Avalanche Forecast
Issued: Dec 28th, 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
Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
Keep in mind that cold temperatures significantly increase the consequence of even minor injuries in the backcountry.
Summary
Confidence
Moderate - Uncertainty is due to the fact that persistent slabs are particularly difficult to forecast.
Weather Forecast
TUESDAY NIGHT: Cloudy / Light variable wind / Low of -32
WEDNESDAY: Sunny / Light northwest wind increasing to moderate in the afternoon / High of -20
THURSDAY: Mix of sun and cloud / Moderate northwest wind / High of -20
FRIDAY: Mix of sun and cloud / Light variable wind / High of -23
Avalanche Summary
Numerous naturally triggered storm slab avalanches up to size 2 were reported on Monday. See MIN report.
Snowpack Summary
Recent storm totals reached over 120 cm! Expect dry loose avalanches (sluffing) running far and fast in steep terrain.
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.Â
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.
- Be aware of the potential for loose avalanches in steep terrain where snow hasn't formed a slab.
- If triggered, loose dry avalanches may step down to deeper layers resulting in large avalanches.
Problems
Wind Slabs
Recent winds have created wind slabs on a variety of aspects and created a lot of variability in the upper snowpack. Recent wind slab formation has been reported at all elevations, including open areas below treeline.
Aspects: All aspects.
Elevations: All elevations.
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 29th, 2021 3:00PM
