Avalanche Forecast

Archived

Mar 11th, 2025–Mar 12th, 2025

Alpine

Natural and human triggered avalanches likely.

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.

"Avalanche control planned on Wednesday at 1pm on the Canmore Hill(EEOR/Mt. Rundle)"

We still have a complex snowpack. Be conservative with route selection.

Confidence

Moderate

Avalanche Summary

Several loose dry avalanches to size 1 were observed. Natural activity seem to have slowed down a bit.

Snowpack Summary

The field team encountered around 45cm of settled snow from the recent storm overlying sun crust or the Jan 30th interface with the persistent slab. The field team also reported extensive whomphing and cracking where they travelled and were very conservative in their route selection and exposure to avalanche terrain. The issue right now is that we have the persistent slab sitting on weak facets and could be easily triggered. Then we have the recent wind slab that is resting on the persistent slab for even more additional load. In a nutshell, it would not take much to trigger the wind slab and then in turn trigger the persistent slab for a fairly large avalanche. It will take some time for this to heal.

Traveling off of established skin tracks at lower elevations is very challenging due to the weak nature of the snowpack.

Weather Summary

Wednesday:

A mix of sun, cloud, and isolated flurries. Day time high of -3c with moderate South winds.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Choose simple, low-angle terrain without steep convex rolls.
Avoid exposure to overhead avalanche terrain; avalanches may run surprisingly far.
Cautiously approach steep slopes that are open or sparsely treed.
Fresh snow rests on a problematic persistent slab, don't let good riding lure you into complacency.
Avoid steep, rocky, and wind-affected areas where triggering slabs is more likely.
Avoid shallow, rocky areas where the snowpack transitions from thick to thin.

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.

Loose Dry

Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.