Avalanche Forecast

Issued: Apr 10th, 2016 4:00PM

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

Conrad Janzen, Parks Canada

Banff Yoho Kootenay.

A good freeze is expected Sunday night before another hot day on Monday. Travel conditions should be good early in the day but plan start early and be down early. Enjoy the spring skiing conditions!

Summary

Weather Forecast

Sunday night should see a reasonable overnight freeze but expect another warm day on Monday with freezing levels around 2400m. Light to moderate West winds may help keep the alpine snowpack a little cooler. Continued warm temperatures, moderate West winds and the possibility of a few light flurries for Tuesday and Wednesday.

Snowpack Summary

A good overnight freeze on Saturday with a couple cm's of new snow. Below the surface crust isothermal snow was found up to treeline on all aspects, and in thin alpine areas on S aspects. N aspects in the alpine are more winter like. In many places the upper snowpack still sits on a weaker deep persistent layer of rounding facets.

Avalanche Summary

No new avalanche activity was observed or reported on Sunday due to a good overnight freeze. Explosive control on Saturday during the heat of the afternoon was able to produce several 2.5-3 loose wet avalanches out of steep treeline terrain in the Kootenay region.

Confidence

Problems

Deep Persistent Slabs

Deep facet layers remain weak especially in thin snowpack areas and may be triggered during the hotter parts of the day.

Travel early before the heat of the day, and avoid big slopes in the afternoon.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Loose Wet

Any steep slopes should be avoided later in the day when the crust on top of the snowpack breaks down due to daytime heating. We expect this to occur mostly at lower elevations and on sun exposed alpine slopes on Monday. Start early and finish early!

Watch for clues, like sluffing off of cliffs, that the snowpack is warming up. Travel early on frozen crusts before the heat of the day.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Cornices

We have seen numerous cornice failures in the past week during periods of warm temperatures. Some of these have triggered large slabs on the slopes below. Minimize your time under cornices at this time of the year, especially later in the day.

Cornices become weak with daytime heating, so travel early on exposed slopes.Even small cornice falls may trigger larger avalanches.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Apr 11th, 2016 4:00PM