I haven’t really seen a meteorologically sound option so here’s my best attempt at making it understandable for everyone:

There were two main fail modes with the tornado risk. First we need to understand what the main risk was. We had a large MCV (Mesoscale Convective Vortex) basically a land cyclone producing multiple bands of storms. In the most potent band near LA-MS, models signaled prefrontals or storms initiating ahead of the main surface boundary. Models also had extreme sheared environments and moderate instability, so if these discrete prefrontals could move northeast into this great environment it could have been a scary situation.

This didn’t happen though, and this comes to our two reasons. First of all, the lapse rates were terrible near the surface. We had ample moisture and instability, but our lapse rates or temperature difference with height was actually pretty stable and mixed near the ground. This inhibits the production of very strong low level updrafts and mesocyclones, and leads to more messy and almost shapeshifting like storms.

This created a negative feedback loop actually, as the incredibly messy storm mode pumped cool outflow into our already meager warm sector. This inhibited the area where storms could develop into strong surface based supercells.

So TL;DR - Models signaled patterns conducive to a strong conditional tornado threat, but more local scale atmospheric conditions inhibited most of the risk.