That's a little complicated to be certain. Granted, speculation here; but two points: 1) It would not have needed a full day at the rate the pressure fall it was experiencing into landfall to have become a more intense. Between 4:30AM and 10:30AM CDT recon missions recorded a pressure drop from 937 mb to 923 mb. The last pass recorded 919 mb at 12:30PM CDT. A mere six more hours over those above-normal GOM SSTs and exquisite upper tropospheric conditions and it would have likely bottomed out around 910 hPa, taking into account some leveling off as well. At that rate of pressure fall and gradient increase, even nine more hours we would have seen Michael flirt with 150-160 kts (175-185 mph) winds. 2) On the other hand, the eye was also contracting and a concentric band was beginning to form. So given too much more time, very probable that an ERC would have most likely initiated given another full 24 hrs, and we would have likely seen Michael level off and weaken.
Yeah and I guess it was flirting with MPI so it couldn't have strengthened too much more. Would have naturally leveled off........ even without an ERC.