Nothing is more awe-inspiring (or to some more frightening) than the thunderstorm. It’s one of nature’s most powerful forms of weather and brings with it violent winds and heavy rain. But what separates it from your garden variety heavy shower? The hail, the lightning, and in rare cases, the tornado.

Over the next two chapters, I’ll explain what causes thunderstorms and the severe weather we most commonly associate with it. But before we talk about severe weather, let’s first discuss how thunderstorms form.