Winter storm watch on tap for Triangle

"There are still a lot of questions about how intense this storm will be and how close it will track to the Carolina coast. Both play a pivotal role in how much snow we'll see around the Triangle," WRAL meteorologist Mike Maze said Friday.

The National Weather Service issued a winter storm watch for the eastern half of the state from late afternoon Saturday through Dec. 26 at 5 p.m. Counties further to the west and around Charlotte were under a winter weather advisory.

Maze said he expected the weather service would upgrade the Triangle's watch to a warning at some point Saturday afternoon.

A mixture of snow and rain will develop late Saturday afternoon and quickly change to all snow by evening, according to the National Weather Service.

Two to four inches is possible for the Triangle and up to six inches of snow for areas to the east of Interstate 95 is possible by Sunday evening, Maze said. 

Some forecast models showed a heavier band of snow dumping four to six inches in central North Carolina, but the development and output of the coming storm are still very much up in the air, Maze said.

The total will be based on how two weather systems combine off the Carolina coast. An upper-level disturbance from the west will cross the mountains early Saturday and gradually spread over the state.

As that system moves out of the state, it will be followed Saturday night by a low-pressure system passing along the coast of North Carolina. 

Temperatures will dip into the upper 20s Saturday night and won't get above freezing Sunday.

If the low stays close to the coast, the Triangle and areas to the east could more snow. If the low moves south and east, so does the chance for accumulation.

Raleigh has not seen snow accumulation on Christmas Day since 1947.