Archived

Avalanche Forecast

Jan 19th, 2019–Jan 20th, 2019

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: 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

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

Avalanche 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