system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What causes the American South and Midwest to have so many tornadoes, and why are they so relatively rare everywhere else in the world?
gpt
The American Midwest is a flat steppe that runs from the Artic of Northern Canada, to the deserts of Northern Mexico. The lack of natural barriers(mountains) for such a long stretch allows cold Artic air to mix with hot tropic air which creates the conditions necessary for tornadoes to form.