Avalanche Forecast

Issued: Dec 4th, 2014 7:56AM

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

Avalanche Canada pgoddard, Avalanche Canada

I'd veer away from thin snowpack areas, rock outcrops and large steep alpine slopes which didn't avalanche last week.

Summary

Confidence

Fair - Due to the number of field observations

Weather Forecast

Warm air from the Pacific will push in, bringing milder temperatures but not much precipitation in the short term.Friday: Light snow.  Remaining cool. Winds increasing to moderate SW. Saturday: Light snow. Light to moderate SW winds. Temperatures increasing. An inversion (warmer temperatures at ridge top than in the valleys) may form.Sunday: Light snow. Light winds. Temperatures may start to rise at all elevations.

Avalanche Summary

There was a widespread cycle of large (up to size 3) naturally and remotely-triggered avalanches last Friday/Saturday. Since then, whumpfs have reminded travelers of the lurking beast. While avalanche activity has diminished, the consequences of triggering a deep layer would be severe.

Snowpack Summary

Surface layers consist of variable wind slabs or dry snow. Below this you may find a hard rain crust. In the Golden area this crust exists up to around 1600m, whereas in the south it is up to 2000m or higher. In total, last week's storm produced slabs up to 1m thick in the north of the region and around 60cm thick in the south. This slab sits on the mid-November weak layer (surface hoar, facets, and/or a crust). Below this you will likely find a 15-20cm thick layer of sugary facets, which is sitting on a solid rain crust from early November. The reactivity of these layers may be slowly diminishing, but they still warrant cautious consideration. Snowpack tests are getting hard pops and drops results, indicating the potential for large propagation and large avalanches.

Problems

Persistent Slabs

An icon showing Persistent Slabs
Persistent slab avalanches are most likely to be triggered by people from thin snowpack areas, near rocky outcrops, and on steep alpine slopes.
Be aware of the potential for full depth avalanches due to deeply buried weak layers.>Caution around convexities or areas with a thin or variable snowpack.>Avoid thin, rocky or sparsely-treed slopes.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 5

Valid until: Dec 5th, 2014 2:00PM