Avalanche Forecast

Issued: Dec 25th, 2014 7:19AM

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

ghelgeson, Avalanche Canada

Kootenay Boundary.

Conditions like these frequently lead to avalanche accidents. Stay disciplined with your approach to the mountains during the holiday weekend.

Summary

Confidence

Fair

Weather Forecast

Synopsis: The storm to strong cold ridge pattern seems to be stuck on repeat. Looks high and dry as yet another ridge of high pressure takes over provincial weather for the foreseeable future.Friday: Freezing Level: Valley Bottom; Precipitation: Nil; Treeline: Light, NW | Ridgetop: Moderate, NWSaturday: Freezing Level: Valley Bottom; Precipitation: 0-3mm | 0-5cm; Wind: Treeline: Light, SW | Ridgetop: Strong, W/NWSunday: Freezing Level: Valley Bottom; Precipitation: Nil; Wind: Treeline: Light, NE | Ridgetop: Moderate to Strong E/SE

Avalanche Summary

Although there isn't any new activity to report from Wednesday, there's been quite a bit of avalanche activity since Sunday featuring remote triggers, human involvements and plenty of naturals running on all aspects to size 2.5 on the Mid-December rain crust/surface hoar interface.

Snowpack Summary

30 - 70 cm of recent storm snow is consolidating into a slab above a thick rain crust / surface hoar combo that extends as high as 2400 m. Natural activity on this layer has slowed way down but it is now primed for human triggering. High elevation north facing slopes 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 has become less likely to trigger, although a recent avalanche that occurred on this layer near Rossland indicates this layer should remain on our radar on steep, smooth terrain at treeline and in the alpine.

Problems

Persistent Slabs

Storm snow from the last few days is coalescing into a slab that rests precariously on a potent combination of weak surface hoar and stout rain crust. Conditions are prime for large human triggered avalanches failing 30 - 70 cm deep.

Stick to simple terrain and be aware of what is above you at all times.>Use conservative route selection, stick to moderate angled terrain with low consequence.>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

Deep Persistent Slabs

An avalanche on Sunday stepped down to deeply buried weak layers which formed in November. These destructive layers should remain on our radar as they could be triggered with large inputs such as a cornice fall or an avalanche in motion.

Be aware of thin areas that may propogate to deeper instabilites.>Caution around convexities or areas with a thin or variable snowpack.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 5

Valid until: Dec 26th, 2014 2:00PM