Avalanche Forecast

Archived

Mar 19th, 2024–Mar 20th, 2024

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

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 unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

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

Some light snow amounts to freshen up the landscape.

Confidence

Moderate

Avalanche Summary

No new avalanches have been reported but there are lots of signs of recent activity from the weekend.

Snowpack Summary

Expect to find the new snow(5-10cm) lying on top of an extensive frozen crust at all elevations, especially on solar aspects. This crust is providing strong bridging over any weak layers. On the shady aspects, there are older lingering surface wind slabs under this new snow that one should pay attention to. Both the persistent slab and the deep persistent slab could still be triggered on steep open alpine features. Take the time to dig and investigate these buried layers. You might see some sluffing in steep terrain with this new snow.

Weather Summary

Snow and slight cooling is the recipe. This next weather system seems to have stalled a bit but there is hope. Models are showing 5-10cm for Wednesday with light to moderate SW winds. Alpine temperatures will climb to -1c. Freezing level is expected to be 2100m. More cooling on Wednesday night with snow on Thursday.

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.

Problems

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.