*06:00 Update* The storm is underdelivering in the Whistler area but hazard will increase over the day. Stick to lower consequence terrain and avoid avalanche terrain in the alpine.
A November crust/facet layer was 50 to 120 cm deep before recent storms. Conditions have lent well to cleaning out and stabilizing the problem, but it may still be possible to trigger, particularly in thin-to-thick areas in the alpine.
Heavy snowfall will rapidly form a reactive storm slab problem for Thursday. Expect greater accumulations in the south of the region. The more snow accumulates and the more it is affected by wind, the greater the danger.
Tuesday's reports were limited to ski cut and explosives-controlled slab and loose dry results to size 1.5 in the Whistler area. All ran on the new atmospheric river crust.
A wet slab avalanche cycle to size 3 was observed in the Whistler area after around 90 mm of rain below 2000 m. Monday morning, new size 1.5 wet loose releases were observed and explosives produced a size 2.5 wet slab.
Expect more active avalanche conditions with the next storm pulse.
30 to 50 cm of new snow should accumulate Wednesday night through Thursday, with greatest amounts in the south of the region. Dangerous storm and wind slabs should form as a result.
The new snow will add to an existing 20 to 50 cm of storm snow from this week overlying crust and a wet snowpack from Monday's 2200 m freezing levels and heavy rain. The limited terrain above this elevation may have substantially greater accumulations.
A crust with facets, formed in mid-November, is buried an estimated 80 -150 cm deep. It may still exist as a problem in alpine locations where it hasn't been capped by a strong crust, particularly in thin-to-thick snowpack areas.
Wednesday Night
Cloudy with increasing snowfall bringing 10 to 20 cm of new snow. 40 km/h south ridgetop wind. Treeline temperature -4 °C. Freezing level 900 m.
Thursday
Cloudy with continuing snowfall bringing 20 to 30 cm of new snow. 40 km/h south ridgetop wind. Treeline temperature -3 °C. Freezing level 1100 m.
Friday
Mostly cloudy with flurries bringing 10 to 20 cm of new snow, including overnight amounts. 30 km/h southwest ridgetop wind. Treeline temperature -5 °C. Freezing level 800 m.
Saturday
Cloudy with flurries bringing 10 to 20 cm of new snow. 20 to 30 km/h southwest ridgetop wind, easing. Treeline temperature -5 °C. Freezing level 800 m.
More details can be found in the Mountain Weather Forecast.
