12:00 noon, Friday, January 6, 2017
After a cold start on Saturday, temperatures should rebound. Temperatures in the Front Range urban corridor should approach freezing on Saturday, 50 on Sunday, and get well into the 50s on Monday but with increasing chances of high clouds. Across Colorado and Wyoming temperatures will probably be above average by Sunday afternoon.
The milder air mass is from the Pacific and will be laden with moisture as it slams into California and Oregon this weekend. That moisture will have an impact across western Colorado late Sunday and Monday. Because of the mild and wet characteristics of the air mass the snow may be more dense than usual, and rain is likely in lower elevations of the West Slope. Be prepared for wintry travel at the high passes and some enhanced avalanche danger by Monday. The Front Range lower foothills and plains should stay dry through Monday.
This has been a season when snowstorms are characterized by narrow west-to-east bands aligned with the jet stream but only shallow upslope (wind from the east). Although that is not an uncommon occurrence, deep upslope associated with storm systems moving by to our south (4 corners lows) is a more familiar cause of big snowstorms. The result this season has been moderate intensity snow with sub-regions of that exceed expectations due to periods of intense snow associated with those bands. In the December 16-17 snowfall, the region of enhanced snow was right over Denver and DIA, and in the recent storm Boulder County got the big amounts.