Avalanche Forecast
Issued: Jan 6th, 2020 4:30PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
astclair,
Avalanche Canada
Snow, wind, and buried weak layers are keeping conditions complicated and dangerous. Stay vigilant with simple terrain choices as this pattern continues.
Summary
Confidence
Weather Forecast
Monday night: Partly cloudy with isolated flurries with trace accumulations, light west winds, alpine temperature -12 C.
Tuesday: Cloudy, 5-15 cm of snow, moderate south winds, alpine high temperature -8 C.
Wednesday: Cloudy, 10-20 cm overnight and throughout the day, moderate west winds, alpine high temperature -9 C.
Thursday: Mix of sun and cloud, isolated flurries with trace accumulations, light southwest winds, alpine high temperature -11 C.
Avalanche Summary
There have been many reports of small to large (size 1.5-2.5) avalanches from both natural and human triggers on a variety of aspects and elevations. Most of these avalanches released on a surface hoar layer formed in late December. A few avalanches have been remote-triggered, like this one observed Wednesday.
Be sure to check out this MIN, this MIN, and this MIN for helpful illustrations of slopes that are likely to harbor this problem. A sincere thanks to the community for submitting these reports!
Snowpack Summary
Recent snowfall has been redistributed by wind in exposed areas, loading lee features with stiffer, more reactive slabs.
Over the past week, a total of 70-100 cm of snow has accumulated burying a weak layer of feathery surface hoar and a hard melt-freeze crust on sun-exposed aspects. This layer formed in late December and continues to produce large avalanches across aspects and elevations. Snowpack tests have also confirmed this weak layer's propagation potential (check out this MIN from Saturday).
Terrain and Travel
- Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
- Choose simple, low-angle, well supported terrain without convexities.
- Be aware of the potential for large avalanches due to the presence of buried weak layers.
Problems
Wind Slabs
Recent strong winds with ample snow for transport over the past 48 hours have formed touchy wind slabs in exposed areas, particularly near ridge features.
Aspects: North, North East, East, South East, South, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
A layer of surface hoar from late December is now buried 60-100 cm deep. This layer has produced many large avalanches across aspects and elevations with incremental loading from new snow and wind. A few of these avalanches were human-triggered remotely from adjacent slopes.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Jan 7th, 2020 5:00PM
