Violent Derecho struck the Midwest US

After the severe fires in the U.S., now a violent wind storm system called derecho, produced hurricane force winds that gusted as high as 91 miles per hour from the Midwest to the Ohio Valley, and all the way to the Mid-Atlantic Coast on June 29.

Millions of people were left without power as trees snapped on power lines, when the derecho advanced eastward across Indiana, Ohio, Virginia, Columbia, Maryland, and in parts of New Jersey.



Violent Derecho struck the Midwest U.S.

Image credit: Kevin Gould  NOAA. Caption by Michon Scott.

Violent Derecho struck the Midwest US



The above radar animation, shows the progression of a severe derecho from the Midwest to the Ohio Valley, and all the way to the Mid-Atlantic Coast on June 29.

A derecho “straight” is a severe windstorm that, produces damaging winds in excess of 60 mph along a swath of at least 240 miles in length.

It 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.