Avalanche Forecast
Issued: Dec 6th, 2020 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Deep Persistent Slabs.
ahanna,
Avalanche Canada
The next storm will start to trickle into the north of the region over the day. If more than 10 cm of new snow falls, avalanche danger will rise to MODERATE in the alpine and wind exposed treeline areas.
Summary
Confidence
Moderate - Uncertainty is due to the timing, track, & intensity of the incoming weather system.
Weather Forecast
The incoming storm will deliver the bulk of its goods on Monday night and over the day Tuesday. Highest snowfall amounts will be in the north of the region.
Sunday night: Increasing cloud with flurries starting in the early morning, moderate southwest wind, freezing level valley bottom to 700 m.
Monday: Up to 10 cm new snow, moderate southwest wind, freezing level 800-1200 m.
Tuesday: 15-30 cm new snow, moderate southwest wind, freezing level 1100 m.
Wednesday: 5-15 cm new snow, light northwest wind, freezing level 1000 m.
Avalanche Summary
Small loose dry sluffing may be observed in the new snow Monday. If more than 10 cm of new snow falls, small storm slabs may be triggerable in wind loaded lee features at upper elevations.
Our eyes and ears in the mountains are limited this winter due to fewer professional observations. If you go out in the mountains, please share your observations on the Mountain Information Network (MIN). Photos are especially helpful! Thank you so much for all the great MINs submitted so far!
Snowpack Summary
Around 5 cm of new snow falls ontop of a melt-freeze crust on south aspects and widespread surface hoar. Generally speaking, new snow does not bond well to these types of surfaces.
The lower snowpack is characterized by a couple of crusts, the most notable of which is sitting near the base of the snowpack, likely surrounded by a weak layer of sugary facets. It does not appear to be a concern at this time.
Terrain and Travel
- Be aware of the potential for loose avalanches in steep terrain where snow hasn't formed a slab.
- Expect slab conditions to change drastically as you move into wind exposed terrain.
Problems
Storm Slabs
Even with 10 cm of new snow over the day, slabs of any concern will be isolated to wind loaded pockets in lee terrain features at upper elevations.
You may see some loose dry sluffing under your skis in steep terrain.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
A crust sits near the base of the snowpack.
On the one hand, there hasn't been any associated avalanche activity in weeks.
On the other hand, it's surrounded by weak crystals and still producing hard results in snowpack tests.
Although we don't think it presents an avalanche problem under the current conditions, we're reluctant to throw it out altogether, especially with significant new snow accumulations on the horizon. If it were to rear its head, it would most likely be in shallow, rocky areas in the alpine.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 7th, 2020 4:00PM
