10-25 cm of new snow and strong winds is forecast for Wednesday night and into Thursday. If this materializes, the danger will rise to HIGH on Thursday
10-25 cm of new snow overnight Wednesday with strong westerly winds on Thursday will build new windslabs in alpine and treeline terrain. Avoid overhead avalanche terrain and watch for signs of windloading if approaching exposed terrain.
There is a layer of facets/surface hoar/crust in many parts of the region down 30-90 cm. New snow and wind on Thursday may be enough of a trigger to overload this layer in some areas.
Lake Louise Snow Safety triggered several size 2's in steep alpine terrain on Wednesday. These were windslabs 40 cm deep that propagated a bit wider and ran further than expected.
Monday, skiers remotely triggered a size 2 avalanche on the Peyto Hut access moraines likely on the persistent layer.
20–40 cm of recent storm snow exists above ~1800m. Below 1800m, a supportive rain crust exists with ~5-20 cm on top. Beneath this, a persistent weak layer comprised of facets and/or surface hoar exists 30-90 cm down. This has been most reactive near treeline in Yoho & Kootenay, but has also caused avalanches in other areas, including the alpine.
A frontal system is approaching Wednesday PM which will bring 10-25 cm by Thursday AM. Temperatures will stay cool throughout and ridgetop winds will generally be light to moderate from the west other than some strong winds on Thursday.
