Avalanche Forecast

Issued: Feb 27th, 2017 3:00PM

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

jeremy.mackenzie, Alberta Parks

Kananaskis.

Despite the MODERATE hazard rating, forecasters are being very conservative due to the snowpack structure. While it may be only "possible" to trigger, any avalanche will likely step down to the weak basal layers and be very large and destructive.

Summary

Confidence

High -

Weather Forecast

Tuesday will be cloudy with sunny periods and isolated flurries. Alpine temperatures are only expected to reach a high of -17 Â°C, which along with moderate westerly winds will contribute to significant wind chill values. Wednesday will remain cool with some light flurries.

Avalanche Summary

Two size 2.0 naturally triggered slabs occurred on Little Tent Ridge in the last 24 to 48hrs. These were both size 2.0 avalanches initiating near 2400m on a steep East aspect. Depths ranged from 40 to 60cm, with up to 80m wide propagations and ran for approximately 500m.

Snowpack Summary

1cm of new snow overnight. Fresh thin wind slabs have formed at Treeline and above. A test profile in the Ten Bowl area today revealed a 165cm deep snowpit with the entire bottom 100cm consisting of very weak facets and depth hoar. Moderate compression test results were found down 25 to 30cm. Moderate to hard test results occurred down 60 to 70cm within the facets, indicating the possibility for an avalanche to step down to the weak basal layers. The current snowpack structure is very concerning, and despite the recent lack of natural avalanches human triggering of a very large avalanche is possible.

Problems

Wind Slabs

Recent winds have created isolated thin wind slabs in lee and cross loaded areas at Treeline and above.

Avoid lee and cross-loaded terrain near ridge crests.Avoid freshly wind loaded features.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Persistent Slabs

The buried hard slab is the concern here. Probing with a ski pole is the best way to monitor its location. Expect wide propagations if it does get triggered.

Minimize exposure to overhead avalanche terrain, large avalanches may reach run out zones.Be aware of the potential for wide propagations.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Deep Persistent Slabs

This layer will be with us for the year and should be put into every slope decision. The current snowpack structure is very concerning, with the possibility of very large avalanches if a trigger point is found.

Avoid steep convexities or areas with a thin or variable snowpack.Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 4

Valid until: Feb 28th, 2017 2:00PM