Avalanche Forecast
Issued: Jan 28th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
Lisa Paulson,
There is still a lot of uncertainty around the deeper facets in the snowpack. It is very difficult to assess slopes with these types of layers. Your terrain choices will be the best risk management.
Summary
Weather Forecast
For Saturday and Sunday, temperatures will range from -10C to -5C and winds will remain strong from the West. No snow is expected until Sunday night when an Arctic cold front moves down the Rockies dropping temperatures as we head into next week.
Snowpack Summary
Wind effect and wind slabs in the alpine and exposed tree-line areas and suncrust on steep south facing terrain. In sheltered areas, 20-40 cm of soft snow overlies facets and is good skiing. Facets and a weak mid-pack remain the dominant concern and the Dec 2 crust is down 100-150 cm and producing hard test results in most of Yoho.
Avalanche Summary
Skiers triggered a cornice that triggered a size 3 avalanche on the east face of Mt. Carnarvon (above Hamilton Lakes in Yoho Park) on Tuesday. This stepped down to a deeper persistent layer, which illustrates that big triggers or "hitting the sweet spot" can still produce large avalanches. Nothing new reported on Thursday.
Confidence
Due to the number and quality of field observations
Problems
Wind Slabs
Recent winds have created windslabs in the alpine and some treeline locations. Older slabs may still be reactive where they overly facets. New wind slabs can be expected to be very thin and only in immediate lees.
- Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
This represents the Dec. 2nd crust/ facet layer (treeline and below) and layers of faceted snow that were formed during the late December cold snap (all elevations). BTL concern likely only for thinner snowpack areas such as Mt. Stephen and Dennis.
- If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
- Forecasters are operating with alot of uncertainty at this time.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Jan 29th, 2022 4:00PM
