Archived

Avalanche Forecast

Jan 3rd, 2017–Jan 4th, 2017

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

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.

Lake Louise area has had more wind effect and more recent avalanche activity. Alpine hazard is rated CONSIDERABLE in this area.

Weather Forecast

A mix of sun and cloud for Wednesday. Temperatures will moderate somewhat with day time highs in the alpine reaching -14. Winds will be light to moderate from the north. Thursday may bring some isolated flurries along the divide.

Snowpack Summary

20-30 cm of last weeks storm snow sits over top of a very weak (Dec 19 layer) facet layer which in turn sits on the Nov 12 crust. Winds over the past week have created wind slabs in exposed areas. In many places these wind slabs sit on a weak snowpack comprised of facets and depth hoar.

Avalanche Summary

No new natural avalanches reported today, however a field trip in the Lake Louise area showed numerous avalanches up to size 2.5 from the past four days. These mostly initiated as windslabs and then stepped down into the weak facet layer below. Of note were four avalanches up to Class 2.5 in the Corral Slide Paths adjacent to Lake Louise Ski Resort

Confidence

Wind effect is extremely variable

Avalanche Problems

Wind Slabs

Wind slabs up to 40 cm thick exist in the alpine and some treeline locations. Even a small wind slab has the potential to step down into the weak facetted mid-pack resulting in a bigger avalanche.

If triggered the storm/wind slabs may step down to deeper layers resulting in large avalanches.Be careful with wind loaded pockets while approaching and climbing ice routes.

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 2

Persistent Slabs

The mid and lower pack is weak and facetted, and will remain this way for the foreseeable future. This layer is most concerning in areas where a cohesive slab overlies this weak foundation.

Watch for whumpfing, hollow sounds, and shooting cracks.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 2 - 3