Avalanche Forecast

Issued: Dec 7th, 2012 4:00PM

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

Brad White, Parks Canada

Banff Yoho Kootenay.

The recent storm snow has helped create very good conditions. Some hidden hazards remain. JBW

Summary

Weather Forecast

A short lived ridge on Saturday will be followed by a weak system Sunday. In the wake of Sunday's storm, the Arctic Front will descend southwards bringing colder temperatures

Snowpack Summary

Some wind slabs in open areas at and above treeline. Lower snowpack is well settled with some shears that are producing moderate resistant planar results. Major concerns are stubborn to touchy windslabs on north and east aspects with avalanche potential to size 2 and deep persistent slabs stubborn, isolated to size three failing on November crust.

Avalanche Summary

No new avalanches in the past 24 hrs. Storm related avalanches from the last week to size two in wind effected areas. Explosive control to size 3 stepping down to Nov. Crust.

Confidence

Wind speed and direction is uncertain on Sunday

Problems

Wind Slabs

Soft to hard wind slabs can be found on lee and cross loaded slopes at and above treeline. Triggering is still possible on the right slope.

Be careful with wind loaded pockets while approaching and climbing ice routes.Avoid steep lee and cross-loaded features

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Deep Persistent Slabs

Isolated deep slabs have been noted every few days over the last month. Some of these have been explosive triggered and some natural, all failing near the ground on Nov 6 rain crust or glacial ice. There is still a concern for human triggering.

Be aware of the potential for full depth avalanches due to deeply buried weak layers.Choose well supported terrain without convexities.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Valid until: Dec 8th, 2012 4:00PM