Avalanche Forecast

Issued: Jan 12th, 2018 3:00PM

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

Alberta Parks matt.mueller, Alberta Parks

Skiing is still good in sheltered areas but expect wind slab formation to increase as time goes on and winds pick up. Treeline will become a likely place for avalanches as the Jan 6th loads.

Summary

Confidence

High -

Weather Forecast

Cloudy with sunny periods and isolated flurries tomorrow. Alpine highs of -3.  Ridge wind west 40 km/h.

Avalanche Summary

The widespread cycle involving the storm snow has continued. There was numerous loose dry out of all aspects in the alpine. Including a low density slab that was witnessed today (E asp, 2500m out of steep unsupported terrain). We also had a report of small pockets of the Jan 6th surface hoar waking up. These were in the Warspite drainage and at treeline. They happened early yesterday and were up to sz2.

Snowpack Summary

The winds were noticeable today with lots of snow transport at summit elevations. This increase in winds has created fresh windslabs on Northeast to South aspects in the alpine. At treeline, the Jan 6th & Dec 15th layers start to become apparent, but still unreactive due to the lack of snow load and a slab. The Dec 6th becomes more apparent the lower you go. But again, the lack of a slab is preventing an avalanche problem. Today's notable observation was multiple stability tests with repeatable results below the Nov 27 crust(down 85cm). All tests failed with moderate loads. The technical details are: ECTP21 & CTM(19) sudden collapse. In a nutshell, this is telling us that those layers are breaking down and we should keep them in mind when assessing the snowpack.

Problems

Wind Slabs

An icon showing Wind Slabs
These start right at the treeline/alpine border. In some sheltered areas, there is still a buried windslab that is worth some consideration.
Avoid lee and cross-loaded terrain near ridge crests.Be careful with wind loaded pockets while approaching and climbing ice routes.Avoid steep lee and cross-loaded slopes

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Persistent Slabs

An icon showing Persistent Slabs
This shows up as either surface hoar or facets. It has been inconsistent with test results, but we're working under the assumption that it could be triggered in the right (or wrong?) terrain.
Avoid open slopes and convex rolls at treeline where buried surface hoar may be preserved.Evaluate unsupported slopes critically.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 3

Loose Dry

An icon showing Loose Dry
Running far and fast up to sz 2. From steep unskiable areas. Ice climbers be aware. Expect spindrift on lee slopes.
Be cautious of sluffing in steep terrain, particularly where the debris flows into terrain traps.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Jan 13th, 2018 2:00PM

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