Avalanche Forecast

Archived

Jan 2nd, 2023–Jan 3rd, 2023

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely.

Regions

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

Avoid large open alpine terrain and overhead hazard. Best to stay on low angled and well supported terrain. The snowpack is weak and there is the potential to trigger avalanches from below.

Confidence

High

Avalanche Summary

A size 1 slab occurred in the last 24 hours on a NE aspect on Mt. Black Prince near 2600m. There have been several skier involved avalanches West of our region in the last week but with a similar snow pack to us. Check out the MIN on avalanche.ca

Snowpack Summary

This a hard snowpack description to write. It is hard to convey the seriousness of a snowpack in a short written description. We are essentially sitting on a house of cards known as the Nov 25 depth hoar layer. In a nutshell, the lower third of our snowpack is the worst we've seen in a very long time. It is a 30-40cm thick layer of rotten sugar snow. It's bad, and its everywhere. The upper 2/3 of the snow pack is slightly denser snow made up of several layers. Within this denser snow we have another persistent layer we know locally as the Dec 17th surface hoar. While not as bad as the Nov 25, this layer is also reacting in tests as it's only down 20-30cm. We have noted a fair bit of regional variability in the depths of these layers layers, be sure to dig and locate them in your terrain of choice. The forecasters are approaching all terrain conservatively and do not have much confidence in the snow pack.

Weather Summary

A high pressure system has settled into the region with mostly clear skies and no snow. Temperatures will range from -17c in the morning and warm up to -6c by mid day. Winds are forecast to be Light from the South.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
Be aware of the potential for surprisingly large avalanches due to deeply buried weak layers.
If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.

Problems

Deep Persistent Slabs

Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.

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.