Avalanche Forecast

Issued: Feb 22nd, 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.

stephen holeczi, Parks Canada

Banff Yoho Kootenay.

Extensive wind effect can be found in open areas. We are slowly gaining confidence with the snowpack, but a cautious approach to terrain is important as large avalanches are still possible.

Summary

Weather Forecast

The arctic ridge starts to break down Friday over the area with increasing cloud but still cold conditions for Friday.Â Winds will increase to moderate/strong above 3000m but will stay light at valley bottom.Â Some light snow over the weekend with 5-10cm at treeline by Sunday evening and slightly warmer (but not warm!) temperatures.Â

Snowpack Summary

The upper pack consists of settling storm snow with extensive wind effect in open areas. This overlies the mid-pack where there are three weak layers that are gaining strength. These layers continue to produce moderate, sudden planar test results on surface hoar in deep tap tests, and hard to no results with standard compression tests.

Avalanche Summary

A couple of wind slabs in steep terrain were reported and were suspected to be in the last 24-36 hours, 1 triggering a deeper slab. No other reports of avalanches in the last 24 hours with good visibility.

Confidence

Problems

Persistent Slabs

A strong upper snowpack overlies three weak layers in the mid snowpack: Jan 16, Jan 6, and Dec 15. All are a mix of sun crust, surface hoar and facets depending on location, and we are slowly gaining confidence with these layers.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely

Expected Size

2 - 3

Valid until: Feb 23rd, 2018 4:00PM