Avalanche Forecast

Issued: Mar 3rd, 2014 4:00PM

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

tim haggarty, Parks Canada

Waterton Lakes.

Warming temperatures and active weather may lead to an increase in avalanche activity this week. Stay conservative with your terrain selection

Summary

Weather Forecast

Warm, wet pacific air is battling with cold arctic air over the prairies. One low is pushing through Mon and a second will move through Thurs. Warm temperatures with freezing levels near 15-1700m. Moderate to Strong Southwest winds should be expected through Thursday. Precip will be steady Tuesday with significant amounts expected Wed and Thursday.

Snowpack Summary

West winds began to redistribute the recent low density storm snow today. This snow buried a thin crust on solar aspects and isolated windslabs found at treeline and above. Between 70 and 150cm now buries the weak February Facet Layer. Large avalanches will result if this layer is triggered given the demonstrated ability of this slab to propagate..

Avalanche Summary

One significant persistent slab released just before the cold snap. A few skier triggered windslabs have been seen in the neighboring areas. As we emerge from the cold temperatures there is concern for the persistent slabs to become touchy again. Rapid loading from the forecast wind and snow may result in significant avalanche activity.

Confidence

Intensity of incoming weather systems is uncertain

Problems

Persistent Slabs

These slabs became less sensitive with cold temperatures and increasing depth. Now as conditions change with rapid loading and warming, limit your exposure to significant slopes. Do not get taken by surprise. Long propagations may still be possible.

Use conservative route selection, choose moderate angled and supported terrain with low consequence.Dig down to find and test weak layers before committing to a line.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 3

Wind Slabs

Variable winds have been actively creating windslabs over the last week. Now with more snow and moderate to strong SW winds in the forecast, expect to encounter slabs as you enter open terrain.

Avoid freshly wind loaded features.Use caution in lee areas. Recent wind loading have created wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Mar 6th, 2014 4:00PM