Avalanche Forecast

Issued: Dec 20th, 2012 3:00PM

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

burke.duncan, Alberta Parks

Kananaskis.

Some new snow in the forecast but ending by early Friday AM as the colder arctic air pushes in. If we do see some new snow we are looking at a bit of a jump in danger ratings over the next couple days - otherwise just getting colder!

Summary

Confidence

Good - Forecast snowfall amounts are uncertain on Friday

Weather Forecast

Snow fall amounts totalling 10+cm by Friday morning are in the forecast however little of what was forecast for Thursday has shown up yet. The arctic front will arrive early Friday and temps will drop and remain there for a few days. Expect lows in the -15 degree range. Only minor amounts of new snow are expected after the arctic front arrives. Winds in the forecast area will be in the light to moderate range out of the south-west.

Avalanche Summary

Minor sluffing in very steep terrain on north and east aspects due to wind action.

Snowpack Summary

General weakening of snowpack taking place due to strong temperature gradient. The Nov crust layer continues to deteriorate and recent field tests continue to produce compression test results in the HARD range.

Problems

Wind Slabs

Wind slabs are highly variable in their depth and distribution, but are prominent in alpine areas and isolated locations at treeline. Cross-loaded features and terrain immediately below ridge crests are possible trigger points.

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

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 5

Deep Persistent Slabs

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

Be aware of thin areas that may propagate to deeper instabilites.>

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 6

Valid until: Dec 21st, 2012 2:00PM