Reactive storm slabs likely exist at treeline and in the alpine. They could be touchier on leeward slopes due to wind loading.
At lower elevations, loose wet avalanches are possible with high freezing levels and a rain soaked snow pack.
30 to 60 cm of recent storm snow has blanketed upper elevations. The likelihood of triggering a storm slab increases in steep or convex terrain and in wind loaded areas.
Lower elevations host a rain soaked snowpack. Loose wet avalanches are easily triggered from steeper terrain features at treeline and below treeline.
No new reports on Wednesday by 4 pm.
On Tuesday, numerous size 1 wet loose avalanches were reported at below treeline elevations. Poor visibility made for limited alpine observations.
On Monday, our field team observed widespread natural avalanche activity size 1-2.5. A skier-triggered size 2 storm slab was reported at Mt Cain on Sunday in this MIN.
Change is in the air with an unstable airmass bringing convective, spring-like weather. Generally, overcast skies and a drying trend will exist Thursday. The ridge should be set up by Friday with clearing skies and light northwest winds.
Wednesday Night: 5-10 cm of new snow above 1000 m and rain below. Freezing levels dropping to 1000 m overnight and moderate southwesterly wind at ridgetop.
Thursday: Cloudy skies. Light northwest wind and freezing levels 1000 m.
Friday: Sunny skies with spring-like (diurnal) freezing levels dropping to 1000 m overnight and rising to 1500 m during the day. Ridgetop wind moderate from the northwest.
The recent storm snow is topped with a thin freezing rain crust and 5 cm of recent moist snow. Within the 40-60 cm of new snow, a wet layer on the surface is stacked on top of lower density, dry snow. This configuration is referred to as upside-down and is often associated with short-term instability while the soft bottom settles. Above 1900 m, the surface remains dry and has seen extensive wind effect, with extremely variable depths and areas of hard wind slab.
The storm snow sits over a thin layer of weak crystals on a thick, widespread rain crust which makes a great sliding surface for avalanches. This crust is capping a well settled and strong mid and lower snowpack.
