Avalanche Forecast

Issued: Nov 29th, 2017 3:46PM

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

Avalanche Canada jlammers, Avalanche Canada

Expect the avalanche hazard to increase throughout the day on Thursday as new snow accumulates.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

Thursday: 8-15cm of new snow / Moderate southwest winds / Freezing level at 1100m Friday: 3-5cm of new snow / Light southerly winds / Freezing level at 1100mSaturday: Mix of sun and cloud / Light southerly winds / Freezing level at 900m

Avalanche Summary

No new avalanches have been reported. This may speak more to a lack of observations rather than actual conditions. I'd expect a round of storm slab avalanche activity on Thursday with forecast snow and wind. We currently have very limited observations in this region. Please submit your observations to the Mountain Information Network (MIN).

Snowpack Summary

Up to 20cm of new snow has fallen in the past few days. I'd expect reactive storm slabs to exist in wind-exposed terrain or in places where the recent storm snow has a weak bond with a series of crusts from late November which lie up to 30cm below the surface.Another feature in the snowpack is a 3-5 cm thick crust which was formed around Halloween and can be found approximately 100cm down at treeline elevations. This layer is generally stubborn to trigger; however, I'd be increasingly cautious of it in the north of the region where it may remain reactive. The depth of the snowpack varies greatly with elevation. Recent reports suggest the average depth is 200+cm in the alpine, 100-150cm at treeline, and decreasing rapidly below treeline where the primary hazards are rocks, stumps, and open creeks. We currently have very limited snowpack observations within this region and it is critical to supplement this information with your own observations.

Problems

Storm Slabs

An icon showing Storm Slabs
New wind and snow on Thursday will form reactive new storm slabs. Storm slabs may be larger than expected in areas where underlying crusts remain reactive.
Be cautious as you transition into wind affected terrain.Be alert to conditions that change with elevation.The new snow may require several days to settle and stabilize.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Nov 30th, 2017 2:00PM