A powerful storm will crawl across the southern tier of the United States over the next several days, delivering a nasty mix of snow, ice, heavy rain, floods and even a few tornadoes.
As of midday Thursday, about 20 million people were under some level of weather alert. Many tens of millions more should be added to this total over the next few days.
The storm could save its worst for last: Late Saturday and through the day Sunday, it's forecast to paste the central and southern Appalachians with heavy snow. "From central and western North Carolina to parts of southern West Virginia and southwestern and south-central Virginia, this will be a major storm with the potential for a foot or more of snow," according to AccuWeather meteorologist Brian Wimer.