Avalanche Forecast

Archived

Dec 20th, 2023–Dec 21st, 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.

Now would be a great time to postpone your daily ski trip and visit your local Christmas Market. A snow globe might remind you of what a storm looks like. Warm and dry until at least Saturday; lots of time to hit the Market.

Confidence

Moderate

Avalanche Summary

Nothing to report.

Snowpack Summary

Temperatures have been hovering around zero at valley bottom for the last day or so. Treeline temps have been slightly cooler with -3 being the low at 2200m. Snow height at 2200m is hanging in there at 65cm at the weather station, but likely more than that in many areas. Factoring in wind transport, 80-100cm wouldn't be unrealistic in gullies and lee areas. The windslabs should be improving with the warmer temps, and we'd expect them to be less reactive as this balmy december draws to a close. The problematic deeper layers will see no change until we get some significant change in weather.

Weather Summary

This weather is getting ridiculous! As nice as it is to not be freezing off the important bits, it would be nice to get some snow. Take a deep breath or two, here's tomorrow's forecast:

No snow, temperatures between -4 and +1, light SW winds

There. I said it.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Approach lee and cross-loaded slopes with caution.
Avoid rock outcroppings, convexities, and anywhere the snowpack is thin and/or variable.
Watch for areas of hard wind slab on alpine features.

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.