Avalanche Forecast

Issued: Dec 12th, 2011 8:50AM

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

Avalanche Canada mpeter, Avalanche Canada

Summary

Confidence

Fair - Intensity of incoming weather is uncertain

Weather Forecast

Tuesday & Wednesday: A weak ridge is giving a couple more dry days. Expect light westerly winds and daytime highs of -5 under clear skies or high cloud. Thursday: Clouds are likely to develop in the morning with a chance of light flurries throughout the day. Continued westerly winds with daytime temperatures climbing to -5.

Avalanche Summary

No new avalanches.

Snowpack Summary

3-5cm of new snow has fallen in the past couple of days. This overlies surface hoar (as large as 20mm in protected areas), surface facets, the odd old windslab and sun crusts (on steep south through west aspects). The new snow has fallen with limited winds effect. All of these newly buried surfaces are good sliding interfaces; all that's lacking is a large enough load. As more snow arrives and/or the wind picks up (as per the forecast) the avalanche danger will increase. Due to the slow, incremental increase in load (dribs and drabs of new snow and sporadic winds), this increase in danger is difficult to pinpoint and could be very site specific.In some locations there is a rain crust buried between 20-35cm. This crust extends as high as 2200m. Some faceting has been observed around the crust; definitely worth remembering this one.The early November surface hoar remains a layer of concern. Buried 100-150cm it is unlikely to trigger, but consequences of triggering would be a large (up to size 3.0) destructive avalanche.

Problems

Wind Slabs

An icon showing Wind Slabs
Hard windslabs linger in isolated lee locations in the alpine.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Persistent Slabs

An icon showing Persistent Slabs
Difficult to trigger, but with high consequences. Weaker thin spots on convexities or around protruding rocks/clumps of small trees may be likely trigger locations.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 5

Valid until: Dec 13th, 2011 8:00AM

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