Avalanche Forecast

Issued: Apr 12th, 2014 4:00PM

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

conrad janzen, Parks Canada

Banff Yoho Kootenay.

Spring conditions are here. Excellent skiing on high North aspects and supportive travel early in the day! The hazard will rise as the temperatures heat up during the day. Start your trips early and be off of big slopes before they heat up. CJ

Summary

Weather Forecast

Sunday looks like a cool clear day with overnight lows around -12`C, light W winds and freezing levels near 1700m.Â Monday will see increasing cloud, Light SW winds, alpine temperatures up to -2 and freezing levels near 2000m. Tuesday will see some snow flurries, freezing levels near 2000m and light W winds.

Snowpack Summary

10-12cm of new snow over a supportive crust on all aspects and elevations today. Some moist snow at lower elevations. Snow pack becoming isothermal below 1700m later in the day. Small wind slabs present near ridge crests in the alpine from strong NW winds.

Avalanche Summary

Some loose sluffing out of steep terrain today up to size 1. In the past several days we saw numerous slab avalanches on all aspects and elevations up to size 3 failing on basal facets when the temperatures got really warm. Loose wet avalanches and cornice failures were also observed.

Confidence

Freezing levels are uncertain on Tuesday

Problems

Deep Persistent Slabs

Triggering this layer is most likely during warm periods and from thin rocky locations. Large triggers such as cornices may also trigger this deep weakness. This hazard will gradually increase as temperatures warm up over the next few days.

Be aware of thin areas that may propogate to deeper instabilites.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

1 - 3

Loose Wet

With tomorrows clear skies and sunshine we will likely see loose wet slides on steep S aspects in the afternoon. Cornice failures are also possible as things warm up. Plan to finish your trips by early afternoon.

Cornices become weak with daytime heating. Watch for clues, like sluffing off of cliffs, that the snowpack is warming up.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Apr 13th, 2014 4:00PM