Avalanche Forecast

Issued: Dec 17th, 2014 7:37AM

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

South Rockies.

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

Summary

Confidence

Fair - Due to the number of field observations

Weather Forecast

A mix of sun and cloud and no snow expected for Thursday and Friday with some very light flurries possible Friday afternoon into Saturday morning. Freezing levels reaching 1600 each day and winds remaining light but gusty from the southwest.

Avalanche Summary

No new reports of avalanches from the region on Tuesday or Wednesday morning.

Snowpack Summary

Surface hoar is likely growing on 10-20 cm of loose dry snow that is sluffing readily on a thick hard supportive rain crust that extends into alpine elevations. This near surface crust is effectively bridging triggers from penetrating to deeper persistent weaknesses that formed earlier in the season. However, on slopes above the recent rain line poorly bonded crusts, facets, and/or buried surface hoar may be susceptible to triggers. Including a weak layer of crust and/or facets that is now down between 70-100 cm. This buried crust from November may continue to be triggered by large additional loads. Pockets of fresh wind slab may also be triggered at or near ridgetops in areas where the snow was dry enough to be transported by the strong Southwest winds during the storm.

Problems

Loose Dry

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

Be very cautious with gully features.>On steep slopes, pull over periodically or cut into a new line to manage sluffing.>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.

Avoid large alpine slopes that have a deeply buried crust with facets. >Avoid slopes with variable snowpack depths. Avalanches may be triggered from thin spots around boulders or small trees.>

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

Elevations: Alpine.

Likelihood

Unlikely

Expected Size

2 - 4

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