Avalanche Forecast

Archived

Feb 3rd, 2017–Feb 4th, 2017

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Regions

Kananaskis.

The new snow will pose a few problems while the snowpack adjusts. Loose dry avalanches, storm slabs and persistent slabs should be on your radar as avalanche problems. Also keep in mind that the snow will make thin areas hard to detect.

Confidence

Moderate - Intensity of incoming weather systems is uncertain

Weather Forecast

Snow. That's right, snow. Haven't heard that in awhile have ya? Not much at first, but as the week-end goes on we are expecting a total of 26cm. By tomorrow afternoon there may be up to 10cm. This will come in cold for the entire storm. A high of -15 is expected for tomorrow with temps falling by Sunday. Monday's low is -29! Winds will be light and from the southwest.

Avalanche Summary

Nothing new today.

Snowpack Summary

As of this afternoon snow has started to fall on the Spray Rd. Amounts are still small, but so far all indications are that we'll have 5cm by tomorrow morning. This snow will hide the widespread hardslabs in the alpine and windslabs at treeline. At the moment, there are multiple slabs within the snowpack to be concerned about. At treeline and alpine elevations, the bond between these slabs is suspect and not especially strong. The other layer we are watching closely is the deeper Nov 12 depth hoar/facet layer. This is down 80cm at treeline and worth investigating. This layer is widespread and won't adjust to a new snow load for some time.

Problems

Storm Slabs

Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.

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.