Avalanche Forecast

Issued: Mar 13th, 2019 3:00PM

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

jeremy.mackenzie, Alberta Parks

Kananaskis.

Avalanches have the potential to run far in certain terrain. Stick to low angle slopes and avoid terrain traps such as gullies.

Summary

Confidence

Moderate - Timing or intensity of solar radiation is uncertain

Weather Forecast

Weather models disagree on the outlook for Thursday. It will be either mostly sunny, or totally overcast with light flurries in the afternoon. Winds will be moderate from the west and ridge-top temperatures will climb to -5 by afternoon. Temperatures will be get progressively warmer through the week.

Avalanche Summary

Widespread loose dry avalanches up to size 1.5 in Alpine areas of the Eastern Ranges due to the recent fresh snow. There has also been very isolated thin wind slab activity up to size 1.5 in Alpine and Treeline terrain. Further west, there was little to no avalanche activity observed.

Snowpack Summary

An upslope storm deposited only 10 to 15cm along the Continental divide, with as much as 25cm in the Front Ranges closer to Canmore. This new snow overlies a variety of previous surfaces including sun crust, wind slab, breakable wind crust, sastrugi and facets. A couple of reports today of very poor quality skiing in the Spray. No change to the mid-pack and basal layers - they are still primarily weak and facetted and only have some residual strength in the deeper snowpack areas. Expect occasional ski penetration to ground, especially at lower elevations.

Problems

Wind Slabs

Wind slabs are now buried by the fresh snow, but expect to find them virtually everywhere. They will be most sensitive to triggering in steep and unsupported terrain.

Be careful with wind loaded pockets while approaching and climbing ice routes.Caution in lee and cross-loaded terrain near ridge crests.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Deep Persistent Slabs

This layer is still concerning and could be woken up by a skier/rider in a thin shallow snowpack area, warmer temps with some solar radiation or a cornice failure. This problem deserves respect as any resulting avalanche will be full depth.

Be aware of the potential for wide propagations due to the presence of hard windslabs.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

Unlikely - Possible

Expected Size

1.5 - 3

Loose Dry

Weather forecasts are inconsistent. If it is actually sunny, this problem could be quite active, but if cloudy conditions prevail, it may be a relative non-issue. Avoid terrain traps and keep an eye on overhead terrain.

Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.Avoid travelling on ledges and cliffs where sluffing may have severe consequences.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Mar 14th, 2019 2:00PM