Avalanche Forecast

Issued: Feb 2nd, 2014 7:49AM

The alpine rating is low, the treeline rating is low, and the below treeline rating is low. Known problems include Wind Slabs and Loose Dry.

ghelgeson, Avalanche Canada

South Columbia.

Summary

Confidence

Good

Weather Forecast

Synopsis: A very strong ridge of high pressure continues to dominate the weather pattern with no end in sight.Monday: Sky: Mix Sun/Cloud; Freezing Level: Valley Bottom; Precip: Nil Wind: Light, NE, Mod NE at ridgetop.Tuesday: Sky: Mix Sun/Cloud; Freezing Level: Valley Bottom; Precip: Nil Wind: Light, NEWednesday: Sky: Mix Sun/Cloud; Freezing Level: Valley Bottom; Precip: Nil Wind: Light, NE, Mod NE at ridgetop.

Avalanche Summary

In two separate incidents, skiers triggered small wind slab avalanches on north & east facing aspects around 2000m. Deep Persistent Slabs have been removed from the problem portion of the forecast because it's probably a 1:1000 slope event at this time, but they haven't totally gone away. Two large natural avalanches (size3) were observed on a steep south facing alpine feature south of Revelstoke.

Snowpack Summary

The upper and mid-snowpack are generally well consolidated and layers are well bonded. However, in thinner snowpack areas a facet/crust weakness may exist near the bottom of the snowpack and this remains a concern. The depth of this layer makes triggering an avalanche unlikely but the consequences would be large, destructive avalanches. This is referred to as a 'low probability, high consequence' event. We are recommending avoiding thin or rocky areas on steep, convex, unsupported slopes. In most areas, a widespread weak layer is now buried by around 10cm of new snow. This weak layer consists of large surface hoar (widespread in most sheltered and shaded areas at all elevations), a sun crust on open south facing slopes, facet grains (in colder areas or areas with a thinner snowpack), or a combination of any of the above. This layer may become a problem in the future when we finally get more snowfall.

Problems

Wind Slabs

Thursdays light density snow has been formed into thin soft slabs on alpine features. Increased ridgetop winds Monday will likely form another round of sensitive, albeit small wind slabs that are primarily a concern on steep alpine features.

Highmark or enter your line well below ridge crests to avoid wind loaded pillows.>Carefully consider the impact a thin wind slab will have on your proposed line, especially in high consequence terrain. Have a backup line in mind in case you need to seek more sheltered riding.>

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Loose Dry

Thursdays light density snow will likely continue to produce active sluffing, especially in steep terrain.

Be aware of party members below you that may be exposed to your sluffs.>On steep slopes, pull over periodically or cut into a new line to manage sluffing.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Feb 3rd, 2014 2:00PM