Archived as part of an accident report file for Dec 12 2019 Avalanche Warning Issued: Saturday, December 14, 2019 at 5:00 AM Expires: Sunday, December 15, 2019 at 8:00 AM An Avalanche Warning is in effect for the Steamboat, Front Range, Vail and Summit County, Sawatch, Aspen, and Gunnison zones. Very dangerous avalanche conditions exist. Heavy snowfall and strong winds have increased the avalanche danger. Large human triggered avalanches are likely today. You can trigger avalanches from below and from adjacent slopes. If you trigger an avalanche it will break near the ground. Avalanches will be large enough to bury and kill you. Travel in and under avalanche terrain is not recommended. Backcountry Avalanche Forecast Sun, Dec 15, 2019 at 7:10 AM Issued by: Kreston Rohrig Today, Tomorrow, All Elevations: Considerable (3) Dangerous avalanche conditions. Cautious route-finding and conservative decision-making essential. Summary The avalanche danger has eased slightly but the mountains are still dangerous. One to three feet of snow coupled with strong westerly winds has created prime avalanche conditions. It will be easy to trigger avalanches on slopes steeper than around 30 degrees, especially in deeper, wind-drifted areas. If you trigger an avalanche it will likely break to the ground and be very hard to escape. Even in wind-sheltered areas nasty weak layers buried just below the storm snow may fail easily below you. Watch for shooting cracks and large collapses as sure signs of unstable snow. The bottom line is: many slopes are dangerous and the snowpack will need time to adjust to this heavy load. Conservative terrain choices and cautious route-finding are essential to all backcountry travelers for the next few days. Avalanche Problem: Persistent Slab Aspect: N, E, NW, NE Elevation: All Likelihood: Likely Size: Large What You Need to Know About These Avalanches: Persistent Slab avalanches can be triggered days to weeks after the last storm. They often propagate across and beyond terrain features that would otherwise confine Wind and Storm Slab avalanches. In some cases they can be triggered remotely, from low-angle terrain or adjacent slopes. Give yourself a wide safety buffer to address the uncertainty. Avalanche Problem: Storm Slab Aspect: All Elevation: All Likelihood: Likely Size: Small - Large What You Need to Know About These Avalanches: Storm Slab avalanches release naturally during snow storms and can be triggered for a few days after a storm. They often release at or below the trigger point. They exist throughout the terrain. Avoid them by waiting for the storm snow to stabilize. Discussion Sun, Dec 15, 2019 at 7:45 AM Issued by: Kreston Rohrig Dangerous avalanche conditions exist. Travel in and under avalanche terrain is not recommended. One to three feet of snow along with strong winds are overloading the snowpack in the Northern Mountains. If you are recreating in the backcountry at all today, plan your route very carefully. Make sure you do not cross under steep slopes especially ones that face northerly and easterly. Stay out of any gullies with steep sidewalls. Stay well back from the edge of cornices, even on flat ridges. Cornices can break much further back than you would expect. If you trigger an avalanche today it will break at the ground, and could be triggered from the bottom of a slope or remotely from an adjacent slope. Avalanches will be large and possibly deadly. For the next few days, you should highly consider avoiding any travel on or around any steep slopes, especially those that are receiving wind-drifted snow. This storm was unusually powerful and many snowpacks have seen an increase of 30-50% throughout the north. Piling that much snow on top of a weak early season snowpack is going to be troublesome for many days to come. Be patient and let the snowpack adjust to this heavy load before even thinking about steeper slopes. Thick slabs are now connected through large pieces of terrain and can break wider and run farther than you would expect.