Avalanche Forecast
Issued: Dec 13th, 2020 4:33PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Loose Dry and Deep Persistent Slabs.
Conrad Janzen,
Continue to watch for sluffing of the faceted surface snow in steep terrain. Although fairly small, they can travel far, move fast, and gain enough mass to push you around in narrow gullies or couloirs. Enjoy the great ski conditions!
Summary
Weather Forecast
Mainly cloudy with sunny breaks on Monday and slightly warmer temperatures than Sunday. Alpine winds will stay in the light to moderate range out of the NW before increasing to the strong range on Tuesday. No new snow forecast on Monday with light flurries expected on Tuesday and Wednesday.Â
Snowpack Summary
Trace of new snow and light wind effect in the alpine. 20-40 cm of faceted snow sits on the Dec 7th layer of sun crust, facets or surface hoar depending on your location. The Nov. 5th crust / facet layer persists at the bottom of the snowpack and continues to weaken over time. Snowpack depths are 90-160cm at tree line.
Avalanche Summary
No new avalanches reported on Sunday, but reports of skier triggered sluffs running far and fast in steep terrain. Previous reports of loose, dry avalanches up to sz 2 in steeper alpine features like gullies when the wind picked up Saturday. Sporadic reports of explosive triggered deep slab avalanches running on the Nov 5 crust or the basal facets.
Confidence
Due to the number and quality of field observations
Problems
Loose Dry
20-40 cm of recent snow is now faceted. In steep terrain, wind or people can start a small avalanche in the surface snow that will run far on the layer of facets, sun crust or surface hoar underneath it. This trend will increase over the next days.
- Be careful of loose dry power sluffing in steep terrain.
- Be cautious with gully features.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
The Nov 5 crust has facets above and below it, and exists up to 2500m on shady aspects and higher on solar aspects. We have only had isolated observations of a deep slab avalanches since the storm, but it is still on our minds in shallow areas.
- Be aware of thin areas that may propogate to deeper instabilites.
- Pay attention to overhead hazards like cornices which could trigger the deep persistent slab.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 14th, 2020 4:00PM
