Avalanche Forecast

Archived

Dec 26th, 2023–Dec 27th, 2023

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

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

Good skiing exists where the wind has not disturbed the surface snow. The winds have been in the strong to extreme range for the last couple days. Caution immediate Lee's and cross loaded features where windslabs may be present.

Confidence

Moderate

Avalanche Summary

Teams travelled in the Murray moraine valley today. Evidence of the early December avalanche cycle is still clearly visible. Continuous sluffing off steep rocky alpine features today with the wind. No slab activity was observed.

Snowpack Summary

The snowpack, where not affected by the wind is holding good quality skiing on low angle planner slopes. The early December crust found about 20-35cm down is keeping the ski's from diving down into the deeper weaker snowpack. In the short this crust is providing us with a good supportive snowpack to travel and ski on. In the long term however this will likely be the main sliding interface for avalanche activity. Continue to dig in the snowpack and observe the bond of the various crust/ snow interfaces. No snowpack summary is complete without a quick blurb about the deeper, basal problems. Depth hoar (extremely loose snow), is out there lurking at the bottom. Thick to thin transitional areas are the likely places for us to disturb it and cause a big avalanche.

Weather Summary

Tuesday brought strong to extreme winds at ridge top, Wednesday will see similar weather. With cloudy sky's and very strong winds from the SW. Day time highs will hover around +1 with freezing levels at 2000m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Wind slabs are most reactive during their formation.
Approach lee and cross-loaded slopes with caution.
Stay off recently wind loaded slopes until they have had a chance to stabilize.

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.

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.