Avalanche Forecast

Issued: Nov 27th, 2012 9:48AM

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

jlammers, Avalanche Canada

Kootenay Boundary.

Summary

Confidence

Poor - Intensity of incoming weather is uncertain on Thursday

Weather Forecast

Wednesday will see mostly cloudy skies with moderate snowfall occurring throughout Thursday and Friday. Winds will be moderate to strong from the west on Wednesday switching to strong and southwesterly for Thursday and Friday. Freezing levels should remain at about 1350m for the forecast period.

Avalanche Summary

No new avalanches have been reported. If you and your friends have been out exploring and riding in the backcountry, and have some observations to share please send an email to forecaster@avalanche.ca.

Snowpack Summary

Last week's storm/wind slabs have most likely gained considerable strength with the break in the weather over the past few days. In some parts of the region an early November rain crust sits near the bottom of the snowpack. Where it exists, this crust has been seen from 1700 m to ridgetop on all aspects. Some tests have resulted in CTM-H ranges with sudden planar characteristics. I have also received reports of a SH layer buried up to 100 cm down. Tests on this layer are in the hard range with sudden planar characteristic. At this time the surface hoar may be specific to certain parts of the region. As you're traveling through the mountains, be on the look-out for current surface hoar development and think about how it will affect the snowpack as new snow arrives over the next few days.

Problems

Storm Slabs

Although last week's snow has had time to gain significant strength, triggering storm/wind slabs may still be possible, particularly in steep, unsupported terrain.

If you are increasing your exposure to avalanche terrain, do it gradually as you gather information.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 4

Persistent Slabs

There is a faceted crust that exists in the lower snowpack. Although no recent avalanches have been reported on this layer, triggering seems most likely on unsupported terrain at higher elevations or within start zones with smooth ground cover.

Choose well supported terrain without convexities.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 5

Valid until: Nov 28th, 2012 2:00PM