Avalanche Forecast
Issued: Dec 14th, 2020 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
ahanna,
Avalanche Canada
New snow and strong southwest winds are forming reactive wind slabs in lee terrain features at upper elevations. A shallowly buried crust offers a slick bed surface for avalanches.
Summary
Confidence
Moderate - Uncertainty is due to the limited number of field observations.
Weather Forecast
Monday night: Partly cloudy, wind increasing to moderate southwest, freezing level valley bottom.
Tuesday: 5-10 cm new snow, strong southwest ridgetop wind, alpine high -8, freezing level 500 m.
Wednesday: Partly cloudy, moderate southwest ridgetop wind, alpine high -6 C, freezing level 700 m.
Thursday: 5-10 cm new snow, moderate southwest ridgetop wind, alpine high -5 C, freezing level 900 m.
Avalanche Summary
Over the last week, avalanche activity has been limited to size 1 skier triggered storm/wind slabs running on the crust. This great MIN from Friday near Nelson includes a photo of an accidental wind slab.
Please submit your observations to the Mountain Information Network (MIN). Photos are especially helpful! Thank you so much for all the great MINs submitted so far!
Snowpack Summary
5-10 cm of new snow falls on a layer of surface hoar 5-20 cm above a crust. At upper elevations, strong southwest wind is blowing the new snow into fresh wind slabs amongst previously wind affected surfaces.
The early November crust is sitting about 10-30 cm up from the ground. There is a late November crust in the midpack in some places as well. Uncertainty with these crusts exist due to limited observations, but there haven't been any recent avalanches reported on these layers in this region.
Snowpack depths vary with elevation, treeline averages between 50-100 cm.Â
Terrain and Travel
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Wind slabs are most reactive during their formation.
- Keep in mind the crust offers an excellent bed surface for avalanches.
Problems
Wind Slabs
New inputs of snow amid strong southwest winds are forming fresh wind slabs in lee features at upper elevations. Wind slabs may sit over previously wind affected surfaces, directly over a crust, or over a layer of surface hoar 5-20 cm above the crust. The crust offers a slick bed surface for avalanches.
Aspects: North, North East, East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 15th, 2020 4:00PM
