An intense line of storms known as a derecho developed over the central United States late Monday morning, causing significant damage and widespread power outages as it blitzed eastward.
Thunderstorms ignited in southeastern South Dakota and eastern Nebraska on Monday morning, but gained strength and evolved into a derecho across central Iowa by midday. The worst of the storms focused on a zone from around Des Moines through Davenport, Iowa.
Large trees, branches, debris and power lines littered streets and yards all across Iowa with many residents finding themselves in the dark in the wake of the storms.
Strong winds in Clive, Iowa, ripped apart a tree branch about 18 inches in diameter from a tree near Valley West Mall, causing it to land on a hot tub and air conditioning unit. (photo/@robintatam)
Over 350,000 were without power across Iowa alone as of early Monday afternoon, according to PowerOutage.us, including the entire town of Ames - and these numbers may continue to climb into the evening.
Marshalltown, Iowa, has been one of the towns hit the hardest by the derecho and recorded a wind gust of 99 mph observed at the town's airport. A few other weather stations across east-central Iowa clocked gusts higher than 100 mph.
The damage will continue to mount as the derecho blasts eastward, with Chicago on alert. At its current pace, the storms will arrive in Chicago before 5 p.m. CT.
A particularly dangerous situationsevere weather watch is in effect until 7 p.m. for northern Illinois and southern parts of Wisconsin, and it states that significant wind gusts up to 100 mph are likely, similar to what was observed across central Iowa.
Derechos are sometimes called "inland hurricanes" due to the extensive damage that they can cause and how they appear on radar images.
|A derecho raced across Iowa on Monday, Aug. 10, 2020, packing wind gusts over 100 mph in some areas. The storms were racing eastward, putting areas like Chicago at risk for damaging winds into the evening hours. (AccuWeather)|
By definition, a derecho is a long-lived complex of intense thunderstorms that travels at least 250 miles. Additionally, wind gusts along its path must exceed 58 mph with at least several reports of gusts over 75 mph, according to the Storm Prediction Center (SPC).
The SPC classified this complex of storms a derecho during an updated thunderstorm outlook late Monday morning.
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In 2012, a particularly strong derecho traveled 800 miles from the Midwest to the coast of the mid-Atlantic, causing $3 billion in damage and leaving some in the dark for days during the peak of summer heat.