Avalanche Forecast

Archived

Mar 20th, 2025–Mar 21st, 2025

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

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

Recent snow and strong southwest winds may form fresh wind slabs reactive to human triggers.

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

Confidence

Moderate

Avalanche Summary

No new avalanches were reported in this region on Wednesday.

Snowpack Summary

Up to 40 cm of recent snow and southwest winds formed slabs that may still be 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 down 50 to 100 cm. Rocky slopes with a convex shape on northerly and easterly facing aspects at treeline and above are the most likely places to trigger this layer.

Weather Summary

Thursday night

Cloudy with flurries, 0 to 5 cm of snow. 20 to 30 km/h southwest ridgetop winds. Treeline temperature -11 °C. Freezing level valley bottom.

Friday

Cloudy with 3 to 10 cm of snow. 30 to 40 km/h southwest ridgetop winds. Treeline temperature -3 °C. Freezing level 1700 m.

Saturday

Mix of sun and cloud. 10 to 20 km/h west winds. Treeline temperature -4 °C. Freezing level 1600 m.

Sunday

Mostly cloudy. 30 to 40 km/h southwest ridgetop winds. Treeline temperature -1 °C. Freezing level 1900 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Watch for newly formed and reactive wind slabs as you transition into wind-affected terrain.
Avoid steep, rocky, and wind-affected areas where triggering slabs is more likely.
If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
Be mindful that deep instabilities are still present and have produced recent large avalanches.

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.