Avalanche Forecast

Issued: Jan 19th, 2019 3:00PM

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

mike.koppang, Alberta Parks

Kananaskis.

Full depth skier triggered avalanche are a real possibility. Avoid thin terrain where the snowpack is weak.

Summary

Confidence

High -

Weather Forecast

Another 5cm of snow is forecast overnight with temps on Sunday looking to be slightly cooler around -10C. Winds are forecast to be light out of the SW under a partly cloudy sky. Dribs and drabs of snow are forecast this week but no significant accumulations.

Avalanche Summary

Numerous loose dry slides out of steeper terrain up to sz 1.5. Besides this, no new slab activity was observed.

Snowpack Summary

5-10cm of new snow over the past 48hrs at treeline and above. This snow is now burying the Jan 17th surface hoar and sun crust layers that were being found up to 2300m. This will be important to note later as the winter continues. Otherwise our main concern is still for the weak basal layers under the Dec 10th interface down 80-110cm. Thin areas we were able to get easy results and the tests also indicate that this layer will likely propagate across a given terrain feature given the widespread nature of the basal problem. We backed off steeper terrain on Saturday due to variable snowpack depths and are still very cautious in and under bigger terrain. Sheltered areas were offering some good skiing!

Problems

Deep Persistent Slabs

Full depth avalanches failing on ground have been observed over the past few days. Thin areas where you may trigger the basal layers should be avoided. Test also indicate that propagation across a feature is likely

Carefully evaluate and use caution around thin snowpack areas.Remote triggering is a concern, watch out for adjacent slopes.Be aware of the potential for full depth avalanches due to weak layers at the base of the snowpack.

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

1.5 - 3

Wind Slabs

Expect to find wind slabs at all elevations. The depth and sensitivity to triggering are highly variable across the forecast region.

Avoid convexities or areas with a thin or variable snowpack.If triggered the storm/wind slabs may step down to deeper layers resulting in large avalanches.Be aware of thin areas that may propogate to deeper instabilites.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Loose Dry

Extensive sluffing from steeper terrain was observed flowing into skiable areas.

Avoid travelling under cliffs that are exposed to sluffing from above.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Very Likely

Expected Size

1 - 1.5

Valid until: Jan 20th, 2019 2:00PM