First I want to tell you what a derecho is, by the way in Spanish means (straight). It is a very long lived intense wind storm. It can have winds of 58 miles and above. Though fairly rare, the last Super Derecho was on May 30 2012. It started with a warm front and, the jet stream (fast flowing air currents) separating the warm air from the cold which is made instability around the jet stream. Those same conditions are present now. That’s why weather forecasters are saying a derecho could occur, on Thursday or today (Wednesday).