Avalanche Forecast

Archived

Dec 16th, 2022–Dec 18th, 2022

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

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

If you do head out over the next few days, bring extra equipment to help with the cold. The cold won't cause any immediate increase in avalanche hazard, but over a few days it will start to negatively effect the deeper layers. Good luck out there and don't forget the hot tea!

Confidence

High

Avalanche Summary

No new avalanches, but visibility was poor.

Snowpack Summary

Today's trip took us into the south access for Hero's knob/Sweet 16. Like the rest of the region, there isn't a lot of snow. We had 85cm at treeline and the odd pocket of 1m. What really caught our attention was the snowpack variability based on elevation. The surface hoar from last month is very prominent up to about 2100m. This layer will vary from area to area, but be sure to have a look for it as it is notable. The other general statement is how weak and poor the regional snowpack is. There is a theme of a somewhat settled upper snowpack resting on a foundation of facets and growing depth hoar. Where the snowpack failures occur seems to vary in depth, but the failures are very, very consistent in their character. They are failing fast, with little warning. It's easy to get caught up in the semantics of layer types and descriptions, but at the end of the day we have a nasty weak layer that is predictably failing. Do your homework, dig your holes and be sure you have a good grip on your local terrain before you commit to consequential terrain.

Weather Summary

In case you haven't heard yet, it's going to get cold in the next few days. Tomorrow isn't crazy cold, a morning low of -27 and an afternoon low of -28. But later in the week it will be in the -30's. Winds will be light for most of the day tomorrow, but the windchill will be annoyingly cold. As for snow, there may be a few centimeters coming, but not enough to make a difference.

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.

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.