The 2020 Midwest Derecho: 4 Dead, 700 Miles of Destruction

A single line of thunderstorms once caused more financial damage than most hurricanes ever have. The 2020 Midwest derecho remains the most expensive thunderstorm event in modern U.S. history, a storm so powerful that meteorologists and residents alike compared it to an inland hurricane.

What Exactly Is a Derecho

A derecho is a fast-moving, long-lived line of thunderstorms that produces widespread, damaging straight-line winds over a huge distance, as opposed to the concentrated, rotating winds of a tornado. To officially qualify, the damage swath typically needs to stretch at least 250 miles and include wind gusts of at least 58 mph along most of its length.

The August 2020 storm went far beyond that minimum. It carved a path roughly 700 to 770 miles long, sweeping from southeastern South Dakota through Nebraska, Iowa, Illinois, Wisconsin, and Indiana before weakening over Ohio. The full event lasted about 14 hours.

Why This Derecho Was So Unusual