Avalanche Forecast

Archived

Nov 28th, 2024–Nov 29th, 2024

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Regions

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

As winds pick up, slabs are growing and beginning to become more widespread. We may see new slabs build on top of older, weaker snow. Watch thin to thick transitions.

Confidence

Moderate

Avalanche Summary

Nothing new today, however there was a sz 2 noted in the MIN's that's worth a quick relay. It was on Wedge Peak (north slope), sz 2-2.5, appeared to be cornice triggered and went to ground.

Snowpack Summary

Changes are happening. Between wind and temperature changes we are seeing the addition of windslabs in the alpine and upper treeline and a general weakening of the lower elevation snowpack. A bit of a contrast for sure, but the different snow character is easy to see and predict. Valley bottom up to about 2300-2400 is weak with little structure in untouched areas. The Oct crust is still evident, however it is slowly breaking down. Above the 23-2400m mark wind transport is the name of the game. Windslabs, sastrugi and exposed rock are in plentiful supply.

Weather Summary

Treeline winds will increase slightly tomorrow with an expected speed of 50km. They'll be straight out of the west, with some slight variation in valley bottom. Our forecast says we can expect a few flurries, with only trace amounts of new snow. Temperatures will be steady all day at about -12.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Be careful with wind-loaded pockets, especially near ridge crests and rollovers.
Be aware of the possibility for full depth avalanches due to deeply buried weak layers.

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.