Avalanche Forecast
Issued: Dec 17th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Wind Slabs.
TRettie,
Avalanche Canada
Avoid "thick to thin" areas and steep roll overs, especially in wind effected terrain. Persistent slabs are challenging to manage. When in doubt choose more conservative terrain.
Summary
Confidence
Weather Forecast
Friday night: Low of -14 at 1700m. No new snow expected. Winds will be moderate from the Southwest.
Saturday: A storm arrives bringing 20 to 40cm of new snow with the greatest snowfall at Kootenay Pass. Strong Southwest winds. High of -8 at 1700m.
Sunday: light winds and no new snow expected. High of -6 at 1700m.
Monday: Some flurries in the afternoon with moderate Southwest winds. High of -7 at 1700m.
Avalanche Summary
A size 1.5 skier accidental was observed in a part of the South Columbia region that has similar snowpack conditions to the Kootenay boundary. This avalanche failed on the facets above the early December crust which was down 35cm on a North aspect at 2200m.
Snowpack Summary
The incoming weather will form new wind slab in exposed terrain.
The defining feature of the snowpack is a widespread crust that now sits 30-80cm below the surface. In some places overlying snow is well-bonded to the crust but in others, including Kootenay Pass, weak faceted grains have been observed above it around treeline.
Snow depths are roughly 140-180 cm at treeline throughout the region.
Terrain and Travel
- Be careful as you transition into wind affected terrain.
- Be aware of the potential for large avalanches due to the presence of buried persistent weak layers.
- In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
Problems
Persistent Slabs
Use extra caution on "thick to thin" areas and steep roll overs. Sensitivity to triggering will be greatest where wind slab overlies this layer.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
The incoming storm will form wind slab in exposed terrain.
Aspects: North, North East, East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 18th, 2021 4:00PM
