Avalanche Forecast
Issued: Dec 15th, 2020 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Persistent Slabs.
kdevine,
Avalanche Canada
20-40 cm of new snow with southwest winds have likely formed reactive storm slabs. Choose conservative terrain and watch for signs of instability such as whumphing, cracking and recent avalanches.
Summary
Confidence
Moderate - Uncertainty is due to the limited number of field observations.
Weather Forecast
TUESDAY NIGHT - Cloudy with flurries, 5-10 cm / southwest wind, 25-50 km/h / alpine low temperature near -8
WEDNESDAY - Mainly cloudy with isolated flurries, 5 cm / southwest wind, 20-40 km/h / alpine high temperature near -7Â
THURSDAY - Flurries, 5-15 cm / southwest wind, 20-40 km/h / alpine high temperature near -7
FRIDAY - Periods of snow, 15-20 cm / southwest wind, 30-60 km/h / alpine high temperature near -7
Avalanche Summary
With 20-40 cm of new snow and moderate to strong southwest winds, human triggered avalanches are likely, especially in wind loaded areas.
Snowpack Summary
20-40 cm of snow has fallen in the region since Monday afternoon. This new snow has buried a weak layer of surface hoar in many areas. Moderate to strong southwest winds will mean that this new snow will likely form reactive slabs.
A weak layer that was buried about a week ago is now down 40-60 cm. This layer is variable and has been reported to exist as either a crust or surface hoar. In any case, it is a persistent weak layer with a significant load above it now, and it may react easily to human triggers.
Another crust that was buried in early November can be found near the base of the snowpack. There have been no recent avalanches reported on this layer, however it may be possible to trigger it from shallow, rocky terrain.
Terrain and Travel
- Choose conservative terrain and watch for clues of instability.
- Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
- Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
Problems
Storm Slabs
20-40 cm of new snow sits on a weak layer of surface hoar. This new snow combined with southwest winds has likely created slabs that may be easy to trigger.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
40-60 cm of snow sits above a layer of surface hoar and/or crusts.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 16th, 2020 4:00PM
