The LLJ doesn't really have much to do with this IMO. It's 55-70 kts out of the SSW, which is more than plenty for a big severe day down here (actually would probably favor it over the due south LLJ given moisture trajectories in the SE). Additionally, the low level response here was always further north and the trough is lifting away with time, which limits forcing for ascent. The thermos just aren't there due to the cold front earlier this week and combining that with decreased large scale ascent is a death knell for stronger convection.
Put 1500-2000 J/kg CAPE over this warm sector and you're talking a potential high risk event. I should say the timing is also a bit off, the most favorable period of the trough's evolution was 2-6 hours ago. This might not matter much though if the temperatures and dewpoints were 10 degrees higher.
Gotcha, thanks. Most of the forecast soundings I saw were pretty much due southwesterly at 850mb, not south-southwesterly. Also, some of the soundings I saw for Tuesday's event had close to 80kts at that level.
As to the second bolded, absolutely.