Avalanche Forecast

Issued: Mar 17th, 2019 4:59PM

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

adam greenberg, Parks Canada

Waterton Lakes.

Spring is here with a bang! Avalanche activity will continue to increase with the temperatures. If you choose to travel in avalanche terrain be sure to start and end your day early and avoid overhead hazard.

Summary

Weather Forecast

Get your hawaiian shirt out and lather on that sunscreen! Expect light winds and increasing temperatures through the forecast period with little to no overnight freeze. Alpine Highs will be in the 5 degree range, while in town it will reach 12. The clear skies and strong March sun will work to further increase the temperatures on solar aspects.

Snowpack Summary

Wind slabs formed on Thursday and Friday and loose snow in sheltered areas are sitting on a sun crust on steep south aspects, facets in sheltered areas, and hard wind affected surfaces everywhere else. The lower snowpack remains weak and facetted, and as the warm temperatures continue there is a possibility this layer could produce large avalanches

Avalanche Summary

A number of Size 2 loose avalanches were observed on Mt. Bertha and along the Akamina Parkway over the past 2 days. They entrained a substantial part of the facetted snowpack in some areas, making them larger than one might expect. In the Castle Mountain region, there were reports of Size 3 avalanches in the past week on layers deep in the snowpack

Confidence

Problems

Loose Wet

Loose avalanches are either running on hard bed surfaces, or entraining the faceted lower snowpack and running larger than normal.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.If triggered loose wet sloughs may step down to deeper layers resulting in larger avalanches.

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

Elevations: All elevations.

Likelihood

Very Likely - Certain

Expected Size

1 - 2

Wind Slabs

Wind slabs formed on Thursday may still be reactive at higher elevations.

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

Deep Persistent Slabs

There remains a concern for deep weak layers in thin snowpack areas. Rapidly warming temperatures and solar radiation have the potential to wake them up.

Avoid steep convexities or areas with a thin or variable snowpack.Avoid shallow snowpack areas where triggering is more likely.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1.5 - 3

Valid until: Mar 20th, 2019 4:00PM