Avalanche Forecast

Issued: Jan 9th, 2017 4:47PM

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

A wind slabs to size 1.5 were noted on Sunday in high elevation 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 all 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. 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 likely shifted by southwest winds into fresh wind slabs in exposed high elevation terrain. On Tuesday, a switch to northerly winds may promote a reverse loading pattern and new 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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