Purcells

Tricky conditions warrant a conservative approach. A little warming, precipitation and/or wind-loading could be all we need to awaken a volatile persistent slab, especially at treeline.

Moderate - Freezing levels are uncertain

Thursday: Clear in the alpine, with valley cloud. A layer of warm air is expected between about 2000-2500 m, while valleys remain cold. Light variable winds. Increasing cloudiness in the evening, with flurries possible overnight.Friday: Cloudy with flurries. Light southwesterly winds.Saturday: Light snow (~5 cm). Light westerly winds.More details can be found in the Mountain Weather Forecast.

Little avalanche activity was reported in the last two days, but whumpfing and cracking was observed in the north of the region on Tuesday between 1700 and 2100 m. Last weekend, a size 1.5 avalanche involving two people near Invermere was reported. It was suspected to have run on the mid-December weak layer. On Saturday a skier triggered a size 2 persistent slab avalanche running on a layer of facetted snow from mid-December. This happened in the north of the region's Dogtooth Range on a west aspect at 2400m. Expect the potential to trigger persistent slabs to increase as last week's storm snow continues to settle into a cohesive slab.

Warming is starting to turn dry powder into a cohesive slab in some areas. The main troublemaker in the snowpack at the moment is a layer of feathery surface hoar down 40-70 cm, buried in mid-December. In places this interface exists as a crust/facet combo. It is most prevalent around treeline, but has been reported as high as 2400 m. A little more warming, precipitation and/or wind-loading could be all that is needed to turn powder into an easy-to-trigger slab above this touchy interface. It's tricky to predict and even professionals are scratching their heads a bit about exactly when and where this beast will wake up. It’s a good time for conservative decision-making.Deeper in the snowpack (about 70-110 cm down), a rain crust from November remains in the back of our minds, but it is considered dormant for now. If you have any recent observations, please share them through the Mountain Information Network.