Avalanche Forecast

Issued: Dec 13th, 2014 8:09AM

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.

Avalanche Danger is trending down due to below freezing temperatures after the recent rain.

Summary

Confidence

Fair - Due to the number and quality of field observations

Weather Forecast

Some cloud is forecast to remain in the Southeast corner of the province overnight Saturday and into Sunday morning. Moderate Northwest winds are expected overnight as the ridge of High pressure moves South into the region. There is a chance of 3-5 mm of precipitation due to moisture left in the area being cooled by the air descending from the North. Freezing levels should drop down to valley bottoms by Sunday morning. We should see gradual clearing on Sunday with light Northeast winds. Monday should be clear with light winds and freezing levels remaining at valley bottoms during the day and alpine temperatures around -8. Increasing cloud is forecast for Tuesday as a weak Southwest flow begins to push into the region. At this time there is not much precipitation associated with this cloud.

Avalanche Summary

No new reports of avalanches from the region.

Snowpack Summary

Light rain from the past week has saturated the upper snowpack at higher elevations, and the entire snowpack below treeline. With forecast cooling, these surfaces will likely exist as a new crust. There may be a buried persistent weak layer of crust and/or facets that is now down between 70-100 cm. This buried crust 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.

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

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 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: All aspects.

Elevations: Alpine.

Likelihood

Unlikely

Expected Size

2 - 4

Valid until: Dec 14th, 2014 2:00PM