Avalanche Forecast

Low - Timing or intensity of solar radiation is uncertain

SATURDAY NIGHT: Cloudy with clear periods. Light southwest wind with moderate guests. temperature inversion with above freezing layer between 1500-2500 m.SUNDAY: Mainly cloudy. Light south wind with occasional moderate gusts. Alpine temps reaching +5 C, weak temperature inversion with above freezing layer between 1500-3000 m.MONDAY: Mix of sun and cloud. Light south-southeast wind. Alpine temps reaching +7 C, temperature inversion with above freezing layer between 1500-3000 m.TUESDAY: Sunny, Light south-southeast wind. Alpine temps reaching +6 C, freezing level dropping below 2000 m.More details can be found in the Mountain Weather Forecast.

Friday morning explosives triggered large (size 2) cornice failures. As the snowpack warmed through the day, 30-50 cm surface snow gained reactivity as small slabs on convex and unsupported features. On Thursday morning, a natural storm slab avalanche cycle size 2-3 was reported on rocky features around 2000 m and loose wet avalanches were reported below 1700 m. Explosives triggered numerous size 1-2 storm slabs with good propagation across features. A MIN report from Thursday in Area 51 noted a rapid temperature rise and skiers triggered storm slab avalanches. See the MIN here.Numerous storm slab avalanches to size 2 were triggered by explosives and skiers on Wednesday. Additionally, a large (size 2) cornice failed under the weight of a person. On Monday, Several small wind slabs were triggered by skiers near ridge crest.

Warm temperatures have moistened surface snow and promoted settlement. On Saturday morning, a melt-freeze crust was noted on all aspects up to 1900 m and south to southwest aspects in the alpine. Cold, dry snow may still be found on north aspects in the alpine. Cornices are large and suspect with warming. Warm temperatures are expected to penetrate to high alpine areas, poor overnight recoveries are expected up to 2000 m.The recent new snow has buried old wind slabs on a variety of slopes at alpine and treeline elevations. At treeline and below, two weak layers exist in the upper 2 m of the snowpack. These layers consist of surface hoar (feathery crystals) in more sheltered areas and a crust on solar aspects and on all aspects below 1600m.In the lower snowpack, a crust/facet (sugar snow) layer is now over 2 m deep. There have been no recent reports of avalanches on this layer, but it may still be reactive to heavy loads (such as a cornice fall) in isolated areas.