Avalanche Forecast

Issued: Nov 15th, 2015 4:00PM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is low. Known problems include Storm Slabs and Loose Dry.

Conrad Janzen, Parks Canada

Banff Yoho Kootenay.

A natural cycle is tapering off as of Sunday. Remain vigilant on Monday as human triggering will remain likely on Monday. Ice Climbers: Be wary of steep gully features. AB

Summary

Weather Forecast

Another small storm will give the region about 20cm of snow on Tuesday. Likely, this will keep danger ratings elevated. Wednesday an arctic high pressure will start to develop bringing very cold temperatures to the region. We expect the cold temps to slow down any natural avalanche cycle that may develop as a result of Tuesday's storm.

Snowpack Summary

85cm of snow on the ground at tree line near Bow Summit today. 10-15cm of that fell overnight. The snowpack in this area lacks cohesion, and forecasters were routinely breaking through to the ground. Snowpack tests produced moderate results, the failure being right on the ground. Nov 5 and 11 layers found 15cm and 30cm from ground respectively.

Avalanche Summary

Observations near Bow Summit today indicate a widespread loose/dry avalanche cycle. They ran from steep gullies and poured out onto the fans below (up to size 2). Additionally two substantial avalanches to ground were reported near the Lake Louise ski area. The Lipalian slide path produced a size 2.5 and West Bowl avalanched size 2.

Confidence

Problems

Storm Slabs

70cm of recent snow is settling into a 50-60cm slab sitting over a mix of surface hoar, facets and sun crust near the ground. Combined with wind loading in open areas, this is creating ideal conditions for human triggered slabs in steep terrain.

The new snow will require several days to settle and stabilize.Be careful with wind loaded pockets while approaching and climbing ice routes.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Loose Dry

As a result of Sunday's loose dry avalanche cycle in steep gullies ice climbers in particular should expect sluffing in the features on Monday

Avoid travelling on ledges and cliffs where sluffing may have severe consequences.The volume of sluffing could knock you over; choose your climb carefully and belay when exposed.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Nov 16th, 2015 4:00PM