North Columbia

Warmer temperatures and rising freezing levels starting late Friday will make a more cohesive, easier-to-trigger slab above the weak interface. Pay attention to rapid change to snow surface with temperature warming and direct solar radiation.

Moderate - Freezing levels are uncertain on Saturday

THURSDAY NIGHT: Mainly cloudy with isolated flurries, moderate west winds, alpine temperature -7 C, freezing level at valley bottom.FRIDAY: Cloudy with isolated flurries, moderate west winds, alpine temperature -2 C, freezing level at 1100 m.SATURDAY: Mainly cloudy with isolated flurries, moderate to strong west winds, alpine temperature around 0 C, freezing level rising up to 1800-2000 m with a weak temperature inversion.SUNDAY: A mix of sun and clouds with isolated flurries, moderate to strong northwest winds, alpine temperature -2 C, freezing level at 1200 m.

Several storm slabs and persistent slabs avalanches up to size 2 triggered by people have been reported on all aspect at treeline and below on Wednesday.  In the alpine, size 2 wind slabs avalanches have been triggered remotely on east and northeast slopes.  All those avalanches ran on the buried surface hoar and crust interface which is now 20 to 40 cm below the surface.

20-35 cm of snow sits above a layer of large surface hoar crystals and sun crust. In areas that have had wind effect the recent snow has been settling into a thin but reactive slab above this weak layer, with enhanced reactivity noted at elevations between 1500-1800 metres. In sheltered areas the snow lacks cohesion above this layer and is only reactive as dry loose sluffing. Expected warmer temperatures starting late Friday will change this and promote increased cohesion in the upper snowpack.The middle and lower portions of the snowpack are generally well-settled and strong.