Formation of Lightning

During a thunderstorm, water droplets, ice, and air move inside the storm cloud. As a result, positive and negative charges build up. Postitive charges often build at the top of the cloud...

...while negative charges build at the bottom.

Different parts of clouds have different charges.

In fact, most lightning happens within and between clouds.

The negative charge at the bottom of the cloud may induce a positive charge on the ground. The large charge difference causes a rapid discharge called lightning.

By: Chisato Jacobson

Formation of Lightning in Five Steps