Avalanche Forecast

Issued: Jan 1st, 2017 4:00PM

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

grant statham, Parks Canada

Banff Yoho Kootenay.

2017 begins with a complex snowpack in the central Rockies. While temporarily stabilized as a result of the cold air, the snowpack contains numerous weak layers - the key now is whether or not there is a slab overlying this weak base. Dig and test.

Summary

Weather Forecast

An arctic ridge of high pressure is descending into the area and will dominate for the next few days. Dress warm, as lows of near -30 are expected with daytime highs reaching -18 under clear skies with light winds from the north. It looks like the temperatures will start to moderate and rise slowly by Wednesday.

Snowpack Summary

The snowpack is mostly weak and facetted, with 15-25 cm of recent snow as the surface layer. Winds over the past week have created wind slabs in exposed areas, and in many places these slabs overlie a weak snowpack comprised of facets and depth hoar. A snow profile done today in the Helen Shoulder area showed a very weak snowpack structure.

Avalanche Summary

No new avalanches observed or reported on Sunday.

Confidence

Problems

Wind Slabs

Pay close attention to the texture of the snow surface as you are traveling, and watch out for dense, wind drifted snow which could indicate the presence of a wind slab. Areas near ridge crests or sides of gullies are obvious places to find these.

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

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Persistent Slabs

The bottom of the snowpack is weak and facetted, and will remain this way for the foreseeable future. Right now there is not much of a cohesive slab overlying this weak foundation, but it is still advisable to avoid large avalanche start zones.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 3

Valid until: Jan 2nd, 2017 4:00PM