ThunderBolt Storm Detector is a professional-grade hand held storm detector ideal for maximizing school safety for out door athletics, bus lines, gym classes, field trips, and more. ThunderBolt detects and tracks thunderstorm activity from 75 miles, detemining severity, approach speed, and estimated time of arrival. ThunderBolt also indicates when it is safe to be outside again through its Time to Clear function. All warning information appears on the ThunderBolt's LCD display. Flashing LED's and audible alarm provide provide addtional warning for all forms of operating environments.