Avalanche Forecast

Issued: Feb 7th, 2017 3:36PM

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

jeremy.mackenzie, Alberta Parks

Kananaskis.

An avalanche cycle is slowing down slightly, but very touchy conditions remain due to extensive wind slab development. It is time to be extremely cautious in your route selection, and avoid any overhead hazard.

Summary

Confidence

High -

Weather Forecast

Wednesday looks like a mix of sun and cloud with no new snow fall and moderate westerly winds A cold morning will then warm up to around -12 Â°C. Thursday brings another wave of precipitation with 15 to 20cm of snow expected, but this time it will be warm and windy when the storm hits us. Flurries are expected on Friday.

Avalanche Summary

A widespread avalanche cycle up to size 2.5 has occurred on all aspects at all elevations. Many of the fracture lines and debris piles have become hidden, as a large number of these slides occurred during the big storm and were subsequently covered by further snowfalls. Numerous loose dry and wind slab avalanches also occurred today, so the cycle is not quite over yet.

Snowpack Summary

Storm snow totals in excess of 100cm have fallen at Treeline elevations in the previous 3 days. This snow has been drastically redistributed by strong winds and wind slabs now dominate Alpine and Treeline areas. In many areas this storm snow / wind slab condition sits on a previously formed very dense wind slab, which may provide an ideal sliding layer. Forecasters have a concern that the recent new load will cause failures in the deeply buried weak layers of Dec 18 and Nov 12, causing deep and destructive avalanches.

Problems

Wind Slabs

Wind slabs are everywhere in Alpine and Treeline areas. We are at the tail end of a large natural avalanche cycle, but many slopes remain prime for human-triggering. Winds have been strong from numerous directions, so wind slabs exist on all aspects.

The new snow will require several days to settle and stabilize.Avoid steep lee and cross-loaded featuresAvoid freshly wind loaded features.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 3

Loose Dry

Large sluffs continue to occur, many of which are running long distances and/or triggering slabs on the underlying slopes.

Be cautious of sluffing in steep terrain, particularly where the debris flows into terrain traps.Sluffs may trigger deeper instabilities.Be cautious of sluffing in steep terrain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 3

Persistent Slabs

Triggering of these slabs from a thin weak area may cause an avalanche that involves the entire snowpack. With the recent additional snow load, triggering of these deeper layers is now more likely.

Use caution on open slopes and convex rolls Be aware of thin areas that may propogate to deeper instabilites.Minimize exposure during periods of heavy loading from new snow and wind.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 4

Valid until: Feb 8th, 2017 2:00PM