Avalanche Forecast

Issued: Apr 2nd, 2017 3:00PM

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

jeremy.mackenzie, Alberta Parks

Kananaskis.

The snowpack has not yet made the transition to Spring Conditions, but keep an eye on the effects of the intense April sun. Look to sheltered north aspects for good quality skiing.

Summary

Confidence

High - Forecast snowfall amounts are uncertain

Weather Forecast

Convective flurries are expected Monday with accumulations of up to 10cm. However, spring storms are difficult to forecast for precipitation amounts, so it is quite possible to receive significantly more, or less, snowfall then predicted. Winds will be light to moderate from the North. The freezing level is expected to be 1500m with Alpine temperatures near -8 °C. By mid-week warmer temperatures are likely with freezing levels as high as 2300m.

Avalanche Summary

A few avalanches were observed today in very steep Alpine terrain. These were generally small in size and consisted of mostly loose dry avalanches or small cornice chunks rolling down steep cliffs. No new slab avalanches were observed or reported today.

Snowpack Summary

Up to 15cm of new snow fell at Treeline in the past 24hrs. This new snow amount varies from valley to valley, and tends to taper to only a few cm's at lower elevations. Wind slabs are present in Alpine terrain, but are more isolated or absent at Treeline elevations. By early in the afternoon the snow was turning moist at lower elevations and despite the cloudy skies, solar aspects received some heat today. 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 in Alpine terrain and a few spots at Treeline. In convex and unsupported features these are likely to be human-triggered. On Monday northerly winds coupled with light flurries may cause reverse wind loading.

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

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

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.

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

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 4

Valid until: Apr 3rd, 2017 2:00PM