Avalanche Forecast

Issued: Dec 15th, 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.

snow safety, Parks Canada

Banff Yoho Kootenay.

Good alpine ski quality reported on sheltered SE through NE aspects West of the divide today. Wind exposed areas have variable ski quality. Generally good ice climbing conditions until Monday. SH

Summary

Weather Forecast

Continued cool temperatures, light to moderate SW winds, and no new snow will not change the hazard for Sunday.Â Monday expect moderate to strong winds switching from SW to NW in the alpine, and possibly 10cm of snow at upper elevations which may increase the overall hazard.

Snowpack Summary

Cold temps facetting the snowpack, especially in thinner areas. In thicker snowpack areas there is generally a well settled midpack with the Nov. 6 crust lying 20-30cm above the ground up to 2700m. This has been observed to be breaking down as time goes on, facetting in thinner snowpack areas. Thin windslabs from previous NW winds in exposed areas.

Avalanche Summary

No new avalanche activity observed in the past 24 hrs.

Confidence

on Sunday

Problems

Wind Slabs

A trip report from Surprise pass (N/NE aspect) found pencil hard, thin windslabs in wind exposed terrain. These have also been found near ridge top but have been stubborn to unreactive in field tests.

Caution in lee and cross-loaded terrain near ridge crests.

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

Elevations: Alpine.

Likelihood

Unlikely - 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.

Carefully evaluate and use caution around thin snowpack areas.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Dec 16th, 2012 4:00PM