Avalanche Forecast

Issued: Nov 18th, 2011 4:00PM

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

Brad White, Parks Canada

Banff Yoho Kootenay.

Wind transport triggered two size 2.5 slab avalanches on Bourgeau 7 near Sunshine in the last 24 hrs. These slabs failed on the DH at the ground with crowns approximately 80cm thick and 100m wide. Be very cautious as human triggering is likely. JBW

Summary

Weather Forecast

Snowpack Summary

Avalanche Summary

Confidence

Problems

Persistent Slabs

Steep open slopes at and above treeline have a soft to hard surface slab that is sensitive to human triggering near the ground on the basal depth hoar. Wind loading triggered Na avalanches up to size 2.5 that failed to ground in the last 24 hrs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Wind Slabs

Slopes that look inviting for skiing have a wind slab over depth hoar layering. Cracking, whumphing, natural and skier triggered avalanches have been observed. This layer collapses with EASY results. Pick lower angled low consequence terrain.