Powerful derecho wreaks havoc across the Midwest – one of the worst weather events of 2020 in the U.S.

A rare derecho — severe storm with hurricane-force winds — ripped through the Midwest on Monday, August 10, 2020, leaving almost 1.5 million customers without power, toppling numerous trees and vehicles, and causing major, widespread property damage across several states. Northern Illinois University meteorology professor Victor Gensini described the event as one of the worst weather events of 2020 for the U.S.

The storm tore through a straight-line path, hence the name derecho, across eastern Nebraska, Iowa, Wisconsin, and Illinois.

It lasted for several hours and likely caused more extensive damage than a usual tornado, according to Patrick Marsh, science support chief at the National Weather Service (NWS) Storm Prediction Center (SPC).

Widespread damage was reported south of the U.S. Highway 20 south to around Interstate 80 in Iowa. Several vehicles were flipped over, trees were downed, and communication services were interrupted to the point where the entire Fayette County lost connection.

Marsh pointed out that a derecho is not considered a hurricane as it has no eye and its winds come across in a line, but the damage it inflicts is spread over such a massive area that it is more like an inland hurricane than a more powerful tornado.

In northern Illinois, NWS recorded a wind gust of 148 km/h (92 mph) near Dixon as the storm toppled trees and power lines. Roadways were blocked in Chicago and its suburbs as a result. 

Professor Gensini said the derecho may go down as one of the strongest ones in recent history, also describing the event as one of the worst severe weather events of 2020 for the country.

As the storm left the city, it became more powerful as it swept through north-central Indiana. In central Iowa, winds of up to 161 km/h (100 mph) injured several people and damaged numerous properties in Marshall County. 

"We had quite a few people trapped in buildings and cars," said homeland security coordinator Kim Elder, adding that the extent of injuries is unknown but no casualties were reported.

"We’re in a life-saving mode right now," Elder stated. Dozens of cars at one factory had windshields blown out. Some buildings were also caught on fire.

Marshalltown mayor Joel Greer declared a civil emergency. As of 20:00 UTC (15:00 LT), almost 450 000 customers lost power supply. In the Des Moines area, nearly 101 000 were left without electricity.

Damage to buildings was reported in areas including Cedar Rapids, Iowa City, and Des Moines. Winds also tore the roof off a hockey area in Urbandale. In Lisbon, a newly-built press box was blown away.

"There's a lot of tree damage. Very high winds. It will be a significant effort to get through it all and get everybody back on," said MidAmerican spokeswoman Tina Hoffman. "It was a big front that went all the way through the state."

Public safety spokesman Greg Buelow said Cedar Rapids had "both significant and widespread damage throughout the city." He added, "We have damage to homes and businesses, including siding and roofs damaged. Trees and power lines are down throughout the entire city."

By Monday evening, almost 1.5 million customers were without electricity in the wake of the storms– from eastern Nebraska through Indiana. 

SPC has issued a Moderate Risk for severe thunderstorms for parts of the Midwest. The ongoing derecho is forecast to continue Tuesday afternoon, August 11. 

"Expect strong to severe storms to continue farther east into lower Michigan and Indiana, while extending south into central Illinois this evening before dissipating overnight," NWS said.

Featured image credit: NOAA/GOES-East, RAMMB/CIRA. Acquired 13:10 UTC on August 10.