Cold and snow before a little weekend relief
Especially areas west and south of Billings will see occasional light snow Thursday night through Friday. Some areas could pick up 2 to 3 inches, but most that see snow will stay closer to 1"-2" in accumulation.
As the arctic air deepens, the snow becomes lighter. And the surge of cold air will drive temperatures below zero Friday morning with highs mainly in the single digits above / below zero Friday afternoon in southern Montana and northern Wyoming.
Expect cold wind chills of 15-30 below zero, and localized blowing snow with even a little wind. The National Weather Service has issued a Winter Weather Advisory for Yellowstone and surrounding counties. Counties closer to the Dakotas snowfall but will be the coldest, with a Wind Chill Advisory for these areas.
Friday night / Saturday morning looks to be a very cold night with a clearing sky, fresh snow and light wind.and before the foothills wind develops. Most locations should see at least 10 below.Miles City and Baker will likely see -20 or colder.
Stay safe if you will be out on New Years Eve.