Avalanche Forecast

Issued: Dec 13th, 2013 8:03AM

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

Avalanche Canada triley, Avalanche Canada

New storm snow, strong winds, and rising temperatures are increasing the avalanche danger.

Summary

Confidence

Poor - Due to the number of field observations

Weather Forecast

Tonight and Saturday: Very strong Westerly winds tonight becoming very strong Southwest by morning. Expect 10-15 cms of snow above about 900 metres elevation overnight and another 10-20 cms during the day. Warm Pacific moisture is forecast to push Eastward, driving out any remaining arctic air.Sunday:Models do not agree on how much Pacific moisture will continue to push into the Inland region. The range is 5-20 cms, I am expecting closer to 5 cms. Expect strong Southwesterly winds, cooling temperatures and dropping freezing levels. Monday:Winds becoming more Westerly. Freezing levels continue to drop and light flurries continue.

Avalanche Summary

New storm snow is expected to increase the avalanche danger. The weak shallow snowpack may not support the added load of new storm snow. Strong winds, new snow, and rising temperatures are expected to increase the sensitivity to triggering by skiers and sledders.

Snowpack Summary

Rising freezing levels and warm temperatures are settling the new snow into a cohesive slab above the recently buried weak surface layers. The snowpack is generally shallow across the region and in some areas is below the recorded minimum values. New snow is expected to develop a storm slab at higher elevations. Very strong winds are transporting snow into deep pockets of stiff slabby snow. Cold temperatures at the beginning of December created near surface facetted snow and surface hoar above old wind crusts. The new warmer storm snow is not expected to bond well to these old buried layers. Expect a lot of variation in snow depths across the region, with areas in the Southwest likely to be more like the Northwest Coastal region.

Problems

Storm Slabs

An icon showing Storm Slabs
Forecast new snow and strong winds are expected to continue to develop storm snow slabs at higher elevations. Rising freezing levels may cause touchy conditions at lower elevations where the recent storm snow has settled into a cohesive slab.
Be cautious as you transition into wind affected terrain.>Minimize exposure during periods of heavy loading from new snow, wind.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 4

Valid until: Dec 14th, 2013 2:00PM