ATLANTA — Across the South, winter-weary residents woke up Wednesday to a region encased in ice, snow and freezing rain, with forecasters warning that the worst of the potentially “catastrophic” storm is yet to come.

From Texas to the Carolinas and the South’s business hub in Atlanta, roads were slick with ice, tens of thousands were without power, and a wintry mix fell in many areas. The Mid-Atlantic region also was expected to be hit as the storm crawled north and east.

Officials and forecasters in several states used unusually dire language in warnings, and they agreed that the biggest concern is ice, which could knock out power for days in wide swaths. Winds, with gusts up to 30 mph in parts of Georgia, promised to exacerbate problems.

In Atlanta, where a storm took the metro region by surprise and stranded thousands in vehicles just two weeks ago, tens of thousands of customers were reported without power across the state. City roads and interstates were largely desolate, showing few vehicle tracks as most people heeded warnings to stay home.

Stinging drops of rain fell, punctuated by strong wind gusts, and a layer of ice crusted car windshields. Slushy sidewalks made even short walking trips treacherous. One emergency crew had to pull over to wait out the falling snow before slowly making its way back to the Georgia Emergency Management Agency’s special operations center.

In normally busy downtown areas, almost every business was closed, except for a CVS pharmacy.