Sudden warming and sun will cause a natural avalanche cycle on Thursday. Avoid avalanche terrain.
Two potential weak layers are buried 80 to 140 cm deep. While we have not seen widespread evidence of this problem, it will likely become reactive with the heat and sun.
Warming, and/or cornice falls, could trigger slabs in the recent storm snow.
Sudden warming will produce widespread wet loose avalanches, especially on steep sun-exposed slopes.
Reports of avalanche activity have been limited. A notable size 2 persistent slab avalanche was observed in Manning Park and likely occurred over the weekend (photo below).
Looking forward, warming will cause large wet loose, cornice, and slab avalanches.
Sudden warming on Thursday will cause moist surfaces on all but the highest north-facing terrain. 30 to 50 cm of snow from the past few days is rapidly settling, but some storm slab instabilities may still be present. Storm snow sits above a thin sun crust on south aspects.
There has been evidence of two persistent weak layers roughly 80 to 120 cm deep. The upper one is a thin layer of facets and crusts or surface hoar while the deeper one is facets above a thick crust. While we have not seen many reports of persistent slab avalanches in this region, these layers should not be trusted based on notable activity in neighbouring regions.
Wednesday Night
Clearing skies. 25 km/h north ridgetop wind. Treeline temperature -4 °C.
Thursday
Sunny. 15 km/h north ridgetop wind. Treeline temperature +4 °C with freezing level climbing to 2500 m by midday and 3000 m by the afternoon.
Friday
Sunny. 30 km/h east ridgetop wind. Treeline temperature +6 °C with freezing level climbing to 3400 m.
Saturday
Sunny. 45 km/h east ridgetop wind. Treeline temperature +8 °C with freezing level sustained at 3500 m.
More details can be found in the Mountain Weather Forecast.
