Avalanche Forecast

Archived

Mar 9th, 2023–Mar 10th, 2023

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Regions

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

Some snow is on its way. The snow pack is generally weak and conservative route selection is the best approach to a safe day out.

Confidence

Moderate

Avalanche Summary

No new avalanches were observed today but many of our neighbours have recently reported large avalanches, some of which have been triggered by cornices. Kananaskis Country have had several large natural avalanches in the last 5 days.

Snowpack Summary

Generally a weak snowpack. The surface wind slab at tree line and above is slowly gaining strength but is still producing planar results down 20cm from the surface. In our test profile near Tent Ridge today, the basal facets were found up to 80cm up from the ground. Further test results were occurring at the November layer interface about 40cm off the ground. Natural avalanches are possible and the consequences would be significant because any trigger would likely make the entire snow pack slide. If more snow falls in the Park than expected, along with strong winds, expect fresh wind slabs to form. Check out part 2 on how significant the month of March is on our present snow pack: https://www.instagram.com/kananaskissafety/

Weather Summary

Flurries are expected to begin near noon on Friday with snow amounts from 2-10cm depending on the weather model. Temperatures will range from -17c to -10c. Winds are expected to increase to strong from the SE by mid day.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Be aware of the potential for surprisingly large avalanches due to deeply buried weak layers.
Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
Pay attention to cornices and give them a wide berth when traveling on or below ridges.

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.