Avalanche Forecast

Issued: Jan 7th, 2019 4:00PM

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

adam greenberg, Parks Canada

Waterton Lakes.

Lingering uncertainty about the ability to trigger deep persistent weak layers requires a cautious approach to terrain. Avoid thick to thin snowpack transitions, and have a healthy respect for what is above you.

Summary

Weather Forecast

TUESDAY Temperatures warming throughout the day, with freezing levels at valley bottom. Light SW windsWEDNESDAY Flurries up to 10cm with moderate SW winds building to strong overnight. Freezing levels to 1600mFRIDAY Flurries up to 5cm with Moderate to Strong W winds. Freezing level to 1600m.

Snowpack Summary

The Alpine is highly wind affected from strong west winds. Snowpack at treeline is comprised of 20-30cm of new wind slabs above many layers of old wind slabs. These have bonded well to create a strong mid pack, though the bottom of the snowpack remains facetted and weak. Snow cover is variable, with a treeline average of 160cm at Cameron Lake.

Avalanche Summary

Recent snow and winds led to a limited natural cycle on west aspects on the weekend, with avalanches to size 2 observed along the Akamina Parkway and cornice fall triggering a size 2.5 in Red Rock Canyon. Small skier controlled windslabs were reported in the Castle Mountain region.

Confidence

Problems

Wind Slabs

New windslabs will be building as winds and snowfall increase on Wednesday.

Use caution in lee areas. Wind loading could create slabs.If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

There has not been much recent activity on the facets deep in the snowpack, but there is still the possibility to trigger them in shallow areas.

Avoid convexities and thin snowpack locations.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 3.5

Valid until: Jan 10th, 2019 4:00PM