Avalanche Forecast

Archived

Apr 11th, 2024–Apr 12th, 2024

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Regions

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

Spring temperatures return for the week end. Expect an avalanche hazard roller coaster as our snow pack goes through two melt/freeze cycles.

We are approaching Spring like conditions. This means start early and finish early with your adventures. Check out what Spring conditions is all about at: https://avalanche.ca/spring-conditions

Confidence

High

Avalanche Summary

No new avalanches observed or reported today.

Snowpack Summary

Freezing levels crept up to about 2400m today. Crusts are still found on all aspects below 2400m, and higher on solar aspects. Wind slabs are found in alpine areas along ridgelines and in lee and cross-loaded features. Below treeline has turned into a Spring snowpack with a solid crust when it is cold and moist snow on solar aspects. Be aware of wet loose avalanches on solar aspects later in the day.

Weather Summary

Flurries starting tomorrow morning and running all day long. Only trace amounts expected. Winds will be light from the SW and occasionally gust to about 20km/hr at treeline. On paper, temperatures will approach zero, but in reality they will creep a bit higher than that. Especially if the cloud breaks up.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

The more the snowpack warms-up and weakens, the more conservative you`ll want to be with your terrain selection.
Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
Recent wind has varied in direction so watch for wind slabs on all aspects.
Use caution above cliffs and terrain traps where even small avalanches may have severe consequences.

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.

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.