Avalanche Forecast
Issued: Feb 8th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Deep Persistent Slabs.
lbaker,
Avalanche Canada
Evaluate snow conditions as you transition into open terrain features, and be on the lookout for signs of instability like shooting cracks. Stiff, wind deposited snow can be expected to avalanche under the weight of a rider.
Avoid shallow, rocky snowpack areas where triggering the deep persistent weak layer is still possible
Summary
Confidence
Low
Avalanche Summary
No new avalanches have been reported, but field information is very limited in this region.
We suspect users who head to the backcountry will see evidence of a natural wind slab avalanche cycle from recent storm snow and strong southwest winds.
Snowpack Summary
+20 cm of storm snow in the alpine is being redistributed by southwesterly winds into wind slabs in lees. The recent storm snow sits on previously wind-affected surfaces. Below this, a melt-freeze crust is found on sun-exposed slopes and everywhere below 1600 m.
Several crust/facet/surface hoar layers exist in the upper and middle portions of the snowpack. The most concerning persistent weak layer is at the base of the snowpack from large and weak facets formed in November. This layer is widespread and most likely problematic in steep, rocky alpine terrain.
In general, the snowpack is weak and shallow in this area with an average snowpack depth of 100 cm at treeline.
Weather Summary
Wednesday Night
Partly cloudy. Ridge wind southwest 40-50 km/h. Alpine temperatures -10 C. Freezing level valley bottom.
Thursday
Mix of sun and clouds. Moderate ridge wind from the southwest picks up to 50-70 km/h in the evening. Alpine temperatures rise to -2 C. Freezing level rise to 1400m.
Friday
Mainly cloudy with sunny periods and isolated flurries, trace accumulation. Moderate ridge wind from the southwest picks up to 50-70 km/h in the evening. Alpine temperatures rise to -3 C. Freezing level 1300m.
Saturday
Mainly sunny with cloudy periods and isolated flurries, trace accumulation. Moderate ridge wind from the southwest picks up to 50-70 km/h in the evening. Alpine temperatures rise to -4 C. Freezing level 1000m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Watch for areas of hard wind slab on alpine features.
- Use ridges or ribs to avoid areas of wind loaded snow.
- Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
- Avalanche hazard may have improved, but be mindful that deep instabilities are still present.
Problems
Wind Slabs
+20 cm of storm snow and southwest winds are building fresh wind slabs in treeline and alpine lees. Approach lee and cross-loaded terrain with caution.
Keep in mind that wind slabs have the potential to step down to deeper weak layers, resulting in large and consequential avalanches.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
A layer of large and weak facets sits near the base of the snowpack. This layer is most prominent in upper treeline and alpine elevations. Riders are most likely to trigger an avalanche on this layer in steep, shallow terrain. Your best defence is to stay diligent in choosing low-consequence terrain away from overhead exposure. See more on the potential of triggering deeper weak layers in our latest Forecasters' Blog.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Feb 9th, 2023 4:00PM
