11:45 AM MST, Friday, December 22, 2017
Very cold air in the north-central United States and mild air in the Southwest will be vying for control of the Front Range region Saturday through Monday, with the colder scenario likely being more dominant (but probably not bitter cold). Snow will be mainly in the mountains, with some heavy amounts above treeline Saturday and Saturday night.
The Front Range can expect a surge of colder air from the north and northeast Saturday afternoon or evening (it may be morning in Cheyenne). At mountaintop level Pacific moisture on west winds will bring snow mainly near and above treeline (mostly west of Peak to Peak Highway).
Mountains: widespread 6 inches near and above treeline and over a foot along and west of the divide (heaviest along and north of I-70).
Nederland, Estes Park, and Cheyenne: 1-4 inches
Fort Collins, Boulder, Denver: little or no accumulation most areas, but some narrow east-west bands in the evening may bring 1-2 inches in some spots.
Colorado Springs: little or no snow
Dry and cold day across Wyoming and Colorado. There is some chance for the milder air from the Southwest to work its way in during the day, but just a small chance. If the milder air does manage to come in, it might get a bit breezy in and near the foothills.
It appears that the next surge of colder air from the north or northeast will push its way down the Front Range on Christmas. Timing is uncertain, but probably during the day. It should be mainly dry in the foothills and plains, but low clouds and flurries can’t be ruled out. There is a better chance for some snow in the mountains.