Avalanche Forecast

Issued: Dec 17th, 2011 8:44AM

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

Avalanche Canada triley, Avalanche Canada

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Summary

Confidence

Fair - Forecast snowfall amounts are uncertain on Sunday

Weather Forecast

A cold front is expected to move through the interior on Saturday night. This trailing cold front will follow in the wake of the warm air that we saw on Saturday and is forecast to bring another 10 cm by Sunday morning to the North and West regions of the Monashees and Cariboos. Less snow is forecast for the South and East areas of the Selkirks and Purcells. Freezing levels are expected to fall back to valley bottoms as cold air and moderate to strong Northwest winds move over the interior. Sunday is expected to be mostly dry but probably still overcast. Clearer and colder weather should be across the interior on Monday. The next Pacific system is expected to start moving in from the coast on Tuesday. It is a little early to determine intensity and timing for the next system.

Avalanche Summary

Loose snow sluffing in steep terrain up to size 2.0 has been reported in the region.

Snowpack Summary

A cold front is expected to move through the interior on Saturday night. This trailing cold front will follow in the wake of the warm air that we saw on Saturday and is forecast to bring another 10 cm by Sunday morning to the North and West regions of the Monashees and Cariboos. Less snow is forecast for the South and East areas of the Selkirks and Purcells. Freezing levels are expected to fall back to valley bottoms as cold air and moderate to strong Northwest winds move over the interior. Sunday is expected to be mostly dry but probably still overcast. Clearer and colder weather should be across the interior on Monday. The next Pacific system is expected to start moving in from the coast on Tuesday. It is a little early to determine intensity and timing for the next system.

Problems

Wind Slabs

An icon showing Wind Slabs
These windslabs may be sliding easily on the recently buried surface hoar. Winds are forecast to switch from Southwest to Northwest by Sunday morning. Windslabs may be low down on slopes due to strong winds.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 4

Storm Slabs

An icon showing Storm Slabs
The new storm snow may settle into a cohesive slab that could be touchy to human triggers. Cooler temperatures on Sunday should tighten up the moist slab below treeline.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 4

Persistent Slabs

An icon showing Persistent Slabs
Variable snow depths may make it possible to trigger a deeper instability on steep, unsupported terrain features. Areas that get more new snow may have enough load to make this layer active again.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

3 - 6

Valid until: Dec 18th, 2011 8:00AM