Avalanche Forecast
Issued: Nov 26th, 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
Watch for reactive wind slabs at upper elevations, and be aware of the potential for larger avalanches due to a crust that was buried in early November.
Summary
Confidence
Weather Forecast
Thursday night: Mostly cloudy, light to moderate northwest wind, freezing level 500 m.
Friday: Mostly cloudy, moderate southwest wind, freezing level 1000 m.
Saturday: Up to 5 cm new snow overnight then clearing, moderate southwest wind, freezing level 500-1000 m.
Sunday: Scattered cloud, light southwest wind, freezing level 700 m.
Avalanche Summary
Small loose avalanches were observed out of steep terrain on Wednesday.
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 while out in the field, please consider sharing it with us and fellow recreationists via the Mountain Information Network (MIN). Even just a photo of where you went is helpful. A big thank you to those that have already shared their observations thus far.
Snowpack Summary
The snowpack is deepest in the north of the region and shallowest in the south. Expect to find around 100 to 150 cm at treeline in the north and 50 to 100 cm in the south.
About 10 to 15 cm of recent snow may have been redistributed by the wind, forming deeper and cohesive deposits in lee terrain features at higher elevations. This recent snow may overly a layer of weak and feathery surface hoar that likely only exists in sheltered terrain features and perhaps only in the south of the region (e.g., Kootenay Pass).
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. Some reports suggest the snow is well-bonded to these crusts but other reports have found unstable conditions, where sugary faceted grains exist above the crust.
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
Strong southerly wind has likely formed wind slabs in lee terrain features at higher elevations.
Aspects: North, North East, East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
A crust found near the base of the snowpack may have weak and sugary faceted grains immediately above it. For areas where this is the case, there is potential for large avalanches to form. The most likely terrain features of concern are where the ground cover is smooth, such as on scree slopes, grassy slopes, or rock slabs.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Nov 27th, 2020 4:00PM
