Avalanche Forecast

Archived

Mar 19th, 2025–Mar 20th, 2025

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

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.

Natural avalanches are still occurring. We will remain at an elevated rating for the foreseeable future.

Confidence

High

Avalanche Summary

1 size 3 slab avalanche occurred in the last 24 hours in the Pocaterra Ridge zone.

Snowpack Summary

Fresh wind slabs in the alpine were building on Wednesday and are expected to continue on Thursday. The top half of the snowpack is a 40-80cm dense slab that sits on top of 40-80cm of depth hoar and facets. This interface between the two is the January 30th interface and has produced repeatable sudden collapse test results. This is what is causing all of the bigger avalanches. Unfortunately we will be in this pattern for the foreseeable future.

More Detail: Wind slabs exist in the alpine and if triggered, could easily step down to the January 30 layer(facets). The March 3 layer is mostly a sun crust on solar aspects and can be found down about 50cm. Conservative terrain choices that avoid being attached to a bigger piece of terrain is the way to go right now. Forecasters are sticking to low angle, well supported terrain only. The profile below shows you what you will find if you take the time to dig.

Weather Summary

Thursday: Mostly cloudy with up to 6cm of snow. Winds will be moderate from the West in the morning and increase to strong in the afternoon. Temperatures in the alpine are expected to climb to -4c.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Fresh snow rests on a problematic persistent slab, don't let good riding lure you into complacency.
Avoid exposure to overhead avalanche terrain; avalanches may run surprisingly far.
Remote triggering is a big concern, be aware of the potential for wide propagations and large, destructive avalanches at all elevations.

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.