Avalanche Forecast
Issued: Dec 17th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Wind Slabs.
TRettie,
Avalanche Canada
Avoid "thick to thin" areas and steep roll overs, Especially in treeline terrain. Persistent slabs are challenging to manage, if in doubt choose conservative terrain. If you observe more than 30cm of new snow consider the hazard rating to be high in the treeline and alpine.
Summary
Confidence
Moderate -
Weather Forecast
Friday night: No new snow expected. Moderate Southwest winds and Low of -17 at 1600m.
Saturday: a storm arrives bringing up to 30cm of new snow with the greatest snowfall in the Monashees. Winds will be strong from the Southwest. High of -9 at 1600m.
Sunday: some light snow in the morning. Strong Southwest winds in the morning becoming light in the afternoon. High of -8 at 1600m.
Monday: some flurries in the afternoon with moderate Southwest winds. High of -11 at 1600m.
Avalanche Summary
On Tuesday one skier triggered size 1.5 was reported on a North aspect at 2200m. This avalanche occurred on the facets above the early December crust. The avalanche was triggered by the sixth skier to enter the slope.
Snowpack Summary
The incoming weather will form new windslab in the alpine and treeline.
The defining feature of the snowpack is a widespread crust that reaches as high as 2400 m and now sits 30-100 cm below the surface. In some places overlying snow is well-bonded to the crust but in others weak faceted grains have been observed above it. The faceting is most prominent in the treeline where the crust is thinner. We expect the incoming weather to increase the likelihood of triggering this layer.
Average snowpack depth at treeline is 200cm.
Terrain and Travel
- Be careful as you transition into wind affected terrain.
- Be aware of the potential for large avalanches due to the presence of a persistent slab.
- In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
Problems
Persistent Slabs
A few people have been surprised by this layer over the last week. Avoid "thick to thin" areas and steep roll overs where sensitivity to triggering could be greater.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Wind Slabs
The incoming weather will form new wind slab in the treeline and alpine.
Aspects: North, North East, East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 18th, 2021 4:00PM
