Avalanche Forecast

Issued: Dec 19th, 2014 3:00PM

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

pgoddard, Avalanche Canada

South Columbia.

New snow, strong winds and rising temperatures make a good recipe for rising avalanche danger over the next few days.

Summary

Confidence

Fair - Intensity of incoming weather systems is uncertain

Weather Forecast

Expect light to moderate snow from Saturday to Monday. In the snowiest parts of the region, there may be 30-40cm of snow by Sunday. Temperatures rise towards 0 at 1500m by Saturday. Winds are expected to be moderate to strong from the west to south-west throughout the period.

Avalanche Summary

At the start of the storm on Friday, new snow was sluffing in steep terrain. As the storm progresses, this may build into a storm slab or wind slab problem. Explosives control on Thursday produced size 1-1.5 results.

Snowpack Summary

Storm snow and wind slabs are building up. These are expected to bond poorly to a layer of large surface hoar crystals. Below around 2100m, this surface hoar sits on a hard rain crust. Above 2100m the surface hoar sits on well settled and faceted snow. A thick rain crust with facets from early November is buried over 1 m down and may still be reactive in isolated areas.

Problems

Storm Slabs

Building storm snow is expected to be shifted by winds into slabs on lee slopes. In more sheltered areas, loose snow avalanches are likely. The new snow sits above a weak layer of buried crystals.

Avoid freshly wind loaded features by sticking to ridges and ribs.>Be cautious of sluffing in steep terrain.>Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Deep Persistent Slabs

There is still the potential to trigger a deeply buried weak layer, resulting in a surprisingly large avalanche.

Avoid shallow snowpack areas where triggering is more likely.>

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely

Expected Size

2 - 5

Valid until: Dec 20th, 2014 2:00PM