Avalanche Forecast

Issued: Feb 17th, 2016 4:00PM

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

rupert wedgwood, Parks Canada

Jasper.

Pay close attention to terrain selection and signs of instabilities such as shooting cracks and whumffing.

Summary

Weather Forecast

Low pressure in the gulf of Alaska is driving a warm westerly flow over the park. Overnight temps will drop below freezing but will rise to 2,100m tomorrow. Flurries at upper elevations may shed 5cm with moderate SW winds. Temperatures will cool off on Friday and into the weekend.

Snowpack Summary

Moderate SW winds are building a wind slabÂ at treeline and into the alpine. These slabs may be up to 40cm thick and are weekly bonded to the snowpack below. The mid-pack consists of buried wind and persistent slab with a failure plane down 60cms. In the valley bottom the snowpack is very week and unconsolidated making for tough trail breaking.

Avalanche Summary

Field team in the Whistler Creek drainage reported isolated large avalanches to size 3 in the alpine.Â It is possible to trigger slab avalanches from a distance at treeline and above in wind loaded features; as was done on the 16th to size two in the Whister Creek drainage.

Confidence

Timing or intensity of solar radiation is uncertain

Problems

Persistent Slabs

Previously formed slabs now comprise the upper and mid-pack in many locations. Natural and human triggered avalanches are possible.

If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Wind Slabs

Strong winds have redistributed storm snow and wind slab can be found at all elevations. Caution on cross loaded gullies and lee aspects.

Caution in lee and cross-loaded terrain near ridge crests.Use caution in lee areas. Recent wind loading has created wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Feb 18th, 2016 4:00PM