Regions
Northwest Coastal.
Confidence
Fair - Timing, track, or intensity of incoming weather is uncertain for the entire period
Weather Forecast
Thursday: Continued moist precipitation. 10 -15mm/15-25cm expected over the south portion of the region, very little precip expected in the north. Freezing Level: 200m. Wind: Strong, South.Friday: Occasional light showers/flurries. 10mm/10-20cm expected. Freezing Level 300m. Wind Strong, South.Saturday: A weak pulse of moisture makes its way inland. 5mm water expected. Freezing level tops out around 700m in the afternoon lowering to the surface by Saturday night. Wind: Light, SW
Avalanche Summary
Reports from Tuesday include human and naturally triggered avalanches to size 2 on a variety of aspects. In most of these avalanches the March 9th Surface Hoar/Facet/Crust combo is to blame.
Snowpack Summary
20 - 40cm of unconsolidated new snow is bonding poorly a variety of old surfaces which include: a crust at lower elevations and on solar aspects; old wind slabs in exposed areas, and fairly widespread large surface hoar. Moderate to locally extreme west/southwest winds have redistributed the new snow into soft and hard wind slabs in exposed terrain. This new snow is currently reactive to human triggers primarily where cohesive wind slabs have formed, but reactivity is expected to become more widespread as the overlying slab develops with continued loading. The mid snowpack layers are generally well settled and strong. Facets at the base of the snowpack may resurface as a concern now that spring warming is on the doorstep and full-depth releases are becoming more likely (primarily in the northern part of the region).
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.