Cloud and slight cooling should help temporarily drop avalanche danger on Tuesday, but continue to exercise caution if the sun appears during the day.
Weather Forecast
TUESDAY: Mainly cloudy with a chance of showers/flurries and afternoon sunny breaks. The freezing level dips to around 1400 m overnight and rises to 1600-1800 m during the day. Winds are moderate to strong from the W-NW. WEDNESDAY: Clearing. The freezing climbs to 2600 m and winds are light to moderate from the West. THURSDAY: Mainly sunny. The freezing level continues its ascent up to 3200 m. Winds should ease to light and variable.
Avalanche Summary
Recent soaring temperatures and strong sunshine have resulted in significant natural avalanche activity for the past several days. Slab avalanches to size 2.5 have been very common over the last few days on almost all aspects (the exception being high elevation north). Large loose wet avalanches and cornice falls have also been a common theme. Cloud cover and slight cooling might halt natural activity briefly this week.
Snowpack Summary
Recent warm temperatures, weak/non-existent overnight refreeze, and rain have moistened the upper snowpack at all elevations. Elevations above 2000 m may getting snow on Monday (5-10 cm is possible), and a cooling trend could create a crust at or near the surface down to around 1500 m. Below 1400 m, the snowpack is likely fully isothermal. The March 22nd rain crust is present to around 2000 m, but the warm temps have likely allowed the overlying 30 to 40 cm of snow to bond well. Once it freezes, this layer should not be much of a concern. The late February persistent weak layer is now down 40 to 100 cm below the surface, and may
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.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.