Avalanche Forecast

Archived

Mar 25th, 2023–Mar 26th, 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.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

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

New snow may entice you to push into bigger terrain in search of turns but the base and mid pack is still weak. Its hard to be disciplined for the entire season, but thats whats gonna pay off long term.

Confidence

High

Avalanche Summary

Numerous loose dry avalanche up to sz 1 on all aspects but no new slab avalanche activity was noted.

Snowpack Summary

10-13cm fell overnight on Friday giving a nice reset to the region. This new snow has seen very little wind and as such, not much for new windslab development was observed. How this new snow bonds to the crust will be important to consider. We now have multiple crusts on solar aspects, and more are expected to come as spring continues. Dig down on these aspects and check this interface. A fracture line profile was done today on a possible skier triggered sz 3 avalanche from a few days ago in the Murray Moraines drainage on a N aspect at 2200m. The failure layer was a layer of facets/depth hoar down 100cm. This layer was producing moderate sudden collapses. Also the propagation on this layer was over 200m. This layer has been noted in snow profiles throughout the region and rockies so be sure to dig down before committing to a feature. The slope that avalanched took out and buried numerous ski lines. Forecasters are still avoiding being on any steeper or large features due to high levels of uncertainty within the snowpack.

Weather Summary

Sunday will be much like Saturday with a few cm of new snow forecast from convective flurries and winds will continue to be light out of the north. Temperatures will be around -4C during the peak of the day but that can quickly change when the sun comes out and solar radiation intensifies on the solar aspects.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Minimize exposure to sun-exposed slopes when the solar radiation is strong.
Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.

Problems

Persistent Slabs

Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.

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.