Avalanche Forecast

Archived

Feb 28th, 2025–Mar 1st, 2025

Alpine

Natural and human triggered avalanches likely.

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 possible, human triggered probable.

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

Skyrocketing alpine temperatures and a rotten snowpack structure are a recipe for large natural avalanches. Saturday will be a great day to soak up the sun outside of avalanche terrain.

Confidence

Moderate

Avalanche Summary

Two size 2 wind slabs were targeted with explosives on Wednesday in the Castle area. They featured 10 - 30 cm crowns that were noted for containing three distinct wind slab layers from recent loading events.

On Monday, explosives control in the same area produced avalanches to size 2 on east/southeast facing slopes. These involved both storm snow and the buried late-January weak layer, which is expected to remain reactive during the ongoing warmup.

Snowpack Summary

A melt-freeze crust moist or snow now glazes the surface on solar aspects and potentially to mountaintop by Saturday afternoon. High overnight freezing levels mean crust recovery may be weak. This process will affect around 30 cm of settling recent snow, which has been redistributed by strong southwest winds at treeline and above.

The main feature of the region's overall shallow snowpack is a persistent weak layer of surface hoar or facets from late January now buried 40 to 60 cm deep (see photo below). This layer is expected to be increasingly reactive as warming tests the snowpack.

Check out this MIN for recent conditions in the Elkford area.

Weather Summary

Friday Night

Partly cloudy. 15 to 20 km/h west ridgetop winds, easing. Freezing level falling from 2200 m to 1700 m.

Saturday

Becoming sunny. 15 to 20 km/h west ridgetop wind. Freezing level to 3300 m, remaining high overnight. Treeline temperature 6 °C.

Sunday

Sunny. 5 to 10 km/h west ridgetop wind, shifting northeast. Freezing level falling from 3000 m to 2600 m. Treeline temperature 7 °C.

Monday

Cloudy with scattered flurries bringing less than 5 cm of new snow above 1500 m. 15 - 25 km/h northeast ridgetop wind. Freezing level 1600 m. Treeline temperature -1 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Make conservative terrain choices and avoid overhead hazard.
Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
Even brief periods of direct sun could produce natural avalanches.

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.

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.