Avalanche Forecast

Archived

Apr 20th, 2026–Apr 21st, 2026

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 unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

Dogtooth, East Purcell, West Purcell.

Watch for changing conditions as you change aspect and elevation.

The highest avalanche danger will be on wind-loaded slopes, and steep slopes seeing intense spring sun.

Confidence

Moderate

We are uncertain due to a limited number of field observations.

Avalanche Summary

On Sunday, southeast of Glacier National Park, several large (size 2) loose wet avalanches were reported on steep slopes facing the sun.

In a similar area on Saturday, a small (size 1) remote human triggered avalanche was reported on a steep, wind-loaded feature.

Please consider submitting a MIN to let us know what you're seeing out there.

Snowpack Summary

Sun and rising freezing levels will turn snow moist during the day, warm temperatures overnight will likely prevent a strong crust from forming.

At higher elevations, 20 to 40 cm of recent snow sits on moist snow below treeline or a hard melt-freeze crust in the alpine. Some areas may have facets on this crust; field data is limited, so investigate in your area.

A thick crust from mid-March is 30-80 cm deep, which extends up to about 2400 m. Near Invermere, a weak layer of facets may be found above this crust.

Check out this Conditions Update for tips on managing the current spring conditions.

Weather Summary

Monday Night

Clear skies. 40 km/h west ridgetop wind. Treeline temperature 5 °C. Freezing level 3000 m.

Tuesday

Sunny. 35 km/h southwest ridgetop wind, dropping off to 15 km/h through the day. Treeline temperature 6 °C. Freezing level rising to 3200 m.

Wednesday

Mix of sun and clouds. 1 to 5 mm of rain at treeline. 20 km/h west ridgetop wind. Treeline temperature 3 °C. Freezing level 2700 m.

Thursday

Mix of sun and clouds. 5 to 10 cm of snow. 30 km/h northwest ridgetop wind. Treeline temperature -5 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Be alert to conditions that change with elevation, aspect, and exposure to wind.
Avoid lee and cross-loaded slopes in the alpine.
Avoid steep, sun-exposed slopes when the air temperature is warm or when solar radiation is strong.
Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Problems

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.

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.

Cornices

Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.