Avalanche Forecast
Issued: Nov 29th, 2020 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.
ahanna,
Avalanche Canada
Find the best snow in wind sheltered areas. A lack of decisive data on the basal crust is keeping it on our radar for now.
Summary
Confidence
Low - Uncertainty is due to the limited number of field observations.
Weather Forecast
Sunday night: Clear, southwest wind building moderate to strong, freezing level valley bottom.
Monday: 5-15 cm new snow, moderate to strong southwest wind, freezing level 800-1000 m.
Tuesday: Clear, light NW wind, freezing level 500 m.
Wednesday: Clear, light wind, freezing level 500 m with an above freezing layer 1500-3000 m.
Avalanche Summary
Explosive control work produced size 1-1.5 wind slab avalanches on Friday. We have received no reports of recent natural avalanche activity.
Our eyes and ears in the mountains are limited at this time of year and may continue this winter due to fewer professional observations. If you see anything (or don't) while out in the field, please consider sharing via the Mountain Information Network (MIN). Photos are especially helpful! Thank you so much for all the great MINs submitted so far!
Snowpack Summary
Previous southerly wind has formed wind slabs in lee terrain features at upper elevations. In more sheltered areas, 10-15 cm may overly a layer of weak and feathery surface hoar (observed at Kootenay Pass).
Treeline snowpack depths sit around 100 to 150 cm in the north and 50 to 100 cm in the south of the region.Â
Melt-freeze crusts from mid- and early-November are generally found 30 cm below the snow surface and 30 cm up from the ground, respectively. While they are still showing results in snowpack tests, most reports indicate that the bonds at the interfaces with these crusts are improving.
Terrain and Travel
- Be careful as you transition into wind affected terrain.
- Be aware of the possibility for full depth avalanches due to deeply buried weak layers.
- Be cautious of buried obstacles especially below treeline.
Problems
Wind Slabs
Previous southerly wind has formed wind slabs in lee terrain features at upper elevations.
Aspects: North, North East, East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
A crust exists near the base of the snowpack. A lack of decisive data on this layer is keeping it on our radar for now. While it's been showing results in snowpack tests in some areas, most reports describe an improving bond to the overlying snow. Potential for full depth avalanches may exist in areas where weak, sugary facets overly this crust, especially in areas of smooth ground cover such as scree slopes, grassy slopes, or rock slabs.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Nov 30th, 2020 4:00PM
