Avalanche Forecast

Issued: Dec 12th, 2012 9:21AM

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

ccampbell, Avalanche Canada

Sea To Sky.

Summary

Confidence

Fair - Timing, track, or intensity of incoming weather is uncertain on Saturday

Weather Forecast

Thursday: Cloudy with light snow starting in the afternoon, freezing levels rising as high as 500m and moderate northwesterly winds becoming strong southwesterlies with the onset of precipitation. Friday: Snow easing throughout the day with 10-15cm total since Thursday, moderate northwesterly winds and freezing levels hovering around 500m. Saturday: Heavy snow, extreme southwesterly winds and freezing levels rising as high as 1000m.

Avalanche Summary

There have been reports of small human triggered wind slabs over the past few days. Most activity seems to be in high alpine start zones.

Snowpack Summary

Recent winds have been stiffening the low density storm snow and forming reactive slabs. Below these recent storm snow weaknesses, the snowpack is well settled and strong. A layer of surface hoar that formed during late November has been found intact or decomposing in some locations down a meter or more. The early November crust/facet combination near the base of the snowpack seems to be dormant, at least in deep snowpack areas where it is buried too deeply by a stiff snowpack to be affected by light triggers on the snow surface.

Problems

Wind Slabs

Expect to encounter touchy wind slabs below ridge crests, behind terrain features, and in cross-loaded gullies. Be especially diligent as northerly winds start to reverse load unusual aspects.

Be cautious as you transition into wind affected terrain.>Avoid freshly wind loaded features.>If you are increasing your exposure to avalanche terrain, do it gradually as you gather information.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 4

Valid until: Dec 13th, 2012 2:00PM