Avalanche Forecast

Issued: Dec 17th, 2016 7:33AM

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

Parks Canada andrew jones, Parks Canada

The cold snap persists today but watch for changes with incoming weather. Warmer temperatures and new snow will raise the avalanche hazard significantly in the coming days.

Summary

Weather Forecast

Cold arctic air continues to dominate the weather pattern with today's temperature reaching a high of -21 in the alpine. Moderate NW winds will make it feel even colder. Temperatures begin rise Sunday morning with the arrival of a moist southwesterly flow. Expect accumulation amounts of 5cm for Sunday and 21cm for Monday.

Snowpack Summary

Moderate southerly winds overnight promoted the development of wind slabs in the lee of ridges and alpine features. This new windslab buries previous hard wind slabs formed during the cold Arctic outbreak. In sheltered spots the top 20cm of the snowpack is mostly facetted and still unsettled due to very cold temps. November 13 crust is down 1-1.5m.

Avalanche Summary

Two natural size 2.5 wind slab avalanches were observed in MacDonald Gullies #7 and #10 on the north face of Mt MacDonald. Isolated wind slabs have been reactive to skier loads in the past couple of days.

Confidence

Intensity of incoming weather systems is uncertain

Problems

Wind Slabs

An icon showing Wind Slabs
Fresh wind slabs are prevalent near ridge-crests or in alpine cross-loaded features and reactive where unsupported. The biggest concern with these would be cutting a small pocket and riding it over steep, unforgiving terrain.
Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Use caution above cliffs where small avalanches may have severe consequences.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 18th, 2016 8:00AM