Confidence
Fair - Due to the number of field observations
Weather Forecast
The ridge of high pressure will be replaced with a low pressure system on Thursday. The low will hit the North Coast early Thursday and should reach the South Coast by late Thursday. A weak ridge will build behind this system on Saturday.Thursday: Clear in the morning with increasing cloud cover in the afternoon, light precipitation in the evening, freezing levels at valley bottom, winds moderate northerly becoming light south-westerly in the afternoon.Friday: Light snowfall, freezing levels near valley bottom, light south-westerly winds.Saturday: Cloudy in the morning, clearing as the ridge builds, light NW 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.