Avalanche Forecast

Archived

Feb 25th, 2026–Feb 26th, 2026

Alpine

Natural avalanches possible, human triggered probable.

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 possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Regions

Purcells, Flathead, Lizard, Crawford, Moyie, St. Mary.

Wind slab formation has been extensive and could extend into openings below treeline.

Persistent slabs sitting on a weak layer of surface hoar remain possible to human trigger.

Confidence

Moderate

We are uncertain about how quickly persistent slabs are gaining strength.

Avalanche Summary

On Tuesday, a naturally triggered size 2 wind slab and numerous explosive triggered size 2 wind slabs were reported on north and east aspects in the alpine.

Numerous persistent slab avalanches up to size 3 were reported on all aspects and elevations over the weekend. They were triggered accidentally, naturally, and remotely.

See recent MIN reports here and here for further details.

Snowpack Summary

Up to 20 cm of recent snow accompanied by strong southwest wind has formed deeper deposits on north and east aspects. In sheltered terrain it will overlie a layer of surface hoar or a sun crust. The snow surface is expected to become moist on sun exposed slopes.

A couple concerning weak layers exist in the upper snowpack:

60 to 80 cm deep, there is a supportive crust on south-facing terrain. On north-facing terrain, this layer maybe a breakable crust or surface hoar.
The late January layer is buried 70 to 120 cm deep. It consists of a crust with facets or surface hoar above it.

The mid and lower snowpack is well settled.

Weather Summary

Wednesday Night
Cloudy. 60 km/h west ridgetop wind. Treeline temperature -7 °C.

Thursday
Cloudy. 3 to 15 cm of snow. 70 km/h southwest ridgetop wind. Treeline temperature -7 °C.

Friday
Mostly cloudy. 5 to 15 cm of snow. 60 km/h west ridgetop wind. Treeline temperature -5 °C.

Saturday
Sunny. 35 km/h west ridgetop wind. Treeline temperature -4 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Keep your guard up at all elevations. Wind slab formation has been extensive and could extend into openings below treeline.
Recent wind has varied in direction, so watch for wind slabs on all aspects.
Be aware of the potential for remote triggering and large avalanches due to buried surface hoar.
Watch for signs of instability like whumpfing, hollow sounds, shooting cracks, or recent avalanches.
In times of uncertainty, conservative terrain choices are our best defense.

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.