Avalanche Forecast

Archived

Dec 12th, 2022–Dec 15th, 2022

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Regions

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

As expected, today's field trip offered no change in our confidence. Keep those tails tucked and avoid exposure to bigger terrain. Its an odd year and it will require patience to wait until it improves.

Confidence

High

Avalanche Summary

Nothing new today.

Snowpack Summary

For such a shallow snowpack, we sure do have a lot to say about it! Right now we basically have 3 layers of concern. The upper half ranges from low density snow below treeline to reasonably stiff windslabs at treeline and above. The trouble starts with a thin layer that sits almost exactly at the mid pack line. It seems to be a different layer type from area to area, but it is consistently bad. Whether it's surface hoar or facets doesn't really matter. Regardless of the grain, its a touchy layer that is reliably failing with little to no load. Not great news right now. The bottom half of the snowpack is a thick layer of facets which also spells trouble. Lots of whumphing and cracking during our travels today.

Weather Summary

Overnight low of -20 with a day time high of -8. Clear skies for most of the day, with no snow expected. Ridge winds will be light to moderate out of the north.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Be especially cautious as you transition into wind affected terrain.
Avoid convexities, steep unsupported terrain and rocky outcroppings.
Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
Remote triggering is a concern, watch out for adjacent and overhead slopes.
Watch for areas of hard wind slab on alpine features.

Problems

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.

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.