Avalanche Forecast
Issued: Dec 22nd, 2020 3:00PM
The alpine rating is Wind Slabs and Deep Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includePull in the reins! Lots of new snow, but hazard is high. Human triggering of avalanches is very likely.
Summary
Confidence
Moderate -
Weather Forecast
Wednesday should be mainly sunny with a brisk -20c to start the day. Temperatures should rise to near -11c with winds out of the north in the light to moderate range. No new snow is expected.
Avalanche Summary
Observations have been somewhat limited by poor visibility, but an avalanche cycle is occurring. Numerous slabs and loose dry avalanches up to size 2.5 have occurred in the past 24 hours. These are occurring at all elevations and on all aspects.
Snowpack Summary
40 to 50cm of snow fell in a very short period of time, which has overloaded the snowpack. Winds were strong out of the north during the storm, so expect widespread wind slabs at Treeline and above. The Dec 8th layer of surface hoar/crust/facets remains on the radar, especially with this new load. The Nov rain crust is now deeply buried in the snowpack, and while it hasn't been reactive recently, it could easily wake up with the new snow load. Field observations were very limited today, and forecasters will be going out with eyes wide open on their next field day - the snowpack has experienced significant change!
Terrain and Travel
- Avoid steep convex slopes.
- Back off steep and aggressive lines, stick to simple terrain.
- Make conservative terrain choices and avoid overhead hazard.
- Be cautious of sluffing.
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
Problems
Wind Slabs
Freshly formed surface wind slabs could be as deep as 60-80cm and will be very sensitive to human triggering. Also watch for previously formed (now buried) wind slabs with failure planes deeper in the snowpack.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
A lot of new load has been added to the snowpack. The deep weak layer of the Nov crust may become active.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 23rd, 2020 3:00PM