Avalanche Forecast

Issued: Jan 21st, 2012 9:52AM

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

Avalanche Canada triley, Avalanche Canada

Summary

Confidence

Good - -1

Weather Forecast

Light snow is expected to continue overnight into Sunday morning. A weak ridge of high pressure is expected to dry out the area during the day on Sunday; you may even see some broken skies. Snowfall should start again on Sunday night combined with light easterly winds, resulting in about 10 -15 cm by Monday morning. Light flurries during the day on Monday are forecast to become moderate to heavy snowfall and strong southwest winds by Tuesday noon. The freezing level should be near valley bottom until Tuesday afternoon, when it is expected to rise to near 1000 metres.

Avalanche Summary

No new reports of avalanches observed.

Snowpack Summary

The new storm has brought about 15 cm to the Interior. The snowpack depth in the Smithers-Hankin area is about 250-275 cm at the upper extent of the treeline elevation band. Some surface facetting has been observed above treeline, and some surface hoar observed below treeline. Very strong northeast outflow winds have scoured north and east aspects and reduced previous cornice growth. The snow has been transported into stiff windslabs on south through west aspects. These windslabs should be stiff enough in most areas that the forecast southerly winds will not be able to re-distribute the snow. The mid-december crust has been observed to have bonded to the mid-pack in most areas, but may be found to have become facetted in areas with a shallow snowpack. The mid-pack is considered to be strong and well settled in most areas. No basal weak layers of concern have been reported.

Problems

Wind Slabs

An icon showing Wind Slabs
Stiff windslabs have developed during the strong northeast outflow winds. New soft windslabs are expected to develop as the new storm develops from the south or southwest.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 5

Storm Slabs

An icon showing Storm Slabs
Dry light snow falling at the beginning of the storm may become heavier as the temperatures rise, and develop a storm slab that may not bond to the old cold surface. If temperatures stay cool, expect sluffing in the new snow.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 4

Valid until: Jan 22nd, 2012 8:00AM