What is a derecho?

A derecho is a line of severe thunderstorms whose winds blast in a mostly straight direction over hundreds of kilometres. Under a commonly used definition, the damage swath must stretch at least about 400 kilometres, with wind gusts of at least 93 km/h along much of it. The name, Spanish for 'straight', was coined in 1888 by physicist Gustavus Hinrichs to distinguish these winds from the rotating winds of tornadoes. The August 2020 Midwest derecho crossed Iowa and Illinois, flattening millions of acres of crops and causing billions of dollars in damage. Derechos are most common in the central and eastern United States in late spring and summer.