Avalanche Forecast

SATURDAY NIGHT: Cloudy with isolated flurries, light south winds.

SUNDAY: Cloudy with scattered flurries bringing 10-15 cm of new snow, continuing overnight. Moderate southwest winds, possibly strong in the alpine. Alpine high temperatures around -6 with freezing levels to about 1400 metres.

MONDAY: Mainly sunny. Light variable winds. Alpine high temperatures around -6 with freezing levels to 1500 metres.

TUESDAY: A mix of sun and cloud. Light variable winds shifting west. Alpine high temperatures around -6 with freezing levels to 1500 metres.

More reports from Friday were a mix of small (size 1.5) new skier triggered wind slabs (northeast aspect) and additional observations of natural activity from the warming event the day prior. A size 3 natural wind slab release in the Monashees south of Revelstoke stands out in these reports.

Warm sunny weather between Wednesday and Friday resulted in a widespread cycle of wet loose avalanches on sun-exposed slopes. These were mostly small (size 1-1.5), but a few large (size 2.5) wet avalanches were also reported. Heating also caused some cornice falls, ice falls, and small wind slab avalanches. 

On Thursday there was a fatal avalanche between New Denver and Kaslo where a snowmobiler triggered a size 3 persistent slab avalanche on a west aspect at 2400 m. The avalanche likely failed on the late January weak layer (see the Incident Report here). This avalanche problem has become much less reactive as cooling temperatures have helped stabilize the snowpack

The primary concern for Sunday will continue to be new wind slabs forming on north and east facing slopes.

15-20 cm of new snow (with some locations closer to 30 cm) from Friday night accumulated above moist and crusty interfaces that formed during the recent warm up. Some deeper accumulations can be expected in lee terrain features. High, shaded terrain will have a mix of soft snow and some old buried wind slabs. 

The lower snowpack has strengthened over the past week as previous persistent weak layers have become mostly unreactive. The main layers that we had been tracking are a layer of facets that was buried in mid-February (50-100 cm deep) and a layer of surface hoar and/or crusts that was buried in late January (80-120 cm deep).

• Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
• Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
• Seek out sheltered terrain where new snow hasn't been wind-affected.