WeatherNut, I think that mild, ghosting circulation may just be a weak MCV from the ongoing convective blowup over there. Best I can tell (and I can't tell much, because this is not a very well defined Invest, at all) it seems that the weak surface low is indeed now already in the process of tucking itself under a different MLC (which was actually a mid-level remnant of Hurricane Carlotta, first, before getting caught up in the broad trough), and the two look to have moved onshore in tandem.

Now seemingly onshore, in the short term, this synergism looks to be getting further aided and abetted by some more traditional diurnal thunderstorm development over land; however, if this process of combing the incipient LLC with that MLC coupled with deep convection continues, we could very well see #4 develop while just inland, assuming it doesn't drift back offshore any time soon, and develop just offshore.

If this region does not take within 24-48 hours, then I might start looking farther north for a new LLC to become dominant, perhaps an incarnation of the surface eddy currently around 24.5N 89N.