Regions
South Coast Inland.
Lingering wind slabs may be reactive to rider triggers.
Confidence
High - The weather pattern is stable on Thursday
Weather Forecast
Thursday: Mix of sun and cloud with alpine temperatures near -10. Ridgetop winds light from the northeast.Friday: Snow amounts 5-10 cm with alpine temperatures near -5 and freezing levels 1100m. Ridgetop winds light from southwest.Saturday: Snow amounts 5-15 cm with alpine temperatures near -1. Freezing levels 1300m and ridgetop winds light-gusting strong from the southwest.
Avalanche Summary
On Tuesday, isolated wind slabs up to size 2 were reported from the Chilcotin area, primarily from west aspects above 2000 m. Wind slabs will likely remain reactive to rider triggers 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. Lingering reactive wind slabs and wind scoured snow exist on exposed terrain at treeline and in the alpine. 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 northern areas (Duffey), the mid-January surface hoar and facet interface is now buried 50-80 cm down. This interface produced large avalanches a week during the storm, and may still be poorly bonded in thin snowpack areas such as the Hurley and/ or South Chilcotins. In southern areas (Coquihalla), the lower snowpack is reportedly well settled compared to the North.
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.