Lots More Information Lots More Information Prev Next Related HowStuffWorks Articles How Snow Makers WorkHow Icemakers WorkWhy is it colder at the top of a mountain than it is at sea level?Why is snow white?Why do bridges ice before the rest of the highway? More Great Links The USA Today Weather Book: How winter storms bring rain, ice and snowIce Storms: Hazardous Beauty Up Next How rare are double rainbows? How big can hail get (and how is that even possible)? Could there be a triple rainbow? Does a wet summer mean a brilliant fall? Can you predict winter weather based on summer weather?