COLORADO — Residents of the San Luis Valley who are traveling over the Thanksgiving week for outdoor activities should pay close attention to avalanche and road conditions.  

The Colorado Avalanche Information Center (CAIC), a trusted authority on avalanche safety, is warning backcountry travelers of a significant increase in avalanche danger across the Colorado mountains. An atmospheric river is bringing heavy snowfall to Colorado this week, with up to three feet expected in some areas and at least two feet across much of the mountains. 

Locally, as of Tuesday afternoon, the National Weather Service was forecasting rain/snow likely, then a chance of snow for the Valley, and clear conditions through Sunday. Elsewhere, the weather service is calling for snow in Aspen, Steamboat Springs, and Vail through Wednesday. 

"We're particularly worried because we'll see the most dangerous avalanche conditions we've seen so far this season when more people than usual will be getting out to recreate because of the holiday," said CAIC Director Ethan Greene. 

This rapid and heavy snowfall, combined with an already weak snowpack, will lead to dramatically different and significantly more dangerous avalanche conditions than seen so far this season. Avalanche danger is HIGH (Level 4 of 5) in areas in Colorado, with large, dangerous avalanches possible.  

This Avalanche Watch is in effect for the Park Range, Flat Tops, Gore Range, Indian Peaks, Sawatch Range, Elk Mountains and the San Juan Mountains. Avalanches and backcountry travel in these areas will be easy to trigger while this watch is in effect. 

"There will be an increased likelihood of natural and human-triggered avalanches that are large enough to seriously injure or kill a person this week," said Greene.  

CAIC issues avalanche danger ratings based on the North American Public Avalanche Danger Scale, which ranges from LOW danger (Level 1) to EXTREME danger (Level 5). During certain avalanche conditions, CAIC also issues Avalanche Watches and Warnings when the avalanche hazard will be or is HIGH (Level 4) or EXTREME (Level 5). Special Avalanche Advisories are issued to alert the public of an increased safety risk due to potentially dangerous conditions for many people, such as a big storm occurring during a holiday weekend.  

"The avalanche danger is going to be higher, and avalanche conditions are going to be trickier this coming week than what we've seen so far this season," said Greene. "There are still lots of great, safe places to go. We want people to check the avalanche forecast and make a plan that keeps them out of avalanche terrain or off of the dangerous slopes."  

Forecast Timeline: 

• Wednesday: Snowfall totals may reach 3 feet in areas like the Park Range, Flat Tops, and Elk Mountains, with 2 feet or more across most mountains Avalanche danger will likely reach HIGH (4 of 5) in much of the Northern and Central Mountains, and in the western San Juan mountains.
• Thanksgiving: Avalanche conditions are expected to remain very dangerous  (CONSIDERABLE (3 OF 5) 
• Friday-Sunday: While the storm ends late Wednesday or early Thursday, dangerous avalanche conditions will continue as the snowpack adjusts to this rapid load. With clear skies, fresh snow, and the holiday weekend, backcountry activity will likely increase. Special Avalanche Advisories are anticipated.

It is crucial for all backcountry travelers to stay informed about the latest avalanche conditions. Always visit CAIC's website at Colorado.gov/avalanche for the most up-to-date information. The CAIC strongly advises all backcountry travelers to check the avalanche forecast regularly and adjust their plans accordingly. Always carry proper avalanche safety gear, including a transceiver, probe, and shovel, and know how to use them. Avoid avalanche-prone terrain during periods of heightened danger.  

As of Tuesday afternoon, the Colorado Department of Transportation had this warning: Long-duration moderate to heavy snowfall rates will make mountain driving conditions very difficult through tonight and perhaps into much of Wednesday (Nov. 27). While the heavy volume of snow will contribute to the majority of impacts, stronger winds will also support areas of blowing snow and reduced visibility, especially over the passes in the central and southern mountains today. Ski and holiday travelers should expect difficult driving conditions and be prepared for the possibility of road closures or delays. Front Range roadways may see snow into Wednesday with heaviest accumulations probable in the Monument Hill/Palmer Divide area north of Colorado Springs. 

Also, visit the Colorado Department of Transportation road conditions site: www.cotrip.org. 

Since 1950, avalanches have killed more people in Colorado than any other natural hazard, and in the United States, Colorado accounts for one-third of all avalanche deaths nationally.