Avalanche Forecast

Issued: Jan 10th, 2017 4:16PM

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

Avalanche Canada jlammers, Avalanche Canada

Wind effect will drive the avalanche danger in many areas. The safest, and best, riding may be in lower elevation terrain sheltered from the wind.

Summary

Confidence

Moderate - Wind effect is extremely variable

Weather Forecast

Wednesday: Mainly clear skies / Moderate northerly ridgetop winds / Alpine temperatures of -15Thursday: Clear skies / Light and variable winds / Alpine temperatures of -10Friday: Mainly clear skies / Moderate southwest ridgetop winds / Alpine temperatures of -8

Avalanche Summary

Naturally triggered wind slabs to size 2 were noted in exposed terrain on Monday. These formed in response to new snow and strong variable winds. Continued northerly winds on Tuesday will likely promote a reverse loading pattern increasing the likelihood of human-triggered wind slab activity on all aspects.

Snowpack Summary

Up to 30 cm of low density snow fell on Sunday night and Monday. Moderate to strong southwest and then northerly winds have shifted these fresh accumulations into wind slabs at treeline and above. These accumulations have covered old, thicker wind slabs from previous wind events. A layer of faceted "sugar snow" and spotty surface hoar which formed during December's cold snap now lies roughly 1 metre below the surface. This layer is now dormant in many areas, but remains a concern in shallow snowpack parts of the region. I'd continue to investigate this layer before committing to any large, unsupported features. The lower snowpack seems to be well bonded, but features a crust/facet deep persistent weakness near the ground which remains a concern on rocky features in shallow snowpack areas.

Problems

Wind Slabs

An icon showing Wind Slabs
New snow on Monday was shifted by southwest winds into reactive wind slabs in exposed high elevation terrain. A more recent switch to northerly winds may promote a reverse loading pattern and wind slabs may exist on all aspects.
Be alert to conditions that change with aspect and elevation.Avoid areas where the snow feels stiff or slabby.Be cautious as you transition into wind affected terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Jan 11th, 2017 2:00PM

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