Avalanche Forecast

Archived

Mar 18th, 2023–Mar 19th, 2023

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Regions

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

Nice skiing is being found in sheltered locations. Enjoy the sunny weather, be mindful of your overhead as you work though terrain. The sun continues to pack a punch!

Confidence

Moderate

Avalanche Summary

On a road patrol today, No new avalanches were observed. Natural triggering has tapered off, but human triggered avalanches remains possible.

Snowpack Summary

Last week's storm snow has settled into a pleasant 20cm of settled snow. So far the winds haven't made an appearance which means we've been spared a widespread wind slab problem. There are some wind slabs still lurking in the alpine, but they generally seem to be high and in steep alpine terrain. But there is a catch (when isn't there?), the March 12th crust (solar) or facet (polar) layer is a slippery one and it doesn't need much of a cohesive surface layer to pose a problem. Unsupported alpine and treeline terrain is still concerning. The mid to lower pack remains variable, in every sense of the word. The depth changes dramatically on elevation, and the supportiveness of it seems to change at the drop of a hat. Thin spots and rocky areas are still a likely place to trigger the deeper problem layers.

Weather Summary

Sunday will bring partially sunny sky's with Light SE winds. Freezing @ 1900m

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
Cornices become weak with daytime heating or solar exposure.

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.