ATLANTA (AP) — Forecasters at the National Weather Service have issued a winter storm warning for 12 Georgia counties in the northwest and northern parts of the state.

The winter storm warning will be in effect from 10 a.m. Thursday until 7 a.m. Friday. It includes the cities of Rome, Calhoun, Chatsworth, Dalton and Blairsville.

Forecasters say a cold polar air mass spreading into Georgia was expected to bring rain that will mix with and change over to snow Thursday afternoon and evening.

The weather service said the heaviest snow was expected to fall in the mountains, with lighter amounts possible in parts of the Atlanta area.

Most of the Atlanta metro area will be under a winter weather advisory through Friday morning. Light snow and black ice will be possible in the metro area.

The Georgia Department of Transportation was planning to finalize an inclement weather action plan Thursday morning.

The agency has 11 strategic staging areas with salt and stone along the interstates, and officials may use a brine maker to coat highways with a mixture of salt and water, DOT Operations Director Meg Pirkle said.

"This is the first winter we have had the capability to make liquid salt," Pirkle said in a statement. "We believe it will start the chemical process more quickly, speeding up the melting process on our roads and bridges."

More than 1,500 employees in middle and north Georgia will be available to help address any issues that may result from snow, freezing rain or ice on the state's highways, DOT officials said.