Avalanche Forecast

Good - -1

The weekend brings cool, dry, mainly sunny conditions as a ridge of high pressure remains over the region. Ridgetop winds from the northwest will be near 30km/h. Alpine temperatures steady at -9, expect a few flurries with freezing levels rising to 600m then dropping back to valley bottom. On Monday we may see milder conditions, and a westerly flow ahead of the next approaching cold front.

Being the start of December more backcountry operations are headed into the field. This means more information, and observations are making there way into our office. Thank you!There is still numerous avalanches occurring in the backcountry. Natural activity up to size 2.0, on various aspects above 2000m have been reported. As well, there are reports of rider triggered activity. On Thursday there was a large (size 3) rider triggered avalanche on a south east aspect at 2900m. The crown depth being 200cm and the slide running 800 vertical meters, over a kilometer. One of the people involved has sustained serious injuries. With the clear, sunny skies ahead don't be fooled. The snowpack is still touchy with weaknesses buried below. Please refer to the Forecaster's Blog for further information and suggestions help you make the right choices in the backcountry. As well, continue to follow our bulletins. We update everyday. Have a safe, fun weekend.

As we head into the weekend, backcountry travelers need to remain vigilant in the hunt for wind slabs. The strong to extreme southerly winds that persisted on Sunday have formed wind slabs on lee slopes, and terrain features. Winds are now blowing out of the north creating new wind slabs on reverse slopes. The snow depth is currently 200 - 250cm in the alpine. An early November surface hoar layer is buried around 150cm down. Triggering this layer is difficult, but test results continue to show sudden planer shears meaning that this layer has energy and wants to propagate. This is the classic low probability/high consequence avalanche problem. Mid-November storms produced a widespread avalanche cycle on this layer.On Thursday Nov. 24th we received reports from the Southern Selkirks of a widespread avalanche cycle. Large avalanches released near the ground on several aspects. The majority of these observations were from north-east facing slopes. This was likely the result of an early season rain crust that until last week was bridging over weak basal facets at the ground. Last weekend's storms pushed it to the breaking point resulting in an avalanche cycle. Very little is known about this rain crust, especially when it comes to distribution. Is it limited to the Southern Selkirks, or is it more widespread?Last weekend's warm storm deposited 40-60cm's of snow which has been pretty heavy at all but the highest alpine elevations as freezing levels rose to 1800m. Rain also fell 1500m and below leaving us with a rain crust. Mid week up to 30cm fell on top of this rain crust. this crust. We'll need to watch for faceting above and below this crust as we move forward.