Avalanche Forecast

Issued: Mar 13th, 2016 8:00AM

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

andrew jones, Parks Canada

Glacier.

Although temperatures have cooled, the spring sun is strong and can have a major effect on avalanche danger and cornices. Careful decision making is still required with multiple avalanche problems.

Summary

Weather Forecast

A break in the stormy weather today with a mix of sun and cloud. Freezing levels have dropped with the passing of a cold front and will climb to 1500m this afternoon. Moderate ridge winds from the south with gusts to 45km/hr. An intense low pressure system arrives later tonight with another 10cm of accumulation. Cool weather continues this week.

Snowpack Summary

10cm of new snow and strong southerly winds overnight. Wind slabs are widespread in the alpine and treeline. Warm temps and strong sun formed surface crust below 1700m and on solar aspects. Feb 27 is down 50-70cm is most reactive where SH overlies a sun crust. Feb 10 is down 100-120 and reactive in isolated locations. Well settled & strong below.

Avalanche Summary

Four size 2 avalanches with moist deposits were observed in the highway corridor yesterday.

Confidence

Problems

Persistent Slabs

The Feb 27th interface is down 80cm and is producing sudden planar results on a crust on S though W aspects and surface hoar in isolated spots. This layer has been active recently, triggered by small wind slab avalanches and cornice falls.

Dig down to find and test weak layers before committing to a line.Be aware of the potential for wide propagations.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 3

Wind Slabs

Wind slabs are widespread and reactive in the alpine and treeline. A skier was partially buried on Friday after triggering a wind slab on a relatively small feature. When triggered on open slopes, wind slabs may step down to deeper persistent layers.

Be cautious as you transition into wind affected terrain.If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 3

Cornices

Additional storm snow accompanied by SW winds has allowed cornices to grow and become fragile. Limit your exposure to these overhanging beasts along the ridge crests and be mindful of overhead hazard when the intense spring sun is shining.

Extra caution needed around cornices with current conditions.Avoid slopes when the solar radiation is strong, especially if they have large cornices overhead.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 4

Valid until: Mar 14th, 2016 8:00AM