Avalanche Forecast

Issued: Apr 14th, 2017 4:34PM

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

jsmith, Avalanche Canada

Purcells.

The key weather factors to keep your eye on this weekend will be the sunshine accompanied by rising freezing levels. Solar radiation is a common trigger for cornices which is currently our primary concern.

Summary

Confidence

High -

Weather Forecast

SATURDAY: Mix of sun and cloud. Light southwesterly ridgetop winds. Freezing level around 1600m.SUNDAY: Sunny. Light southerly ridgetop winds. Freezing level rising to around 2000m.MONDAY: Mix of sun and cloud. Light southwesterly ridgetop winds. Freezing level hovering around 2000m.

Avalanche Summary

Several size 2 natural and skier triggered wind slab avalanches were reported in this region on Thursday. Wind slabs may continue to linger in the alpine but the key weather factor to keep your eye on this weekend will be the sunshine accompanied by rising freezing levels. Solar radiation is a common trigger for cornices which is currently our primary concern.

Snowpack Summary

Recent snow and wind have formed wind slabs in the alpine on a variety of aspects caused by shifting wind directions. Cornices are large, looming, and the primary concern due to their potential to trigger large avalanches failing on facets at the bottom of the snowpack.

Problems

Cornices

Minimize exposure to slopes with large cornices overhead when it is cool and cloudy and completely avoid them if it is warm and/or sunny.

Cornice failures could trigger large avalanches.Give cornices a wide berth when travelling on or below ridges.

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Wind Slabs

Lingering wind slabs may still be reactive to human triggers in isolated locations.

Be especially careful with wind loaded pockets near ridge crests and roll-overs.Keep an eye out for reverse loading created by shifting winds.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Apr 15th, 2017 2:00PM