The National Weather Service in Missoula is forecasting a very wet weekend, with the least confidence still in the snow levels.

“This is very problematic for this system because it is so wet, and we expect relatively high rates of precipitation,” NWS said in a press release. “As a result, a 2-3 hour error in the timing of the transition from snow to rain could amount to a difference of several inches of snow.”

Over the weekend, residents should expect widespread, very light snow to start in Central Idaho and Northwestern Montana on Saturday morning which will spread across to the Continental Divide by Saturday evening.

During the day, mountain locations are expected to receive 1-2 inches of snow. The heaviest precipitation and snow level changes are expected to occur Saturday night and Sunday, NWS said.

Snow levels on Marias Pass will rise from 2,800 feet to 4,400 feet with around half an inch of total liquid precipitation and 4-8 inches of snow likely.

By Sunday and Monday, precipitation intensity is expected to start to decrease, so snow showers and light rain showers will slowly decrease throughout the day, NWS said, and snow levels will start to fall again.

NWS also forecasts a potential winter storm on Christmas Eve that will run into Christmas Day, bringing snow and associated travel impacts to nearly all elevations of Central Idaho and Western Montana.

“It is still too early to say for sure which areas will be affected, as forecast models have large disagreements in the storm track,” NWS said. “The model differences could be the difference between rain and snow, especially for the valleys. We should gain more confidence in the coming days and be able to provide a better forecast of the areas that will be affected.”