A thin rain crust is helping to keep wind slabs in check at lower elevations, but they may remain touchy in the alpine - especially if the sun hits them.
Weather Forecast
Thursday: Sunny with cloudy periods and no new snow. Winds light from the west. Alpine temperatures of -6.Friday: Cloudy with sunny periods and no new snow. Winds light gusting to moderate from the west. Alpine temperatures of -2Saturday: Cloudy with sunny periods and no new snow. Winds light to moderate from the south.
Avalanche Summary
No new avalanches observed.
Snowpack Summary
The mountains of the South Coast region received 15-20cm of snow over Sunday and Monday. The southwest flow of the storm, followed by strong northeast winds over Tuesday resulted in pockets of wind slab being formed on all aspects in exposed areas. A thin rain crust can be found 5cm below the surface at treeline and below. This has limited the wind redistribution at lower elevations. The new wind slabs have already gained considerable strength but could remain reactive on steeper unsupported terrain at higher elevations where this crust does not exist. The new snow came in wet and heavy (especially in the North Shore mountains) and bonded well to 15 cm of settling snow from Friday's storm. Friday's snow buried a variable interface composed of faceted (sugary) snow and old hard wind slabs (especially at higher elevations). Recent reports suggest the snow has bonded well to this interface. The mid and lower snowpack are well settled and stable.
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind 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.