Avalanche Forecast

Issued: Mar 6th, 2017 4:00PM

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

garth lemke, Parks Canada

Jasper.

Avalanche control along the Icefields Parkway on Sunday produced results up to size 3. The new will require some time to stabilize, choose simple terrain that is well supported. Be vigilant if the sun comes out where it can wake up the new snow.

Summary

Weather Forecast

Tuesday and Wednesday will be -12 to -16, 25km/hr SW to S winds, and flurries. Thursday and Friday will be a deep freeze down to -24 with light East winds.

Snowpack Summary

45cm of storm snow from Friday and Saturday arrived with light and some moderate southerly winds. It continues to settle into a soft slab at treeline and above. The mid and lower snowpack is structurally weak, the base of which is 5mm depth hoar crystals and a deteriorating rain crust.

Avalanche Summary

Avalanche control work on Sunday produced up to sz 3, some stepping down to deep persistent layers or to the ground where weak facets and depth hoar exist. Natural activity was most prevalent in the alpine and similar to the control work, was stepping down, resulting in deep releases, sz 2-3. Sun came out today resulting in some natural activity.

Confidence

Problems

Storm Slabs

40cm of storm snow is forming a soft slab at treeline and above. It will remain reactive to triggering for the next few days. Where stronger winds in the alpine have transported the snow it may be up to 60cm thick.

Use caution in lee areas in the alpine and treeline. Storm snow is forming touchy slabs.If triggered the storm slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Deep Persistent Slabs

Increased loading above this layer from the recent storm snow has produced a number of releases up to size 3. These are mostly from the alpine and treeline elevations and are running down to the valley bottoms.

Use caution on open slopes and convex rolls Use conservative route selection, choose moderate angled and supported terrain with low consequence.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 3

Persistent Slabs

Increased loading on this layer from the recent storm snow has produced a number of releases up to size 3. Triggering is mostly likely from shallower locations around rocky terrain.

Be aware of the potential for wide propagations.Be wary of slopes that did not previously avalanche.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 3

Valid until: Mar 7th, 2017 4:00PM