Avalanche Forecast

Archived

Jan 1st, 2023–Jan 2nd, 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.

This is a year to remain disciplined with a very conservative approach to terrain. The current snowpack is very weak with the potential for large destructive avalanches, and this condition is unlikely to change in the short term. Stick to low angle, well-supported terrain and avoid overhead hazard.

Confidence

High

Avalanche Summary

No new avalanches observed or reported in the last 24 hours. A serious skier-triggered avalanche accident occurred yesterday in Yoho National Park to the West of us (check out the MIN on avalanche.ca). This is notable as they have a similar snowpack condition to our region.

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.

Weather Summary

High pressure moves into the region leading to dry conditions (again!). Alpine temperatures range from -5 to -10C with light winds on Monday. Not much change expected in the weather for the next few days.

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.