Avalanche Forecast

Issued: Dec 28th, 2014 7:41AM

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

triley, Avalanche Canada

South Columbia.

Avalanche danger is expected to remain at Considerable during the forecast cold and clear weather for the end of the year.

Summary

Confidence

Fair

Weather Forecast

Gradually clearing overnight with light Northeast winds and alpine temperatures dropping down to about -16. Mostly clear and cold on Monday with light to moderate Northeast winds and alpine high temperatures around -14. Clear and cold on Tuesday with light Northwest winds. Continued clear and cold on Wednesday.

Avalanche Summary

A report from one operator on Saturday described remotely triggering several avalanches up to size 2.5 that were releasing down 45-60 cm on the buried surface hoar between 2200-2450 metres elevation. The persistent slab problem is expected to continue for the forecast period.

Snowpack Summary

5-15 cm of light dry new snow has been added to the recent storm slab. In some parts of the region a thin breakable rime crust exists between the new snow and the storm slab. The upper 40-90 cm of storm snow is slowly consolidating into a slab above a touchy surface hoar layer buried mid-December. Below 2100 m this slab sits on a thick, solid crust/ surface hoar combo and acting as a perfect sliding layer. Persistent slabs may be touchy to the weight of a skier or rider, especially in wind effected areas where the slab is stiffer. Deeper in the snowpack is a hard rain crust with facets from early November. This is buried over 1 m down and is currently unreactive but triggering from shallow rocky, unsupported terrain remains a concern.

Problems

Persistent Slabs

The 50-70 cm deep slab continues to be triggered from steep convex rolls and adjacent terrain. The forecast cooling is expected to help preserve the buried weak layer, resulting in this problem persisting through the Holidays.

Stick to simple terrain, small features with limited consequence and be aware of what is above you at all times.>Use conservative route selection, dig down and test weak layers before committing to anything.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

2 - 5

Wind Slabs

New windslabs are expected to develop as the wind direction shifts to the Northeast and the wind speed increases overnight.

Avoid fresh windslabs and areas that have been reverse loaded by changing wind direction.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 4

Valid until: Dec 29th, 2014 2:00PM