Regions
South Coast Inland.
Wind slabs may be found in immediate lee (down wind) features at higher elevations. Watch for how the new snow is bonding to the old surface on south aspects.
Confidence
Moderate - Due to the number of field observations
Weather Forecast
Monday will see a brief lull in the active weather pattern before significant precipitation arrives on Tuesday.MONDAY: Cloudy with isolated flurries. Accumulation of 5 cm possible. Ridge wind moderate from the west. Temperature near -5. Freezing level 700 m.TUESDAY: Snow. Accumulation 15-25 cm. Ridge wind moderate from the southeast. Temperature near -7. Freezing level 500 m. WEDNESDAY: Clearing in the morning. Ridge wind moderate northerly. Freezing level at the surface.
Avalanche Summary
Small natural dry loose avalanches to Size 1 were reported in the north of the region (Duffey Lake zone) on Saturday.
Snowpack Summary
10-20cm of new snow covers crusts of variable thickness that formed on almost all aspects in early December. On steep southerly aspects the crust is supportive, whereas on northerly aspects the crust is quite thin and variable. In the south of the region (Coquihalla), moderate southerly winds have redistributed the storm snow, creating wind slabs on northerly aspects behind ridge crests and rib features. Lower down, the snowpack is well settled and overlies the late November rain crust, now 20-50 cm deep. Treeline snow depths are approximately 1 m throughout the region.
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.