Dangerous avalanche conditions exist at upper elevations as riders-triggered slabs are likely.
Watch for signs of instability like whumpfing, shooting cracks or recent avalanches.
Up to 30 cm of storm snow is found at upper elevations and reactive storm slabs have developed, especially on leeward terrain features where deposits are deep. Closely monitor the bonding of the new snow with the underlying surface. Be aware that slab avalanches could step down to deeper layers and produce larger-than-expected avalanches.
Numerous size 1 wind/storm slabs were human-triggered on steep terrain at treeline and above near Whistler. Natural avalanche activity was also reported, with small storm slabs and dry loose avalanches on steep terrain at treeline and below. On Monday, a skier accidentally triggered a small storm slab on south-west alpine lee feature near Blackcomb.
Up to 35 cm of new snow has fallen into the region since Monday. Ongoing southerly and previous northerly winds have affected the storm snow in any open terrain and near ridgelines. On sheltered slopes, up to 70 cm of powder storm snow can be found. Snow is heavy and moist at lower elevations.
A thick widespread crust formed in late December is down 40 to 70 cm. In the alpine, it is thin and breakable. Professionals are concerned that small avalanches may run down to this crust and create larger-than-expected avalanches.
Near the base of the snowpack, a weak facet/crust layer from mid-November can be found and remains a concern for triggering with large loads or on thin spots. In general, the snowpack is weak, faceted, and shallow.
Overcast skies and dry conditions are expected until a deeper system will push snowfall into the region early Thursday. Heavy precipitation and high freezing levels are forecasted until Saturday.
Tuesday night
Mainly clear, no precipitations, light southeasterly winds, freezing levels around 1200 m, low of -5C at treeline.
Wednesday
Increasing cloudiness, moderate southerly winds gusting 40 km/h, freezing levels around 1200 m, high of -2C at treeline.
Thursday
Stormy 15-35 cm of snow, rain at lower elevation, moderate southerly winds gusting 60 km/h, freezing levels around 1500 m, high of -1C at treeline.
Friday
Stormy 25-40 cmof wet snow, rain at lower elevation, moderate southerly winds gusting 60 km/h, freezing levels around 2000 m, high of +2C at treeline.
More details can be found in the Mountain Weather Forecast.
