Raleigh, N.C. — State and local transportation officials and several school districts girded Wednesday evening for the too-familiar kind of North Carolina winter storm that could foul roads with ice Thursday , even if its precipitation follows predictions and changes to rain by late afternoon.

Schools in Wake, Durham, Orange County, Chatham, Caswell, Vance, Person and Granville counties and the Chapel Hill-Carrboro City Schools had closed for Thursday. Johnston, Vance and Franklin counties had called two-hour delays, and Harnett County set a 10 a.m. opening. A number of local businesses also reported closings and delays. Up-to-the-minute information is available on the .

The State Zoo in Asheboro announced that it would be closed.

The National Weather Service put Wake County and counties to the east under a winter weather advisory, while Durham, Orange and Chatham counties and areas to the west and north were put under a winter weather warning. Those conditions begin  at 6 a.m. and go through midnight.

The advisory means "periods of snow, sleet, or freezing rain will cause travel difficulties." The weather service advised residents to " be prepared for slippery roads and limited visibilities and use caution while driving."

A warning, WRAL Chief Meteorologist Greg Fishel explained, means an accumulation of 3 inches is considered possible. An advisory indicates forecasters think less than 3 inches would accumulate.

Fishel said precipitation may not begin until mid-morning in parts of the Triangle. When it begins, we will see a mixture of snow and sleet around the Triangle and areas north and west. Anywhere from 1 to 2 inches of snow and 0.25 inches of ice could accumulate.

In most areas where it begins as snow, it probably will switch over to freezing rain by early afternoon, then to rain in late afternoon as the air close to the ground warms, Fishel said.

Areas around Durham and Chapel Hill and west and north have a "respectable possibility" of getting 1 to 2 inches or perhaps even 3 inches of snow initially, Fishel said. The Raleigh area will probably get about 1 inch, he said.

The weather in the southern part of the state is expected to start as snow and then switch to rain, Fishel said.

Gov. Mike Easley activated the State Emergency Response Team. Preparations included coordinating preparations for emrgency shelters if they become necessary. Easley urged residents to be cautious, saying "We do not want a repeat of what happened two years ago when people were surprised by the weather at midday and were stranded for hours on our highways."

The state Department of Transportation said crews went out today Wednesday, "pre-treating bridges, overpasses and sections of major highways in areas along and west of Interstate 95 in preparation for the forecasted winter weather. "

"The department will work to clear interstates first, then major U.S. and N.C. routes, then secondary roads. People who must travel should use extra caution, especially while driving on secondary roads, bridges and overpasses," officials said.

Raleigh Mayor Charles Meeker urged residents to use caution in deciding whether to drive Thursday, and he asked employers to be flexible if employees need to be late for safety reasons. He said city trucks would be pre-treating roads after the Wednesday rush-hour traffic cleared. A storm that hit roads during the day in January 2005 closed schools early and brought traffic to a standstill for hours.

The Town of Chapel Hill said it was pre-treating roadways late Wednesday.

Utilities readied for the storm, too.

“We are ready for any frozen precipitation that may come,” said Hershell McCarty, system storm coordinator-Progress Energy Carolinas. “We are monitoring the forecast closely and are mobilizing our crews so we can restore’s any power outages as quickly and safely as possible.”

"It's going to be a painful day for a lot of folks," said Jonathan Blaes, a meteorologist with the National Weather Service in Raleigh.

Widespread power outages are not expected to occur, Blaes said, but he noted that temperatures have been cold for the past 10 days, creating more of a chance for accumulation.

Thursday's highs are expected to be in the lower to mid-30s. With the potential in the forecast for freezing rain, motorists are urged to use caution, especially on bridges.

"The speed limit may say 55, it may say 45, but that doesn't mean you can travel at that speed," said state Highway Patrol spokesman Lt. Everett Clendenin. "The No. 1 type of collision we have is the rear-end fender-bender."