Avalanche Forecast

Issued: Apr 3rd, 2017 3:00PM

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

jeremy.mackenzie, Alberta Parks

Kananaskis.

Though Spring has not yet arrived to our snowpack, the intense April sun is having an effect - pay attention to rapidly changing conditions on sunny days. Good skiing is being found on sheltered northerly aspects.

Summary

Confidence

Moderate - Timing or intensity of solar radiation is uncertain

Weather Forecast

Tuesday looks to be mostly sunny with freezing levels climbing to at least 1800m. It will likely feel very warm in the sun. Winds will be moderate from the West. Conditions continue to warm up through Wednesday and Thursday.

Avalanche Summary

Solar triggered pin-wheeling and sluffing occurred on steep solar aspects, but generally not much mass was involved.

Snowpack Summary

Up to 10cm of new snow at Treeline in the past 24hrs, with much less at lower elevations. This snow was turning moist on solar aspects by late morning, and by tomorrow morning should be frozen into another in a series of previously formed crusts on these solar slopes. On polar aspects between 20 and 30cm of dry snow is currently on the surface, but buried crusts are found at lower elevations. Wind slabs are widespread in the Alpine on all aspects, but are more isolated at Treeline. Not much natural avalanche activity has occurred with these wind slabs, but many areas like ripe for human-triggering. As previously reported the mid-pack remains dense and strong, but the basal layers are very weak consisting of anywhere between 50 and 100cm of facets sitting on the ground. Forecasters still have low confidence for traveling in large Alpine terrain, unless there has been widespread previous avalanching.

Problems

Wind Slabs

Wind slabs are found on all aspects in the Alpine and a few spots at Treeline. While not much natural avalanche activity has yet occurred, human-triggering is likely in convex and unsupported features.

Avoid freshly wind loaded features.Use caution in lee areas. Recent wind loading has created wind slabs.Avoid cross loaded slopes at or above treeline.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 3

Deep Persistent Slabs

This deep layer is still a threat in any avalanche terrain that has not yet had extensive previous avalanching. While there is a lower probability of triggering, the consequences are high.

Pay attention to overhead hazards like cornices which could easily trigger deep slabs.Be wary of slopes that did not previously avalanche.Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 4

Loose Wet

The intense April sun will cause a rapid increase in loose wet avalanche activity on solar aspects as the day progresses.

Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.Avoid slopes when the solar radiation is strong, especially if they have large cornices overhead.

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Apr 4th, 2017 2:00PM