Avalanche Forecast

Archived

Apr 1st, 2025–Apr 2nd, 2025

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.

If the storm brings more snow than forecast, then the avalanche hazard will increase from the posted one. Deeper weak layers are still a concern in the snowpack. Natural avalanche activity has tapered, but human triggering remains likely at upper elevations.

Confidence

Moderate

Avalanche Summary

2 size 2 solar triggered avalanches were observed today on an East aspect at higher elevation.

Snowpack Summary

The forecast calls for 15-25cm of snow with light winds. This new snow will rest on the previously settled snow which includes a sun crust on solar aspects. Take the time to evaluate this bond between the new snow and the crust. At treeline, an average of 30-40cm of recent snow overlies the Mar 28 crust. This crust is 10cm thick at valley bottom, and 5cm thick at treeline, which easily carries the weight of a skier. Take the time to monitor the presence of this crust; if it is not there, then there could be a higher likelihood of triggering the basal facets. The Jan 30th layer buried 60 to 100cm deep is still a concern. It could become active with intense heating (daytime temps and/or solar input), and it is also problematic on northern aspects at higher elevations and in shallow snowpack areas. Human triggering is possible to likely in these areas. Forecasters continue to have low confidence in the snowpack due to an exceptionally weak base with dense slabs over top.

Weather Summary

Snow starting Tuesday evening and is expected to last until Thursday. After that, expect sun and hot temperatures.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Be aware of the potential for loose avalanches in steep terrain where snow hasn't formed a slab.
Keep in mind that human triggering may persist as natural avalanches taper off.
Avoid shallow snowpack areas, rocky outcrops, and steep terrain where triggering is most likely.

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.

Loose Dry

Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.