Quick report
We took the Surprise Creek summer trail, then mostly followed the trail up to Trap Pass. After that we followed the ridge, dropping below Slippery Slab, traversing the east side, then worked our way up the south face to the summit block. The first 10' summit block proved difficult/impossible to scramble without some kind of traction. We opted not to climb the true summit given how slippery the rock was and its associated fall risk. It was mostly cloudy in the morning, became broken in the afternoon, then cleared up completely by sunset. An inversion layer at ~4k' had settled into the Thunder Lakes drainage and elsewhere by sunset. We crossed a D0.5 (south face; start point was <40°) and D1 (east face/col; start point was 45°+) slide path. Snow BTL under rain shadows was extremely icy/punchy, whereas snow BTL/out in the open was slightly punchy, with powder/facets underneath. Many glide cracks were open in lower boulder fields. HSTs and RPTs with trekking poles correlated in-field conditions with NWAC obs for the day in the Stevens Pass zone. Multiple stout/supportive crusts found near the ridge. Found a shallow/small soft storm/wind slab on the surface in a somewhat sheltered area along the ridge, but snow on steeper aspects didn't exhibit this behavior (was much more consolidated/icy). 5 of 6 in party wore crampons from the summit down the south ridge; I opted for snowshoes (MSR Lightning ascents; aggressive side crampons) after the south ridge due to postholing issues. MSR Evo users had a difficult time breaking the icy crust in the last few hundred feet (several in our party had sliding problems since the crust was so hard).