Avalanche Forecast

Issued: Dec 17th, 2012 8:36AM

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

Avalanche Canada triley, Avalanche Canada

Summary

Confidence

Fair - Timing, track, or intensity of incoming weather is uncertain on Wednesday

Weather Forecast

Overnight and Tuesday: The Low pressure system is forecast to move out of the region this evening. Strong Southwesterly winds should slow down to moderate Westerly as the Low exits to the East. Flurries are expected to continue overnight without much accumulation.Wednesday: A weak upper ridge should move into the Southern Interior by Tuesday evening and continue to provide dry conditions on Wednesday. Light Westerly winds should become strong Southwesterly as the next system moves in from the Coast during the evening.Thursday: Strong Southwest winds and heavy precipitation are forecast. Timing is uncertain.

Avalanche Summary

Explosives control at Kootenay Pass created soft slab avalanches up to size 1.5 in the morning. Poor visibility and travel conditions have limited observations.

Snowpack Summary

Another 20 cms of snow on Monday brings the recent storm snow up to about 50 cms. The storm snow initially fell with very light winds and settled into an unconsolidated or very soft slab. On Monday the strong Southwest winds started transporting that snow and stiffening the slab. Expect very touchy soft slab conditions in sheltered terrain and stiff wind slab conditions on North thru East aspects. The storm snow may not bond well to old surfaces at lower elevations. The Rossland Range has a buried surface hoar layer at treeline and below that may become reactive with added load of this storm snow.

Problems

Storm Slabs

An icon showing Storm Slabs
The new storm is expected to develop a thick slab on all aspects and at all elevations. Recent light snow may also be transported by forecast strong Southwest winds into deep wind slabs on North thru East aspects.
Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.>The new snow will require several days to settle and stabilize.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

2 - 5

Valid until: Dec 18th, 2012 2:00PM