Avalanche Forecast

Issued: Jan 17th, 2016 9:23AM

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

jsmith, Avalanche Canada

South Columbia.

Extra caution required below treeline where a buried weak layer is easily triggered. Check out the new forecaster blog at avalanche.ca/blogs or click here

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain

Weather Forecast

As this weekends storm exits the interior regions we may squeeze out a few more cm of snow by Monday morning. No additional snow is expected Monday to Wednesday. Freezing levels should remain at or near valley bottom, though there is some disagreement in the models regarding freezing levels. Ridgetop winds are expected to stay in the light to moderate range out of the southwest. For additional weather information see avalanche.ca/weather

Avalanche Summary

Over the weekend we had limited observations of new avalanches due to inclement weather. However, there were reports of human triggered avalanches to size 2.5 below 1800 m. Of note, a size 2.5 was remotely triggered from 50 m away. We anticipate continued human triggering of persistent slab avalanches on the surface hoar layer that was buried in early January.

Snowpack Summary

10-15 cm of new snow has been added to a 40-60 cm persistent slab which overlays a variety of surfaces including large surface hoar, sun crusts, and facets. This slab is ripe for human triggers and is especially touchy below 1800 m. Expect fresh wind slabs sitting on top of old snow surfaces on lee features in the alpine. The mid and lower snowpack are generally well settled and strong.

Problems

Persistent Slabs

Numerous backcountry travelers have been surprised in recent days by a nasty layer of surface hoar. This layer has been especially reactive below 1800 m.

Use conservative route selection, stick to moderate angled terrain with low consequence.>Avoid steep open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.>Extra caution required below 1800 m>Avoid slopes with glide cracks.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 4

Wind Slabs

Expect touchy wind slabs on wind loaded features in the alpine.

Avoid lee and cross-loaded terrain near ridge crests.>

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

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Jan 18th, 2016 2:00PM