Avalanche Forecast

Archived

Mar 2nd, 2024–Mar 3rd, 2024

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural and human triggered avalanches likely.

Below Treeline

Natural and human triggered avalanches likely.

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural and human triggered avalanches likely.

Below Treeline

Natural and human triggered avalanches likely.

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural and human triggered avalanches likely.

Below Treeline

Natural avalanches possible, human triggered probable.

Regions

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

Good time to avoid all avalanche terrain and head to a local resort.

Avalanche control is planned again on East end of Mt. Rundle & Mt. Buller avalanche control zone on Sunday Feb 3rd. The spray road remains closed from Grassi lakes to Goat creek parking lot.

A Special Public Avalanche Warning is in effect. Click the red SPAW link for details.

Confidence

High

Avalanche Summary

A good Min report found: Here

Avalanche control was attempted once again on East end of Mt. Rundle, poor visibility all day stopped the team from accessing the high targets. A good clean out however on the backside of Three sisters showed slab properties and the new snow moving quickly.

Snowpack Summary

60-90cm of recent snow is now overlying the Feb 3rd crust complex. Storm slabs and wind slabs can be expected in this new snow which will be easy to trigger with a skiers weight. A weak layer of faceted crystals also exists above and below this crust that has been producing moderate sheers. This new snow is beginning to overload this layer and cause a natural avalanche cycle. The November basal facets are alive and well and back on our radar as the February 2 rain crust is deteriorating and not locking in the weaknesses below as it once did. Skier weight has now been able to break through the Feb 2 rain crust in some places, which means that the basal facets can now be more easily affected.

This is a good time to avoid all avalanche terrain

Weather Summary

Sunday will bring partially sunny skies and a day time high of -14. Winds will be light out of the West.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Avoid exposure to overhead avalanche terrain, avalanches may run surprisingly far.
Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.

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.

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.