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 possible, human triggered probable.

Regions

Kananaskis, Bow Valley, Highwood Pass, North 40, Spray - KLakes.

Conservative terrain choices are imperative with the current snowpack conditions. Wind slabs are reactive to human triggering. Choose low angle slopes and avoid overhead hazard.

Confidence

High

Avalanche Summary

Good visibility today revealed evidence of a widespread naturally triggered slab avalanche cycle up to size 2.5 at Alpine and Treeline elevations in the past 24 to 72hrs. Forecasters observed cracking and whumpfing today indicating a snowpack ripe for human triggering. Finally, a "goat accidental" was observed on a steep south aspect at 2200m. The goat was traversing a slope and triggered a size 2 slab avalanche 10-30cm thick. There was no involvement, as the goat was observed traversing slopes adjacent to the avalanche immediately following the event.

Snowpack Summary

5cm of new snow fell in the past 24hrs. Winds have heavily scoured westerly aspects. All S, E and N aspects have wind slabs at Alpine and Treeline elevations. Forecasters observed cracking and whumpfing today with the failures noted down 50cm on average. This coincides with the persistent weak layer of the Jan 30th facet/sun crust/ dense wind slab layer. At lower elevations there is also a storm slab or "settlement slab" that overlies the Jan 30th layer. All elevations show snowpack conditions that are sensitive to human triggering. Travelling at lower elevations involves ski penetration to ground if you leave any established trail.

Weather Summary

Thursday will be a mix of sun and cloud with temperatures near -3C for the high. Winds will be extreme topping out near 130km/h from the SW. No new snow is expected. Freezing levels could climb as high as 2400m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Avoid steep terrain, including convex rolls, or areas with a thin, rocky, or variable snowpack.
Wind slabs are most reactive during their formation.
Be careful as you transition into wind-affected terrain.
Keep in mind that human triggering may persist as natural avalanches taper off.
Make conservative terrain choices and avoid overhead hazard.

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.

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.