Avalanche Forecast
Issued: Dec 23rd, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs, Wind Slabs and Persistent Slabs.
Lynnea Baker,
The storm has arrived bringing 20 cm snow high winds and warm temps. Over the next few days expect to see storm slabs become more reactive as more snow continues to load weak layers.
Summary
Weather Forecast
Friday: Overcast and snowing up to 20 cm. Light NE winds. Alpine temps high -12. Freezing levels valley bottom
Saturday: Overcast and snowing 15 - 20 cm. Light NE winds. Alpine temps high -16. FL valley bottom.
Sunday: Overcast with flurries, amounting to 5 cm. Light NE winds. Alpine temps high -30. FL valley bottom.
Snowpack Summary
20 cm new snow and variable winds are creating storm slabs and crossloading features. Warm temps are promoting cohesion of storm slabs. New snow overlies a series of previous windslabs 20-60 cm thick in AL/TL. This sits atop facets above Dec 4 crust. A 20-60 cm thick Nov MFcr complex completes the snowpack to ground. HS at TL is 110 - 170.
Avalanche Summary
No new avalanches reported in park with very limited visibility in the last few days. Operation north and west of the park are reporting several wind slabs up to size 2. If you go out into the mountains please share your observations on the Mountain Information Network.
Confidence
Intensity of incoming weather systems is uncertain
Problems
Storm Slabs
20 cm of new snow, variable winds and warm temps are creating a cohesive storm slab. With 20-30 cm more snow in forecast as winds and temperatures decrease we may also see a dry loose problem develop.
- If triggered the storm/wind slabs may step down to deeper layers resulting in large avalanches.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
Buried wind slabs 20 -60 cm is not bonded well to facets above Dec 4 crust. New load may wake up wind slabs as they reach threshold..
- Use caution in thin snowpack areas.
- If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
No avalanches observed on this layer this week, however with a large enough trigger this layer could produce results.
- If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 26th, 2021 4:00PM
