Avalanche Forecast

Issued: Dec 7th, 2014 8:33AM

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

triley, Avalanche Canada

South Rockies.

Avalanche danger is expected to increase as the new storm develops. The freezing level and precipitation amounts will decide how high the danger ratings climb.

Summary

Confidence

Poor - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

Cloud is forecast to increase on Monday morning as a Southwest flow develops into the region. Expect strong Southwest winds by Monday afternoon combined with a trace of precipitation and freezing levels climbing up to about 2000 metres elevation. Very strong Southwest winds, light precipitation and freezing levels rising up to about 2200 metres elevation are forecast for Tuesday. Continued Very strong Southwest flow on Wednesday with light precipitation amounts; the models may change with respect to precipitation as this system develops, stay tuned for more information in the next few days.

Avalanche Summary

No avalanche activity reported. Have you seen anything recently?

Snowpack Summary

There is at least one, maybe more, problematic layers in the South Rockies snowpack. Last weekends 30 - 60cm of storm snow buried a weak layer of facets over a crust which formed during November's dry spell. That interface is probably around a meter down now. Not much is known about the reactivity of this layer, nor the slab above it. But, it doesn't take much of a leap of faith to understand that a meter deep slab sitting on a persistent weak layer is a potentially bad thing.

Problems

Wind Slabs

Strong winds have developed windslabs in the alpine and at treeline in areas with snow available for transport. Forecast new snow may develop a new storm slab above these windslabs.

Avoid freshly wind loaded features.>Use ridges or ribs to avoid pockets of wind loaded snow.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Persistent Slabs

A deeply buried crust with a weak layer of facets or surface hoar at the interface may exist in some parts of this region. Dig down and locate the crust, and then test how the upper snowpack is bonding to the crust.

Avoid convexities or areas with a thin or variable snowpack.>Be aware of thin areas that may propogate to deeper instabilites.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 5

Valid until: Dec 8th, 2014 2:00PM