Avalanche Forecast

Issued: Jan 19th, 2015 7:22AM

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

jeremy.mackenzie, Alberta Parks

Kananaskis.

Recent snowfalls and strong winds that have switched from SW to NW are creating touchy wind slabs. Conditions are ripe for human triggering.

Summary

Confidence

Fair

Weather Forecast

A NW flow will keep temperatures a bit on the cool side under mostly cloudy skies on Tuesday. Winds will be light to moderate from the NW. Only a trace amount of precipitation is expected over the next 48hrs.

Avalanche Summary

Visibility was limited today, but one large naturally triggered avalanche (possibly a size 3.) was observed on a SE aspect at Treeline. This slide was not very wide but the fracture was estimated at 100cm deep. This slide appeared to be 24 to 48hrs old.

Snowpack Summary

Up to 10cm of new snow in the past 24 to 36hrs has further buried the Jan 16th surface hoar layer which is now down 20 to 30cm at treeline. Moderate to strong SW winds have formed wind slabs in Alpine areas and open areas at Treeline. Where buried surface hoar exists, these slabs will be quite touchy to human triggering. A layer of facets remains above the December 13th crust now down 40 to 50cm is still producing moderate sudden collapse results. This will be a key layer to watch for the next little while. Alpine areas remain heavily wind effected.

Problems

Wind Slabs

Between 20 and 30cm of recent snow now sit on the Jan 16th surface hoar. Where wind slabs are present above this layer, conditions will be touchy to human triggering.

Avoid freshly wind loaded features.>Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Persistent Slabs

A layer of facets sits on the Dec 1th crust layer which is reactive in the moderate range down 40 to 50cm at Treeline. With the recent wind and snow load this layer has become more sensitive to triggering.

Avoid cross loaded features.>Avoid unsupported slopes.>

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Deep Persistent Slabs

The weak basal layers are not going anywhere soon. Use caution in steep terrain where the snowpack is shallow and/or variable. Full depth avalanches are still a possibility.

Caution around convexities or areas with a thin or variable snowpack.>

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 4

Valid until: Jan 20th, 2015 2:00PM