Avalanche Forecast

Issued: Nov 20th, 2013 5:59PM

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

brian webster, Parks Canada

Banff Yoho Kootenay.

There is lots of snow available for transport. Pay attention to local winds and be aware of fresh wind slabs.

Summary

Weather Forecast

High pressure dominates the region. Mixed sun and cloud with no snow in the forecast. Another cool day for Thursday and then a warming trend for the weekend.

Snowpack Summary

Thirty to 50 cm of low density storm snow received throughout the area in past six days. Sunshine reporting lots of reactive wind and storm slabs while north of Lake Louise wind effect not as wide-spread. The mid pack is slowly gaining a bit of strength. The Oct rain crust persists at ground level in some alpine terrain.

Avalanche Summary

From Lake Louise to Bow Summit there was evidence of a cycle up to Class 2 occurring during the storm, however surprisingly little recent natural activity. Explosive work at Sunshine produced many avalanches on N-NE aspects up to Class 3. There was wide propagation with some avalanches stepping down to the Oct crust.

Confidence

Problems

Storm Slabs

Sunshine Village reporting a touchy storm slab that is easily triggered and has wide propagation. Some slabs have stepped down to the October rain crust layer producing avalanches up to Class 3. See avalanche reports.

Use caution in lee areas in the alpine and treeline. Recent storm snow has formed touchy slabs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Wind Slabs

Thirty to 50 cm of recent storm snow and moderate winds have produced wind slabs in alpine terrain. This wind effect is more pronounced in the Sunshine area.

Be careful with wind loaded pockets while approaching and climbing ice routes.Use caution in lee areas in the alpine. Recent wind loading have created wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Nov 21st, 2013 4:00PM