Avalanche Forecast
Issued: Nov 24th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
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Avalanche Canada
Heightened avalanche conditions exist on steep and wind loaded slopes. We recommend extra caution as we have very limited field observations at this point.
Summary
Confidence
Low - Uncertainty is due to the limited number of field observations.
Weather Forecast
WEDNESDAY NIGHT: Periods of snow with accumulations of roughly 5 cm, moderate southwest wind with gusts to 60 km/h, treeline temperatures around -8 C.
THURSDAY: Cloudy with periods of snow totalling 3-5 cm, light southwest wind with gusts to 40 km/h, treeline temperatures around -6 C.
FRIDAY: A weak front brings 5-15 cm of snow, strong south wind, treeline temperatures around -8 C.
SATURDAY: Mostly cloudy with some light flurries, light wind, treeline temperatures around -10 C.
Avalanche Summary
Reports of avalanches this season have been limited to small slabs and cornice falls on steep wind-affected slopes. The current weather pattern is favourable for forming new wind slabs in steep open terrain.Â
With uncertainty about the snowpack structure, it may also be possible to trigger large avalanches from thin areas on big alpine slopes. Until there is more information about the snowpack we recommend an extra cautious approach and careful snowpack evaluation, especially in high-consequence terrain.
Snowpack Summary
Moderate snowfall and strong wind over the past few days has likely formed pockets of soft snow in sheltered areas and wind slabs in lee terrain. While the snowpack depth is only 65 cm at Fraser, reports indicate more than 100 cm has accumulated at higher elevations. This means many upper elevation slopes have reached the threshold depth for avalanches.Â
One or multiple crusts formed near the bottom of the snowpack in October, and the snow around these crusts has likely been forming weak faceted layers. These crusts and weak layers will now be buried 40-80 cm below the surface. While there have not been reports of avalanches on these layers, this structure is suspect and could develop into a bigger problem this season.
Terrain and Travel
- Pay attention to the wind, once it starts to blow fresh sensitive wind slabs are likely to form.
- Use ridges or ribs to avoid areas of wind loaded snow.
- Avoid shallow snowpack areas, rock outcroppings and steep convex terrain where triggering is most likely.
Problems
Wind Slabs
Expect unstable slabs in steep leeward terrain. The current snowy and windy weather pattern is likely forming wind slabs at upper elevations.
Aspects: North, North East, East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Nov 25th, 2021 4:00PM
