Warm temperatures will keep the danger rating high for the next few days. Give cornices a wide berth. Conservative terrain choices are essential until things cool down.
Confidence
Moderate - Due to the number and quality of field observations
Weather Forecast
A pacific cold front will move into the region bringing cloudy skies and light amounts of precipitation. MONDAY: Cloudy, with the freezing level slowly descending from 2700m Sunday night to 2000m early Monday morning, then continuing its descent Monday evening to level off around 600m early Tuesday morning. Light south to southwest winds, scattered very light rain showers below 2000m. TUESDAY: Cloudy with flurries and/or light rain , freezing level is forecast to drop to 600 m overnight, then rise to 1600 m during the day. Winds are forecast to be light from the south to south west. WEDNESDAY: Cloudy with very light precipitation possible in the late afternoon, winds forecast to be light from the south. No overnight recovery on on Wednesday night, with the freezing level hovering around 1600 m.
Avalanche Summary
Reports from yesterday speak of storm slab activity on NE terrain as well as loose wet releases running in steep terrain on South aspects. Cornices are reported to be touchy and sensitive to triggering. Over the course of the last week we have received many reports of cornice failure with some of them being quite large.
Snowpack Summary
Earlier in the week, 15 to 25 cm of new snow fell with light northwest winds. Recent winds from the South west have redistributed the storm snow onto high NE aspects. These wind slabs may be sitting on the mid-March crust, still being found around 20 cm below the snow surface. An earlier March crust can be found down at 50 cm below the surface. Both of these crusts are reported to be present from valley bottom to around 2300 m, after which they begin to disappear. There are thin snowpack areas in the South Rockies region where deeply buried weak layers near the ground remain sensitive to triggering. Huge cornices still hang over many ridge-lines and with solar radiation and warming temperatures, may now be quite reactive.
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.
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.