Alright, imagine you're in the kitchen and you mix hot water with cold water. What happens? They don't just stay separate, right? They start to mix and swirl around. Tornadoes are kind of like that, but with air.
So, when warm air from the ground meets cold air from up high, they don't mix smoothly. The warm air wants to go up because it's lighter, and the cold air wants to come down because it's heavier. This can create a swirling effect, like when you stir your hot chocolate.
Now, if there's also wind blowing in different directions at different heights (like if you're blowing on your hot chocolate while stirring it), it can make that swirling air start to spin faster and faster. This spinning air can create a funnel, which is what we see as a tornado. The bottom of this funnel touches the ground, and it can move around, picking up anything in its path like a super powerful vacuum cleaner.
So, a tornado happens because of a mix of warm air rising, cold air sinking, and winds coming together in just the right way to make the air spin in a powerful, twisting funnel.