Avalanche Forecast

Issued: Dec 4th, 2013 8:45AM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Wind Slabs and Persistent Slabs.

triley, Avalanche Canada

South Rockies.

Summary

Confidence

Fair - Due to the number of field observations

Weather Forecast

Mostly clear and cold for the forecast period. There is a chance of some cloud and very light flurries in the Southeast.

Avalanche Summary

No reports of avalanche activity. We suspect that the storm slab continues to be reactive to human triggers where it is sitting on a weak layer of buried surface hoar, facetted crystals, or crust.

Snowpack Summary

A storm slab has developed above the existing shallow weak snowpack. We don't know how deep the storm slab is due to a lack of observations from the field. I expect that there is 10-40 cm of new snow depending on your location in the region. This variability is due to the convective nature of the recent storm. The new storm slab is not expected to bond well to the old surface weak layers of crusts, wind slabs, and surface hoar.

Problems

Wind Slabs

Northeast winds have developed wind slabs at higher elevations. These wind slabs may have reverse loaded terrain features that were stripped by Westerly winds during the storm.

Be cautious as you transition into wind affected terrain.>Be careful with wind loaded pockets. Be aware of wide variation in snowpack depth>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Persistent Slabs

We expect the recent storm snow to continue to be reactive above the surface hoar and crusts that were buried at the end of November.

Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.>Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 4

Valid until: Dec 5th, 2013 2:00PM