Confidence
Fair - Due to the number of field observations
Weather Forecast
A low pressure system moves onto the north coast Monday night/Tuesday morning. The edge of this system will bring light precipitation and moderate winds to the South Coast late Tuesday or Wednesday. A ridge of high pressure follows the low and should be in place over the South Coast by late Wednesday or Thursday.Tuesday: A mix of sun and cloud, light precipitation, freezing levels around 2000m with a temperature inversion, moderate alpine winds from the SWWednesday: Light precipitation, freezing levels dropping to valley bottom, wind speeds decreasing and switching to northerly late WednesdayThursday: Generally dry conditions, a mix of sun and cloud, light winds
Avalanche Summary
No recent avalanches have been reported.
Snowpack Summary
Snowpack depths vary greatly across the region with 130cm reported at treeline in the Northern Cascades but only 50 cm along the Duffy. In general, the snowpack across the region is significantly thinner than average for this time of year. Terrain below treeline is still mostly below threshold for avalanche activity.The recent warm temperatures have generally promoted snowpack settlement and bonding within the snowpack. The recent storm snow is bonding well to the mid-Dec facet interface at treeline and below. Previous weak interfaces deeper in the snowpack are generally well bonded and unreactive to snowpack tests. In the alpine, strong SW winds have redistributed the recent storm snow creating wind slabs in leeward features and wind scoring on windward slopes.Early season riding hazards such as rocks, stumps and logs are lurking below the surface at treeline elevations and below.
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.