Purcells

Avalanche danger will increase over the day as a warm spring storm builds fresh storm slabs at higher elevations.

Moderate - Forecast snowfall amounts are uncertain

Thursday: Cloudy with wet flurries bringing 5-10 cm of new snow, continuing but cooling overnight. Moderate to strong southeast winds, increasing overnight. Freezing level to 1800 metres with alpine high temperatures around -1.Friday: Cloudy with continuing isolated flurries and a trace of new snow, continuing overnight. Moderate to strong southwest winds. Freezing level to 1300 metres with alpine high temperatures around -7.Saturday: Cloudy with scattered flurries bringing another 4-8 cm of new snow. Light to moderate southwest winds. Freezing level to 1000 metres with alpine high temperatures around -9

Reports from Monday included observations of recent loose dry releases that reached size 2 as well as a recent natural size 2 storm slab release in the northern half of the region. The slab failed down 30 cm on a steeper east aspect in the alpine.On Saturday there were reports of small (size 1) skier and sled triggered slab avalanches (15-25 cm deep) on north and northeast aspects in the alpine. Explosive control work also produced several cornice failures up to size 2.5 that entrained loose snow on the slopes below but no deeper slab releases.

Recent light snowfalls (5-15 cm each) have been followed by warm daytime temperatures and glimpses of sun, setting up a couple of thin storm snow layers over temperature and sun crusts at lower elevations and on south aspects. On shaded aspects at higher elevations, Sunday's snowfall buried a layer of surface hoar now found 10-15 cm deep.New snow amounts taper with elevation and below 1700 m, only minimal accumulations have buried a supportive crust on all aspects. This crust will likely break down with daytime warming, becoming moist in the afternoon. Deeper persistent weak layers from mid-late February (down 40 -100 cm deep) as well as January and December layers are generally considered dormant, but could wake up with a surface avalanche stepping down, cornice fall, or a human trigger in a shallow or variable-depth snowpack area. These layers consist of sun crust, surface hoar and/or facets. Facets also linger at the base of the snowpack.