Archived

Avalanche Forecast

Mar 22nd, 2017–Mar 23rd, 2017

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: 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.

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.

Avalanche 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