Overcast all day, with very brief, very limited pockets of sun poking through. Winds calm at lower and middle, blowing light gusting/mod out of the W at upper. HN=1cm at highway, 2cm at upper elevations.
I observed quite a bit of wet loose activity, mostly on shady slopes at middle and lower elevations. I did not observe any recent slab avalanches.
Primary goals were to look at amount of recent avalanche activity, elevation of rain line from 2/27 storm, the gradually developing persistent slab problem, amount of new snow and the presence/extent of the wind slab problem.
Recent avalanches: I observed quite a bit of wet loose activity, mostly on shady slopes at middle and lower elevations. I did not observe any recent slab avalanches. Most solars at low and middle elevations have taken quite a beating, a lot of the south facing terrain along the summer road does not have enough snow for significant wet snow problems.
Rain line: rain crust was pretty prominent to 8,500', becoming more subtle up to and somewhat above 9,000'. Solar margins had developed sun+ambient temp crusts up as high as I traveled (9,700'). Only the northern quarter of the compass was crust free.
Persistent slab problem: below the rain line, weak snow developed in January and February is buried just 10-12cm down. Above the rain line, this snow is buried 20-24 cm down. There is not yet enough of a slab on this for it to be a problem in sheltered terrain. That will change if it decides to snow again or in places where wind has piled up a deeper/stiffer slab. At 8,500' on a NE slope I received ECTN 5 and 7 on the drought interface (calling this 1/20 for simplicity). At 9,100' I received ECTN 8, 9, and 13 on 1/20.
New snow and wind slabs: last night and today's storm brought 1-2cm of new snow to this area. Light winds had not done much to transport this recent snow. Above the rain line, the 2/27 storm brought 8-12cm of new snow to this zone.
The rain crust is creating it's own future weak layer (given loading resumes). I built two artificial slabs on top of this in my pit at 9,100' (by disaggregating snow and allowing it to sinter for about 15 minutes). Both of these produced ECTPVs when I rested my shovel on them. Aereal extent of this layer is probably pretty specific (above where it was really raining, maybe 8-8,500 to 9-9,500
I did not directly encounter any avalanche problems today. The biggest avalanche hazard here today were isolated wind slabs, particularly if these are deposited on the layers of weak snow that exist in the upper portion of the snowpack.