Avalanche Forecast

Issued: Jan 23rd, 2015 4:00PM

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

conrad janzen, Parks Canada

Banff Yoho Kootenay.

Watch for increasing overhead hazard as the new snow arrives with strong winds and warming temperatures. Minimize your exposure to cornices or large start zones, and expect sluffing out of steep terrain.

Summary

Weather Forecast

Snow has started to fall in the Western areas of the region. The next several days will have moderate precipitation, strong to extreme West winds, and warming temperatures with freezing levels hovering around the 2000m level in most of the forecast region, with higher freezing levels in the East.

Snowpack Summary

The snowpack remains fundamentally weak. Snowpack tests continue to produce moderate to hard sudden results on the Dec. 18th interface/basal weakness which has become one and the same in most areas with less than 1m of snow. New snow, warming temperatures and strong W winds will create more of a surface slab over the next few days.

Avalanche Summary

No natural avalanches observed in the last 48 hrs. We are still experiencing whumphs in some open areas below tree line in the Little Yoho region indicating human triggering of deeper weak layers is still possible in the right terrain.

Confidence

Intensity of incoming weather systems is uncertain

Problems

Wind Slabs

New wind slabs will be forming in open areas above tree line with the strong W winds, precipitation and warming temperatures. These can be triggered by skiers and climbers.

If triggered the wind slabs may step down to deeper layers resulting in large avalanches.Be careful with wind loaded pockets while approaching and climbing ice routes.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Deep Persistent Slabs

In shallower snowpack areas (most of the region) the weak base of the snowpack persists and could be triggered in steep, rocky terrain features. Although in some areas, the Dec. 18th layer persists, management of both layers should be the same.

Avoid thin, rocky or sparsely-treed slopes.Be aware of the potential for wide propagations.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Jan 24th, 2015 4:00PM