I never heard the term derecho before Monday’s violent storms. Why is it referred to as a “derecho”?
Terri Finch, Bolingbrook
The term derecho was coined by Iowa meteorologist Gustavis Hinrichs in the 1880s. A Spanish word meaning “straight ahead” (to differentiate from rotary tornadic winds), derecho is used to describe a long duration high wind event in which downburst winds up to 100 mph plow out of fast-moving thunderstorms, producing damage for hundreds or even thousands of miles. A derecho with 100 mph winds hit Chicago on August 26-27, 1965 causing more than $7 million of damage. On Aug. 4, 2008, a derecho with top winds of 94 mph caused widespread damage from northwest Illinois to Michigan.