2020,” he said. “But this, for us, was actually on the lower end of the intensity scale.”
In a broad sense, a derecho is a widespread, long-lived, straight-line windstorm that brings a band of rapidly moving rain showers or thunderstorms. Although derecho season peaks in the hot and humid summers, derechos can also form under cooler conditions — like one that hit Iowa on Dec. 15, 2021.
Specific criteria for defining a derecho according to its path length and width varies per agency, Kinney said.
The National Weather Service follows the Storm Prediction Center’s guidelines: Gusts must blow at least 58 mph for most of the storm’s path, which must persist continuously or intermittently for at least 400 miles in length and stretch at least 60 miles wide.
“That's what distinguishes a derecho from just a normal, shorter-lived, less-impactful line of thunderstorms, which are pretty common,” Kinney said. “The derecho is at the extreme end of those lines of storms.”
He confirmed that the storm Tuesday met the Storm Prediction Center’s criteria for a derecho. From its start around the edge of South Dakota to its end in Illinois, the complex’s path amounted to about 800 miles in length. At 5 p.m. Tuesday — hours before the weather hit Cedar Rapids around 9 p.m. — the Storm Prediction Center officially labeled it a derecho in a tweet.
According to the National Weather Service, the strongest reported winds in Eastern Iowa were recorded at 60 to 70 mph, which brought down some trees, tree limbs and power lines.
The city of Cedar Rapids issued a media release Thursday that said residents can report trees blocking streets and driveways.
Removal of fallen trees and tree limbs on private property would be left up to the owners, with qualifying debris available for curbside pickup or accepted at the Cedar Rapids/Linn County Solid Waste Agency’s A Street location.
For debris larger than 5 inches in diameter, residents can request assistance help from the city, but crews cannot enter private property to retrieve tree debris.
Kinney said derechos should always be taken seriously regardless of their severity.
“We were fortunate that we didn't get some of the winds that were more 90 to 100 miles an hour yesterday,” he said.
Comments: (319) 398-8370; brittney.miller@thegazette.com
A wave of storm clouds swoops over downtown Cedar Rapids Tuesday night. (Brittney J. Miller/The Gazette)