To be called a derecho, severe storms must have winds in excess of 58 mph and cause damage spanning at least 250 miles. Storms will grow and join together creating a line of strong winds, possibly over hurricane strength of 74 mph, causing widespread damage and power outages to the region. "Given the degree of instability and strong flow aloft, the development of a derecho is certainly possible with widespread wind damage caused by hurricane-force winds. Damage caused by derechos is frequently referred to as straight-line wind damage. In August 2020 , a severe thunderstorm event impacted the Midwest as a derecho and produced severe wind damage across Nebraska, Iowa, Illinois, Wisconsin, Illinois, and Indiana.

Source: CNN July 28, 2021 16:52 UTC