Avalanche Forecast

Archived

Mar 13th, 2025–Mar 17th, 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 unlikely, human triggered possible.

Regions

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

The snowpack is tricky right now and conservative terrain is the answer. Stick to low angle, well supported features and give the snowpack time to adjust to the new recent load.

Confidence

Moderate

Avalanche Summary

Continued evidence of last weeks cycle with avalanceh up to sz 3 are being observed. 2 new Sz 2 windslabs were observed in the Murrays Twins area initiating in a steeper SE alpine feature.

Two skiers reported a Skier accidental sz 1.5-2 avalanche to the south of black prince on a south east aspect treeline feature around 2300m. The suspected bed layer for this avalanche was the Jan30th interface.

Snowpack Summary

10-15cm of snow has fallen over the past 24hrs at treeline with generally light westerly winds. Over the past week up to 60cm has fallen and been settling under the influence of warmer temperatures. 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 non injury skier accidental avalanche in the Black Prince area was reported to field teams on Friday with the suspected interface being the Jan30th facets.

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

Winds will continue to be light over the next 24hrs with convective flurries adding 3-5cm of snow to the overall snowpack throughout the evening. Saturday will bring a mix of sun and cloud with daytime highs around -8C.

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.
Continue to make conservative terrain choices while the storm snow settles and stabilizes.
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.