Avalanche Forecast

Issued: Dec 28th, 2018 4:00PM

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

snow safety, Parks Canada

Banff Yoho Kootenay.

Watch for windslabs developing with the storm tomorrow. Avalanches could step down into basal weaknesses creating larger than expected events. Whumphing is common and indicates the potential for propagation. Avoid avalanche terrain for a while again.

Summary

Weather Forecast

There is great variability in the weather models. Environment Canada is calling for 20cm of snow and high winds on Saturday. Touchy avalanche conditions can be expected as the day progresses, especially in lee areas. If less than 10cm of snow falls, the size of potential avalanches will be greatly reduced..

Snowpack Summary

The majority of the BYK region is a 40-50cm slab of stiff snow overlying 40-50cm of weak facets and depth hoar. This nasty combination has been stabilizing over the past few days but continues to produce whumphing and easy test results. Deeper snowpack areas are stronger, but have a 60-80cm slab over top of the Dec10 surface hoar/facet layer.

Avalanche Summary

No new avalanches observed or reported in the Banff, Yoho and Kootenay region on Friday.

Confidence

Intensity of incoming weather systems is uncertain

Problems

Deep Persistent Slabs

This problem dominates the central and eastern part of the forecast region and will continue to do so for some time. Natural activity on this layer has decreased but human triggered avalanches on this layer are still possible.

Be wary of large slopes that did not previously avalanche.Use caution in lee areas. Wind loading could create slabs.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1.5 - 3

Valid until: Dec 29th, 2018 4:00PM