Avalanche Forecast

Issued: Mar 20th, 2016 3:00PM

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

mike.koppang, Alberta Parks

Kananaskis.

Solar aspects have a mixture of crusts and northern aspects are still full on winter with a weak facetted snowpack. Solar radiation is strong at this time of year so pay close attention to the sun!

Summary

Confidence

High - Due to the number and quality of field observations on Sunday

Weather Forecast

Freezing levels are forecast to drop to near 1600m over the next few days with conditions being a bit more cloudy. Temperatures in the Alpine tomorrow will be around -2C with a few small cm's of snow expected overnight.

Avalanche Summary

A few loose wet avalanches up to sz 1 were being observed on solar aspects out of steep unskiable terrain. More avalanches may have occurred but forecasters were out of the field by 1pm.

Snowpack Summary

Moist snow was being encountered on solar aspects up to 2700m. North aspects still had dry snow but the snowpack on these areas is far from a stable spring snowpack. Many areas had a weak facetted base that would be prone to triggering by a skier from a thinner snowpack area. Cornices are still large and looming over many alpine features. As temperatures cool moving into the week, solar aspects will have a rugged temperature crust that will make skiing challenging.

Problems

Persistent Slabs

Wind slabs up to 40cm thick are present in lee and cross-loaded features in alpine areas and in very specific locations at treeline.

Avoid lee and cross-loaded terrain near ridge crests.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 5

Cornices

Cornices are large and we have seen a few collapse of late with the warmer temperatures and continued loading. When these do fail the heavy loads on underlying slopes may awaken the basal instabilities and produce very large avalanches.

Stay well back from cornices.>Pay attention to overhead hazards like cornices.>

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

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

3 - 6

Deep Persistent Slabs

Basal facets and the Jan 6th FC interface are likely to be triggered from thinner snowpack areas.

Be aware of the potential for large, deep avalanches.>Avoid convexities or areas with a thin or variable snowpack.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

3 - 6

Valid until: Mar 21st, 2016 2:00PM