Regions
Northwest Inland.
Confidence
Poor - Due to limited field observations
Weather Forecast
Synopsis: A brief ridge of high pressure builds in for Monday bringing drier conditions and a mix of sun and cloud. The next system is forecast to affect the region on Tuesday. Monday: A mix of sun and cloud. The freezing level is around 700 m. Winds are light from the northwest.Tuesday: Light to locally moderate snowfall – 5-10 cm. The freezing level is around 600 m and winds increase to moderate or strong from the south-southeast. Wednesday: Unsettled with flurries or periods of snow. The freezing level is steady near 600 m and winds remain moderate from the south.
Avalanche Summary
There are no new reports of avalanches; however, observations have been limited due to poor visibility and weather.
Snowpack Summary
40-60 cm of storm snow has fallen in the past week. This new snow was accompanied by strong southwest winds forming touchy wind slabs in exposed terrain in lee of ridges, in gullies, and behind terrain features. There are a variety of old interfaces now down 60 - 100cm which include facets, crusts and isolated pockets of surface hoar. There is very limited information about the nature of these layers. I would stress the importance of digging down to find and test weak layers before committing to larger and steeper slopes.A strong mid-pack currently overlies a weak base layer of facets/depth hoar. It is worth noting that the snowpack in general is quite shallow compared to averages; triggering the basal weakness may still be possible from thin spots, rocky outcrops or under the weight of larger triggers such as cornice fall.
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.
Cornices
Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.