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.

In Atlanta, where public schools were closed, forecasters expect freezing rain and up to three inches of snow starting Friday morning. With the northern half of Georgia under a winter storm warning, Gov. Brian P. Kemp declared a state of emergency on Thursday because of the forecast and said it would be in place through Tuesday.

A powerful winter storm that dumped heavy snow and glazed roads with ice across much of Texas and Oklahoma lumbered eastward into southern U.S. states overnight, prompting governors to declare states of emergency and shuttering schools across the region.