Avalanche Forecast

Issued: Jan 18th, 2013 9:38AM

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

jlammers, Avalanche Canada

Northwest Inland.

Summary

Confidence

Fair - Due to limited field observations

Weather Forecast

Only trace amounts of new snow are expected for the forecast period. Winds should remain mainly light to moderate from the southwest with freezing levels hovering between 800-900m.

Avalanche Summary

There have been no recent avalanche observations.

Snowpack Summary

Rain below treeline has continued to maintain moist surfaces at lower elevations, although a nightly crust recovery is likely with forecast clear skies . Light to moderate amounts of new snow and strong to extreme winds at higher elevations have most likely formed hard windslabs in the lee of terrain breaks and ridges.A surface hoar layer that was buried at the end of December is now down 60-80 cm, and was reactive in some areas with recent warming. An otherwise strong mid-pack overlies a weak base layer of facets/depth hoar and the remnants of a crust.

Problems

Wind Slabs

Strong westerly winds have created windslabs on lee terrain. With higher than normal wind values, watch for loading lower on the slope and in other unsuspecting locations.

Be cautious as you transition into wind affected terrain.>Be aware of the potential for wide propagations due to the presence of hard windslabs.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 4

Persistent Slabs

A layer of surface hoar buried at the end of December may still be reactive. Watch for triggering in sheltered, unsupported terrain.

Be aware of the potential for large avalanches due to the presence of buried surface hoar.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 4

Deep Persistent Slabs

A deeply buried facet/crust weakness exists near the base of the snowpack. This layer could be triggered by large loads such as a cornice collapse or from a thin-spot trigger point.

Be aware of thin areas that may propagate to deeper instabilites.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 5

Valid until: Jan 19th, 2013 2:00PM