Avalanche Forecast

Archived

Mar 15th, 2025–Mar 16th, 2025

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 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.

New snow & wind are building reactive slabs.

Stick to simple low angle terrain and avoid overhead hazard.

Confidence

Moderate

Avalanche Summary

On Friday, a few small (size 1-1.5) natural and rider-triggered avalanches occurred near Castle Mtn.

On Thursday, two notable cornice failures in the northern Elk Valley produced slabs on northeast facing ridges that stepped down to the persistent weak layer. Numerous small size 1 wind slabs and loose dry avalanches were observed in the Crowsnest, as well as size 2 wind slabs by Castle Mtn.

Snowpack Summary

10 to 20 cm of snow accumulated over the last few days and formed wind slabs at upper elevations. Up to 20 cm of new snow combined with strong southwest winds is forecast to fall overnight and through Sunday. This is expected to create reactive new storm slabs, especially on wind-loaded north and east facing slopes near ridgetops.

A persistent weak layer of surface hoar or facets from late January is currently buried 40 to 80 cm. 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

Saturday Night

Cloudy with 4 to 10 cm of snow. 30 to 50 km/h southwest ridgetop wind. Treeline temperature -9 °C.

Sunday

Cloudy, with 5 to 10 cm of snow. 30 to 50 km/h southwest ridgetop wind. Treeline temperature -2 °C. Freezing level rising to 1700 m.

Monday

A mix of sun and cloud. 25 to 35 km/h west ridgetop wind. Treeline temperature -4 °C. Freezing level rising to 1500 m.

Tuesday

Partly cloudy, with flurries up to 2 cm. 20 to 30 km/h west ridgetop wind. Treeline temperature -5 °C. Freezing level rising to 1500 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Watch for fresh storm slabs building throughout the day.
As the storm slab problem worsens, the easy solution is to choose more conservative terrain.
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.

Problems

Storm Slabs

Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.