Spanish for Straight — Wikipedia has a nice entry:
A derecho is a widespread and long-lived, violent convectively induced straight-line windstorm that is associated with a fast-moving band of severe thunderstorms in the form of a squall line usually taking the form of a bow echo. Derechos blow in the direction of movement of their associated storms, similar to a gust front, except that the wind is sustained and generally increases in strength behind the “gust” front. A warm weather phenomenon, derechos occur mostly in summer, especially June and July in the Northern Hemisphere. They can occur at any time of the year and occur as frequently at night as in the daylight hours.
The usage has been around for a while:
Derecho comes from the Spanish word for “straight”. The word was first used in the American Meteorological Journal in 1888 by Gustavus Detlef Hinrichs in a paper describing the phenomenon and based on a significant derecho event that crossed Iowa on 31 July 1877.
The storm that hit Chicago to Washington DC has been classified as a Derecho. It was a 600-mile straight track from Chicago onward.
AccuWeather has some images — that trampoline does not belong there.
Hat tip to Firehand at Irons in the Fire for the link.Posted by DaveH at July 1, 2012 03:00 PM