Avalanche Forecast

Issued: Mar 30th, 2017 4:00PM

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

deryl kelly, Parks Canada

Jasper.

Cautiously moderate at treeline. Not seeing natural activity but it's critically important to continue to avoid shallow snowpack areas and be aware of the overhead hazards. Wind effect prominent in the alpine.

Summary

Weather Forecast

Precip expected to taper off over the evening on Thursday. By Friday morning expect cold temps to start the day near -12 to -15. Broken and clearing skies developing through the day with moderate SW winds and freezing level rising to 1800m.

Snowpack Summary

Creamy and settled surface snow with some wind effect in the open. Near surface non-persistent weaknesses, active on typically problematic features like convexities and immediate lees. March Interfaces melting into the mid-pack with inconsistent mod to hard field test results. All this, sitting on a large, facet layer off the ground.

Avalanche Summary

Field teams reporting cornice failures in the Alpine to 2.5.

Confidence

Problems

Cornices

Large cornices on ridge top lee features. Their sheer mass is a problem. Recent cornice failures have been generally small (a few tons or so;) but are consistently triggering large deep persistent slab avalanches in alpine terrain.

Give cornices a wide berth when travelling on or below ridges.Pay attention to overhead hazards like cornices which could easily trigger the deep persistent slab.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Deep Persistent Slabs

The deep persistent slab can be triggered by travelers from shallow or weak locations or naturally from large loads such as cornice failure or windslab avalanches.

Avoid paths that have not avalanched recently.Avoid shallow snowpack areas where triggering is more likely.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 4

Loose Wet

No expectations for activity first thing in the morning but, as the day progresses expect to see snowballing, and loose slides on solar aspects at TL and below.

Travel early before the heat of the day, and avoid big slopes.Use extra caution on solar slopes or if the snow is moist or wet.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Mar 31st, 2017 4:00PM