Avalanche Forecast

Issued: Jan 14th, 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 and Deep Persistent Slabs.

Alberta Parks jeremy.mackenzie, Alberta Parks

Despite the Moderate hazard rating, forecasters are treating large Alpine features with caution due to the deep persistent weak layers.

Summary

Confidence

High -

Weather Forecast

Sunday will be cloudy with sunny periods and no precipitations. Temperatures should be fairly mild with moderate westerly winds. A system is approaching that could bring some snow to us on Tuesday.

Avalanche Summary

One new slab avalanche observed today on an East aspect in the Alpine. This slide was naturally triggered and appears to have occurred in the past 24hrs. The fracture line was up to 100cm deep.

Snowpack Summary

Variable depth wind slabs are found in Alpine terrain along ridgelines and in cross-loaded gully features. Snowpack tests today indicate failures in the moderate range down 35cm, as well as on the Nov crust layer buried deeply in the snowpack. Much of the snowpack is very weak and facetted, especially at lower elevations. Any avalanche that is initiated in the upper snowpack will likely step down and involve the entire snowpack.

Problems

Wind Slabs

An icon showing Wind Slabs
Snow and wind over the past week have created wind slabs up to 30cm thick immediately below ridge crests on all aspects. These slabs are on all aspects as a result of the Northerly flow this past week.
Evaluate unsupported slopes critically.Avoid steep lee and cross-loaded slopes

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Deep Persistent Slabs

An icon showing Deep Persistent Slabs
More likely to be triggered from thinner areas and step down to the basal facets and involve the entire winters snowpack.
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 15th, 2017 2:00PM