Rare derecho winds batter Midwest

Freak storm leaves hundreds of thousands without power.

IOWA CITY, Iowa — A rare storm packing 100-mph winds and with power similar to an inland hurricane swept across the Midwest on Monday, blowing over trees, flipping vehicles, causing widespread property damage and leaving hundreds of thousands without power as it moved through Chicago and into Indiana and Michigan.

The storm, known as a derecho, lasted several hours as it tore from eastern Nebraska across Iowa and parts of Wisconsin and Illinois. It had the wind speed of a major hurricane and probably caused more widespread damage than a normal tornado, said Patrick Marsh, science support chief at the National Weather Service’s Storm Prediction Center in Norman, Okla.

In northern Illinois, the National Weather Service reported a wind gust of 92 mph near Dixon, about 100 miles west of Chicago, and the storm left downed trees and power lines that blocked roadways in Chicago and its suburbs.

After leaving Chicago, the most potent part of the storm system moved over north central Indiana by late afternoon.

“The storm system as a whole is definitely beginning its decay,” said Northern Illinois University meteorology professor Victor Gensini.

A derecho is not quite a hurricane. It has no eye, and its winds come across in a line. But the damage it is likely to spread over such a large area is more like an inland hurricane than a quick, more powerful tornado, Marsh said. He compared it to the devastating Super Derecho of 2009, which was one of the strongest on record. It traveled more than 1,000 miles in 24 hours, causing $500 million in damage, widespread power outages and the deaths of a handful of people.

“This is our version of a hurricane,” Gensini said in an interview from his home about 15 minutes before the storm was about to hit.

Gensini said this derecho will go down as one of the strongest in recent history and be one of the nation’s worst weather events of 2020.

“It ramped up pretty quick” around 7 a.m. Central time in eastern Nebraska. “I don’t think anybody expected widespread winds approaching 100, 110 mph,” Marsh said.

Several people were injured and widespread property damage was reported in Marshall County in central Iowa after 100-mph winds swept through the area, said emergency management coordinator Kim Elder.

She said the winds blew over trees, ripped road signs out of the ground and tore roofs off of buildings.

“We had quite a few people trapped in buildings and cars,” she said. She said the extent of injuries is unknown and that no fatalities have been reported.

Elder said some people reported their cars flipping over from the wind, power lines falling and injuries from flying debris. Buildings also caught on fire, she said.

MidAmerican Energy said nearly 101,000 customers in the Des Moines area were without power after the storm moved through the area.

Across the state, large trees fell on cars and houses. Some semi trailers flipped over or were blown off highways.

Farmers reported that some grain bins were destroyed and fields were flattened, but the extent of damage to Iowa’s agriculture industry wasn’t yet clear.

What makes a derecho worse than a tornado is how long it can hover over one place and how large an area the high winds hit, Marsh said. He said winds of 80 mph or even 100 mph can stretch for “20, 30, 40 or God forbid 100 miles.”

What happened is unstable super-moist air has parked over the northern plains for days on end, and it finally ramped up Monday morning into a derecho.

“They are basically selfsustaining amoebas of thunderstorms,” Gensini said. “It’s really hard to stop these suckers.”