Avalanche Forecast
Issued: Dec 29th, 2021 3:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
JSmith,
Avalanche Canada
Westerly winds overnight are expected to form reactive wind slabs on lee features at treeline and above.
Keep in mind that cold temperatures significantly increase the consequence of even minor injuries in the backcountry.
Summary
Confidence
Weather Forecast
WEDNESDAY NIGHT: Mostly cloudy / Strong west wind / Low of -25
THURSDAY: Mix of sun and cloud / Light northwest wind / High of -19
FRIDAY: Mix of sun and cloud / Light north wind / High of -21
SATURDAY: Sunny / Strong northwest wind / High of -17
Avalanche Summary
Explosive control work on Wednesday produced numerous size 3 wind slab avalanches in the alpine.
Numerous naturally triggered storm slab avalanches up to size 2 were reported on Monday. See MIN report.
Snowpack Summary
Recent winds have created wind slabs on a variety of aspects and created a lot of variability in the upper snowpack.
A crust from early December is now 60-100 cm below the surface, and is found up to 2400 m. A layer of weak facets (sugary snow) has been reported above and below this crust. This is the layer of concern in our persistent avalanche problem, snowpack tests are generally showing hard results on this interface, however, areas where avalanches have recently failed on this crust continue to be problematic once reloaded with new snow.
Below 2300 m, several early-season crusts make up the lower snowpack. Snowpack depths range from 80-150 cm at treeline elevations and taper quickly below 1900m.
Terrain and Travel
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Recent wind has varied in direction so watch for wind slabs on all aspects.
- Be aware of the potential for large avalanches due to the presence of a persistent slab.
- Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
- Seek out wind sheltered terrain below treeline where you can avoid wind slabs and find great riding.
Problems
Wind Slabs
Forecast strong westerly winds Wednesday night are expected to form fresh wind slabs on lee features at treeline and above.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
A persistent slab problem formed by a crust down 60-100 cm has created a low likelihood, high consequence scenario that is difficult to forecast.
Avoid likely trigger spots such as steep, rocky slopes with a shallow or thin to thick snowpack.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 30th, 2021 3:00PM
