Answer:
Atmospheric Static
Scientists are still trying to work out exactly how lightning forms, but we know it has something to do with the interactions between positive and negatively charged ions within clouds.
If you’ve ever walked across a carpet and then touched a doorknob only to get shocked, you’ve experienced a discharge of static electricity. Your movement across the floor generated a static (non-moving) electric charge, which looks for this first possible opportunity to escape and discharge. The same thing happens with lightning inside clouds, just on a much larger scale.
HARP: Another tool that causes Lighting and Thunder is HARP which is a government-managed tool, which they can make any type of weather happen artificially.