Avalanche Forecast

Archived

Mar 17th, 2025–Mar 18th, 2025

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

South Rockies, Akamina, Crowsnest North, Crowsnest South, Elkford East, Elkford West.

Up to 40 cm of recent snow and southwest winds formed slabs reactive to human triggers.

Avoid steep, rocky, and wind-affected areas where triggering slabs is more likely.

Confidence

Moderate

Avalanche Summary

On Sunday, a naturally triggered size 3 avalanche was reported on a northeast facing, large, steep, and convex slope in the alpine. The avalanche was observed from a distance and the type is unknown.

Additionally, several explosive triggered storm slab avalanches up to size 2 were reported on a variety of aspects in the alpine.

Snowpack Summary

Up to 40 cm of recent snow and southwest winds formed slabs reactive to human triggers.

In most areas, the storm snow rests on a melt-freeze crust, except for high elevation north and east facing slopes.

A persistent weak layer of surface hoar or facets from late January is currently buried 50 to 100 cm deep. It has been the cause of recent large avalanches, and remains reactive in snowpack tests. The greatest concern for this weak layer is on upper-elevation northerly and easterly slopes.

Weather Summary

Monday Night

Partly cloudy with isolated flurries, 0-3 cm snow, 10 to 20 km/h west ridgetop winds, treeline temperature -8 °C, freezing level valley bottom.

Tuesday

Mix of sun and cloud, 10 to 20 km/h west ridgetop winds, treeline temperature -7 °C, freezing level 1400 m.

Wednesday

Sunny, 20 to 30 km/h southwest ridgetop winds, treeline temperature -4°C, freezing level 1600 m.

Thursday

Cloudy with isolated flurries, 3-5 cm snow, 30 to 40 km/h southwest ridgetop winds, treeline temperature -4 °C, freezing level 1600 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Avoid steep, rocky, and wind-affected areas where triggering slabs is more likely.
Be mindful that deep instabilities are still present and have produced recent large avalanches.
Even brief periods of direct sun could produce natural avalanches.
Avoid steep, sun-exposed slopes when the air temperature is warm or when solar radiation is strong.

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 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.