Avalanche Forecast

Archived

Mar 7th, 2026–Mar 8th, 2026

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 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, human triggered possible.

Regions

Dogtooth, East Purcell.

A persistent weak layer remains the primary concern - stick to conservative terrain free from overhead hazard.

Watch for new and reactive wind slabs forming at upper elevations.

Confidence

Moderate

We are confident that there are persistent slabs in the snowpack, but uncertain about how likely they are to trigger.
We are uncertain due to the variability of wind effect on the snowpack.

Avalanche Summary

On Thursday, two large natural wind slab avalanches and a very large explosive-triggered persistent slab were reported from the northern part of this region.

On Friday, one small persistent slab avalanche was triggered on a northwest facing slope, below treeline.

Snowpack Summary

Light snow accompanied by strong west wind has likely built small wind slabs treeline and above. Below this, a new surface hoar/surface crust layer has been buried.

A persistent weak layer of surface hoar or crust is buried 40 to 60 cm, with deeper snowpacks like the Dogtooth Range, reporting this layer up to 100 cm deep. While reports of persistent slab avalanche activity has tapered, the snowpack structure remains a concern.

The mid and lower snowpack are generally well settled. In shallow snowpack areas, large facets or depth hoar are present at the bottom of the snowpack.

Weather Summary

Saturday Night
Mostly cloudy. 4 to 10 mm of precipitation as snow or rain at treeline. 80 km/h west ridgetop wind. Treeline temperature -1 °C. Freezing level 2100 m.

Sunday
Mostly cloudy. 5 cm of snow. 70 km/h west ridgetop wind. Treeline temperature -3 °C.

Monday
Mix of sun and clouds. 3 cm of snow. 40 km/h west ridgetop wind. Treeline temperature -9 °C.

Tuesday
Mostly sunny. 1 cm of snow. 30 km/h west ridgetop wind. Treeline temperature -12 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Watch for signs of instability like whumpfing, hollow sounds, shooting cracks, or recent avalanches.
Avoid shallow snowpack areas, rocky outcrops, and steep terrain where triggering is most likely.
Be aware of the potential for remote triggering and large avalanches due to buried surface hoar.
Watch for newly formed and reactive wind slabs as you transition into wind-affected terrain.

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.