Most avalanches occur after a big snowstorm ... Sometimes, barrelling snow can create a powder cloud that can travel over 180 m.p.h. and cause significant damage on its own.

Heavy snowfall began Tuesday night and continues into Thursday. Rain-snow limit has dropped as low as 600–800m in some valleys. Snowfall rates up to 3–4 cm per hour, with 1.5–2.5 meters of new snow ...