Avalanche Forecast

Issued: Mar 4th, 2018 4:00PM

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

aaron beardmore, Parks Canada

Banff Yoho Kootenay.

Storm snow distribution is variable throughout the forecast region. Expect up to 35cm in Kootenay and as little as 5cm in the Lake Louise area.

Summary

Weather Forecast

Gradual warming is expected over the next few days. However, valley temperatures will not exceed zero degrees. The ridge temperatures will also increase but will not exceed -10. Cloud cover and very light precipitation will advance into the region through Wednesday. Wind will increase tonight to the strong range at ridge top from the SW.

Snowpack Summary

Variable amounts of low density storm snow (5-35) that arrived in the last 24 hours now sit on top of a firm mid-pack. The higher amounts of storm snow are to the south of the region. The Dec/Jan surface hoar layers are rounding and inactive in tests. The deeper facet layers down 80-150 cm remain weak but are presently difficult to propagate.

Avalanche Summary

A recreational party reported triggering (skier controlled) a size 1.5 storm slab today on the East aspect of Vermillion Peak at 2600m. 20cm deep by 60m wide by 200m long. Otherwise some sluffing (loose dry) up to size 1 was observed in the Simpson slide paths.

Confidence

Wind effect is extremely variable

Problems

Storm Slabs

This problem is isolated to Kootenay and the region surrounding Sunshine where snowfall amounts were up to 35cm. Expect this problem to transition to a wind slab problem as the low density snow is redistributed by increasing wind.

Use caution in alpine and open treeline lees. Recent snowfall has created storm slabs.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Loose Dry

This problem will be more pronounced in the parts of the forecast region that received more storm snow. It will be particularly prevalent in steep confined areas.

The volume of sluffing could knock you over; choose your climb carefully and belay when exposed.On steep slopes, pull over periodically or cut into a new line to manage sluffing.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 1.5

Valid until: Mar 5th, 2018 4:00PM