system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do tornados only seem to occur in the US?
gpt
They don't only occur in the US. However, they are more common in the US because air currents from the gulf collide with warmer air coming up from Mexico, and colder air coming off the Rockies. This causes great conditions for what is called tornado alley. 

Also, news about them is usually local, and doesn't go international unless there are lots of casualties, so you don't hear about them as much when they're in Bangladesh.