how does a thunderstorm occur?
Thunderstorms occur when large air masses rise quickly into the atmosphere, forming huge cumulonimbus clouds. Severe air currents inside the clouds cause water droplets and ice crystals to crash into one another continually, and the friction between these particles creates static electricity in the cloud. Over time, opposite charges build between the top and bottom of the cloud, and the bottom of the cloud and the earth. When these opposing charges become intense, a gigantic spark occurs (lightning) which jumps the gap between the cloud and the earth. The thunder accompanying lightning is the noise produced by the discharge.