Avalanche Forecast

Issued: Nov 15th, 2013 4:01PM

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

snow safety, Parks Canada

Banff Yoho Kootenay.

The hazard is rising. The areas with enough snow to ski are also the features that will be the most likely places for triggering these avalanches. Ice climbers should be aware of increased loading going on above them over the next few days. CJ

Summary

Weather Forecast

Another 10-15cm of snow is expected over the next couple of days. Temperatures will begin falling as the winds shift to the NW with overnight lows near -18'C. Gusty winds will continue for the next 24 hrs and then ease off slightly.

Snowpack Summary

20-40cm of storm slab exists above treeline with moderate West winds loading N and E aspects and forming soft and hard wind slabs. Near Lake Louise the Nov 13 sun crust can be found on steep solar aspects. In the alpine the Oct 27 melt freeze crust near the base of the snowpack continues to provide a good sliding layer over the basal facets.

Avalanche Summary

Storm slabs on lee and cross loaded features have been easily triggered by skiers or explosives over the past 24 hours up to size 2. These are running in the storm snow and on the Oct 27 melt freeze crust or basal facets, and in some locations on a Nov 13 sun crust. Cornices are fragile and growing, and several recent failures have been observed.

Confidence

Timing, track, or intensity of incoming weather system is uncertain

Problems

Wind Slabs

New snow and moderate W winds have created slabs that are susceptible to human triggering especially in the alpine. These areas may be tempting for skiers as they have greater snow depth than the surrounding terrain.

Use caution in lee areas in the alpine. Recent wind loading have created wind slabs.Be careful with wind loaded pockets. Be aware of wide variation in snowpack depth

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Storm Slabs

In some alpine areas there is enough new snow that storm slab failures have been observed. These have been failing on the new snow interfaces or on the basal facets. Give this some time to settle out before entering committing terrain.

The new snow will requires several days to settle and stabilize.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Nov 16th, 2013 4:00PM