A brief but intense snowstorm overnight Saturday, followed up by sleet and freezing rain, will make driving hazardous and promises a sloppy end to the holiday weekend.

A storm system forecast to move up from Texas then pick up moisture and energy over the Great Lakes is due to hit southern Maine early Saturday night.

The storm should start with snow in southern Maine, possibly an inch an hour, though only for a brief period, before turning over to icy conditions before dawn Sunday, said Andy Pohl, meteorologist with the National Weather Service in Gray.

“That’s when things get interesting and when we lose a little confidence in the forecast,” said Pohl, noting that a front could set up over Cumberland County with some communities getting rain, and nearby towns getting freezing rain. “It’s a fairly dynamic system. Eventually warm air will win out, and everything turns to rain. When that happens is the magic question.”

The weather service is predicting snow starting in the evening in Kennebec County, then snow and sleet after midnight. Accumulations are expected to be4 to 6 inches with lows around 18.

Sunday morning will bring freezing rain and sleet with rain likely in the morning, but it will be a little warmer, in the 30s.

Franklin County and other areas north of Augusta and Waterville are expected to get more snow than sleet, with snow before 2 a.m. Sunday, then snow and sleet between until around 4 a.m., then snow. Accumulations are expected to be 4 to 8 inches, and the low around 15.

Sunday will bring freezing rain and sleet before 10 a.m., then freezing rain likely between 10 a.m. and 2 p.m.

Conditions farther east, in Somerset County, will be a little warmer, with less accumulation and snow and sleet changing over to freezing rain. Some 3 to 7 inches of accumulation is possible.

The Portland area should get 4 to 6 inches of snow, with higher accumulations inland before the changeover, he said.

While motorists may resent the precipitation, the storm is welcome news to snowmobilers, many of whom have been idle since a warm spell dissolved the snow cover on many of the state’s trails.

“The trails are not fit to drive on,” said Steve Fox, trailmaster for the Stoneham Knight Riders in Oxford County. “Our trails around here are very rough, and they need a good foot of snow before we can start grooming them and maintaining them.”

Stoneham, a small town near the base of the White Mountains, could get up to 8 inches of snow before warm upper air turns the precipitation to icy pellets.

“We have somewhat of a frozen base now. As long as we don’t get a lot of rain after it, there’s a good chance some of the trails will open up by the first of the week,” Fox said.

In eastern Vermont, the National Weather Service forecast calls for up to 5 inches of snow and some ice in Caledonia, Orange, Washington, Windsor and in eastern Addison and Rutland counties this weekend.

Freezing rain after snow is easier for road crews to deal with than ice on black pavement, Vermont state highway dispatcher Larry Dodge said.

“We’re not looking forward to it, but I’m sure they’ll be able to handle it,” he said.

Some areas that didn’t see a white Christmas welcomed the snow but not the rain.

The Rikert Nordic Center, which makes snow on the Bread Loaf campus of Middlebury College, in Middlebury, Vt., expected to have nearly 2 miles of cross-country trails open Saturday. The storm could drop 5 to 8 inches of snow on the 35 miles of trails, followed by rain, director Mike Hussey said.

“This pattern that was set up back in November seemed to stick with us, the warming trend at the end,” said Hussey, who’s more concerned about the sub-zero temperatures next week following the rain that will harden the snow.

A snow storm in mid-December dumped heavy wet snow in northern New England and caused extensive power outages, but the storm was followed by a warm-up that left the ground bare for weeks in parts of the state.

Maine ski mountains won’t see the snow till late Saturday; and then by Sunday morning, skiers might well be contending with a icy glaze on the trails, Pohl said.

Kennebec Journal staff and the Associated Press contributed to this report.