Avalanche Forecast

Issued: Dec 24th, 2013 4:00PM

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

ian jackson, Parks Canada

Banff Yoho Kootenay.

Some of you must have been naughty, as we've gotten facets instead of stellars so far... Happy Holidays and lets hope for snow in the New Year!

Summary

Weather Forecast

A surface high just off the coast is keeping any major systems away. Generally, we will see alpine temps in the -5 to -10 range, with some light snow on Thursday and Friday. Alpine winds will be moderate to strong from the W/SW.Â Valley winds will be light.

Snowpack Summary

5-10cm of new snow in the W tapers to nothing in the E.Â A variety of surface weaknesses including widespread windslabs in the ALP and surface hoar at TL and BTL sit on a generally weak snowpack. The real concern is the facet/depth hoar/crust combo at the base of the snowpack which been triggered by light loads recently and can't be trusted.

Avalanche Summary

A size 2.5 was observed yesterday on a N aspect of Mt. Fairview. It was initiated as a wind-induced spindrift avalanche which pulled out a slab that failed near the ground. This is indicative of the widespread basal weakness present in the snowpack.

Confidence

Due to the number of field observations

Problems

Deep Persistent Slabs

Overall the snowpack is very weak, and full depth avalanches are likely to be human triggered in specific areas. There is no quick fix to this problem, and it will likely stick with us for the foreseeable future.

Avoid steep, open slopes.Avoid areas with overhead hazard.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 3

Wind Slabs

Wind slabs may exist in some areas of wind loading at higher elevations. While these avalanches may be initially small, once started they have the potential to trigger a larger, deep slab.

Use caution in lee areas in the alpine. Recent wind loading have created wind slabs.Be aware of the potential for full depth avalanches due to weak layers at the base of the snowpack.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Dec 25th, 2013 4:00PM