It will almost feel like summer for the next couple days. The heat and sunshine will cause the avalanche danger to rise during the day, especially on solar aspects. Choose terrain carefully.
Weather Forecast
THURSDAY: Cloudy but clearing throughout the day. The freezing level shoots up to 3200 m. Winds should ease to light and variable. FRIDAY: Mainly sunny. The freezing level stays well above 3000 m and winds should remain light. SATURDAY: A mix of sun and cloud. The freezing level could drop to 2500 m and winds could kick up to moderate from the west.
Avalanche Summary
Several small (size 1) storm slabs were triggered in steep convex-shaped north-facing terrain on Tuesday. There was also one report of a natural cornice fall that triggered a size 3.5 deep persistent slab on a north-facing alpine slope. As we move back to warm and sunny weather I would expect renewed loose wet activity on solar aspects, natural cornice falls, and isolated large persistent and wet slab avalanches.
Snowpack Summary
20-40 cm of new snow sits on melt-freeze crust with westerly winds forming fresh wind slabs in exposed lee and cross-loaded terrain. The March 22nd rain crust is buried 50-70 cm deep up to around 2000 m. We could see more activity on this layer when temperatures soar later in the week. The late February persistent weak layer is now down 60 to 120 cm below the surface. While it may be a concern in isolated terrain, it would probably take a large trigger like a cornice fall or surface avalanche in motion to provoke it. The lower elevation snowpack (below 1500 m) is moist and isothermal.
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.