Avalanche Forecast

Issued: Dec 21st, 2014 7:46AM

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

pgoddard, Avalanche Canada

South Columbia.

Have a safe and fun holiday.

Summary

Confidence

Fair - Intensity of incoming weather systems is uncertain

Weather Forecast

Expect a brief period of cooler and drier weather on Monday (flurries possible), before the next pulse of snow arrives on Tuesday (10-20cm). Snowfall becomes lighter on Wednesday. Winds are moderate to strong westerly to north-westerly, easing by Wednesday. Freezing levels are expected to fall from 1300m on Monday to near 800m by Tuesday.

Avalanche Summary

On Friday and Saturday, the storm snow was reacting very easily with skier traffic, creating small avalanches failing on the buried surface hoar (including one remote trigger with a partial burial). As the storm snow depth builds, it’s likely that avalanche activity will become larger and more widespread. Field observations have been limited during the storm.

Snowpack Summary

Storm snow and wind slabs have built up above a touchy 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

Recent new snow has built up over a touchy layer of buried surface hoar crystals.

Avoid freshly wind loaded features by sticking to ridges and ribs.>Choose well supported terrain without convexities.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 4

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 - 6

Valid until: Dec 22nd, 2014 2:00PM