Avalanche Forecast

Issued: Feb 4th, 2018 3:00PM

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

Alberta Parks michael.olsthoorn, Alberta Parks

Lots of new snow and good skiing.  Tread carefully as the snowpack is complex and  human triggered avalanches are still likely in many areas.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

Monday is suppose to bring a mix of sun and cloud with an alpine temperature of -13c.  Winds are expected to be light from the West.  More snow is forecast for the latter part of the week.

Avalanche Summary

Some loose dry avalanches were noticed starting from the alpine in unskiable terrain.  One size 2.5 slab avalanche was noticed in the French creek area on a SE aspect at 2500m.

Snowpack Summary

There is about 40cm of snow from this most recent storm.  In the alpine and tree line, this storm snow is reactive to skier traffic as a slab on lee features.  In the Commonwealth area, the Jan. 6th surface hoar was found at 2350m was about 100cm down from the top.  This layer produced variable results from easy to hard but was very planar in nature. Some reverse loading from recent North winds was noticed; which means that some of the south aspects have more snow than usual.

Problems

Loose Dry

An icon showing Loose Dry
Ice climbers, avoid gullies.  Expect sluffing in steeper terrain.
Sluffs may trigger deeper instabilities.Avoid areas with overhead hazard.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 1.5

Wind Slabs

An icon showing Wind Slabs
Wind slabs are extensive in the alpine down to tree line. These may also step to deeper layers.
Avoid freshly wind loaded features.Avoid steep lee and cross-loaded slopes

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

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1.5 - 3

Persistent Slabs

An icon showing Persistent Slabs
These are deeply buried (One meter +).  Be sure to assess them thoroughly.  These can be triggered by loose dry or the wind slabs.
Carefully evaluate terrain features by digging and testing on adjacent, safe slopes.Avoid convex rolls at and below treeline where buried surface hoar may be preserved.Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1.5 - 3

Valid until: Feb 5th, 2018 2:00PM

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