Avalanche Forecast

Fair

A ridge of high pressure continues to be the dominate weather feature for the next three days. Tuesday should see a mix of sun and cloud, freezing levels around 500m, and light NW alpine winds. On Wednesday, an above-freezing layer (AFL) of air will form over the interior. This layer is expected to sit between at around 2500m elevation in the Purcells. Alpine winds should remain light and sky should be mostly sunny with cloudy periods. The AFL persists on Thursday but should break down by Thursday afternoon. Thursday should see a mix of sun and cloud, and alpine winds are forecast to be moderate from the SW. The next weather system is expected for Thursday night or Friday.

No new avalanches were reported on Sunday. On Saturday, ski cutting produced a size 1 avalanche with a depth of 25cm. This was reported to have released on the mid-Dec surface hoar layer. Natural avalanche activity is not expected on Tuesday but remains possible (isolated), especially on solar aspects when the sun is out. A small avalanche could trigger a larger persistent slab. Skier triggering a persistent slab avalanche remains possible for the foreseeable future.

There is a lot of variability in last week's storm snow amounts across the region which is likely affecting the reactivity and the ability to trigger the mid-Dec surface hoar layer which sits below. The West and South have received up to 60 cm of storm last week which was quickly followed by high freezing levels and warm air up into the alpine which has resulted in a breakable surface crust. The North and East of the region have had 20-30 cm of cold dry new snow which has since been redistributed into ageing wind slabs, while large surface hoar is growing in sheltered areas. Recent snowpack tests on the West side of the range produced easy resistant results down 25 cm in the recent storm snow, and moderate to hard but sudden results down 80-90 cm on buried surface hoar sitting on a crust.