Avalanche Forecast

Issued: Mar 9th, 2016 4:00PM

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

snow safety, Avalanche Canada

Little Yoho.

If the forecast storm reaches this far north we will likely see a small avalanche cycle. The snowpack should moderate fairly quickly.

Summary

Weather Forecast

A big system is forecast for Thursday. Models are showing 20 - 40 cms with moderate to strong SW winds and freezing levels rising to ~ 1900m. The danger ratings will rise rapidly if it materializes.

Snowpack Summary

15 to 30 cm of new snow sits on a well settled mid and lower pack. This new snow overlies a temperature crust below 1800m on polar aspects and a sun crust into the alpine on solar aspects. Isolated wind effect exists near ridge-tops. No significant shears found in the mid and lower pack, however thin snowpack areas are still suspect.

Avalanche Summary

We received a report on Monday of a skier triggered avalanche on the Wapta near Mt. Collie and the Richard and Louise Guy Hut. It was a size 2.5 on a SE aspect at 2600m. This failed on a facet layer near the base of the snowpack and took two skiiers for a ride, partially burying one with minor injuries.

Confidence

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

Problems

Wind Slabs

West winds have formed small wind slabs in predictable areas on the leeward sides of ridges. Pay close attention to how the snow surface feels, ski test on small rolls, and look for clues like cracking.

Be cautious as you transition into wind affected terrain.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Persistent Slabs

The persistent weak layers from January and February are bonding well, and have a low likelihood of triggering in most of the forecast area. Overall the snowpack is quite strong, but continue to be wary, especially in shallow snow-pack areas.

Avoid convexities or areas with a thin or variable snowpack.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

2 - 3

Valid until: Mar 10th, 2016 4:00PM