calsfoundation@cals.org
May 8, 2009
A so-called “Super Derecho” nicked northern Arkansas. It is one of the more unusual weather events ever recorded, producing an intense mesoscale vortex just across the Missouri border, with a rare hurricane-like eye structure. All told, this storm traveled 1,000 miles from its start as a collection of rain showers in Colorado. A derecho (pronounced deh-REY-cho) is an event that consists of winds that create a swath of damage that extends for more than 240 miles, has minimal wind gusts of at least fifty-eight miles per hour (mph) for most of this swath, and includes multiple hurricane-force (seventy-five mph or greater) gusts.