Avalanche Forecast

Issued: Dec 25th, 2012 8:50AM

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

sylvia forest, Parks Canada

Glacier.

Do not let the low ratings at treeline fool you - pockets of weak snow over terrain traps can be just as problematic as a higher danger rating. Watch for cornices, tree wells, and if the sun comes out, watch for solar radiation warming the snow.

Summary

Weather Forecast

A week upper ridge of high pressure will bring dry conditions on this Christmas day, with light winds, and mostly cloudy skies. A weak Pacific front will move in on Boxing day, bringing light precipitation, cloudy skies, and less than 5 cm of snowfall. Sunnier skies are expected on Friday.

Snowpack Summary

The snowpack is generally strong and well settled, except for isolated pockets of wind slab in the alpine and treeline. While these weaknesses are stubborn to release in tests, a large trigger such as a cornice drop has the potential to trigger these slabs. Weaknesses deeper in the snowpack are largely dormant right now.

Avalanche Summary

One new avalanche size 1.5 avalanche was noted in the highway corridor yesterday. A size 2.0 low elevation glide crack release on the south side Mt Cheops two days ago. Cornices are getting very large, and could provide the large trigger needed to release avalanches.

Confidence

Timing, track, or intensity of incoming weather system is uncertain

Problems

Wind Slabs

Isolated pockets of wind slab were noted yesterday at and above treeline on wind exposed areas. A 10cm wind skin overlies a 35 cm thick wind slab. Cross loaded and windward areas should be treated with caution.

Be cautious as you transition into wind affected terrain.Stay well to the windward side of corniced ridges.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Loose Dry

Be cautious of sluffing in steep terrain.