Avalanche Forecast

Issued: Jan 5th, 2012 3:00PM

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

Avalanche Canada jfloyer, Avalanche Canada

A prolonged, very active period of avalanche activity is ongoing. Be extremely cautious if venturing into the backcountry at this time.

Summary

Confidence

Good - -1

Weather Forecast

A series of storm fronts will bring further wet and windy weather to this region. On Friday, a relatively weak system will bring 5-10 cm new snow and strong southwesterly winds. Freezing levels will stay at valley bottom. Over the weekend, a punchy storm will drop 20-30 mm precipitation on Saturday and 30-40 mm precipitation on Sunday. Freezing levels will go up to 1200 m on Saturday and 1600 m on Sunday. Winds will continue to be strong from the southwest.

Avalanche Summary

A natural avalanche cycle up to size 3 occurred on Wednesday affecting all aspects and all elevations. Along Bear Pass, 90% of the avalanche paths were reported to have run.

Snowpack Summary

A significant storm dropped 40 to 80 mm of precipitation on this region over the last 48 hours bring treeline snowpack depths into the 3-4 m range. The storm was accompanied by high winds and touchy fresh wind slabs and storm slabs now exist as a result. A rain crust exists below about 1000 m. With all the new snow, earlier weak layers are getting rapidly buried to the point where they are hard to trigger. A relatively thin layer of surface hoar or facets was reportedly buried New Year's day - this may have been the focus of some of the storm snow releases during the current storm; however, I suspect this layer will settle out quite rapidly. Lower down, it is still possible to find a surface hoar/crust/facet combo from mid-December. I suspect it would take a very heavy trigger such as a cornice fall to trigger this layer now, although if you are traveling in an unusually shallow snowpack area I'd still be cautious of it. The lower snowpack is generally well settled and strong.

Problems

Storm Slabs

An icon showing Storm Slabs
Large amounts of new snow with warming temperatures will create very touchy storm slab conditions.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

3 - 8

Wind Slabs

An icon showing Wind Slabs
Extreme winds have set up touchy wind slabs that should be treated with the utmost respect.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

3 - 6

Deep Persistent Slabs

An icon showing Deep Persistent Slabs
Deeply buried persistent weak layers have the potential to be triggered from rapid loading by large amounts of snow or rain and/or cornice falls.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

5 - 9

Valid until: Jan 6th, 2012 8:00AM

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