Lingering wind slabs continue to be reactive to rider triggers.
Confidence
High - The weather pattern is stable on Thursday
Weather Forecast
Thursday: A mix of sun and cloud with alpine temperatures near -10. Ridgetop winds light from the East.Friday: Snow amounts 5-10 cm with alpine temperatures near -5 and freezing levels 1200m. Ridgetop winds light from southeast.Saturday: Snow amounts 5-15 cm with alpine temperatures near -2. Freezing levels 1300 m and ridgetop winds light-gusting strong from the southwest.
Avalanche Summary
On Tuesday, a size 1 wind slab was reported from the Brandywine area. Isolated wind slabs may continue to be reactive in the lee of exposed terrain.
Snowpack Summary
Up to 15 cm of snow fell last weekend. That combined with strong winds have formed stiff, yet reactive wind slabs in the lee of exposed terrain. The new snow sits above a thin breakable sun crust and isolated pockets of buried surface hoar, which provides a weak sliding interface below the new snow. Some recent snowpack tests have shown hard, yet sudden planar results on the mid-January interface (facets) buried approximately 60-100 cm down. A total of 60-120 cm of settled storm snow now forms the upper snowpack and is generally bonded to a crust below. The exception may be thin rocky areas. The mid and lower snowpack are generally well settled, but still feature a number of facet and crust layers that are currently dormant but require monitoring with significant change
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.