Avalanche Forecast
Regions: Purcells.
Confidence
Moderate - Timing or intensity of solar radiation is uncertain
Weather Forecast
Overcast on Wednesday with flurries or light snow, light southerly winds, and freezing levels rising from valley bottoms overnight to about 1200 metres during the day. Overcast with light snow on Thursday combined with moderate southwest wind and freezing levels rising from valley bottoms up to 1300 metres. On Friday, sunny periods with scattered or broken clouds, moderate southwest winds, and freezing levels rising up to 1400 metres.
Avalanche Summary
On Tuesday we had reports of thin new windslabs that were skier controlled, and a size 2.5 deep persistent slab avalanche was reported that probably released on Monday on a west aspect in the alpine. On Monday we had reports of natural wind slab avalanches up to size 2.0, and one wind slab in the alpine that stepped down to a persistent week layer on an east aspect resulting in a size 3.0 avalanche.
Snowpack Summary
Approximately 10 cm of new snow arrived by Tuesday morning. Moderate to strong westerly winds transported the new snow into wind slabs in the alpine and at treeline. The new snow will overlie wind slabs which formed over the past few days. About 15-40 cm below the surface, you'll likely find a melt freeze crust which exists in most places except for in high elevation shaded terrain. In general there seems to be a reasonable bond between the crust and the overlying snow. I'd still keep an eye on this interface as it has become reactive on some features. The early January surface hoar/ facet layer is typically down 70-120 cm. Avalanche activity at this interface has tapered-off over the past week, but I'd be reluctant to trust this potentially destructive layer just yet. In general, the lower snowpack is well settled and strong, apart from some thin snowpack areas where basal facets exist.
Avalanche Problems
Wind Slabs
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 1 - 3
Persistent Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Unlikely - Possible
Expected Size: 3 - 5
Loose Wet
Aspects: North, North East, East.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 2