Thunderclouds build up electric charges, which are polarized and attracted to their opposites, just like a magnet. The bottoms of thunder clouds carry negative charges and the tops carry positive charges. Influenced by the charged clouds, the ground also becomes positively charged. When the electric buildup gets too great, the lightning jumps from the negatively charged cloud base and strikes a positively charged object, usually another cloud. However, about one-third of lightning bolts strike the ground.
Thunder is the sound of the lightning moving rapidly and explosively through the atmosphere.
The air expands and then compresses violently, producing sound waves. There are many myths about thunderstorms. In fact, the best conductor might be a human being. Lightning storms in Canada Storms in Canada can happen anywhere, and they can last for hours, although most usually disperse in less than an hour. Storms generally move from the west at 35 to 50 km-h.