A sunny heat wave is finishing off April with a bang. Poor overnight crust recoveries are expected the next couple of days, increasing the danger ratings.
Weather Forecast
Warm and sunny with cloudy periods. Freezing levels are expected to rise to 3500m today, lower to 3300m overnight, then back up to 3600m tomorrow. This means there will be no overnight recovery of the surface crusts in the next couple of days.
Snowpack Summary
Our weather data shows a poor freeze above 2000m overnight, but an inversion has set up a solid 10cm crust at valley bottom. Dry snow can still be found on due north aspects above 2000m. At tree line, the top 50 cm of snow are moist with several crusts in the top meter of the snowpack.
Avalanche Summary
There have been a few natural moist loose avalanches to size 2 occurring daily. Today will be sunny and warmer than yesterday, so more avalanche activity is expected. In addition, glide cracks are opening up on many slopes.
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.
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.
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.