Freezing rain is the most problematic. It's similar to sleet, but worse. It's what happens when the warm layer is deeper. The snow fully melts, then turns supercooled before hitting the ground. Once it does, it freezes and sticks to whatever it hits: Roads, trees, cars, power lines etc.

A light wintry mix in the afternoon is expected to turn into freezing rain in much of the Midlands late Friday with parts of central South Carolina are under a winter storm watch, according to the National Weather Service.

Winter Storm Cora is sweeping through the Southeast, delivering a mess of snow and ice from Arkansas and Tennessee to the Carolinas and Virginia, including Atlanta, Charlotte and Nashville. The wintry mess is snarling travel and in some cases icing could be heavy enough to cause power outages and tree damage.