What Are They?

Tornadoes are a whirlwind that forms over land. They are spawned from thunderstorms, most of which are known as supercells. They form mainly over the plains where the cold, dry air of the north, and the warm humid air of the south make contact, forming unstable air. This unstable air creates updrafts, downdrafts, wind shear, and more. This is what creates the conditions for the formation of a tornado.

How Strong Are They?