Archived

Avalanche Forecast

Jan 31st, 2017–Feb 1st, 2017

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

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

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 well facetted snowpack is fragile and often unsupportive. These conditions are unlikely to change in the short term.

Weather Forecast

Colder sunny weather is forecast for the week. There is hope of some new precipitation later in the weekend. In the short term, the weather will promote further facetting.

Snowpack Summary

Strong to Extreme S and W have redistributed the 5 to 10 cm of new snow and the 10 to 20 cm that fell last week. Isolated surface hoar may be found buried in sheltered locations. Generally the midpack is weak at TL and above, and the entire snowpack is weak BTL. Near the divide, deeper snow-packs are a bit stronger and more supportive.

Avalanche Summary

A small avalanche cycle ran over the weekend but seems to have ended. Most of these events could be attributed to the wind redistributing recent snowfall and speak to the fragile nature of the snowpack: it required only small inputs to generate natural avalanches.

Confidence

Due to the number and quality of field observations

Avalanche Problems

Deep Persistent Slabs

The snowpack is weak. Slopes where a slab sits over the deeper weak layers should be treated as suspect. Until we get some rounding or compression, the snowpack is going to remain fragile to input.

Be aware of thin areas that may propogate to deeper instabilites.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 2 - 3

Wind Slabs

Strong to extreme South and West winds combined with 5 to 10 cm of new snow continue to form slabs in lees areas Monday. These are likely to remain reactive for some time after the winds abate.

Use caution in lee areas. Recent wind loading have created wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 2