Regions
South Coast Inland.
A storm system is expected to arrive late Saturday and into Sunday, with highest snowfall amounts in the southern part of the region. Watch for new snow and wind building fresh slabs in lee areas.
Confidence
Moderate - Forecast snowfall amounts are uncertain
Weather Forecast
SATURDAY: Mostly cloudy, flurries. Accumulation up to 5 cm. Ridge winds moderate from the southwest. Temperature -4. Freezing level 700 m.SUNDAY: Snow. Accumulation 5-20 cm (highest amounts for Coquihalla area). Ridge winds moderate from the southwest. Temperature -2. Freezing level 700 m.MONDAY: Snow. Accumulation 5-15 cm (highest amounts for Coquihalla area). Ridge winds moderate from the west. Temperature -4. Freezing level 700 m.
Avalanche Summary
There have been no new avalanche reports since last weekend when numerous loose wet avalanches up to size 2 were observed on northerly aspects along the Duffey Lake Road with rapid daytime warming on Sunday.
Snowpack Summary
A light dusting of new snow now covers the crust that formed on all aspects with the exception of shaded north aspects at upper elevations where the old snow surface consisted of dry, sugary snow (facets). Beneath the snow surface the upper snowpack is well settled and overlies the late November rain crust, now 20-50 cm deep. Snowpack tests in the Duffey Lake area early in the week produced hard, resistant compression test results on small sugary, snow crystals (facets) associated with this layer. However these facets were noted to be showing signs of "rounding" or gaining strength. 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.