Avalanche Forecast

Archived

Dec 21st, 2023–Dec 22nd, 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.

Some snow and strong winds will create new wind slabs. Approach avalanche terrain with caution.

Confidence

Moderate

Avalanche Summary

Nothing to report.

Snowpack Summary

Summary of the snowpack:

2100m: The height of snow is around 45cm and has a prominent crust halfway up the snowpack and produced easy test results on the compression test(CTV). The lower half of the snowpack consisted mostly of facets and was very weak.

2250m: The height of snow was around 90cm and felt generally stable. The December rain crust was prominent and found just above the mid mark of the pack and was welded in place.

The warmer temperatures this Fall are keeping the temperature gradient small in the snowpack and is having a positive effect on it over the long term. But this still does not change the fact that we need more snow:)

The stronger winds and up to 10cm of snow on Friday has the potential to create new wind slabs at treeline and above. Be alert to changing conditions.

Weather Summary

Friday will bring flurries and 5-10cm of snow. The alpine high will be -3c with strong SW winds. Be alert of changing conditions at tree line and above.

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.
Avoid rock outcroppings, convexities, and anywhere the snowpack is thin and/or variable.

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.

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.