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

Dec 11th, 2025–Dec 12th, 2025

Alpine
Natural and human triggered avalanches likely.
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

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

Avalanche control on Thursday produced many avalanches to size 3 (see avalanche summary). Human-triggered avalanches are likely for the next few days.

Confidence

Moderate

Avalanche Summary

Busy day for avalanches. Explosive control on Mount Whymper and Mt. Field produced many avalanches to size 3. Most were starting in the storm snow (~30-60cm), then stepping down to one of the deeper layers, likely the Nov. 22 crust/facets (~60-80cm). A few times, the bag hitting the slope triggered the slide. There was evidence of a widespread natural cycle to size 3.5 during the recent storm with similar layering.

Snowpack Summary

10-25cm over the past 36 hours, and 30-60+cm since Dec 7. This, combined with strong SW winds, has developed widespread wind slabs. 60-80 cm of snow sits over the Nov. 22 interface, which is a sun crust or facets. Further down, the Nov. 13 rain crust exists to 2100-2300 m.

Weather Summary

A cold start to Friday as the arctic air sneaks into the valley for a couple of days. -17 to -20C in the AM, warming to -9C with another 5-8cm of snow and moderate gusting strong winds in the alpine.

On Saturday and Sunday, we expect a warm-up with stronger winds.

For more info, click here for Environment Canada tables.

Terrain and Travel Advice

  • Watch for newly formed and reactive wind slabs as you transition into wind-affected terrain.
  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.

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.

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.

Loose Dry

Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.