Avalanche Forecast

Issued: Jan 5th, 2019 4:00PM

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

stephen holeczi, Parks Canada

Banff Yoho Kootenay.

Natural activity has tapered, but human triggered avalanches remain likely.

Summary

Weather Forecast

3-5cm Sunday with Moderate SW winds and slowly decreasing temperatures in the afternoon. A fairly benign weather pattern is expected for the start of next week.

Snowpack Summary

Up to 70 cm of storm snow with variable wind effect has put a dense load over the persistent weak layers. In thicker snow pack areas, the Dec. 10th weak layer of facets is now down 80-120cm with a stronger snowpack below. In thin snowpack areas, the Dec.10th layer is mixed in with the basal facets and October crust.

Avalanche Summary

Avalanche control up to size 3.5 today and a natural cycle from 2 days ago. Some ran full path, and many have scrubbed to ground. Many steeper features at treeline & below have also avalanched. The natural activity has tapered, but slopes will remain hair trigger with any further wind loading or by recreationalists on or near a slope.

Confidence

Problems

Deep Persistent Slabs

There is the very real potential of a slab initiating on the weak basal layers (Oct. 30 layer), or a storm slab "stepping down" to cause a large avalanche. This problem will be around for some time.

Be aware of the potential for wide propagations which could result in large avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

2 - 3.5

Storm Slabs

Lots of recent snow load will require some time to stabilize. These storm slabs exist in many areas and should be treated with caution in avalanche terrain, but should only be a problem in the short term.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1.5 - 3

Valid until: Jan 6th, 2019 4:00PM