The first significant winter storm of the season will move into Connecticut about noon Sunday and bring with it enough snow to make the post-Thanksgiving trip home a white knuckle ride.

Snow will likely overspread the state by lunchtime Sunday and the snowfall will be heavy. By late afternoon or early evening, the snow will change over to a wintry mix of rain, freezing rain, sleet and snow, said Rodney Chai, a National Weather Service meteorologist in Boston. That rain will continue into Monday, then change back over to snow Monday afternoon.

Total snowfall totals could be 8 to 12 inches in the northwest hills, 4 to 9 inches in greater Hartford and 6 to 7 inches in eastern Connecticut. A key factor, Chai said, is when the snow changes over to rain on Sunday, and when the rain turns back to snow on Monday.

“I would encourage everyone to check the forecast regularly,” Chai said.

The storm will be a “long-duration” event and impact travel on Sunday and on Monday.

Dry and breezy weather is forecast through mid-day Sunday, but conditions are going to quickly deteriorate as the storm system from the Midwest moves into southern New England.

“We have the calm before the storm today through the first half of Sunday,” said Kim Buttrick, another National Weather Service meteorologist.

Connecticut Department of Transportation crews were pre-treating bridge surfaces and trouble spots on Friday in anticipation of the storm, and will have crews ready to respond to clear roadways as necessary, said Kevin Nursick, a department spokesman.

DOT is watching forecasts, which seem to be trending toward a more significant storm than originally forecast, Nursick said. Still, that could change as well, he said. He urged travelers to keep an eye on the forecast, consider the heavy volume on roads and plan according.

Sunday’s storm comes on the heels of a large storm that buried Colorado and Wyoming in 3 feet of snow and moved into the Midwest just before Thanksgiving, wreaking havoc on Thanksgiving travel plans.

According to AAA, 2.5 million New Englanders are expected to be flying and driving over the Thanksgiving holiday. The total travelers who are expected to be hitting the roads and skies are up 3 percent from last year — the highest number in more than a decade.