Rapid cooling should help stabilize the snowpack and lower the avalanche danger heading into the weekend.
Summary
Confidence
Fair - Due to the number of field observations
Weather Forecast
Friday: Temperatures start to plummet early with freezing levels dropping to 500 m by mid-day. We could see a pulse of light snow (5 cm) in the afternoon. Winds ease. Saturday: Mainly sunny. The freezing level is at valley bottom. Winds are light to moderate from the NE. Sunday: Sun and cloud. The freezing level remains at valley bottom. Winds are light from the W-NW.
Avalanche Summary
Numerous loose wet and wet slab avalanches up to size 2 were reported near Whistler on Wednesday as temperatures spiked and rain started to fall. It's likely that natural activity continued overnight with the potential for larger slab avalanches at higher alpine elevations. Natural activity should taper off on Friday if temperatures cool as forecast.
Snowpack Summary
It's likely that wet snow continues to fall at higher elevations (above 2000 m). Below this elevation recent snowfall has probably been soaked by rain. As temperatures drop later this week I would expect a new crust to form, possibly with some fresh snow on top. An old snow surface of weak facets sitting on a crust is now down as much as 50-60 cm at treeline elevations and deeper in the alpine. Initial reports suggest this weakness is most pronounced slopes at upper treeline and lower alpine elevations. However, as we begin our forecasting season, we are working with limited information from the field. Check the bond of the snowpack at this level and take a cautious approach as new snow builds deeper above this layer.
Peter,
Avalanche Canada
