Avalanche Forecast

Archived

Mar 6th, 2023–Mar 7th, 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 on low angled terrain. The snowpack has several weak layers which can produce large avalanches.

Confidence

Moderate

Avalanche Summary

Several natural avalanches that were 36-48 hours old were observed. This cycle of natural avalanches has been the theme this winter.

Snowpack Summary

Sheltered areas are still providing good skiing. The forecasting crew were out just East of Tent Ridge and found that the snowpack still has a lot going on. At tree line, the surface wind slab produced easy compression tests 25cm down. Then we got a moderate compression test at the top of the facet layer which was 100cm from the ground. The November surface hoar/facet layer was still producing moderate to hard compression tests which was 45cm off the ground. Not a very inspiring or confidence building snowpack. Be cautious approaching larger slopes. Solar radiation, and daytime heating can have a significant effect in March. One should be aware of exposure to slopes above while travelling below tree line.

Weather Summary

A pretty nice day is forecast for Tuesday with a mix of sun and cloud. The morning will start off cold at around -20c and then warm up to -8c. Winds are forecast to be Light from the West.

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.

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.