Avalanche Forecast

Archived

Mar 21st, 2024–Mar 23rd, 2024

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

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

It appears the new snow is bonding well with the early spring crust. Good skiing can be had, but limit exposure to overhead hazards until we get a better handle on overall conditions.

Confidence

Moderate

Avalanche Summary

A few loose dry avalanches were noted. All involved storm snow only.

Snowpack Summary

20-40cm of new snow has fallen with higher accumulations near the divide and the southern Spray. The sun did try to make the odd appearance today which immediately softened the snow and promoted settlement. Like two peas in a pod, the Mar 20th crust seems to be bonding well with the new snow. It feels like the heat is still being released from the snowpack as the new snow is falling. A very different scenario from the last crust experience we endured. It was hard to tell for sure today, but its safe to assume there are fresh alpine windslabs at higher elevations.

Weather Summary

Flurries will continue overnight and give a few more centimeters of fresh snow. As the snow fades, the temperatures will fall to -12 by 8am. Daytime high will be -3. Skies may temporarily clear in the late afternoon. Winds will be light for most of the day, but expect some swirling winds and snow transport near alpine ridges.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Conditions may have improved, but be mindful that deep instabilities are still present.
Fresh wind slabs will likely form throughout the day, diligently watch for changing conditions.

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.