Avalanche Forecast

Issued: Feb 17th, 2018 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.

deryl kelly, Parks Canada

Jasper.

Persistent weaknesses are present and active in the northern bulletin region, like the slack-country off Marmot Basin Ski Hill, Portal Creek, and the Tonquin.

Summary

Weather Forecast

Gusty North winds expected to persist overnight and through the day Sunday. Temperatures will continue to drop with overnight temperatures to -27, and Sunday's daytime high near -23 for the whole bulletin region.

Snowpack Summary

Available snow has been redistributed by strong, variable direction winds. At all elevations, where transported, new wind slabs will be sensitive to triggering. A persistent slab, down 50 to 80cm, is prevalent through the forecast region. Any large TL avalanche terrain that has not obviously avalanched should be expertly managed or, avoided.

Avalanche Summary

No new avalanche activity observed or reported.

Confidence

Problems

Persistent Slabs

Whumpfing and cracking are signs of this layer's reactivity. Expect long propagation with a wind-stiffened snow surface.

Watch for surface cracking and stiffer surface layers of snow.Watch for whumpfing, hollow sounds, and shooting cracks.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 3

Wind Slabs

Variable direction, strong upper elevation winds are continuing to create fresh windslabs and stiffen the snow surface well into Treeline locations.

The best powder will be found in sheltered locations at or below treeline.Avoid avalanche terrain during periods of heavy loading from new wind.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Feb 18th, 2018 4:00PM