Avalanche Forecast

Issued: Jan 9th, 2017 4:37PM

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

Ridgetop wind speeds are uncertain for Tuesday. If northerly winds are strong, new wind slabs can be expected on all aspects.

Summary

Confidence

Moderate - Wind speed and direction is uncertain on Tuesday

Weather Forecast

Tuesday: Mix of sun and cloud / Moderate north winds / Alpine temperature at -25Wednesday: Clear skies / Moderate north winds / Alpine temperature at -18Thursday: Mix of sun and cloud / Strong northwest winds / Alpine temperature at -14

Avalanche Summary

On Sunday a few size 1 skier-triggered wind slabs were observed in higher elevation wind-exposed terrain. I'd expect a new round of wind slab activity in response to new snow and wind on Sunday night and Monday. Northerly winds on Tuesday may promote a reverse loading pattern increasing the likelihood of wind slab activity on a variety of aspects.

Snowpack Summary

Up to 20 cm of low density snow fell on Sunday night and Monday. Moderate to strong southwest winds are expected to have shifted these fresh accumulations into wind slabs at treeline and above. 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 likely shifted by southwest winds into new wind slabs in exposed high elevation terrain. On Tuesday, a switch to northerly winds may promote a reverse loading pattern and fresh wind slabs may be found on all aspects.
Be cautious as you transition into wind affected terrain.Avoid areas where the snow feels stiff or slabby.Be alert to conditions that change with aspect and elevation.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Jan 10th, 2017 2:00PM

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