Avalanche Forecast

Archived

Apr 8th, 2025–Apr 10th, 2025

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Below Threshold.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Below Threshold.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Below Threshold.

Regions

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

10cm of recent snow has been moved around by moderate winds at upper elevations. Dry snow can be found on northern aspects. Pay close attention to the affect of the solar radiation, freezing levels as well as overnight freezes with regards to planning your trips. These three factors will affect stability throughout the day.

Confidence

Moderate

Avalanche Summary

The forecasting was out of the field by 11am. Some sluffing began around 10am on E and SE aspects. The cliffs on these aspects also became wet around 10am.

Snowpack Summary

Up to 10cm of snow fell at treeline over the past 24hrs. This snow is overlying a thick temperature crust on solar aspects that carries the weight of a skier. East and west aspects have more of a breakable crust and only pure north aspects have dry snow. The March 28th crust is down 20-50cm and found as high as 2600m. Above this elevation on the northern aspects there is still some uncertainty with regards to the basal layers so continue to be curious at this elevation. Some windslabs exist in the alpine at upper elevations.

Intense solar radiation will decrease stability especially if there was a poor freeze overnight due to a high freezing level.

Weather Summary

A few more cm's of snow may fall overnight but amounts are not forecast to be significant. Wednesday will be a mix of sun and cloud with a freezing level around 2200m and moderate winds out of the west in alpine areas. Alpine temperatures will be around -2C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Avoid shallow snowpack areas, rocky outcrops, and steep terrain where triggering is most likely.
Avoid exposure to overhead hazards when solar radiation is strong.
Limit exposure to steep, sun exposed slopes, especially when the solar radiation is strong.

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.