Avalanche Forecast

Issued: Dec 10th, 2012 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.

aaron beardmore, Parks Canada

Banff Yoho Kootenay.

Strong wind from the NW have created wind slabs in alpine lee areas. Human triggering is possible in these areas.

Summary

Weather Forecast

Subsiding wind, warming temperatures and a clearing trend will contribute to decreasing the danger rating from considerable to moderate over the next few days.

Snowpack Summary

Wind slabs of varying thickness have been developing on NE through SE aspects due to the moderate to strong wind. These wind slabs sit over top of a well settled mid pack and the Nov 6 rain crust. The Nov 6th crusts lies approximately 30cm from the ground.

Avalanche Summary

One size two avalanche was observed high on Bourgeau 8, above the Bourgeau Left ice climb. It is suspected to be a recently developed wind slab from todays wind event. No other avalanches were observed or reported. Photo of avalanche in Bourgeau 8.

Confidence

Wind effect is extremely variable on Monday

Problems

Wind Slabs

Strong wind from the NW have created wind slabs in the alpine. These wind slabs vary in thickness between 15 and 30cm.

Be careful with wind loaded pockets while approaching and climbing ice routes.Use caution in lee areas in the alpine. Recent wind loading have created wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Deep Persistent Slabs

The Nov 6th crust should still be in the back of your mind. Recent avalanches on this layer combined with uncertain means of triggering make venturing out onto big open slopes a committing choice.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Dec 11th, 2012 4:00PM