Avalanche Forecast

Issued: May 22nd, 2014 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 Loose Wet, Cornices and Deep Persistent Slabs.

conrad janzen, Parks Canada

Banff Yoho Kootenay.

Regular avalanche bulletins have ended. We will update if there are significant changes. For specific condition information during spring and summer, see Parks Mountain Safety, the Mountain Condition Reports or contact Visitor Safety at 403-762-1470.

Summary

Weather Forecast

Snowpack Summary

Spring conditions exist. After cool clear nights a firm melt freeze crust is present which deteriorates with daytime heating. Below 2200m the snowpack is mostly isothermal. Above 2200m the snowpack is generally supportive with the surface becoming moist with daytime heating. Weak basal facets are still present in many locations.

Avalanche Summary

The last week has seen loose wet slides on steep solar aspects up to size 2.5 with daytime heating. Several cornice failures have been observed. Some slab avalanches have been observed during sustained warming or major rain events and we expect to see more avalanche activity on the basal facets with similar weather events through the spring season.

Confidence

Problems

Loose Wet

Intense sun, daytime heating or high overnight freezing levels will result in loose wet avalanches out of steep terrain. Start trips early and plan to be out of avalanche terrain before things heat up.

Travel early before the heat of the day, and avoid big slopes in the afternoon.Watch for clues, like sluffing off of cliffs, that the snowpack is warming up.

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Cornices

With warm temperatures cornices will become weak and fail. Minimize your exposure to cornices and keep a close eye on the temperatures and solar effect on the slopes above you.

Cornices become weak with daytime heating, so travel early on exposed slopes.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Deep Persistent Slabs

We have seen a lot of avalanche activity on the basal facets during sustained periods of warm temperatures or intense rain and wet snow events up to size 3.

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

Valid until: May 23rd, 2014 4:00PM