Spring conditions. Avalanche danger is expected to rise during the day with warming and solar radiation. Plan to retreat to cooler north-facing terrain if the snow surface is becoming moist or wet.
Weather Forecast
SUNDAY: Mainly sunny. The freezing level dips to 2000 m overnight but shoots up to 2500 m in the afternoon. Winds are light and variable. MONDAY: Increasing cloud. The freezing level remains near 2600 m and winds are light. TUESDAY: Cloudy with possible showers or flurries. The freezing level is around 2400-2500 m. Winds could increase to moderate from the SW.
Avalanche Summary
Several natural and rider triggered loose wet slides to size 1.5 were reported on Friday, while a more widespread but small (size 1-1.5) natural loose wet avalanche cycle was observed on steep solar aspects on Thursday. There were also a few reports of isolated slabs up to size 2 from north-facing alpine slopes. The possibility of persistent slabs and cornice falls should increase if the snowpack does not refreeze overnight and temperatures remain high.
Snowpack Summary
The snow surface is currently going through a typical spring melt-freeze cycle on all aspects and at all elevations, except possibly high true-north slopes which could be holding onto cold snow. A moist/wet, isothermal, and rapidly melting snowpack exists on all aspects below around 1500 m and probably even higher on solar aspects. The strength (thickness) of the surface crust and how quickly it breaks down during the day are important factors to focus on. The late February persistent weak layer is down 80 to 120 cm below the surface. This layer may be a concern in isolated terrain, but it will probably take a large trigger like a cornice fall or surface avalanche in motion to set it off.
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.
Wet Slabs
Wet Slab avalanches are the release of a cohesive layer of snow (a slab) that is generally moist or wet when the flow of liquid water weakens the bond between the slab and the surface below (snow or ground). They often occur during prolonged warming events and/or rain-on-snow events. Wet Slabs can be very unpredictable and destructive.