Avalanche Forecast

Issued: Jan 19th, 2019 4:00PM

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

snow safety, Parks Canada

Banff Yoho Kootenay.

Basal instabilities can result in large avalanches with high consequences. Thinner snowpack areas will be more touchy and prone to avalanche. Make conservative choices. Windslabs may start to show up near ridgecrests

Summary

Weather Forecast

Although more snow is still forecast Saturday, it is not showing up as a problem. Some windslab has been noted but it is very localized to ridgecrests.

Snowpack Summary

40 to 60cm of settled snow sits on large facetted grains of varying strength. Treeline snow depths generally range from 100 to 150 cm. The facets in the lower portion of the snowpack are failing in tests often in the moderate range. Alpine, and open treeline areas can have great variability in snow depth and layering due to local winds.

Avalanche Summary

An avalanche (1.5) was noted today on the north flank of mount Fairview.

Confidence

Intensity of incoming weather systems is uncertain

Problems

Deep Persistent Slabs

The weak facets and depth hoar just above the ground have an significant 50-140cm thick slab sitting above them. This slab has been hardened by wind effect TL and above. Activity is tapering, but human triggering is still possible and consequential.

Be aware of the potential for full depth avalanches due to deeply buried weak layers.Be aware of the potential for wide propagations which could result in large avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 3.5

Wind Slabs

As of publication, we are close to threshold values for windslab. We need a little more input for this to become more widespread.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Jan 20th, 2019 4:00PM