Avalanche Forecast

Archived

Mar 19th, 2026–Mar 20th, 2026

Alpine

Widespread avalanches certain.

Treeline

Widespread avalanches certain.

Below Treeline

Widespread avalanches certain.

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

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

The biggest avalanche cycle of the season is underway now, with Highways 93 South and North closed through Saturday. Our recommendation is to stay out of the backcountry.

Mount Stephen Avalanche Closure Zone is CLOSED on March 20 for avalanche control.

Confidence

Avalanche Summary

A widespread avalanche cycle is underway with large natural avalanches running into the runout zones. We expect larger avalanches to occur on Thursday and Friday as the storm progresses.

Snowpack Summary

30-50 mm of precipitation has fallen since the storm began, which translates into roughly 50-70 cm of snow at higher elevations, combined with steady south winds of 60-100 km/hr. The rain line is about 2200 m. This storm is overloading the snowpack, and avalanches are releasing naturally persistent weak layers and potentially running on the ground at low elevations where the rain has turned the snowpack isothermal. This is the climax avalanche cycle of the winter.

Weather Summary

A major Atmospheric River is pumping the moisture directly through this region from now until Friday night. Temperatures are warm, with freezing levels forecast to range from 2200 to 2500 m; winds are Extreme with gusts exceeding 100 km/hr from the SW; and 30-80mm of precipitation will fall before the storm ends.

Terrain and Travel Advice

Avoid avalanche terrain during periods of heavy snowfall.
Avoid avalanche terrain during periods of heavy rain.
Very large and destructive avalanches could reach valley bottom.

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.

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.

Loose Wet

Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.