5-10cm of forecast new snow and moderate westerly ridgetop winds on Sunday may form small wind slabs below ridgetops.
Weather Forecast
SUNDAY: 5-10cm snow / Moderate westerly ridgetop winds / Freezing level valley bottom.MONDAY: Cloudy with isolated flurries/ Moderate westerly ridgetop winds / Freezing level valley bottom. TUESDAY: 5-10cm snow / Light southeasterly ridgetop winds / Freezing level valley bottom.
Avalanche Summary
No new avalanches were reported within this region on Friday. Please submit your observations to the Mountain Information Network (MIN).
Snowpack Summary
The 5-10cm of new snow on Friday fell on a wide variety of surfaces including large surface hoar (weak, feather-like crystals), hard crusts formed by sun or wind, and sugary facets. There is not yet significant new snow load or slab properties to create big problems, however, it will be important to monitor how the new snow is bonding to the smorgasbord of surfaces out there. When we receive significant new snow and it settles into a cohesive slab, you can bet there will be avalanches. I would be most concerned about areas that have surface hoar sitting on top of a hard crust. A major feature in the snowpack is a crust which was formed by rain in late November. It is down approximately 40-60cm at treeline elevations and snowpack tests suggest the snow is currently bonding well to it.Below treeline, the snowpack depth decreases rapidly. Look out for early season hazards such as rocks, stumps, and open creeks.
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.