The first real Heat Wave of Spring - use increasing caution with rising temps into next week. Scale back your exposure to large slopes, consequential terrain, and cornices.
Weather Forecast
High pressure, clear skies, warm temps, and Light SW winds dominate the forecast period - expect strong solar input every day. Cool temps overnight Saturday, Freezing Level (FL) to Treeline Sunday. Cool again overnight Sunday, then FL into the Alpine Monday, staying high (warm) overnight, then soaring to mountaintop for Tuesday & beyond.
Snowpack Summary
10-15 cm of new snowfall from Friday night became moist on solar aspects up to treeline on Saturday. Light wind transport observed from the SW at ridges. On solar aspects the new snow overlies a crust 15cm down. The midpack is strong, but near the bottom of the snowpack is a weak layer of sugary facets; in deeper areas poorly bonded above a crust.
Avalanche Summary
On Saturday, a natural avalanche cycle was observed within recent storm snow, on steep slopes, all aspects and elevations. Both Loose Dry and Storm Slab avalanches, mainly Small (size 1) but a few Large (Size 2). Many occurred on solar aspects as cold new snow rapidly became Moist in the sun. More activity expected during warm temps Monday onward.
Confidence
Freezing levels are uncertain
Problems
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.
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.