Regions
Northwest Inland.
Recent storm snow combined with predominantly southwest wind is expected to continue to form fresh sensitive wind slabs that rest on a weak layer of facets. Seek out conservative terrain protected from the wind.
Confidence
Low - Wind effect is extremely variable
Weather Forecast
Friday and Saturday look quite convective which means that periods of locally intense snow flurries are possible. The freezing level starts to creep up Saturday as warm air invades from the south. THURSDAY NIGHT: Freezing level at valley bottom, moderate to strong west wind, 2 to 5 cm of snow.FRIDAY: Broken cloud cover, freezing level rising to 1000 m, moderate to strong south/southwest wind, trace of snow.SATURDAY: Broken cloud cover, freezing level rising to 1500 m, moderate to strong south/southwest wind, 1 to 5 cm of snow. SUNDAY: Broken cloud cover, moderate to strong south/southwest wind, freezing level approaching 2000 m, a few mm of precipitation possible.
Avalanche Summary
Few observers in the field this week but reports are consistent with a natural avalanche cycle of storm and wind slabs up to size 2.
Snowpack Summary
20 to 45 cm of slightly upside down storm snow has accumulated since Monday. This new snow rests on previously wind hammered snow, sun crusts (on solar aspects) and sugary facets. February's cold weather weakened the upper and mid-snowpack. In some sheltered areas, 20 to 50 cm of the snowpack was faceting, or sits on facets (sugary snow),In the south of the region, the lower snowpack is generally strong.
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.