The word invokes just as much trepidation as "hurricane" or "tornado" to those who know the power of a derecho, but what's behind this uncommon form of severe weather? A derecho is defined as a ...

This radar looop shows the derecho moving across Indiana, Ohio, Pennsylvania and New York. At least 3 deaths have been reported in Pennsylvania related to the violent storm.

June 29, 2012, is a difficult day for those in and around Washington, D.C., to forget. On that day, an intense line of extremely gusty thunderstorms taught millions of people a new word: derecho. The ...