Avalanche Forecast

Issued: Dec 11th, 2014 8:25AM

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

Avalanche Canada jlammers, Avalanche Canada

The storm may have ended, but "whumpfing" in the snowpack indicates that deeply buried layers may still be reactive with potential for large avalanches.

Summary

Confidence

Poor - Due to the number of field observations

Weather Forecast

On Friday, expect generally overcast skies, light southwest winds and freezing levels at about 1500m. Throughout Saturday and Sunday, a dry ridge of high pressure is forecast to develop bringing clearing skies, light northwest winds and freezing levels closer to 1000m.

Avalanche Summary

Although observations have been limited, I suspect loose wet avalanche 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 the upper snowpack in most areas. The extent of saturation will depend on elevation and the amount of rain that fell. The rain-soaked snow may exist as a hard crust in many areas with forecast cooling. 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 the load from rain or snow.

Problems

Persistent Slabs

An icon showing Persistent Slabs
"Whumpfing" at higher elevations has been reported throughout the region, indicating weak layers near the base of the snowpack are still ready for triggering. Any activity on these layers would be destructive in nature.
Avoid convexities or areas with a thin or variable snowpack.>Avoid large alpine features with smooth ground cover..>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

3 - 5

Storm Slabs

An icon showing Storm Slabs
At upper elevations, snow and strong winds have formed cohesive storm slabs. Watch for increased reactivity in wind-exposed terrain.
Stay off recent wind loaded areas until the slope has had a chance to stabilize.>Be cautious as you transition into wind affected terrain.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Dec 12th, 2014 2:00PM