Avalanche Forecast
Issued: Dec 8th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Deep Persistent Slabs.
Grant Statham,
Cool temperatures and minor amounts of new snow are keeping the likelihood of natural avalanches low, but human triggered windslabs are possible at treeline and likely in the alpine due to sustained winds transporting dry snow into leeward areas.
Summary
Weather Forecast
A NW flow will keep the weather active and temperatures cool over the next few days. Light snow expected to continue overnight Wednesday, tapering on Thursday with accumulations 5-10 cm. Temperatures for Thursday in the -10 to -15 range and sustained moderate winds from the NW. Saturday looks like a potentially big snowfall.
Snowpack Summary
5-10 cm of new snow over the last 24-hrs makes for 15-20 cm of soft surface snow above the Dec 2 rain crust. This crust disappears at about 2100 m. At treeline and above, moderate winds are developing soft slabs in immediate leeward slopes. The Dec 2 crust may cause problems in the future with additional load. Weak facets exist near the ground.
Avalanche Summary
Windslabs up to size 2 were reported by the Lake Louise ski patrol on Wednesday, formed from 36-hours of sustained winds moving snow from fetch areas. Otherwise no new avalanches reported and the last significant one was a skier accidental size 3 triggered on Lipalian Mountain (near Lake Louise) on Sunday.
Confidence
Problems
Wind Slabs
Sustained winds from the west are moving snow from fetch areas and depositing in leeward slopes. These are soft slabs but could be easily triggered. Use caution in all leeward terrain at treeline and in the alpine.
Aspects: North, North East, East, South East, South, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
We continue to see occasional high consequence avalanches on the Nov 5 crust/basal facets in specific terrain features. Some slabs have initiated on this layer, while others were "step down" avalanches triggered as wind slabs or cornices hit them.
- Avoid steep convexities or areas with a thin or variable snowpack.
- Be aware of the potential for full depth avalanches due to deeply buried weak layers.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 9th, 2021 4:00PM
