Avalanche Forecast

Issued: Feb 20th, 2019 3:06PM

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

jeremy.mackenzie, Alberta Parks

Kananaskis.

Look for good skiing in sheltered areas. Recent avalanche activity is a good reminder that MODERATE hazard is not a "green light" to blindly jump into bigger terrain features.

Summary

Confidence

Moderate -

Weather Forecast

Thursday will be mainly cloudy with very light flurries. Overnight lows will drop to near -25, with daytime highs near -14. Winds will be light and variable. Similar conditions on Friday.

Avalanche Summary

No new avalanches observed today, but visibility was very limited. Recent strong winds resulted in several loose dry avalanches yesterday up to size 2.0, primarily in very steep Alpine terrain on all aspects. In addition, the deep persistent layer of basal facets finally woke up and a size 2.0 naturally triggered slab occurred on the north end of Tent Bowl around midday on Tuesday. This slide occurred at Treeline and was only about 40m wide, but was between 120 and 140cm deep and failed on the basal facets.

Snowpack Summary

A few cm's of snow fell through the day, but accumulations were minimal. New wind slabs can be found in Alpine and Treeline features on all aspects, but we are unsure of the extent of these due to a lack of field observations today. The mid pack has enough strength and depth (in most places) that triggering the bottom layers is unlikely. The key to avoiding trouble is avoiding thin areas where the bridging is minimal.

Problems

Wind Slabs

Recent winds led to wind slab development in the Alpine and just into Treeline. Watch for unusual loading patterns due to northerly winds.

Avoid travelling in areas that have been reverse loaded by winds.Caution in lee and cross-loaded terrain near ridge crests.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Loose Dry

This problem should settle out fairly quickly, but watch for sluffing in steep terrain.

Avoid travelling under cliffs that are exposed to sluffing from above.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Deep Persistent Slabs

The basal facets finally woke upon Tuesday. Some time around midday a full depth avalanche occurred at Treeline on Tent Ridge. This layer is still unlikely to trigger, but has severe consequences if it does fail.

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

1 - 2.5

Valid until: Feb 21st, 2019 2:00PM