Archived

Avalanche Forecast

Jan 16th, 2016–Jan 17th, 2016

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: South Rockies.

Recently formed wind slabs remain sensitive to human triggering. Use extra caution in wind-affected terrain and avoid freshly wind-loaded pockets of snow.

Confidence

Moderate - Due to the number of field observations

Weather Forecast

Expect a mix of sun and cloud, isolated flurries and freezing levels at valley bottom for the forecast period. Ridgetop winds should spike to extreme from the southwest on Sunday evening, and then taper to moderate on Monday and Tuesday. For a more detailed weather overview, check out our Mountain Weather Forecast at avalanche.ca/weather.

Avalanche Summary

On Thursday, ski cutting produced isolated soft slab and loose dry avalanches to size 1 in the Castle area. On Wednesday, a natural size 1 wind slab was reported from a steep north-facing hanging snowfield in the Crowsnest Pass area. Also reported was a size 1.5 skier-triggered storm slab avalanche from the Elkford area. This occurred on a north aspect at 1950m elevation. The slab was 10cm thick and released on a layer of surface hoar.

Snowpack Summary

15-30cm of old storm snow is bonding poorly to the old snow surface buried early January. However, east of the divide there has been much less recent snow and much more wind. Extensive scouring has been reported in some areas and and stiff wind slabs exist in lee features at treeline and in the alpine. In areas that have seen less extreme wind, recently formed wind slabs are likely softer, deeper, and may overlie surface hoar, facets, and/or a sun crust which formed at the start of January. The early December crust can be found down around 60-90cm. It is not currently expected to pose an avalanche problem but could wake-up in the future with substantial warming or heavy snow loading.

Avalanche Problems

Wind Slabs

Wind slabs may be particularly deep and touchy west of the divide where there has been more snow and the underlying weakness may involve buried surface hoar. Thin wind slabs also exist east of the divide.

Be cautious as you transition into wind affected terrain.>Avoid freshly wind loaded features. >Be aware of the potential for wide propagations due to the presence of hard windslabs. >

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 3