Avalanche Forecast

Archived

Mar 8th, 2023–Mar 9th, 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.

Good skiing can still be found in sheltered areas. Generally a weak snowpack, approach all overhead hazard and avalanche terrain with caution. Check out this fresh size 3 avalanche at: https://www.instagram.com/kananaskissafety/

Confidence

Moderate

Avalanche Summary

One new natural cornice triggered avalanche that was about 12 hours old in the Burstall Pass area. Check out the video and description at: https://www.instagram.com/kananaskissafety/

Snowpack Summary

The forecasting crew went back to Burstall Pass and were surprised by the large avalanche. The wind slabs in the top 25cm are slowly gaining strength but still reactive to large loads. Generally a weak snowpack that will remain for the rest of the year. At most elevations, the bottom half of the snowpack is made up of facets. The alpine has great variability in snow depth. Cornices have started to be on our radar, choose routes carefully. Have a look at the avalanche summary.

Weather Summary

Thursday will start off with a mix of sun and cloud and -20c. The clouds will roll in during the day and flurries will begin in the afternoon. Temperatures are expected to climb up to -8c, along with moderate SW winds.

Friday

The weather models for Friday are not all in agreement but they all talk about snow. Some models are talking about 5cm and others are up to 20cm. Stay tuned.

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.