Fresh snow rests on a problematic persistent slab at treeline and above.
Use caution anywhere the snowpack is thin and/or variable.
Fresh wind slabs will remain reactive to human triggering on lee terrain and near ridge tops. If triggered, wind slabs avalanches may step down to deeper layers resulting in larger-than-expected avalanches.
Avalanches could be bigger than expected, as some recent avalanches have propagated widely on 50 to 100 cm deep crust and surface hoar layers. Be especially cautious anywhere the snowpack is thin and/or variable.
On Saturday, isolated storm slabs (size 1) were triggered by explosives in lee terrain near Whistler. On Friday, very large persistent slabs (up to size 3) were naturally triggered on Decker Mountain and Panorama Ridge in Whistler, with wide propagation from shallow rocky alpine northern slope. These avalanches involved up to 100-120 cm deep persistent weak layers that resulted in wide propagations.
Up to 15 cm of new snow may sit over a recent thin melt-freeze crust up to 2000 m. Underneath, 65 and 130 cm of soft snow and heavily wind-affected snow overlies a layer of poorly bonded crusts and surface hoar. These have shown sensitivity to natural and remote triggers over the last 3 days. The lower snowpack is strong and bonded.
The snowpack at treeline has been saturated, and a surface crust may form soon with upcoming cooling. Total snow depths remain below average, with 60 to 80 cm at treeline.
Saturday Night
Cloudy with isolated flurries, trace accumulation, alpine wind southwest 30 km/h, treeline temperature around 0 °C, freezing level around 1300 m.
Sunday
Mix of sun and clouds with isolated flurries, trace accumulation, alpine wind west 20 km/h, treeline temperature around -2 °C, freezing level at 1200 m.
Monday
Mostly sunny, no precipitation, alpine wind southeast 20 to 40 km/h, treeline temperature around -3 °C, freezing level at valley bottom.
Tuesday
Cloudy, 3-5 cm of snow, alpine wind southeast 30 to 50 km/h, treeline temperature around -3 °C, freezing level at valley bottom.
More details can be found in the Mountain Weather Forecast.
