Avalanche Forecast

Issued: Mar 22nd, 2017 3:00PM

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

jeremy.mackenzie, Alberta Parks

Kananaskis.

Natural avalanche activity has tapered off, but human triggering is still a real concern. Conservative terrain choices are in order, as the weak basal layers can still produce very large avalanches.

Summary

Confidence

High - Timing or intensity of solar radiation is uncertain

Weather Forecast

Thursday will be a mix of sun and cloud with no precipitation. Winds will be out of the West at 25 km/h gusting to 50 km/h. The freezing level is expected to remain at valley floor with Alpine temperatures near -8 C.

Avalanche Summary

No new avalanches were observed today but the places that have not gone look primed to go. The forecasters are still avoiding any exposure to larger slopes overhead. Avalanches that have occurred over the past weak were very large, had wide propagations and failed in the basal weak layers. In many cases these slides have been reaching or exceeding historic run-outs.

Snowpack Summary

Up to 15cm of recent snow overlies a supportive crust layer. Above 2200m this crust begins to deteriorate. In Alpine and Treeline wind slabs are found on all aspects, but expect deeper deposits on lee and cross-loaded features. The lower 125cm of the snowpack consists of facets and depth hoar. This critical weakness will persist for the rest of the season.

Problems

Wind Slabs

Wind slabs are found on all aspects. Above 2200m these slabs are more prevalent. An avalanche triggered in the upper snowpack could step down to the weak basal layers.

Avoid steep lee and cross-loaded slopesAvoid freshly wind loaded features.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 3

Deep Persistent Slabs

There is still a real concern for larger overhead exposure, especially for those features that have not yet avalanched.

Pay attention to overhead hazards like cornices which could easily trigger the deep persistent slab.Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 4

Loose Wet

The late-March solar impact can be intense. Watch for rapid destabilization of the snowpack during sunny periods, especially in rocky or shallow snowpack areas.

Use extra caution on solar slopes or if the snow is moist or wet.

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

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Mar 23rd, 2017 2:00PM