Cariboos

Snowpack conditions continue to be touchy at all elevations for rider triggered avalanches

Good - -1

Wednesday/Thursday: A ridge of high pressure building over the province will bring a short lived cool, dry spell. Ridgtop winds are moderate from the NW in the am, switching to W in the afternoon. Freezing levels will be valley bottom Wednesday, rising up to 1500m Thursday-back to valley bottom Thursday night. Friday: Light to moderate snow amounts for today (10-15cm). Strong westerly winds, and freezing levels valley bottom.

A rider triggered avalanche was triggered remotely 20m away. This was on a NE aspect at 2100m and was a size 2. Remotely triggered avalanches are an indicator of a very touchy snowpack. You need to be very aware and make observations while you travel in avalanche terrain at all elevations. Numerous natural avalanches up to size 2.5 occurred in the Cariboos on Sunday. They ran on all aspects above 1800m. Most of this avalanche activity has occurred on the early December surface hoar/facet/crust layer.

Some areas of the North Columbia (Cariboos) received up to 50cm of new storm snow over the past few days. The North and West Monashees received up to 60cms. Strong southwest winds and warm temperatures have created wind slabs on North through East aspects in the alpine and at treeline. The storm slab sits between 50-80 cms and have been naturally reactive. This layer is very touchy and rider triggers are likely. The East and South ranges of the North Columbias have been much drier. The new snow load continues to build faster in the northern ranges than in the southern and eastern ranges. The depth of the new storm snow above the various old surfaces is what is driving the danger ratings at this time. This is the mid December surface hoar/facet/crust interface. Some areas have a sun crust in the alpine on steep south and west aspects. There is a rain crust that is buried between 40-55 cm in some areas that reaches up to about 2200 metres. The mid-pack is reported as generally strong and well settled. Observers are still able to find the early November surface hoar layer that sits around 120-150cms down. This layer has not been reactive during the recent long dry spell. Tests show that it is getting harder to pull the snowpack apart at this interface. We may still see this layer become active again if we get the right combination of load and warm temperatures. The midpack is well settled. Going down deeper sits the interface between the snow that did not melt over the summer, the glacial ice, and the October rain event. At this point the interface remains dormant.