Avalanche Forecast

Issued: Dec 26th, 2014 7:22AM

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

ghelgeson, Avalanche Canada

Kootenay Boundary.

Jump over to avalanche.ca/blogs to learn more about the persistent slab problem.

Summary

Confidence

Fair - Due to the number of field observations

Weather Forecast

Synopsis: Light precipitation is possible Saturday afternoon as a weak system passes over the SE portion of the province. On Sunday a strengthening ridge of high pressure drives cold and dry conditions that will likely persist for the next week. Saturday: Freezing Level: Valley Bottom; Precipitation: 2-5mm | 2-10cm; Wind: Treeline: Light, SW | Ridgetop: Strong, W.Sunday: Freezing Level: Valley Bottom; Precipitation: Trace; Wind: Treeline: Light, E/NE | Ridgetop: Moderate to Strong E/SE.Monday: Freezing Level: Valley Bottom; Precipitation: Nil; Treeline: Moderate, NE | Ridgetop: Moderate, NE.

Avalanche Summary

On Thursday a party of skiers triggered a size 2 avalanche on a SW facing slope around 1800m in the Nelson area. Two people were reportedly caught and carried but thankfully ended up on the surface as everything came to a stop. This type of activity is likely to persist for the foreseeable future.

Snowpack Summary

30 - 70 cm of snow from the last week is consolidating into a slab above a touchy weak layer formed in mid-December consisting of surface hoar sitting on a thick rain crust. This combo is thought to extend as high as 2400 m. This layer will likely remain sensitive to human triggering for the foreseeable future. High elevation north facing slopes likely do not have the rain crust, but are still reported to have touchy buried surface hoar. On these slopes, deeper facets or buried surface hoar from earlier in the month may also be lurking. At the base of the snowpack, a crust/facet combo appears to have gone dormant for the time being.

Problems

Persistent Slabs

A slab 30 - 70 cm in depth remains sensitive to human triggering. This problem isn't likely to go away any time soon.

Use conservative route selection, stick to moderate angled terrain with low consequence and be aware of what is above you at all times as remote triggering is a concern.>Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

2 - 5

Wind Slabs

Watch for isolated wind slabs in exposed terrain at and above treeline. Reverse winds forecast for the next few days will likely form wind slabs in unusual locations.

Be cautious as you transition into wind affected terrain.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 4

Valid until: Dec 27th, 2014 2:00PM