A trough of low pressure will move across the Central Rockies this week, bringing snow to a large portion of Colorado over the next couple of days. We’ve already seen several disturbances ahead of the main system impact the mountains of Colorado over the past few days, and will continue to see snow showers today. The southwesterly flow has favored the San Juan Mountains the most, where ski areas have picked up over a foot of snow in recent days.
Looking at the most recent upper level wind pattern at 500-millibars, we can see the trough of low pressure centered over California this morning (image source: College of DuPage).
High Country Snow Outlook
This trough will transition eastward today, with snow showers west of the Continental Divide this afternoon becoming a more widespread snowfall overnight tonight through the first half of the day Wednesday. The next image shows widespread moisture spreading into Western Colorado this evening (image source: Colorado Avalanche Information Center).
Snow will fall heavily at times, with amounts of over one foot possible across the higher mountain passes and ski areas, especially across the central and southwest mountains south of I-70, as well as Steamboat in Northern Colorado.
Snowfall amounts for the mountain towns will likely range from 3-6″ for most areas from the Roaring Fork Valley to Vail and up to Steamboat, with amounts a little higher southward in places like Crested Butte and Telluride, and amounts a little lower in Summit County.
The Wednesday morning commute will be impacted all across the high country, and strong winds will develop Wednesday morning and through the day as well, resulting in blowing and drifting snow. Outside of the high country, even the lower elevations of the West Slope from Grand Junction to Montrose could pick up a couple of inches of snow Wednesday morning, with a slick commute expected.
Front Range Snow Outlook
As the trough moves across Colorado on Wednesday, an arctic cold front will approach from the north and push into Eastern Colorado Wednesday afternoon, resulting in a rapid drop in temperatures. Upslope northeast winds will develop behind the front with snow developing across the Denver-Boulder-Ft. Collins areas Wednesday afternoon. The image below is one model’s projected radar reflectivity at 5pm Wednesday, showing snow filling in across the urban corridor (image source: pivotalweather.com).
Snow will continue across the Front Range through the overnight hours Wednesday night before tapering off early Thursday morning. Temperatures will plummet Wednesday afternoon through the overnight hours, allowing for snow to accumulate on all surfaces. Low temperatures on Thursday morning are expected to approach zero across the metro area.
This will generally be a light/moderate snowfall event with favored upslope areas west of I-25 near the foothills picking up a few inches, perhaps more, with lesser amounts expected east of I-25. Boulder tends to do better than most of the Front Range in this type of pattern, and could end up with some of the higher totals in the area. There will be some potential for banded snowfall as well across the Front Range, in which case isolated higher totals would be possible if and where any heavier, slow-moving bands of snow set up.
The Thursday morning commute will be challenging across the Front Range, even if amounts end up on the lighter side given the cold temperatures in place.