Avalanche Forecast

Issued: Dec 21st, 2014 7:50AM

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

triley, Avalanche Canada

Northwest Inland.

If you have been out over the weekend, it would be great to find out what you saw in your area. Please email observations to forecaster@avalanche.ca

Summary

Confidence

Poor - Due to the number and quality of field observations

Weather Forecast

Light snowfall overnight combined with moderate Southwest winds and freezing levels at valley bottoms. Clearing and cooling on Monday as a ridge of High pressure builds over the province. Strong Southwest winds and snow beginning during the day on Tuesday and continuing into Wednesday. Freezing levels remaining at valley bottoms.

Avalanche Summary

There are no new avalanche reports from the region.

Snowpack Summary

The new storm slab is between 20-40 cm deep. Very strong winds have transported snow in the alpine and at treeline into pockets of windslab that may not be well bonded to the old surfaces. Below the new snow you'll likely find wind-scoured surfaces and old wind slabs in exposed terrain, and settled storm snow closer to treeline. Near the base of the snowpack, weaknesses such as the mid-November crust-facet layer are still of concern. I'd use extra caution around steep, unsupported high elevation terrain as avalanches at this interface could propagate over wide distances.

Problems

Storm Slabs

Storm slabs may continue to be sensitive to human triggers. Pockets of windslab may be easy to trigger from ridges or adjacent terrain.

Be cautious as you transition into wind affected terrain.>Use ridges or ribs to avoid wind loaded and cross loaded slopes.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Deep Persistent Slabs

Deeply buried weak layers may release during periods of high loading from new snow and wind. Deeply buried crusts are more likely to be triggered from shallow areas where boulders or trees are at or near the surface.

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

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

2 - 4

Valid until: Dec 22nd, 2014 2:00PM