Avalanche Forecast
Issued: Dec 5th, 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.
dsaly,
Avalanche Canada
Low hazard doesn't mean no hazard. As you transition from melt-freeze conditions to dry snow, lookout for rogue wind-loaded pockets in lee features. And be wary of moist or wet snow under a hot sun.
Summary
Confidence
Weather Forecast
SATURDAY NIGHT: Cloudy patches / Moderate, south ridgetop wind / alpine low temperature -5 / Light inversion, freezing level dropping to valley bottom.
SUNDAY: Mostly sunny / Moderate, southwest ridgetop wind / alpine high temperature -1 / Freezing level 1400 m.
MONDAY: Cloudy with scattered flurries, up to 5 cm / Light, southwest ridgetop wind / alpine high temperature -3 / Freezing level 1400 m.
TUESDAY: Cloudy with scattered flurries, 5-15 cm / Light, gusty southwest ridgetop wind / alpine high temperature -1 / Freezing level 1300 m.
Avalanche Summary
No recent avalanches reported on Thursday or Friday.
Last Wednesday, numerous loose wet avalanches were reported from NE slopes above 2000 m. These avalanches were up to size 1.5 with no significant propagation.
Have you been out and about in the mountains? If so please submit to the Mountain Information Network (MIN). It doesn't have to be technical it can be as simple as a photo. Photos are especially helpful!
Sending a big thank you to the already submitted MIN's this season. Thanks everyone!
Snowpack Summary
Recent sun and warm air in the alpine likely had the greatest impact on the upper snowpack, melt-freeze conditions exist on most slopes including solar alpine features. In more shaded terrain at upper elevations where dry snow has prevailed, pockets of wind slab may be found on leeward slopes and below ridges. New surface hoar formation can be found at treeline and below where it is protected from the warm temperatures, sunshine and wind.
Treeline snowpack depths sit around 50 to 80 cm in the south of the region.
Crusts from mid-and early-November are generally found 30 cm below the snow surface and 10 cm up from the ground at all elevations. While they are showing resistant planar results in snowpack tests, a lot of uncertainty still exists with limited observations.
Terrain and Travel
- Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.
- Avoid exposure to steep, sun exposed slopes, especially when the solar radiation is strong.
- Back off slopes as the surface becomes moist or wet with rising temperatures.
Problems
Wind Slabs
At upper elevations where snow dry snow prevails (sheltered upper treeline and alpine terrain), winds have redistributed dry snow forming pockets of wind slabs in lee features and below ridgelines.
Aspects: North, North East, East, West, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
A crust exists near the base of the snowpack. We have a lack of decisive data on this layer so we're keeping it on our radar for now. While it's been showing some 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: Dec 6th, 2020 4:00PM
