A rare derecho affected the Rockies and Northern Plains the first weekend of June.

A rare derecho affected the central Rockies and northern Plains on Saturday June 6th. Derechos are very rare for Utah, Colorado, and Wyoming. In fact, only two other derechos are well-documented west of the Rockies according to the Storm Prediction Center. The derecho produced the most significant wind gust reports in a day since at least 2004. Significant wind gusts are estimated or measured at 75 mph or greater. Even more impressive, 41 of the 44 wind gusts were considered signfiicant wind gusts. Here are some of the peak wind gusts recorded: Great Divide Colorado 99 mph

Copper Mountain Colorado 90 mph

Bitter Creek Wyoming 81 mph

Denver Colorado 78 mph

What is a derecho? A derecho is a long widepreead windstorm that is associated with a band of rapidly moving thunderstorms. By definition, if the swath of wind damage extends for than 240 miles, includes wind gusts of at least 58 mph or greater along most of its length, and several, well-seperated 75 mph or greater gusts, then the event is likely to be classified as a derecho. Derechos are most common well east of the Rockies.