Archived

Avalanche Forecast

Jan 6th, 2021–Jan 7th, 2021

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

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

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.

Clear, dry weather pattern over the next few days will help settle the recently created windslabs. A few spotty persistent weak layers exist in the snowpack and should be considered when choosing your objective

Weather Forecast

A ridge is building over the next 3 days. Expect benign weather: light westerly alpine winds, clear skies and cool overnight lows in the -15 to -20 range.

Snowpack Summary

5-10 cm on Wed brings recent storm snow totals to 20-50 cm at treeline. This sits on a spotty stellar/surface hoar layer in some sheltered locations. Wind effect in open areas at treeline and in the alpine. Two weak layers from early Dec persist 50-100 cm down. These have been generally unreactive but still giving hard sudden planar results

Avalanche Summary

Poor visibility today meant limited observations in the alpine, but strong to extreme winds and 5-10 cm snow likely meant avalanches were running. Test pits at treeline show moderate resistant planar results down 30-45 on a preserved stellar/ surface hoar interface and moderate to hard sudden planar results down 50-70 cm on surface hoar/ facets.

Confidence

Wind effect is extremely variable

Avalanche Problems

Wind Slabs

Strong winds and recent snow have formed wind slabs in lee areas at treeline and in the alpine. The likelihood of triggering these is slowly going down, but it is a good idea to avoid travel on or under steep loaded terrain for the next couple days.

Use caution in lee areas in the alpine and treeline. Recent storm snow has formed wind slabs.
Watch for signs of slab formation, such as whumpfing and shooting cracks.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2.5

Persistent Slabs

A spotty layer of stellars and surface hoar 20-50 cm down has been reactive in steep terrain. Most likely an issue in steep terrain that was sheltered from previous winds.

2 weak layers from Dec persist and still produce hard sudden planar results

Convex features and steep unsupported slopes will be most prone to triggering.
Dig down to find and test weak layers before committing to a piece of terrain.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood: Possible

Expected Size: 1 - 2.5