Raleigh, N.C. — The National Weather Service issued a winter weather advisory for most of North Carolina on Thursday as preparations got under way across the state to brace for the possibility of a wintry mix that could snarl Friday's evening commute.

The advisory takes effect at noon Friday in the central region and lasts through midnight for most counties. Eighty of the state's 100 counties were included in the advisory as of 7 p.m.

Schools districts across the region – including Wake, Durham, Orange, Cumberland, Chatham, Lee, Franklin, Person and Johnston counties – announced early closings Friday to give students a chance to get home safely. Wake Tech Community College in Raleigh and Fort Bragg schools were also among the growing list of schools planning to close early in anticipation of bad weather.

State transportation crews spent most of Thursday morning and afternoon pretreating roads with a mixture of salt and water, called brine. A coating of brine helps prevent snow and ice from bonding to the pavement.

The brining was being done along major roadways in the Triangle, Triad and Greater Charlotte areas, as well as the mountains and foothills of western North Carolina and Interstates 95 and 40 in the eastern part of the state.

Once crews are done brining, officials said, plows and spreaders will be on standby.

"We've been putting salt brine down since yesterday," said Jon Nance with NCDOT. "We'll take a break during rush hour traffic, then we'll continue. We're certainly ready."

Many towns and cities, including Cary, Raleigh and Chapel Hill, were also busy Thursday brining the smaller roads typically not treated by NCDOT. In Knightdale, city employees Reed Alexander and Larry Johnson worked to apply 1,300 gallons of brine and planned to add more if needed. In Chapel Hill, public works teams were paying special attention to bridges, steep hills and bus routes.

The North Carolina Zoo in Asheboro said it will close to the public at 1 p.m. Friday. Depending on conditions, the zoo could reopen by noon Saturday.

Officials said the preparations are an effort to avoid a repeat of Jan.19, 2005, when a weather system that was expected to yield only flurries brought just enough snow to snarl traffic, strand 3,000 Wake students overnight at more than 50 schools and produce nightmarish commutes lasting eight or more hours.

On that treacherous night, snow collected on roadways, melted from the heat of exhaust fumes, compacted under the weight of vehicles, then quickly refroze, WRAL Chief Meteorologist Greg Fishel said.

Resident Cindy Mease remembers getting stuck in traffic on her way home from work. She ending up going back to her office, where she slept on the floor.

"It was just a cluster. I mean, it was crazy out there," she said. "(Cars would) hit a hill, and people would just start sliding back down."

The unprecedented gridlock caused local and state officials to revamp their policies for dealing with severe weather. Nance said those improvements have led to better communication and coordination during major weather events. The state now uses social media to communicate with each other and with the public.

"Our information is almost immediately available as we learn things," Nance said.

School districts also have new policies, including releasing students early, Wake school district spokesman Mike Charbonneau said.

"We're going to make sure we put a plan in place so that the buses are rolling while it's still safe and the students are back home before weather becomes an issue," he said.

But all the preparations may prove to be unnecessary. Fishel said there likely won't be much snow.

"Once we get past noon, we'll start to see the precipitation move in from the west," Fishel said. "It may start as snow, but it looks more and more now like we're going to be turning into a sleet and freezing rain scenario as we head through the mid- and late afternoon hours, and on into tomorrow evening."

Winds arrived ahead of the arctic air mass Thursday, with gusts between 20 and 30 mph making daytime highs in the upper 30s feel even colder.

The windchill made it feel like 27 degrees in Raleigh at lunchtime and 23 degrees in Rocky Mount. Along the coast, wind gusts of up to 40 mph prompted the DOT's Ferry Division to suspend the Currituck-Knots Island ferry at 11 a.m. Thursday.

Ferry riders are advised to call ahead to check for weather-related delays through Saturday. More Info     Protecting homes, cars and pets in cold weather

High temperatures will climb to near 40 degrees on Saturday and Sunday under sunny skies, but overnight lows will stay bitterly cold. Sunday's low could dip into the teens.