Avalanche Forecast

Archived

Feb 26th, 2025–Feb 27th, 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 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.

Regions

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

Rising temperatures have professionals moving through avalanche terrain on tiptoe or simply avoiding it. Follow their lead by managing your exposure and avoiding consequential terrain.

Confidence

Moderate

Avalanche Summary

No new avalanches were reported on Tuesday.

Avalanche activity was reported to size 2 on Monday, from explosive triggers on east/southeast facing slopes. Avalanches occurred within the storm snow and on the buried weak layer from late January.

During the weekend's storm natural avalanche activity was observed to size 3.

Sustained warming may increase the reactivity of persistent slabs.

Snowpack Summary

By Thursday, a new melt-freeze crust should glaze the surface on solar aspects and below about 2000 m. The depth of affected snow should increase over the coming days, although crust recovery may be weak. This process will affect around 30 cm of settling recent snow, which has been affected by strong southwest winds at treeline and above.

A persistent weak layer of surface hoar or facets from late January is buried 40 to 60 cm deep (see photo below). This layer is expected to remain reactive as forecast warming tests the snowpack. The mid and lower snowpack is generally well settled.

Check out this MIN for recent conditions near Coleman.

Weather Summary

Wednesday Night

Partly cloudy. 20 to 30 km/h southwest ridgetop wind, increasing. Freezing level to 1200 m.

Thursday

Sunny. 20 to 30 km/h west ridgetop wind, up to 90 km/h in high alpine. Freezing levels rise to 2200 m, treeline temperature 2 °C.

Friday

Sunny. 20 to 30 km/h southwest ridgetop winds, easing. Freezing level to 2500 m. Treeline temperature 5 °C.

Saturday

Sunny. 20 to 35 km/h west ridgetop wind. Freezing level to 2800 m. Treeline temperature 6 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Avoid freshly wind-loaded features, especially near ridge crests, rollovers, and in steep terrain.
Even brief periods of direct sun could produce natural avalanches.
Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
Avoid exposure to overhead hazards when solar radiation is strong.

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.

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.