Daytime and solar heating will weaken cornices, avoid traveling in avalanche terrain during periods of intense solar input.
Weather Forecast
Clear skies with no forecasted snow as a shallow ridge of high pressure moves into our area on Tuesday. Winds will be light from the West with an alpine high of -6 with freezing levels rising to 1500m. Light flurries on Wednesday into Thursday with freezing levels to 2000m.
Snowpack Summary
10cm of new snow in past 2 days has formed windslab along lee ridge-lines and cross-loaded gully features from SW winds. Mid-pack bridging basal weakness. Entire lower snowpack is weak with a combination of facets, Nov rain crust and depth hoar. Below tree line a 5-10cm melt freeze crust sits above a moist facet layer to ground.
Avalanche Summary
No new avalanche observations on Monday, but previous cornice and windslab failures have triggered the deep persistent slab resulting large full path avalanches. Loose wet avalanches have previously occurred on steep south and west aspect below tree-line.
Confidence
Timing or intensity of solar radiation is uncertain on Tuesday
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.
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.
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.