Avalanche Forecast
Regions: Purcells.
Confidence
-
Weather Forecast
MONDAY NIGHT: Snow starting in the afternoon with trace accumulations in the south and up to 10 cm of new snow overnight in the north, wind increasing to moderate from the southwest, temperatures increasing overnight.TUESDAY: Snow continuing throughout the day with another 5-15 cm, moderate southwest winds, freezing level rising with alpine temperatures around -2 in the north and -5 in the south.WEDNESDAY: Flurries with another 5-10 cm of new snow, moderate south winds, freezing level rising to around 1500 m throughout the region.THURSDAY: Cloudy with isolated flurries, moderate southwest winds, freezing level around 1500 m.
Avalanche Summary
Avalanche reports from the weekend included several size 1 loose dry avalanches on a variety of aspects, and a few isolated size 1.5 wind slabs triggered on northeast aspects by explosive and natural triggers. On Tuesday, expect the new snow to build fresh and touchy storm slabs. Warming and loading will also increase the likelihood of triggering persistent slab avalanches.
Snowpack Summary
Expect 10-20 cm of new snow on Tuesday with greater accumulations in the northern part of the region. The new snow, wind, and warming will build touchy storm slabs that will be extra thick and reactive on wind-loaded features. In sheltered areas, the new snow is burying a layer of feathery surface hoar that may produce surprisingly wide propagations. The main concern deeper in the snowpack is a layer of sugary facets from mid-December that can be found between 50 and 100 cm deep. This layer was considered dormant during the recent cold weather, but may become reactive as warm temperatures soften the overlying slab.
Avalanche Problems
Storm Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Likely - Very Likely
Expected Size: 1 - 2
Persistent Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 2 - 3