Regions
South Coast Inland.
Danger will increase throughout the day with a powerful storm forecast for the south (Coquihalla-Manning). Danger ratings in the north (Duffey Lake zone) will be at least one step lower due to lower snowfall amounts.
Confidence
Moderate - Intensity of incoming weather systems is uncertain
Weather Forecast
Heavy snowfall is forecast in the south (Coquihalla), whereas only 10cm is expected in the north (Duffey Lake area).TUESDAY: Snow. 10-15cm overnight and another 15-20cm accumulation throughout the day in the south (Coquihalla-Manning). Northern areas will only see 10cm total. Ridge wind moderate from the north east. Temperature near -4. Freezing level 500 m.WEDNESDAY: Sunny with cloudy periods. Ridge wind moderate northerly. Freezing level at the surface.THURSDAY: Cloudy with isolated flurries. Ridge wind moderate from the north west. Temperature near -3. Freezing level 400 m.
Avalanche Summary
No new reported; however, a natural avalanche cycle is expected to have occurred in the south of the region with Sunday night's storm.
Snowpack Summary
The south of the region saw significantly more snow (30-40cm) from Sunday night's storm compared to the north of the region, which received 10-15cm. This new snow sits on 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. Moderate to strong winds have redistributed the snow, creating wind slabs on down wind (lee) features near ridge crests. Lower down, the snowpack is well settled and has not been showing any signs of activity on the late November rain crust.Treeline snow depths are approximately 1.2 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.