Avalanche Forecast

Issued: Dec 28th, 2013 3:00PM

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

jeremy.mackenzie, Alberta Parks

Kananaskis.

Large and destructive avalanches are possible due to the persistent weak layer at the base of the snowpack. Conservative route selection is advised.

Summary

Confidence

Good

Weather Forecast

Cloudy conditions will prevail with west winds in the moderate to strong winds. Alpine temperatures will reach -9 tomorrow. A trace amount of new snow is possible on Sunday with up to 5cm on Monday.

Avalanche Summary

One size 1.5 Na sluff from steep alpine terrain on East aspect at 2900m. This sluff did not appear to trigger a slab on the underlying slopes.

Snowpack Summary

15 to 20cm low density Hn bonding poorly to previous surfaces which include mfc, hard slab and FC. Variable thickness mfc observed on East and North aspects where traveled today. Test profile at 2250m on East aspect, 32 degrees slope, gave CTM(12) sudden planar down 71cm. Very dense (P+) previously formed slab overlies facets and depth hoar in wind loaded feature at treeline. Whumpfing observed at treeline.

Problems

Persistent Slabs

Avalanches could step down to the basal October layers and involve the entire winters snowpack, especially in shallow snowpack areas. In some areas a dense wind slab overlies this deeply buried weak layer. Large avalanches are possible.

Be aware of thin areas that may propogate to deeper instabilites.>Be aware of the potential for wide propagations due to the presence of hard windslabs.>Avoid convexities or areas with a thin or variable snowpack.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 5

Wind Slabs

Up to 20cm of recent snow is available for transport. Moderate to strong West winds will begin to build slabs in lee and cross-loaded features.

Avoid freshly wind loaded features.>Avoid steep lee and cross-loaded features>

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

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Dec 29th, 2013 2:00PM