Avalanche Forecast

Issued: Feb 17th, 2018 3:00PM

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

mike.koppang, Alberta Parks

Kananaskis.

A few large avalanches in the past 48hrs. Limit your exposure in terrain that has not yet avalanched. Cold temps moving in!!!

Summary

Confidence

High -

Weather Forecast

A few more cm of snow overnight and then the deep freeze arrives... Winds will be out of the north and thankfully light! Temps on Sunday are in the -25s area...

Avalanche Summary

No new natural avalanche activity was obscured but observatons were limited due to poor visibility.

Snowpack Summary

10-13cm of recent snow at treeline and above has helped to freshen up the skiing. Windlslabs are being found on all aspects in the alpine due to westerly and now northerly flow. These slabs had a drummy cakey feel that had us give them a wide berth. Despite the strong winds, these slabs do not appear to extend far downslope but the forecasting team was only in a treeline feature on Saturday. We expect them to be more widespread in the alpine. Deeper in the snowpack the Jan 6th Sh layer was found at 2400m down 120cm. Tests are producing hard sudden planar results on this interface indicating that if you do cause a failure in the wrong spot, expect a large desctructive avalanche.

Problems

Wind Slabs

Widepsread windslabs in Alpine terrain and in more specific areas such as gullies and ridgelines at treeline.

Use caution in lee areas. Recent wind loading has created wind slabs.If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Persistent Slabs

The surface hoar is still intact in many treeline areas. It's depth varies, but a meter down is a good generalization. We are still treating this layer with caution and respect. Surface hoar is known for unexpected surprises.

Dig down to find and test weak layers before committing to a line.Use caution on open slopes and convex rolls at treeline where buried surface hoar may be preserved.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1.5 - 2.5

Deep Persistent Slabs

Recent avalanche activity has shown the potential for avalanches to step down to this layer.

Be aware of the potential for full depth avalanches due to deeply buried weak layers.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3.5

Valid until: Feb 18th, 2018 2:00PM