Avalanche Forecast

Issued: Jan 10th, 2017 3:15PM

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

jeremy.mackenzie, Alberta Parks

Kananaskis.

Watch for fresh wind slabs in the Alpine. Ice climbers should also be cautious with overhead terrain as several loose dry avalanches were observed today in gully features.

Summary

Confidence

High -

Weather Forecast

A clearing trend is expected for the next few days. Temperatures are expected to moderate with a high of -14 °C expected Wednesday. Winds will be out of the N to NW in the light to moderate range. No precipitation is expected for the rest of the week.

Avalanche Summary

Several naturally triggered slabs up to size 2.5 in the Alpine on all aspects. The majority of these avalanches are associated with the recently formed wind slabs, but a few failed deeper on the Dec 18th interface. In addition numerous loose dry avalanches up to size 1.5 have occurred over the past 24hrs in steep Alpine terrain on all aspects.

Snowpack Summary

Another 10cm of new snow in the past 24hrs brings storm snow totals to near 20cm. Variable wind effect in the Alpine, with pockets of fresh wind slab immediately below ridge-crest. The Dec 18th interface is buried 40 to 70cm at Treeline and remains a concern for human triggering. The Nov crust is buried up to 100cm deep and is exhibiting facetting both above and below the crust. At lower elevations the snowpack is weak and unsupportive due to prolonged periods of facetting.

Problems

Persistent Slabs

These slabs are failing down 30-50cm at the main density change. Human triggering from a thin snowpack area is a definite possibility.

Avoid convexities or areas with a thin or variable snowpack.Be aware of thin areas that may propogate to deeper instabilites.Avoid steep lee and cross-loaded slopes

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Wind Slabs

Recent snow and wind have created fresh wind slabs immediately below ridge crests on all aspects.

Avoid freshly wind loaded features.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 2

Deep Persistent Slabs

More likely to be triggered from thinner areas and step down to the November crust producing larger avalanches.

If triggered the wind slabs may step down to deeper layers resulting in large avalanches.Be aware of thin areas that may propogate to deeper instabilites.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Jan 11th, 2017 2:00PM