Avalanche Forecast

Issued: Dec 16th, 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 winds have scoured open windward areas and created some thin fresh wind slabs. Otherwise the snow is generally stable. JBW

Summary

Weather Forecast

A storm tracking along the US border will bring some snowfall and SW winds. We may see 10 cm over higher terrain Monday. Tuesday a short lived ridge will clear out the skies.

Snowpack Summary

Mod-Strong winds over the last 24 hrs have produced some thin fragile hard slabs on immediate lee terrain at and above treeline. Elsewhere the snowpack is weakening with facetting predominating, but there is still good midpack support. The Nov. Crust is giving inconsistent results as it is faceting.

Avalanche Summary

Some very small skier controlled slabs on north and east ridges with the new thin wind slab development, otherwise no new avalanches in the last 24 hrs.

Confidence

Problems

Wind Slabs

There are some freshly formed windslabs on lee terrain at and above treeline that are sensitive to skier triggering. In the right terrain these could take the skier into a terrain trap.

Avoid freshly wind loaded features.Use ridges or ribs to avoid pockets of wind loaded snow.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Deep Persistent Slabs

We are seeing weakening of the Nov 6 crust in thinner areas due to facetting.� Although we haven't seen activity on this layer recently, it is still a prominent feature of the snow pack, and should be evaluated in bigger features.

Be aware of the potential for full depth avalanches due to deeply buried weak layers.Choose the deepest and strongest snowpack areas on your run.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Dec 17th, 2012 4:00PM