Kootenay Boundary

Fair - Intensity of incoming weather is uncertain on Saturday

Friday night: 5-10cm new snow is expected. Saturday:5-10 cm new snow. Treeline temperatures falling to around -13 by the end of the day. Winds moderate to strong westerly. Sunday: flurries or light precipitation. Moderate westerly winds. Temperatures around -10. Monday: Flurries or light precipitation. Temperatures falling to around -15C.

On Thursday a vehicle triggered a size 2 slab avalanche on an E aspect at 2250m. The avalanche slid on a layer of facets buried 60-90cm below the surface. Other recent observations include isolated small human-triggered wind slab and loose snow avalanches near ridgecrests.

Recent light amounts dry snow has maintained the snow supply for fresh wind slab development and cornice growth. Surface condition in wind-exposed areas is highly variable with scoured areas, sastrugi, and pockets of fresh hard and soft wind slabs. Cold temperatures are promoting surface faceting, and a new batch of surface hoar is growing in sheltered areas. A thin melt/freeze crust can be found in the upper snowpack as high as 1900m, and some areas are reporting surface hoar buried early-January now down 10-30cm. The late-December interface is now down 30-60cm and producing moderate to hard resistant snowpack test results. The mid-December surface hoar/facet persistent weakness, down 40-100cm, is generally producing anywhere from easy results where it's shallow to hard results where it's deeper. But recent tests on a north facing treeline slope produced easy results where the surface hoar was found down 70cm, and all tests consistently show a high propensity to propagate fractures. Recent whumpfing suggests basal facets remain concern in shallow snowpack areas especially with heavy triggers in thin spots, and weaknesses in the slab above create the potential for step-down avalanches.