Avalanche Forecast

Issued: Feb 15th, 2013 9:30AM

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

jfloyer, Avalanche Canada

Kootenay Boundary.

Summary

Confidence

Fair - Forecast snowfall amounts are uncertain

Weather Forecast

Synopsis: A frontal system moves through the region on Saturday and is replaced by a ridge of high pressure.Saturday: 5-15 cm new snow. Ridgetop winds 40 km/h from the west, gusting to 60 km/h. Freezing level 1500 m.Sunday: Light snow, 2-5 cm. Winds 30 km/h from the northwest, diminishing in the afternoon. Freezing level 800 m.Monday: Flurries. Light winds. Freezing level around 1000 m in the afternoon.

Avalanche Summary

No recent avalanches have been reported from this region.

Snowpack Summary

5-15 cm of recent snowfall (possibly a little more near Kokanee Glacier Park) overlies a recent layer of surface hoar buried around Feb 12. We have had some reports this layer contains crystals up to 30mm in some locations. This large size of crystal increases the likelihood this layer will present problems as it becomes more deeply buried. Wind slabs are widespread in exposed areas. Two previous buried surface hoar/facet/sun crust layers from Feb 4th and Jan 23 are still being tracked by professionals but have not been reactive recently. They can be found approximately 30 cm and 50 cm below the surface, respectively. These layers may be worth investigating on a safe but representative adjacent slope if you are considering riding in aggressive terrain.

Problems

Wind Slabs

Strong winds have loaded lee features on a potentially weak interface.

Avoid freshly wind loaded features.>Use ridges or ribs to avoid pockets of wind loaded snow.>Highmark or enter your line well below ridge crests to avoid wind loaded pillows.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Storm Slabs

A reactive weak layer is buried in the upper slab. As more snow arrives, I expect this will become a focus for avalanche activity, especially on unsupported (convex) terrain features.

Watch for whumpfing, hollow sounds, shooting cracks or recent avalanches.>Choose well supported terrain without convexities.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Feb 16th, 2013 2:00PM