Here's a breakdown:
* Snow forms when water vapor in the atmosphere freezes into tiny ice crystals. These crystals collide and stick together, forming snowflakes.
* Sleet is formed when rain freezes as it falls through a layer of cold air. It's not directly from ice crystals but involves rain freezing.
* Freezing rain forms when rain falls as liquid through a layer of freezing air and freezes upon contact with a surface. This is also not directly from ice crystals.
* Hail forms in thunderstorms when strong updrafts carry water droplets up into the freezing layers of the atmosphere. These droplets freeze into ice pellets and are repeatedly cycled up and down, growing larger until they become too heavy and fall to the ground.
Let me know if you have any more questions!
