Avalanche Forecast

Issued: Mar 20th, 2016 4:00PM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Loose Wet, Persistent Slabs and Deep Persistent Slabs.

aaron beardmore, Parks Canada

Banff Yoho Kootenay.

Although conditions appear to be improving, forecasters still have low confidence in the snowpack due to large avalanches as recent as Friday. Think critically about your terrain choices.

Summary

Weather Forecast

The freezing level is expected to hover at 1900m on Monday. Some light precipitation is also expected (~4mm). Wind will be moderate at higher elevations from the SW.

Snowpack Summary

The snowpack is complex right now. 40-100 cm of snow sit on crusts on W through E aspects right up to alpine elevations. Sun-crusts exist on the surface on South aspects. Thinner snowpack areas have prominent facets near the base. Large cornices are sitting above many lee slopes.

Avalanche Summary

No new avalanches were observed or reported today.

Confidence

Problems

Loose Wet

High freezing levels may create a condition for loose wet avalanches on Monday. We expect that this will occur at lower elevations and in particular on South aspects.

Watch for clues, like sluffing off of cliffs, that the snowpack is warming up. Avoid slopes when the solar radiation is strong, especially if they have large cornices overhead.

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

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 2

Persistent Slabs

Avalanches on buried crusts with facets have been seen on solar aspects within the last few days. Presently there are several crusts buried with 40-100 cm overlying them.

Dig down to find and test weak layers before committing to a line.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Deep Persistent Slabs

Deep facet layers remain weak, especially in thin or rocky areas. Avoid steep or unsupported terrain and be very conservative with large terrain features. A great deal of variability exists.

Watch for signs of instability such as whumpfing, or cracking. Avoid steep convexities or areas with a thin or variable snowpack.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Mar 21st, 2016 4:00PM