Fresh storm snow will need time to settle and stabilize. Watch for changing snow conditions in wind affected terrain and at higher elevations.
Confidence
Moderate - Due to the number of field observations
Weather Forecast
SUNDAY: Trace amounts of snow overnight then gradual clearing throughout the day, light northwest wind, alpine temperatures around -12 C.MONDAY: Mix of sun and cloud, moderate northwest wind, alpine temperatures around -10 C.TUESDAY: Mix of sun and cloud, moderate northwest wind, alpine temperatures warming to -5 C.
Avalanche Summary
On Friday, skiers triggered numerous small storm slabs in the top 20-40 cm of snow throughout the region, including a size 1.5 storm slab on a south-facing convexity in the Gorge area of the Monashees (see the report on the Mountain Information Network for more details). Widespread sluffing in steep terrain was also reported.
Snowpack Summary
Friday night's storm delivered anywhere from 5-25 cm of new snow. Total amounts of snow over the past few days varies from 30-60 cm, with even deeper deposits at higher elevations. In most areas the new snow sits above crusts left over from the warm rainy weather in late November. Some snowpack tests indicate a weak bond between the storm snow and the crusts, which warrants extra caution in big, steep, unsupported terrain. The average snow depth is over 200 cm in the alpine, 100-180 cm at treeline, and decreases rapidly below treeline where the primary hazards are rocks, stumps, and open creeks.
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.