To stay safe during hail or snow storms, find shelter indoors and stay away from windows. If outside, wear layers and stay a safe distance from buildings. Snow forms when water condenses in the atmosphere and falls as snowflakes. Hail starts as rain that strong updrafts carry high into cold areas of thunderstorms where it freezes before falling to the ground as ice. Hail and snow are forms of precipitation that occur when water vapor freezes and falls to the ground as ice or snow.