Avalanche Forecast

Issued: Jan 2nd, 2012 9:41AM

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

ccampbell, Avalanche Canada

Kootenay Boundary.

Summary

Confidence

Good - -1

Weather Forecast

Tuesday: A couple centimetres possible overnight with up to 5-10cm possible throughout the day. Freezing levels could reach as high as 2000m in the evening with a temperature inversion, and moderate southwesterly alpine winds are expected. Wednesday: Continued light snowfall with moderate to strong southwesterly winds, and freezing levels around 1300m. Thursday: Generally dry with isolated flurries possible.

Avalanche Summary

Reports of avalanches are getting less frequent, but human triggering large avalanches associated with persistent weaknesses remains possible, including remote triggering. A skier recently remotely triggered an avalanche from 50m away and in many places shooting cracks and whumphing are further indicators of a very touchy, unstable snowpack.

Snowpack Summary

Compression tests have been producing easy to moderate sudden results on the mid-December surface hoar, down 30-80cm, and propagation tests have shown that avalanches associated with this persistent slab have a high propensity to propagate over large areas. above the mid-december weak layer of surface hoar. A storm snow weakness down 30cm also gave easy sudden results, recently formed wind slabs remain touchy, and in some places buried wind slabs are a concern.

Problems

Persistent Slabs

Touchy weakness susceptible to human triggering. Particularly a concern on unsupported slopes.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

3 - 5

Wind Slabs

Be alert for wind slabs below ridge crests, behind terrain features, and in cross-loaded gullies. New cornices may be weakly bonded and likely to break off.

Aspects: North, North East, East, South East, South, South West.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 5

Valid until: Jan 3rd, 2012 8:00AM