Regions
Northwest Inland.
Wind slabs are likely to be encountered at upper elevations and may be reactive to human triggering.
Confidence
Moderate - Due to the number of field observations
Weather Forecast
THURSDAY NIGHT - Clear periods / southwest winds 10-20 km/h / alpine low temperature near -10FRIDAY - A mix of sun and cloud with isolated flurries / southeast winds 10-30 km/h / alpine high temperature near -12SATURDAY - Sunny / east winds 15-25 km/h / alpine high temperature near -20SUNDAY - Sunny / east winds, 20-40 km/h / alpine high temperature near -14
Avalanche Summary
On Wednesday, there were several reports of wind slab avalanches to size 1.5, and one size 3 occurring on a south aspect at 2000 m. There were also reports of loose avalanches being triggered by the sun on steep, south facing terrain.
Snowpack Summary
Recent strong winds have formed wind slabs in the alpine and at treeline. Due to variable wind directions, wind slabs may be found on all aspects. The snow surface is likely a crust on south facing slopes.Soft snow can still be found in sheltered terrain, and in most areas, 20-50 cm of snow sits on old wind slabs and a crust on south facing slopes. In some sheltered areas, this snow sits on facets (sugary snow) and surface hoar (feathery crystals).In the south of the region, the lower snowpack is considered generally strong. In the north of the region, there may be a layer of surface hoar and facets buried approximately 50 cm.
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.