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, Deep Persistent Slabs and Persistent Slabs.
lbaker,
Avalanche Canada
Continue to choose conservative terrain and watch for signs of instability as strong winds continue to promote slab development in lees throughout the day.
Avoid shallow, rocky snowpack areas where triggering the deep persistent weak layer is still possible.
Summary
Confidence
Avalanche Summary
The poor visibility over the last few days has kept operators from seeing into higher elevations however on Tuesday, a size one skier accidental avalanche was reported on a northwest feature below treeline.
On Sunday and Monday, several small natural wind slab avalanches were observed, up to size 1.5, at treeline on steep east-facing slopes.
On Saturday, wind slabs were reported to be reactive to skier traffic at treeline. A natural wind slab avalanche, size 2, was reported on an east aspect at 2100 m.
Snowpack Summary
60-100 cm of storm snow from the last week continues to be redistributed by southwest winds. Storm snow sits above a plethora of old snow surfaces including previously wind-affected snow at upper elevations, a sun crust on steep solar aspects, faceted snow, and surface hoar crystals in wind-sheltered terrain.
In the upper meter of the snowpack sits two layers of surface hoar crystals and/or a melt-freeze crust. The surface hoar is most likely found around treeline and lower alpine elevations. The melt-freeze crust is found up to 1800 m on all aspects and into the alpine on sun-exposed slopes.
Large and weak facets from November are near the base of the snowpack and continue to produce very large avalanches in the region.
Weather Summary
Wednesday Night
Partly cloudy. Ridge wind southwest 40-50 km/h. Alpine temperatures rise to -7 C. Freezing level valley bottom.
Thursday
Partly cloudy with isolated flurries, 2-5 cm accumulation. Ridge wind from the southwest 50 km/h picks up to 70 km/h in the evening. Alpine temperatures rise to -3 C. Freezing level rises to 1400 meters.
Friday
Cloudy with sunny periods isolated flurries, 2-5 cm accumulation. Ridge wind southwest 40-50 km/h. Alpine temperatures rise to -2 C. Freezing level rises to 1200 meters.
Saturday
Mix of sun and cloud with isolated flurries, 2-5 cm accumulation. Ridge wind southwest 40-50 km/h. Alpine temperatures rise to -3 C. Freezing level rises to 1000 meters.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Seek out sheltered terrain where new snow hasn't been wind-affected.
- Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
- Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
Problems
Wind Slabs
Make observations and asses conditions continually as you travel into different aspects and elevations. Southwest winds are redistributing storm snow into deep pockets at higher elevations. Slabs will likely be the deepest and most reactive on north and east aspects at treeline and above.
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, West, North West.
Elevations: All elevations.
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: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Two surface hoar layers found in the upper 100 cm of the snowpack have been reactive in scattered areas around the region. Be especially cautious around steep openings within and near treeline elevations, especially where the recent storm snow has been wind affected.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 9th, 2023 4:00PM
