Straight-line winds associated with convective weather activity cause property and crop damage and loss of life each year, comparable with tornado losses. A derecho is such a strong linear wind that is not tornadic, with wind speeds in excess of 26 m/s (meters per second) (58 mph [miles per hour]). The term plow wind applies in the Canadian vernacular. The name, coined by University of Iowa physicist G. Hinrichs in 1888, derives from a Spanish word meaning “direct” or “straight ahead.”

Derecho winds generated convectively from a downburst cluster forms a progressive derecho (major axis of effects less than 400 km [kilometers]; 250 miles), whereas, on a larger scale a group of downburst clusters produces a serial derecho (damage axis more than 400 km). Derechos tend ...