Avalanche Forecast

Issued: Feb 29th, 2012 4:00PM

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

chris gooliaff, Parks Canada

Banff Yoho Kootenay.

A number of skier-triggered avalanches in the past few days shows people want to attack the slopes. This is NOT the time to ski your big line, but instead, show some restraint and give the weaknesses time to heal. It may be a while...

Summary

Weather Forecast

Snowpack Summary

Avalanche Summary

Confidence

Problems

Persistent Slabs

Snow depths over the Valentines surface hoar and suncrust on steep solar aspects range from 20cm E of the Divide, to over 45cm at Sunshine and Yoho. Where the wind has stiffened these slabs, skiers have triggered big enough slides to bury them.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

2 - 3

Wind Slabs

Moderate winds this week have also created thin, but stiffer wind slab conditions 25-35 cm deep on ridgetop lee terrain. These have been seen to step down to the Valentine layer. Skiers on Fairview triggered a large slide yesterday, lucky to survive.

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

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 2

Deep Persistent Slabs

In the Lake Louise backcountry today, we encountered a weak, shallow snowpack. Tests done here showed hard results, but sudden collapse, on the basal facets. The slides reported yesterday on Bosworth and Fairview both had stepped down to ground.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Mar 1st, 2012 4:00PM