Avalanche Forecast
Issued: Dec 7th, 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
As a dusting of flurries and snow enters the region, consider avalanche hazard MODERATE in areas that accumulate over 10 cm.
Summary
Confidence
Moderate - Uncertainty is due to the limited number of field observations.
Weather Forecast
MONDAY NIGHT: Cloudy with isolated flurries / Moderate, south ridgetop wind / alpine low temperature -6 / Alpine inversion
TUESDAY: Cloudy with isolated flurries, trace to 10 cm / Light to moderate, gusty southwest ridgetop wind / alpine high temperature -1 / Freezing level 1100 m, alpine inversion
WEDNESDAY: Cloudy with isolated flurries, 5 cm / Light, gusty southwest ridgetop wind / alpine high temperature -4 / Freezing level 1000 m
THURSDAY: Cloudy / Light, south ridgetop wind / alpine high temperature -6 / Freezing level valley bottom
Avalanche Summary
Other than a few small loose-wet avalanches from steep terrain on the last few sunny days, the last avalanche observations were Wednesday Nov 2 when warming likely triggered numerous wet loose avalanches from NE slopes above 2000 m.
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!
Snowpack Summary
Light flurries are expected to fly around the region. The snowpack surface consists of the recent melt-freeze crust on most slopes. Cold, dry snow and wind affected surfaces are found on more shaded aspects at around treeline and above. Additionally, surface hoar has been observed developing around the region. Snowpack depths vary with elevation, treeline averages between 50-100 cm.Â
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 and while we don't think they're currently a problem, we're not ready to throw them out yet.
Terrain and Travel
- When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.
- Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.
- Small avalanches can have serious consequences in extreme terrain. Carefully evaluate your line for wind slab hazard before you commit to it.
Problems
Wind Slabs
Look for slab development (at colder, upper elevations) as wind redistributes flurries accumulating throughout the region. The most reactive slabs will be in wind-loaded areas or around ridges and convex rolls. Surface hoar growth was observed over the last few days, be wary of areas where snow forms a slab over surface hoar.
Aspects: North, North East, East, South East, West, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
A crust exists near the base of the snowpack, and weak, sugary facets have been observed over this crust. We have a lack of decisive data on this layer - it's been showing some results in snowpack tests in some areas, and most reports describe an improving bond to the overlying snow. Although we don't think it presents a problem, without more information we're reluctant to throw it out. The most likely trigger spots are terrain areas with smooth ground cover such as scree slopes, grassy slopes, or rock slabs.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 8th, 2020 4:00PM
