Avalanche Forecast

Issued: Dec 5th, 2011 4:00PM

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

Snow Safety, Parks Canada

Banff Yoho Kootenay.

An inversion will leave by Tuesday morning. Light snow, seasonal temperatures, with strong NW alpine winds are forecast. Forecasters still have low confidence in the snowpack at higher elevations, especially in thinner areas East of the divide. SH

Summary

Weather Forecast

Snowpack Summary

Avalanche Summary

Confidence

on Tuesday

Problems

Deep Persistent Slabs

These slabs can be triggered from thin snowpack areas and propagate large distances to deeper areas. An example of this was a skier remote size 3 in the Lake Louise area on Sunday. The slab failed 140cm deep on weak basal facets and depth hoar.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 3

Wind Slabs

Deeper snowpack areas, mainly West of the divide, have quite a strong midpack, which was evident in field tests on Monday near treeline in the Little Yoho region. Thinner surface wind slabs, mainly on steep alpine slopes will be a concern.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 3

Valid until: Dec 6th, 2011 4:00PM