Avalanche Forecast

Archived

Dec 8th, 2018–Dec 9th, 2018

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Regions

Lizard-Flathead.

Avalanches are most likely in alpine terrain where the snow feels stiff or slabby, especially on wind-affected slopes.

Confidence

Moderate - Due to the number of field observations

Weather Forecast

SATURDAY NIGHT: Increasing cloud, light wind, alpine temperatures drop to -15 C.SUNDAY: Mainly cloudy with chance of light flurries in the afternoon, moderate wind out of the southwest, alpine high temperatures around -6 C.MONDAY: Cloudy, moderate wind out of the west, alpine high temperatures around -4 C.TUESDAY: Flurries with 2-4 cm of snow, moderate wind out of the west, alpine high temperatures around -4 C.

Avalanche Summary

Recent avalanche activity has been limited to a few small wind slabs and loose dry avalanches mostly in steep alpine terrain.The last notable avalanche reported was a size 2 human triggered avalanche last Sunday in Cornice Bowl north of Fernie. It occurred on a northwest facing feature at 2300 m and ran on a November crust. There are good photos in this MIN report.

Snowpack Summary

Early season conditions prevail in this region with roughly 100 cm of snow in alpine areas and much less at lower elevations. Surface conditions range from soft power, to hard wind slab, and some sun crusts.The main concern is the snowpack is a combination of weak sugary snow and crusts in the bottom half of the snowpack. See the snow profile in our field team's MIN report here for a visual representation of the snowpack. The crust is most prevalent at and above treeline and is likely most problematic on north-facing features, especially those that are large and planar in nature.

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.