Bridges and overpasses, which typically freeze quicker than other surfaces, are particularly hazardous to drivers. Power outages are also common in an ice storm. The weight of ice and freezing rain often causes downed power lines and tree limbs, leaving thousands in the affected area without electricity, sometimes for days at a time. Snow Snow is frozen precipitation in the form of a six-sided ice crystal. Snow requires temperatures to be below freezing in all or most of the atmosphere from the surface up to cloud level.
Snow can fall when surface temperatures are above freezing in a relatively shallow layer.
In situations like this, the snow will not have enough time to melt before reaching the ground - though it will be quite wet with large flakes, the result of wet snowflakes sticking to one another. Generally, ten inches of snow will melt into one inch of water. This commonly happens when snow falls into a very cold airmass, with temperatures of 20 degrees or less at ground-level. Sleet Sleet is frozen precipitation falling as ice pellets . Ice pellets occur when snowflakes melt into raindrops as they pass through a thin layer of warmer air.