Avalanche Forecast
Issued: Dec 16th, 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
We are reaching a tipping point where triggering large, destructive avalanches will become more likely . Where exactly these large avalanches can be triggered will be hard to predict. Read the forecaster's blog to learn more.
Summary
Confidence
Low - Uncertainty is due to the fact that persistent slabs are particularly difficult to forecast.
Weather Forecast
Thursday night: No new snow expected. moderate Northwest winds with a low of -11 at 1500m.
Friday: Sunny with no new snow. moderate Northwest winds becoming light to moderate Southwest in the afternoon. A high of -11 at 1500m.
Saturday: A storm arrives bringing 10 to 40cm of new snow with the greatest snowfall at Kootenay Pass. Strong Southwest winds. High of -6 at 1500m.
Sunday: light winds and no new snow expected. High of -6 at 1500m.
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
Up to 10cm of low density snow overlies old variably wind effected surfaces.
The defining feature of the snowpack is a widespread crust that now sits 30-70 cm below the surface. In many 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. Â
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.
Problems
Persistent Slabs
Use extra caution on South aspects where solar input will increase cohesion in the slab above this layer. We are reaching a tipping point where reactivity on this layer will increase.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
Wind slab can still be found in exposed terrain in treeline and above. Sensitivity to triggering will be greatest where wind slab overlies the early December facet/crust combo.
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 17th, 2021 4:00PM
