Avalanche Forecast

Issued: Jan 25th, 2018 4:00PM

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

landon shepherd, Parks Canada

Jasper.

Expect a lot of variability in snow depth in exposed terrain from this week's gusty winds.

Summary

Weather Forecast

Cool (not cold) arctic air will keep precip to only light and scattered flurries through most of the weekend. Light to moderate SW winds gusting to moderate will accompany the cooler air.

Snowpack Summary

Windslab building above 3 weak interfaces in the top 30 to 50cm of the snowpack. Depth of surface hoar/facet layers varies with the terrain and vegetation shelter, but is most consistently found in sheltered features at TL and above.

Avalanche Summary

Natural windslab avalanches up to size 1.5 were observed Tuesday in windswept alpine moraine features. Appears to be running on the persistent slab interface down 30 to 50cm.

Confidence

Forecast snowfall amounts are uncertain on Sunday

Problems

Persistent Slabs

This problem is made up of 3 significant interfaces in the top 30-50cm of the snowpack. All interfaces seem to be slowly healing but have shown recent sensitivity to light loads in isolated locations.

Watch for whumpfing, hollow sounds, and shooting cracks.The best powder will be found in sheltered locations at or below treeline.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2.5

Wind Slabs

Last week's storm snow with southwesterly winds will continue to build layers of windslab in lee features at ridge crests and open areas at TL and above.

Be careful with wind loaded pockets while approaching and climbing ice routes.Be cautious as you transition into wind affected terrain.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Jan 26th, 2018 4:00PM