Avalanche Forecast

Issued: Dec 24th, 2012 3:00PM

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

jeremy.mackenzie, Alberta Parks

Kananaskis.

Recently formed storm slabs in the Alpine have become slightly more sensitive to trigger as seen by a few small avalanche observations today. Great skiing in sheltered locations. MERRY CHRISTMAS!

Summary

Confidence

Good

Weather Forecast

Christmas Day should bring cool temperatures and clear skies with very little wind. No precipitation is in the forecast.

Avalanche Summary

Several loose dry slides up to size 1 on very steep lee terrain in the Alpine. A few very thin slabs up to size 1 on S and SE aspects of Hero's Knob. One size 1.5 naturally triggered slab on SE aspect at 2500m. Slab was 50 to 60cm deep, 40m wide.

Snowpack Summary

Surface facetting and upper snowpack settling. Shears persist in previous HST. Nov rain crust has been inactive in recent field tests, but remains a concern in shallow snowpack areas.

Problems

Wind Slabs

Wind slabs that developed earlier in the week are tougher to located due to recent snowfalls. Watch for pockets of these slabs on open planar slopes, especially in the Alpine. Steep cross-loaded terrain should also be approached with caution.

Avoid unsupported slopes.>

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 4

Storm Slabs

Recent storm slabs have developed in Alpine terrain where there has been intermittent light and variable winds. These new slabs are in immediate lees and do not extent far down slope. Some recent avalanche activity has been observed on this layer.

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

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 4

Deep Persistent Slabs

This layer is prevalent throughout the forecast area and is buried 100cm on average. Field tests are showing reduced sensitivity on this layer but it should not be forgotten. Thin spots may be areas where light loads could trigger this interface.

Avoid shallow snowpack areas where triggering is more likely.>

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 6

Valid until: Dec 25th, 2012 2:00PM