Avalanche Forecast

Issued: Feb 11th, 2018 4:00PM

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

snow safety, Parks Canada

Banff Yoho Kootenay.

http://www.pc.gc.ca/apps/links/goto_e.asp?destination=Highway 93 south avalanche control is scheduled for Monday. Please avoid the Simpson slide paths and Mt Wardle.

Summary

Weather Forecast

A relief from the arctic air flow will come Monday with a gradual warming trend through the day. Expect a daytime high of -5 with clear skies and light winds. As the westerly flow moves in, light precipitation will bring 5cm Tuesday. With warming temperatures and clear skies on Monday there will likely be some solar input into the snowpack.

Snowpack Summary

Moderate to strong winds have redistributed the recent storm snow forming wind slabs at higher elevations. The three main mid-pack concerns are the Jan 16th, Jan 6th, and Dec.15 weak layers. These are a mix of facets, crusts and surface hoar and can be found 70cm to over 150cm deep in the snowpack and have been producing very large results.

Avalanche Summary

The bulk of the recent avalanche cycle has tapered off. Reports of isolated skier and explosive triggered wind slabs were noted today from local ski patrol. All avalanche terrain is still highly suspect.

Confidence

Problems

Persistent Slabs

Three weak layers exist in the mid snowpack: Jan 16, Jan 6, and Dec 15. All are a mix of sun crust, surface hoar and facets depending on the aspect and elevation. These layers are sensitive to triggering both naturally and by human triggering.

Watch for whumpfing, hollow sounds, shooting cracks or recent avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

2 - 3.5

Wind Slabs

Much of the recent storm snow has now been effected by moderate to strong winds at higher elevations. Expect loading on lee features and new wind slab development on exposed slopes.

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

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Feb 12th, 2018 4:00PM