Avalanche Forecast

Issued: Dec 17th, 2014 7:43AM

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

ccampbell, Avalanche Canada

Kootenay Boundary.

If the riding is good, the snowpack stability might not be.

Summary

Confidence

Fair - Due to the number of field observations

Weather Forecast

Mainly cloudy with around 5 cm of fresh snow on Thursday, 10 cm on Friday and another couple expected on Saturday. Freezing levels are expected to gradually rise from valley bottom on Thursday to 1600 m or higher by Saturday afternoon. Winds should remain light but gusty from the south.

Avalanche Summary

There we no new reports of avalanches on Tuesday and Wednesday morning.

Snowpack Summary

Light flurries are burying large surface hoar sitting on or near a thick hard supportive rain crust that extends as high as 2100 m. Critical slopes are high elevation north aspects where facets or buried surface hoar from earlier in the month may be lurking under dense storm slabs, and older facet/crust weaknesses may be persisting. Recent snowpack tests at 2050 m in a NW aspect in Kootenay Pass produced moderate sudden results down 35 cm under the late-November crust and down 79 cm on facets above the early-November crust. Meanwhile in the Southern Purcells, snowpack tests last weekend gave easy sudden planer results on well preserved surface hoar where it was found down 30 cm on high north aspects.

Problems

Loose Dry

Dry surface snow is poorly bonded to the underlying hard crust and may sluff off in steep terrain.

On steep slopes, pull over periodically or cut into a new line to manage sluffing.>Be very cautious with gully features.>Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

Old facet/crust weaknesses may still be sensitive to triggers on slopes that aren't bridged by a thick near-surface crust. Generally shady aspects in the high alpine.

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

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

Elevations: Alpine.

Likelihood

Unlikely

Expected Size

2 - 4

Valid until: Dec 18th, 2014 2:00PM