As the snowpack warms during the day, the likelihood of loose wet avalanches will increase, especially in areas with fresh snow.
Weather Forecast
MONDAY NIGHT: Cloudy with isolated flurries, trace to 10 cm accumulating by Tuesday morning / northwest wind, 10-25 km/h / alpine low temperature -3 C C / freezing level 1200 mTUESDAY: Mix of sun and cloud / west wind, 15-25 km/h / alpine high temperature -1 C / freezing level 1800 mWEDNESDAY: Flurries, 5-20 cm snow / southwest wind, 20-40 km/h / alpine high temperature -4 C / freezing level 1400 mTHURSDAY: Sunny with cloudy periods / north wind, 15-35 km/h / alpine high temperature 0 C / freezing level 1800 m
Avalanche Summary
Avalanche control work with explosives triggered mostly small storm slabs (size 1-1.5) and cornices in alpine and treeline on Sunday; these avalanches failed on the storm snow - melt-freeze crust interface.On Saturday, small (size 1-1.5) storm slabs and wind slabs were reactive to skier traffic. Cornices were reactive to explosives and triggered large (size 2) slab avalanches as they fell on the slopes below. Small storm slabs were triggered by skiers on Friday, within the recent storm snow up to 40 cm thick. The likelihood of triggering loose wet avalanches will increase if the sun shines, especially in areas with fresh snow.
Snowpack Summary
Snowfall accumulated over the weekend and continuing flurries have been moved by south and westerly winds forming slabs in the alpine and upper treeline. This covers a melt-freeze crust on most slopes, and dry, faceted snow and isolated surface hoar and on high north-facing terrain. Expect a snowpack that changes with elevation and through the day, between 1200-1800 m sun and warm temperatures are producing a moist snowpack. Below 1200 m the snow is melting rapidly.With spring conditions, the avalanche hazard will fluctuate greatly depending on the strength of the overnight freeze and how quickly the snowpack is warmed up each day.
Problems
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.
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.