Avalanche Forecast

Issued: Jan 10th, 2017 4:22PM

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 most 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 to strong 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

On Monday several naturally triggered wind slab avalanches were observed in mostly treeline and alpine terrain. These avalanches formed in response to new snow and wind on Sunday night and Monday. Continued northerly winds on Tuesday will likely promote a reverse loading pattern increasing the likelihood of human triggered wind slab activity on a variety of 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 in exposed terrain. Recent snow has covered old, thicker wind slabs from previous wind events. The mid-December facet/surface hoar persistent weakness can be found buried 70-120 cm deep and is generally considered dormant. However, we are still receiving occasional reports of sudden results, suggesting that it has to potential to propagate into a large avalanche if triggered, particularly in shallow spots where this layer is closer to the snow surface. The lower snowpack is well bonded and features a thick rain crust near the ground.

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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