Avalanche Forecast

Archived

Mar 17th, 2025–Mar 18th, 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.

We will remain at an elevated danger rating for the time being. The upper snowpack continues to settle and strengthen, but this sits upon problematic weak layers that are not to be trusted.

Confidence

Moderate

Avalanche Summary

In Canmore the first bowl on EEOR naturally avalanche to size 3 on a NE aspect in the alpine. This propagated across the whole bowl and ran well in to the gully out of view. Suspect the trigger was wind loading at ridge height.

Mt Buller avalanche paths also had a large Size 3 natural that propagated across the whole feature. Suspect cornice trigger, but unconfirmed.

Snowpack Summary

New snow heights vary between 60cm-100cm. Winds have been very light, however have started to pick up this afternoon. This snow is settling rapidly with the warmer temps. This new snow is overlying a crust from early March on the solar aspects and a mixture of facets and hard windslabs on more polar aspects. Windslabs have developed within the recent snow 10-30cm thick that are reactive to skier traffic. Deeper in the snowpack the problematic Jan 30th facet interface is down 60-90cm and commonly producing sudden collapse sheers at this interface. A failure in the windslabs will likely step down to the Jan30th interface. 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.

Weather Summary

Tuesday: A mix of sun and cloud with isolated flurries. Alpine temperatures of -12

20km/h West wind

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.