1). How does a hot air ballloon work? A burner warms the air inside the balloon. The warm air rises because warm air is lighter than cool air. The warm air takes the balloon with it.
2). How does a hailstone form? A hailstone forms when an updraft carries a water droplet into the cold air of a tall cloud. The droplet freezes and becomes a hailstone.
3). Why do so many twisters occur in "Tornado Valley" in the spring and summer. During the spring and summer, warm air comes from the Gulf of Mexico while cool air comes from Canada. When the warm air meets the cool air, many violent thunderstorms form. These can become tornadoes.