Avalanche Forecast

Issued: Dec 9th, 2012 4:00PM

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

aaron beardmore, Parks Canada

Banff Yoho Kootenay.

Strong wind in the alpine is creating slabs in lee areas. Carefully consider the consequences of traveling in these areas tomorrow (Monday).

Summary

Weather Forecast

Warming temperatures combined with a clearing trend should provide an opportunity for the danger rating to drop back down toÂ moderate by the end of the day on Monday.

Snowpack Summary

The snowpack is surprisingly well settled for early December. Expect to find approx 15cm of low density snow sitting on top of of a well settled mid-pack, all of which is sitting on top of the Nov 6 crust 20-40cm above the ground. Snowpack tests today showed irregular results in the hard range on the Nov 6 crust in our Bow Summit study plot.Â

Avalanche Summary

No new avalanche activity observed or reported today. However, there have been reports and observations of avalanches up to size 3 throughout the forecast region in the past 4 days. It is suspected that many of these large avalanche released on the Nov 6th crust.

Confidence

Problems

Wind Slabs

Strong winds on Sunday have created soft and hard slabs in lee areas in the alpine.

Watch for whumpfing, hollow sounds, shooting cracks or recent avalanches.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Deep Persistent Slabs

The Nov 6th crust should still be in the back of your mind. Recent avalanches on this layer combined with uncertain means of triggering make venturing out onto big open slopes a committing choice.

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

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Dec 10th, 2012 4:00PM