Dashboard Regions Weather Stations Radar Alerts Glossary
Contact About
Log In

Register for an account and never miss a forecast again!

Register

Avalanche Forecast

Archived

Mar 23rd, 2023–Mar 24th, 2023

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.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.

Regions

Banff Yoho Kootenay, Banff, East Side 93N, Kootenay, Lake Louise, LLSA, Sunshine, West Side 93N, Field.

Despite the lack of avalanche activity over past two days don't forget about the persistent layers in the mid and lower pack. Conservative terrain choices are still advised.

Confidence

Moderate

Avalanche Summary

Several wet loose avalanches up to size 2 have been reported out of steep solar aspects over the past two days. On Tuesday, there was a deep persistent slab reported on Observation peak and Sunshine patrol reported observing two size 2.5 deep slabs in the surrounding backcountry. .

Snowpack Summary

Surface sun crusts exist to ridgetop on solar aspects and to 2000 m on shady aspects. The middle of the snowpack holds several crust layers that has produced numerous natural slab avalanches over the past 10 days. The base of the snowpack is weak, unconsolidated depth hoar in almost all areas.

Weather Summary

Friday - A trough of low pressure over the Alberta Rockies will produce cloudy skies and scattered flurries that will increase through the afternoon. Accumulations in the 1-5 cm range. Ridge-top winds will be light and the freezing levels only expected to rise to 1300 m.

Terrain and Travel Advice

  • Uncertainty is best managed through conservative terrain choices at this time.
  • Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.

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.