Avalanche Forecast

Issued: Jan 31st, 2017 4:05PM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is low. Known problems include Deep Persistent Slabs and Wind Slabs.

snow safety, Parks Canada

Banff Yoho Kootenay.

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

Summary

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

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

Valid until: Feb 1st, 2017 4:00PM