What is a derecho?

Published On: Jun 13 2013 10:27:06 AM CDT

Duh-what-choo? Find out more about the possible derecho threatening millions of Americans.

Virginia storm debris
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Kim Uhl/CNN

Derecho warnings usually come hours in advance, and meteorologists urge those in a derecho's path to take precautions similar to an approaching tornado or other severe storm -- secure loose items outside, bring in furniture and other equipment, seek shelter in a sturdy structure and stay away from windows.

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