Avalanche Forecast

Issued: Mar 10th, 2012 9:50AM

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

Avalanche Canada jlammers, Avalanche Canada

Summary

Confidence

Fair - Intensity of incoming weather is uncertain on Sunday

Weather Forecast

Sunday: light snowfall - light southerly winds - freezing level at 400m Monday: trace amounts of snow with some clearing- light southeast winds - freezing level at 400m Tuesday: very light snowfall - light southwest winds - freezing level at 200m

Avalanche Summary

A size 1.5 natural wind slab avalanche was reported on Friday on a cross-loaded slope at treeline. Storm snow avalanches up to size 3.5 were reported from the big terrain around Bear Pass. A few natural size 2 slab releases on the early February persistent weak layer interface were reported on Thursday. They occurred below treeline on steep, unsupported terrain.

Snowpack Summary

Continued strong westerly winds have created widespread reactive wind slabs on lee aspects. A persistent weak layer of surface hoar buried at the beginning of March is as much as 70cm deep and has started to become reactive in some areas. The early February persistent weak layers (surface hoar, facets, crusts) are buried as much as 110cm down and also remain a concern in some parts of the region. Although not widespread throughout the region, persistent slabs would be destructive in nature and may be reactive to human triggers, particularly below treeline on isolated and sheltered steep terrain where buried surface hoar may be preserved. Cornices in the region are reported to be large and unstable.

Problems

Wind Slabs

An icon showing Wind Slabs
Recent strong winds have deposited large and reactive wind slabs in unusual places, but generally lurking below ridgecrests, behind terrain features and in gullies.

Aspects: North, North East, East, South East, South.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 6

Persistent Slabs

An icon showing Persistent Slabs
Persistent weaknesses, where they exist, may be susceptible to rider triggers. Any avalanches failing on these layers are expected to be large and destructive.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 6

Valid until: Mar 11th, 2012 9:00AM