Regions
South Coast Inland.
Fresh storm slabs may bond poorly to a melt-freeze crust on Sunday. If you see more than 30cm new snow on a firm crust, consider the danger to be HIGH.
Confidence
Moderate - Timing, track, or intensity of incoming weather system is uncertain on Sunday
Weather Forecast
Significant storm snow totals are forecast for the south of the region (Coquihalla area), with lesser amounts in the north. SUNDAY: Snow. Accumulation 5-20 cm (highest amounts for Coquihalla area). Ridge winds moderate from the southwest. Temperature -2. Freezing level 700 m.MONDAY: Flurries. Accumulation 5-10 cm (highest amounts for Coquihalla area). Ridge winds moderate from the west. Temperature -4. Freezing level 700 m.TUESDAY: Snow. Accumulation 10-20 cm. Ridge winds moderate from the north. Temperature -4. Freezing level 700 m.
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
About 10cm of new snow covers a crust that formed on almost all aspects: the exception being shaded north aspects at upper elevations, where the old snow surface consisted of dry, sugary snow.Lower down, the snowpack is well settled and overlies the late November rain crust, now 20-50 cm deep. Snowpack tests in the Duffey Lake area produced hard, sudden test results associated with this layer. Treeline snow depths are approximately 1 m throughout the region.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.