Avalanche Forecast
Issued: Dec 15th, 2023 4:00PM
The alpine rating is Storm Slabs and Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeBe patient, choose mellow terrain, and give the snowpack time to adjust to the new load.
Storm slabs and buried weak layers may be primed for human triggering.
Summary
Confidence
Low
Avalanche Summary
No new avalanche reports were submitted on Friday. We expect a natural avalanche cycle to occur overnight and into the early morning with the moderate to heavy snowfall. Human triggered avalanches will still be likely through to the end of the day.
If you go out in the backcountry, please consider sharing your observations on the Mountain Information Network (MIN).
Snowpack Summary
15-25 cm of new snow falling to moderate to strong southwest winds has likely formed reactive storm slabs. This new snow sits on old, hard surfaces, like windslabs or a frozen crust, which are good sliding surfaces for avalanches.
A concerning layer of surface hoar can be found 50-90 cm below the snow surface.
A crust with sugary facets beneath it can be found just above the ground. The snowpack is still shallow for this time of year. Average snowpack depths at treeline range from 65 to 90 cm.
Weather Summary
Friday Night
Cloudy. 15-25 cm of snow expected to valley bottom. Moderate to strong southwest ridgetop wind. Treeline temperature falling to around -5°C.
Saturday
Cloudy. 2 cm of snow expected. Moderate southwest ridgetop wind. Treeline temperature around -5°C. Freezing level rising to 1200 m in some areas.
Sunday
Partly cloudy. No new snow expected. Moderate to strong southwest ridgetop wind. Treeline temperature around -6°C with alpine temperature inversion.
Monday
Mostly cloudy. 3 cm of snow expected. Light to moderate southeast ridgetop wind. Treeline temperature around -6°C with alpine temperature inversion.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Be careful to keep storm day fever from luring you out into bigger terrain features.
- Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
- Storm slabs in motion may step down to deeper layers resulting in large avalanches.
Problems
Storm Slabs
New snow and wind is forming reactive slabs at all elevations. Use extra caution around ridgecrests, rolls, and on convex slopes. Retreat to mellower terrain if you find signs of instability like shooting cracks, or recent avalanches.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
Buried surface hoar is most likely to be found at treeline and above. It's most triggerable where the buried rain crust is thinner and less supportive, or absent.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 16th, 2023 4:00PM