Avalanche Forecast
Issued: Nov 25th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
cgarritty,
VIAC
Friday is a good day to investigate dry snow accumulations in the wake of the storm. Take a cautious approach and monitor its bond to the old surface if you find it - especially in wind-exposed terrain
Summary
Confidence
Moderate - Uncertainty is due to the limited number of field observations.
Weather Forecast
Thursday night: Cloudy with lingering flurries bringing about 5 cm of new snow. Moderate southwest winds.
Friday: A mix of sun and cloud. Light variable winds. Treeline high temperatures around -3 with freezing levels returning to about 900 metres.
Saturday: Cloudy with moderate to heavy rain; 15-35 mm, increasing overnight. Strong to extreme southwest winds. Treeline high temperatures around +5 as freezing levels jump to 2800 metres.
Sunday: Cloudy with light flurries bringing up to 5 cm of new snow. Moderate to strong southwest winds. Treeline high temperatures around 0C.
Avalanche Summary
No avalanches have been reported in the region. After Thursday's rain at most elevations, avalanche potential is expected to be quite limited. Where we see dry snow accumulating as temperatures cool and precipitation tapers, there will be a chance of small but reactive wind slabs to manage in leeward terrain pockets in the alpine and upper treeline.
Reports in the region remain limited. Be sure to post your observations to the Mountain Information Network!
Snowpack Summary
By the end of Thursday's storm, the region will have picked up 40-60 mm of precipitation, however much of this will have fallen as rain. As temperatures cool into the end of the day Thursday we could see around 5-10 cm of new snow accumulate over the rain-wetted surface.
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Any final accumulations of dry snow should bond quite rapidly to the underlying wet grains, however small, reactive wind slabs could still form in specific wind-loaded features in the lee of ridgecrests and other exposed terrain features. This issue will likely be limited to the alpine if it presents itself at all.
Preliminary investigations into the region's existing snowpack suggest the snowline has reached about 850 metres, but that snowpack depths remain below threshold for avalanches below about 1300 metres and in the entire below treeline elevation band. Alpine snowpack depths are likely approaching 150 or more cm, with that depth tapering dramatically with elevation to about 30-60 cm at treeline.
Terrain and Travel
- Be alert to conditions that change with elevation.
- Avalanche danger is often elevated in alpine gullies where snow has accumulated.
Problems
Wind Slabs
If a bit of dry snow accumulates as temperatures cool and precipitation tapers, there is a chance for small but reactive wind slabs to exist in leeward terrain pockets at higher elevations.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Nov 26th, 2021 4:00PM
