Avalanche Forecast

Issued: Mar 26th, 2017 4:00PM

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

deryl kelly, Parks Canada

Jasper.

Meow is not the time to be bold. Excellent creamy riding can be found on most moderate and low angle terrain.

Summary

Weather Forecast

Cloudy with sunny periods and isolated flurries on Monday. Moderate SW ridge top winds. Remaining relatively cool with forecasted alpine temperatures, -3 to -10.

Snowpack Summary

The main concern in the snowpack at tree-line and above is the deep persistent slab over weak facet layer at ground. This slab can be triggered by travelers from shallow or weak locations or naturally from large loads such as cornice failure or windslab avalanches. All steep loaded slopes that have not recently avalanched should be avoided.

Avalanche Summary

A size 3 skier accidental slab avalanche was reported Saturday afternoon north of the Icefields on a NE aspect at tree-line. Cycle continues, especially in the Alpine where new wind load is triggering deep slabs and cornice triggered slabs on North through West aspects, up to size 3 observed in field work today.

Confidence

Due to the number and quality of field observations

Problems

Wind Slabs

Windslabs building at treeline and above on lee aspects and while thin on Sunday afternoon, it is sensitive to triggering.

If triggered the wind slabs may step down to deeper layers resulting in large avalanches.Minimize overhead exposure during periods of heavy loading from wind.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

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. On Mar 25, skiers triggered a sz 3 on this layer.

Avoid paths that have not avalanched recently.Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 4

Cornices

Large cornices on ridge top lee features. Recent cornice failure has triggered large avalanches from 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.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Mar 27th, 2017 4:00PM