Avalanche Forecast

Issued: Jan 29th, 2012 4:00PM

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

lisa paulson, Parks Canada

Banff Yoho Kootenay.

Summary

Weather Forecast

Snowpack Summary

Avalanche Summary

Confidence

Due to the number of field observations

Problems

Storm Slabs

Storm snow amounts vary from 35 cm West side of the Wapta, 20-25 - Sunshine, 20 - Lake Louise, and 15 - Bow Summit. Moderate to strong west winds has created reactive touchy slabs. Expect sizable sluffs off cliffs with ongoing strong winds tomorrow.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 3

Wind Slabs

Recent control in Yoho & field obs in Kootenay confirm the Jan 20 facet interface still active. 70-100 m sits over this layer. If a skier or cornice failure triggered a storm slab, it could step down to the facet interface & become a larger slide.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 3

Persistent Slabs

This layer is of concern in thinner snowpack areas. In Kootenay yesterday, a skier triggered a 60 cm thick size 1.5 slab, propagated 50 m on a 35 deg, open wind affected slope. Skier was carried 150 m and lost their pole - thx for the report!

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Jan 30th, 2012 4:00PM