When meteorologists say derecho, which means direct or straight ahead in Spanish, they're referring to a widespread, long-lived wind storm associated with bands of fast-moving thunderstorms. This type of storm was given the name in the late nineteenth century, and they occur most often in the Midwestern and Great Lakes regions of the United States between May and July. To qualify as a derecho, a storm must cause damage over a 240-mile (400-kilometer) front/line and produce wind gusts of at least 58 miles (93 kilometers) per hour.
When a derecho barreled over the eastern United States in June 2012, the impacts were severe. The powerful storm brought hurricane-force winds to numerous states, killed 22 people and knocked out electric power for millions.
So people were bracing for the worst when a fierce line of storms was bearing down on the same area on June 13, 2013. Although the 2013 storm wasn't as powerful or destructive as the previous year's event, the National Weather Service said it still qualified as a low-end derecho.
Terra image courtesy of NASA.
Radar image courtesy of the National Weather Service and National Oceanic and Atmospheric Administration.