Avalanche Forecast

Issued: Jan 26th, 2016 9:07AM

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

Avalanche Canada jlammers, Avalanche Canada

In the west of the region where recent accumulations were the greatest, new wind slabs are expected to be deeper and more reactive.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

Warm, wet and windy conditions will persist for Wednesday and Wednesday night. Expect between 5-8mm of precipitation, extreme southerly winds and freezing levels at about 1700m. On Thursday, the region should see generally light flurries, strong southwest winds and freezing levels dropping to about 1200m. By Friday, a pattern shift should bring generally overcast skies, decreased winds and freezing levels closer to 600m.

Avalanche Summary

There are very few recent observations from the region. A couple natural size 2 slab avalanches were observed in wind-loaded terrain (N-NE aspects) at around 1800 m last Friday. Light to locally moderate amounts of new snow and extreme southwest winds likely sparked a new round of wind slab activity on Tuesday.

Snowpack Summary

On Monday night a few centimetres of new snow fell in the mountains around Smithers while closer to 15 cm fell in areas further west. Strong to extreme winds have likely redistributed much of this new snow into reactive wind slabs at higher elevations while lower elevation surfaces are likely now moist due to rising freezing levels during the system.  There is a notable persistent weakness of buried surface hoar in many places, generally found between 30 and 60 cm deep. Wind, sunshine, and milder temperatures could help promote slab development in the snow overlying this interface. Stay tuned to signs of instability like recent avalanches, whumpfing, and shooting cracks. The mid pack that was reported to be well settled may have now facetted in the shallower areas, and the deeper basal layers are almost certainly facetted and weak.

Problems

Wind Slabs

An icon showing Wind Slabs
Continued strong winds and new snow have likely formed reactive wind slabs at treeline and in the alpine. New winds slabs are expected to be larger on the west side of the region where recent accumulations were the greatest.
Be cautious as you transition into wind affected terrain. >Choose well supported terrain without convexities.>

Aspects: North, North East, East, South East, South, South West.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Persistent Slabs

An icon showing Persistent Slabs
New snow has been slowly accumulating over a layer of facets and surface hoar and may now be primed for triggering in some areas.
Watch for whumpfing, hollow sounds, shooting cracks or recent avalanches.>Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Jan 27th, 2016 2:00PM

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