Avalanche Forecast

Issued: Jan 27th, 2016 8:58AM

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

Low - Due to the number of field observations

Weather Forecast

Up to 15mm of precipitation is forecast for Wednesday night with another 3-5cm of snow expected on Thursday. Ridgetop winds will remain extreme from the southwest while freezing levels will drop throughout the day from 1600m to about 1000m. On Friday and Saturday the region will see light flurries, significantly decreased winds and freezing levels around 700m.

Avalanche Summary

There are very few recent observations from the region. Light to locally moderate amounts of new snow and extreme southwest winds likely sparked a new round of wind slab activity. Rain may have also promoted loose wet avalanche activity at treeline and below.

Snowpack Summary

Since Monday night light amounts of new snow fell in the mountains around Smithers while closer to 25 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 surfaces at treeline and below 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 70 cm deep. Wind and milder temperatures may have helped to promote slab development in the snow overlying this interface. In other areas, rain may have destroyed the layer. 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.
Choose well supported terrain without convexities.>Be cautious as you transition into wind affected terrain. >

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. In some areas, recent rain may have destroyed the layer. In other areas, the overlying slab may be primed for human triggering.
Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.>Watch for whumpfing, hollow sounds, shooting cracks or recent avalanches.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Jan 28th, 2016 2:00PM