We dug a pit at 8400' on a SW slope (wrong date on the snowpilot image) and got a CT8 on a thin layer of near-surface facets (possibly due to radiation recrystallization as this slope receives a bit of sun during the day)/surface hoar at the new snow-old snow interface. Despite a noticeable collapse, it did not propagate in the ECT (ECTN18), either because the slab was too weak or the weak layer was not continuous enough. I suspect the former, as we had no less than 5 collapses in the few hundred feet of trail breaking we did on a nearby flat slope, including one that propagated to at least 50 feet away. This showed me that southerly slopes are touchy even at lower elevations, and a lot of places that are normally safe to ski during a PWL might not be.