Avalanche Forecast

Archived

Mar 24th, 2023–Mar 25th, 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.

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.

Uncertainty in weather forecasts is preventing a confident avalanche forecast. If we do get snow, expect a sudden increase in avalanche hazard. This forecast is based on a small accumulation of snow tonight and tomorrow and may be inaccurate if heavy snow does arrive.

Confidence

Moderate

Avalanche Summary

No new avalanches observed or reported over the past 24hrs.

Snowpack Summary

Very little change today. Our snow didn't arrive and temperatures barely broke zero degrees. Which means the crust will still be exposed and well frozen for tomorrow. We haven't seen any fresh windslab development or wind transport lately, always a good thing. The Mar 12th crust/facet interface is still triggerable in steep, wind prone areas and only down 20-40cm. Given the Mar 12 crust is only down 20-40cm, and nights are still long and cold, I'm asking myself if facets might be developing on top of it. They very well could be and its worth having a look to satisfy the curiosity. I'll have a look tomorrow and report back.

Weather Summary

Forecasts are still conflicting when it comes to snow amounts. It appears we won't be getting the 20-30cm initially forecasted, But never say never. It could happen yet. The most recent forecasts at the time of writing are calling for 5cm over night, which seems reasonable given the convective weather pattern we saw today. Saturday's winds will be light at most elevations, with summit heights in the moderate range. Temperatures? The day will cool and eventually settle at about -12.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Minimize exposure to sun-exposed slopes when the solar radiation is strong.
Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
Cornices become weak with daytime heating or solar exposure.

Problems

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.

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.