Avalanche Forecast

Archived

Apr 8th, 2024–Apr 9th, 2024

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Regions

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

A touch of new snow and strong winds overnight could create some reactive, but thin wind slabs in the Alpine. Plan to start early and finish early, watch the changing snow conditions, especially on solar aspects if the sun does come out.

Confidence

High

Avalanche Summary

Several loose dry avalanches up to size 1.0 were observed in extreme terrain on N and E aspects Monday due to the very strong westerly flow. No slab avalanches were observed.

Snowpack Summary

Crusts are found on all aspects below 2400m, and higher on solar aspects. At treeline today 1 to 2cm of new snow sits on top of the crust. The crust is supportive to a skier, but not to foot traffic. Strong westerly winds today redistributed a lot of snow at upper elevations and wind slabs are found in alpine areas along ridgelines and in lee and cross-loaded features.

An important thing to consider at this time of year is the quality of the freeze overnight. Avalanche danger can change from low in the cool mornings to high in the hot afternoons. The timing of this change is important to monitor so plan you trips with these factors in mind.

Weather Summary

A brief storm Monday night and into Tuesday morning may bring 5cm of new snow with extreme westerly winds. Daytime temperatures Tuesday will be near -2C and freezing levels will reach 2200m.

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.

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.

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.