Officials with the National Weather Service described the Friday night storm as “a derecho” — a long line of ferocious thunderstorms that produce a large swath of damaging winds. The storm moved from the Ohio Valley east to the mid-Atlantic states at 60 miles an hour, producing winds in some places of up to 90 miles an hour, said Mr. Porter, the meteorologist.

- Sheryl Gay Stolberg and Marc Santora, Storms Leave 3 Million Without Power - NYTimes.com

Northern VA hit by a ‘derecho’:

Wikipedia

A derecho (Spanish: derecho “straight”, pronounced [de̞ˈɾe̞tʃo̞]^[1]), 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.

(via underpaidgenius)

(via underpaidgenius)