Forecast wind and new snow will develop new storm slabs and increase the avalanche danger.
Confidence
Moderate - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
Snow and moderate southerly winds overnight with freezing level down to 500 metres. Expect 10-15 cm in the alpine by Friday morning. Snow continuing during the day with strong westerly winds, expect another 5-15 cm during the day. Light snow overnight and during the day Saturday. Heavy snowfall Sunday morning and during the day Sunday combined with strong southwest winds.
Avalanche Summary
A few loose dry avalanches up ti size 1.5 were reported from Wednesday. Expect widespread storm slabs to develop with forecast new snow and wind.
Snowpack Summary
New snow and wind should develop new storm slabs over the 40-50cm of snow from last weekend's storm. The old surface is a mix of loose snow, wind slabs, and surface hoar in isolated areas. In the Coquihalla area, reports suggest weak surface hoar may exist below the recent storm snow, although there is some uncertainty as to its distribution and reactivity. This interface may be something to keep an eye on as the overlying slab gets deeper and gains cohesion. You'll likely find a hard rain crust buried approximately 100cm below the surface. This rain crust extends up to about 2000m. There is about 200 cm at 1800 metres in the Coquihalla.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.