Avalanche Forecast

Issued: Dec 12th, 2014 8:17AM

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

Avalanche Canada pgoddard, Avalanche Canada

Although avalanche danger has decreased post-storm, take a cautious approach and gather your own snow pack information before committing to exposed terrain.

Summary

Confidence

Fair - Due to the number of field observations

Weather Forecast

Light snowfall should taper off by late Saturday. Winds remain light to moderate from the south. The freezing level is falling towards valley bottom.

Avalanche Summary

A naturally triggered avalanche cycle was observed in response to the recent storm. At low elevations, many of these were wet and dug deep, failing to ground, up to size 2.5. At treeline and above, storm slabs and wind slabs were reported. In the north, large explosives triggered slabs up to size 3 failing on the November crust layer, with wide propagations at alpine elevations.

Snowpack Summary

Heavy rain which recently saturated the upper snowpack resulted in wet, loose, and cohesionless surface snow as high as alpine elevations in the southern part of the region. As freezing levels drop, this may freeze into a solid surface crust with fresh wet snow stuck on top, depending on elevation. Meanwhile in the high alpine and as low as treeline elevations further north, up to 70 cm of recent snow and wind has formed new storm slabs. These have overloaded previous weaknesses buried within the snowpack, such as the mid-November crust-facet layer.

Problems

Storm Slabs

An icon showing Storm Slabs
The weight of a person or snowmobile could trigger a storm slab or wind slab. If triggered, a surface slab may be able to step down and trigger a deeper weak layer.
Avoid recently wind loaded slopes by sticking to ridge crests or ribs. > Stay away from steep slopes below cornices.> Caution around convexities and areas where the snowpack depth transitions from thin to thick.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 5

Valid until: Dec 13th, 2014 2:00PM

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