Avalanche Forecast

Issued: Mar 14th, 2019 4:41PM

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

adam greenberg, Parks Canada

Waterton Lakes.

The rising temperatures this weekend and into next week will be the first real test of the facetted snowpack. If the sun comes out, local hazard levels will rise above what is posted.

Summary

Weather Forecast

Friday: Mainly cloudy, moderate west winds. Freezing Level 1400m.Saturday: Cloudy with sunny periods. Moderate west winds, freezing level 1600m.Sunday: Cloudy with sunny periods. Moderate to Light west winds. Freezing level up to 1800m.

Snowpack Summary

15-20cm of powder is being blown into new wind slabs by moderate west winds. This is sitting on a sun crust on steep south aspects and hard wind affected surfaces everywhere else that are providing a good sliding surface for the new snow. Crust facet combinations remain deep in the snowpack at lower elevations.

Avalanche Summary

Numerous small loose dry avalanches were observed in the Cameron lake and Akamina Parkway area on Thursday, and one older small avalanche with a 60cm deep crown was observed below treeline in a thin snowpack area. In the Castle Mountain region, two large avalanches were reported on NW aspects from the past week likely running on deep week layers.

Confidence

Timing or intensity of solar radiation is uncertain

Problems

Wind Slabs

15-20cm of recent snow has formed windslabs. If the sun makes an appearance during the day, these will become easier to trigger.

Use caution in lee areas. Wind loading will create slabs.Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Deep Persistent Slabs

There remains the possibility to be surprised by deep weak layers in thin snowpack areas. As temperatures rise these will become increasingly unpredictable.

Avoid steep convexities or areas with a thin or variable snowpack.Avoid thin, rocky or unsupported slopes.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely

Expected Size

1.5 - 2.5

Valid until: Mar 17th, 2019 4:00PM