A westerly, moist and relatively mild Pacific flow will bring increasing clouds to western Montana. Some very light snow may develop late Wednesday night across northwest Montana. And, a few very light rain or snow showers are possible Thursday, mainly along and north of I-90 from Missoula to Kalispell. Most of the precipitation will be confined to the mountains. Partly cloudy around Butte and Bozeman. Lows in the 10s in Bozeman and Butte to the 20s in Missoula and Kalispell. Highs in the 30s.
A stronger push of moisture will bring a better chance for a few rain and snow showers Friday area wide. Highs in the 30s.
An even strong push of mild and moist air will bring a good chance of valley rain and high mountain snow Saturday night through Monday. Snow levels will rise, but not before several inches fall in the higher elevations.
Right now weather models are suggesting arctic air to invade the region Christmas Eve and Christmas day, with much colder temperatures and a chance of snow.