Avalanche Forecast

Issued: Dec 10th, 2014 8:34AM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Persistent Slabs, Storm Slabs and Loose Wet.

jlammers, Avalanche Canada

Kootenay Boundary.

Loading and warm temperatures will have a destabilizing effect on the snowpack. Watch your overhead hazard as weak layers may "wake-up" with the potential for large and destructive avalanches.

Summary

Confidence

Poor - Due to the number of field observations

Weather Forecast

The sub-tropical storm cycle will continue through Thursday bringing another round of moderate to locally heavy precipitation, strong southwest winds and freezing levels at about 2300m. As the system moves east on Friday there may be lingering light snowfall, light southwest winds and freezing levels at about 1500m. By Saturday a dry ridge should develop bringing clearing skies, light northwest winds and freezing levels at about 800m.

Avalanche Summary

Numerous size 1 loose wet avalanches were observed in the Kootenay Pass area on Tuesday. Although observations have been limited, I suspect this activity has been fairly widespread with the wet weather. Rain or loading from snow may also spark destructive avalanche activity on persistent weaknesses which exist near the base of the snowpack. If you have any avalanche observations, please share them on our new Mountain Information Network. For more details, go to: http://www.avalanche.ca/blogs/VIYBuScAAJdbdqPz/m-i-n-intro

Snowpack Summary

Rain has likely saturated and weakened the upper snowpack in most areas. The extent of saturation will depend on elevation and the amount of rain that fell. At upper elevations, precipitation may have fallen as moist snow, and may be adding load and cohesion to a storm slab which overlies a weak layer of facets, surface hoar, a hard rain crust or a combination thereof.Near the base of the snowpack is a crust/facet combination which is a concern at higher elevations in many parts of the region. This destructive layer continues to produce whumpfing, and may see a "wake-up" with warming and the load from rain or snow.

Problems

Persistent Slabs

Warm temperatures and the load from rain may spark renewed destructive avalanche activity on weak layers near the base of the snowpack. "Whumpfing" has been reported throughout the region, indicating this layer is still ready for triggering.

Stick to low angle terrain, especially if the snow is moist or wet.>Avoid large alpine features with smooth ground cover..>Avoid convexities or areas with a thin or variable snowpack.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

3 - 5

Storm Slabs

Dense and cohesive storm slabs are forming at higher elevations with the potential for wide propagations. Watch for triggering in lee terrain.

Be cautious as you transition into wind affected terrain.>Stay off recent wind loaded areas until the slope has had a chance to stabilize.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Loose Wet

Rain may trigger further loose wet avalanche activity. Loose wet avalanches can be pushy and entrain mass quickly.

Be cautious of wet sluffing in steep terrain.>Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Dec 11th, 2014 2:00PM