Avalanche Forecast

Issued: Dec 12th, 2012 4:00PM

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

chris gooliaff, Parks Canada

Banff Yoho Kootenay.

Good skiing can be found in sheltered areas, especially below 2500m but above 1750m.

Summary

Weather Forecast

No snow is forecasted for the next 2 days, but we may see moderate W winds higher in the alpine tomorrow. Temperatures should remain at seasonal values or slightly warmer.

Snowpack Summary

Variable surface wind slabs have been found in immediate lee ridge features, as well as open terrain above 2800m. In sheltered locations, very good skiing can be found from 2500m to as low as 1750m. Lower than that and things get a bit thin. A well-settled mid-pack sits atop the Nov 6 rain crust. The crust was observed to be breaking down in Yoho.

Avalanche Summary

Sluffing to size 1 was observed in the last 24 hours from steeper, NE-facing slopes. Evidence of an old skier-triggered slide near Observation Peak in a cross-loaded gully.

Confidence

Problems

Wind Slabs

The wind slabs from earlier this week seem to be isolated to ridge lee features and high, open alpine terrain. A field team ventured into Yoho today and found soft slabs only at ridge-top. Likely there was more wind on the Wapta.

Be careful with wind loaded pockets while approaching and climbing ice routes.Be cautious as you transition into wind affected terrain.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Deep Persistent Slabs

Large planar faces or steeper, convex features that have been recently wind-loaded should still be given a miss due to this lingering problem.

Be aware of the potential for full depth avalanches due to deeply buried weak layers.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Dec 13th, 2012 4:00PM