What is a “derecho”? - NWS
Essentially, a “derecho” is a long-lived, rapidly moving line of intense thunderstorms that produces widespread damaging winds in a nearly continuous swath.
By definition (according Johns and Hirt, 1987), the term “derecho” applies to a complex line of thunderstorms that travels a minimum distance of 240 miles (~400 km) or more, and produces a nearly continuous and widespread swath of damaging winds over that distance, with concentrated areas of wind speeds over 58 mph (93 km/hr). Surface wind gusts accompanying a derecho can often approach or exceed 100 mph.
The term “derecho” was originally coined over a century ago by a physics professor at the University of Iowa, named Dr. Gustavus Hinrichs, in a paper he published in the American Meteorological Journal in 1888. The term “derecho” is Spanish and means “straight ahead”, an attribute Dr. Hinrichs applied to the storm’s ability to produce damage from essentially straight-line winds. (Note: a fascinating description on how this term was developed by Dr. Hinrichs, and how it recently was revived can be found here:https://www.crh.noaa.gov/images/dvn/hinrichs/JohnsDerechoStory.pdf).