Regions
South Coast Inland.
Watch for lingering wind slabs that may be reactive to rider triggers.
Confidence
High - The weather pattern is stable
Weather Forecast
The high pressure continues, resulting in a fairly benign pattern until Friday.Wednesday/ Thursday: Mostly sunny with alpine temperatures near -12. Ridgetop winds will be light from the northeast. Friday: A mix of sun and cloud with snow amounts 5-10 cm. Alpine high of -7 and ridgetop winds light from the southwest.
Avalanche Summary
Recent MIN reports do a great job highlighting avalanche activity in the region. Wind slabs are currently the primary concern and have been very reactive to rider triggers. The reactivity may decrease through the forecast period, however; I'd use caution on the lee of exposed terrain at higher elevations. In thin rocky areas to the north, wind slabs could potentially step down to deeper weak layers.
Snowpack Summary
Last weekend the region received approximately 10 cm of new snow accompanied by strong southwest winds. This has left lingering wind slabs in the lee of exposed terrain. The new snow sits above a thin breakable sun crust and isolated pockets of surface hoar, potentially creating weak interfaces for wind slabs to propagate along. In southern areas (e.g. Coquihalla), the lower snowpack is well settled. In northern areas (e.g. Duffey Lake), the mid-January surface hoar and facet interface is now buried 50-80 cm. This interface produced large avalanches two weeks ago during the last major storm, and may still be poorly bonded in thin snowpack areas such as the South Chilcotins.
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.