Avalanche Forecast

Issued: Dec 14th, 2014 8:02AM

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.

triley, Avalanche Canada

South Rockies.

Danger ratings trending down due to low freezing levels after the recent rain.

Summary

Confidence

Fair - Due to the number of field observations

Weather Forecast

Clearing overnight with light Southeast winds and alpine temperatures around -6. Freezing levels should remain at valley bottoms for the forecast period. Sunny with light Southwest winds on Monday. Tuesday mostly sunny with some valley cloud. Cloud moving in to the region on Tuesday evening and remaining on Wednesday. No precipitation expected for the forecast period.

Avalanche Summary

No new reports of avalanches from the region.

Snowpack Summary

Overnight freezing has developed a surface crust up to about 2100 metres and the whole snowpack has re-frozen into a solid mass below about 1600 metres. Early Sunday 10-15 cm (@Harmer weather station) of dry light new snow has buried the crust that was left after the recent rain.Â There may be a buried persistent 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 in high alpine areas that did not get rain during the recent storm. Pockets of wind slab may continue to be triggered by skiers and riders at or near ridgetops in areas where the snow was dry enough to be transported by the strong Southwest winds during the storm.

Problems

Wind Slabs

Pockets of wind slab may continue to be sensitive to human triggers in the alpine at elevations that were above the rain line during the recent storm.

Avoid lee and cross-loaded terrain near ridge crests.>Be cautious as you transition into wind affected terrain.>

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

The deeply buried November rain crust may be sensitive to large loads in the high alpine in areas above the rain line during the recent storm and where there was enough snow to develop a crust in early November.

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

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely

Expected Size

2 - 4

Valid until: Dec 15th, 2014 2:00PM