Avalanche Forecast

Issued: Jan 2nd, 2014 3:00PM

The alpine rating is high, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Storm Slabs and Persistent Slabs.

mike.koppang, Alberta Parks

Kananaskis.

Up to 30cm of new snow is expected over the next 36hrs with strong W and NW winds. This new snow will likely overload the basal facets and cause a natural avalanche cycle. Avalanches may involve the entire winters snowpack.

Summary

Confidence

Fair - Intensity of incoming weather systems is uncertain on Friday

Weather Forecast

An approaching cold front is expected to cross the region over the next few days giving us 20-30cm of new snow.Â This new snow is expected to come in with some strong west and north west winds so be prepared for new storm slabs to build and develop quickly during the storm.Â This may be enough snow to overload the weak basal facets and cause a natural avalanche cycle with avalanches involving the entire winters snowpack occurring.

Avalanche Summary

A few new sz 2 avalanches were observed on a NE aspect on Tent ridge.Â Both slides occurred around 2400m and failed at ground and on the october crust near the base of the snowpack.

Snowpack Summary

Snowpack generally unsupportive in untravelled terrain below 2000m.Â Above this snowpack becomes more supportive and travel is easier.Â In open areas expect to encounter windslabs overlying the previous midpack and generally 30-50cm of facets and depth hoar at the base of the snowpack.Â CTM(sudden collapse) results were being encountered at the interface of the midpack to the facets and depth hoar down 50-70cm depending upon location.Â The concern now is for low probability high consequence avalanches that have the chance of occurring from this snowpack areas.Â Any avalanche that initiates is likelyÂ to involve most or all of the winters snowpack.Â

Problems

Storm Slabs

Storm slabs will build from snow expected to fall over the next 24hrs. It is uncertain if this will be enough snow to overload the weak base but we can expect natural avalanches within the storm snow that may step down to the deeper layers.

The new snow will require several days to settle and stabilize.>Avoid freshly wind loaded features.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 4

Persistent Slabs

The new snow may be enough load to cause a widepread natural avalanche cycle with avalanches that involve the entire winters snowpack. Thin spots and weak trigger points will be tough to locate.

Be aware of the potential for full depth avalanches due to deeply buried weak layers.>Be aware of thin areas that may propogate to deeper instabilites.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 4

Valid until: Jan 3rd, 2014 2:00PM