Avalanche Forecast

Archived

Mar 16th, 2023–Mar 17th, 2023

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Regions

Kananaskis, Bow Valley, Highwood Pass, North 40, Spray - KLakes.

We are quickly approaching crust building season. In the days & weeks to come, aspect and incline will play a big role in ski quality and avalanche hazard.

Confidence

Moderate

Avalanche Summary

It seems the natural cycle continued yesterday with the warmer temperatures. Numerous sz2-2.5 slabs were seen today. Expect that trend of heat related avalanches to continue over the next few days.

Snowpack Summary

Recent storm snow has settled into a pleasant 20cm of settled snow. So far the winds haven't made an appearance which means we've been spared a widespread wind slab problem. There are some wind slabs still lurking in the alpine, but they generally seem to be high and in steep alpine terrain. But there is a catch (when isn't there?), the March 12th layer is a slippery one and it doesn't need much of a cohesive surface layer to pose a problem. Unsupported alpine and treeline terrain is still concerning. The mid to lower pack remains variable, in every sense of the word. The depth changes dramatically on elevation, and the supportiveness of it seems to change at the drop of a hat. Today, the skis were sinking in odd places with little warning. Thin spots and rocky areas are still a likely place to trigger the deeper problem layers.

Weather Summary

If you like sunny skiing/snowshoeing/ice climbing, the next few days are your time! Clear skies are expected tonight and most of the day tomorrow. Temperatures will start at -16 and rise to -3 by early afternoon. The solar input was noticeable today, expect the same strong inputs tomorrow. As for the wind, only light breezes are expected for the next few days.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
Recent wind has varied in direction so watch for wind slabs on all aspects.

Problems

Wind Slabs

Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.

Deep Persistent Slabs

Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.