Avalanche Forecast

Issued: Feb 12th, 2016 4:00PM

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

Lisa Paulson, Parks Canada

Banff Yoho Kootenay.

Many large natural, explosive and skier triggered avalanches over the past week. Cooler temperatures & cloud cover help, but still wise to avoid steep features and large slopes. Give it time and make conservative terrain choices this weekend.

Summary

Weather Forecast

Expect cloud cover and cooler temperatures through the weekend.Â Light snow tonight will have little impact.Â

Snowpack Summary

A surface windslab 10-30 cm thick continues to be reactive in tests on alpine lees on Friday.Â A 50-100 cm slab overlies the January 6th weak layer of surface hoar, facets and sun crust and snowpack tests indicate an unstable bond between the two. The lower snowpack is facetted and quite weak, especially in shallower areas.

Avalanche Summary

There have been many large natural and explosive triggered avalanches in the past week triggered by warm temperatures & solar radiation. Activity tapered Friday with the lack of solar input. A very close call on Twin Cairns in the Sunshine backcountry on Wednesday - a size 2.5 accidentally triggered took a skier for a ride & partially buried him.

Confidence

Problems

Persistent Slabs

Widespread natural & explosive triggered avalanches on this layer in the past week. In thinner areas, avalanches are scrubbing down to ground. With the cooling temps, this should become less reactive, but is still a concern for skier triggering.

Avoid paths that have not avalanched recently.Avoid areas with overhead hazard.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 3

Wind Slabs

Be mindful of cross loaded features and the lees of ridges where windslabs 10-30 cm thick continue to be reactive. If triggered, there is potential to step down to the persistent weak layer and to ground in thin areas.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Feb 13th, 2016 4:00PM