The latest winter storm is bringing snow and ice to thousands of counties across more than 20 states. Here’s what to know about the forecast, key cities and expected impacts.

The Tennessee Valley could see some of the heaviest snowfall, with 6 inches expected on Friday. A wide swath of the country is under winter weather warnings and advisories and will see impacts including "widespread closures, treacherous travel, scattered power outages, and downed branches," the weather service said.