Avalanche Forecast

Issued: Feb 11th, 2014 2:50PM

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

tim haggarty, Parks Canada

Waterton Lakes.

A widespread avalanche cycle is occurring. New slabs are very easy to trigger. There remains some potential for deep layers to be triggered that would result in large avalanches. With more snow forecast travel in avalanche terrain is not recommended.

Summary

Weather Forecast

A series of three systems is expected over the next three or four days with additional snowfall amounts of 15cm forecast with each. The associated Moderate to Strong West winds and mild temperatures will contribute to rapid slab formation.

Snowpack Summary

15cm of new snow arriving with moderate West winds and warm temperatures has quickly formed slabs over 20 to 30 cm of weak, faceted snow which is bonding poorly to a firm layer beneath. With this change, the Basal Facets remain a concern in shallow areas where the overlying slab of hard snow providing all of the strength to our snow pack is thin

Avalanche Summary

A widespread natural cycle is now occurring with soft slabs to size 2 in the Alpine and on open slopes at Treeline. Skier triggering of slabs is likely right now at all elevations with remote triggering encountered on steep slopes below treeline. With the additional snow and wind in the forecast the size of these events is likely to increase.

Confidence

Intensity of incoming weather systems is uncertain

Problems

Storm Slabs

Soft slabs are forming rapidly with the new snow over a very weak and widespread layer. These slabs can be triggered from a distance on steep slopes and require very conservative terrain selection and route finding.

Avoid steep, open slopes.Choose conservative lines and watch for clues of instability.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 3

Deep Persistent Slabs

With widespread avalanches occurring the potential for the weak snow at the bottom of the snowpack to be triggered as a large avalanche is elevated. Give big terrain a wide berth until things have a chance to settle.

Be aware of the potential for full depth avalanches due to weak layers at the base of the snowpack.Avoid shallow snowpack areas where triggering is more likely.

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

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Feb 14th, 2014 4:00PM