Archived

Avalanche Forecast

Jan 21st, 2015–Jan 22nd, 2015

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

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

Regions: Banff Yoho Kootenay.

The snowpack is slowly strengthening; however, conservative decision making in bigger alpine terrain is still essential! We may see some snow late friday PM which would cause the danger to rise again.

Weather Forecast

Thursday and Friday look to be similar to the last few days - mild temperatures, light winds and scattered clouds. Friday afternoon, we should see increased winds from the West and 10-15 cm's overnight with freezing levels rising to ~1500m.

Snowpack Summary

The snowpack remains fundamentally weak, with a combination of windslab, surface hoar and basal facets all causing concern in different types of terrain. Snowpack tests continue to produce moderate to hard sudden results on the basal weakness/ Dec. 18th interface which has become one and the same in many areas.

Avalanche Summary

No natural avalanches observed, but forecasters on Mt. Field reported a couple large whumphs in an open area below treeline, indicating human triggering of deeper weak layers is still possible in the right terrain.

Confidence

Forecast snowfall amounts are uncertain on Saturday

Avalanche Problems

Wind Slabs

Surface windslabs formed on Jan 18/19 can be triggered by skiers and climbers. Feel for tension in the surface snow and avoid freshly windloaded terrain.

If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2

Deep Persistent Slabs

In shallower snowpack areas (most of the region) the weak base of the snowpack persists and could be triggered in steep, rocky terrain features. Although in some areas, the Dec. 18th layer persists, management of both layers should be the same.

Avoid thin, rocky or sparsely-treed slopes.Be aware of the potential for wide propagations.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 2 - 3