Avalanche Forecast

Issued: Feb 15th, 2019 4:00PM

The alpine rating is high, the treeline rating is considerable, and the below treeline rating is considerable. Known problems include Storm Slabs, Loose Dry and Deep Persistent Slabs.

Marcus Waring, Parks Canada

Waterton Lakes.

Storm snow is reactive and requires a conservative approach to terrain. Avoid large slopes and overhead hazard as we give this new snow time to settle.

Summary

Weather Forecast

Saturday: Cloudy with Scattered Flurries. 5-10cm. Moderate SW wind. Alpine high -9Sunday: Cloudy with Sunny Periods. Trace precipitation. Alpine high -22Monday: A mix of Sun and Cloud with Isolated flurries. Trace precipitation. Alpine high -18

Snowpack Summary

30-45cm of snow in the past 48h with moderate SW winds have created reactive soft slabs. These new storm slabs sit over a variety of wind affected surfaces including pockets of Windslab near ridgetop. The Midpack is strong in deep snowpack areas but this increase in loading will stress the weak, facetted basal snowpack.

Avalanche Summary

Size 2 Natural on Mt.Rowe Wed Feb. 13th.Size 1.5 Natural South end of Forum Ridge Wed Feb 13th.Multiple Loose Dry Avalanches observed in steep terrain

Confidence

Intensity of incoming weather systems is uncertain on Saturday

Problems

Storm Slabs

Moderate Compression Test Results today on Forum Ridge at the Storm snow interface. 15-30cm of snow over the weekend will continue to build storm slabs.

If triggered the storm slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 2

Loose Dry

Use caution in steep, sheltered terrain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Deep Persistent Slabs

A layer of weak facets is lurking at the bottom of the snowpack. This new snow may be enough to affect this basal weakness in shallow snowpack areas.

Avoid steep convexities or areas with a thin or variable snowpack.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Feb 18th, 2019 4:00PM