In the story of the Great Flood it rained forty days and nights. This tells us something about which great flood scenarios would or would not work. The Mediterranean Sea filling scenario does not necessarily require or create a lingering storm, that lasts over a month. That scenario could also happen in sunny weather. That scenario does not check all the boxes.
The best scenario I could come up with, that can check all the boxes, is connected to a recent discovery by science, of oceans of water, below the crust, in the upper mantle. Say there was an earthquake, that create a small fissure, that allows this very hot high pressure super ionic water to lower pressure, phase change, and work its way to the surface. It then open the fissure, wider and wider, as it time goes on.
It would eventually be like a huge steam geyser, that gets stronger and stronger, filling the atmosphere with hot water and steam. As it grows, clouds form and spread across the globe. There is an ocean of water below the crust and this scenario does not need all of it. It would create very serious rain storms, with torrential rains, until all the added atmospheric water falls from the atmosphere; mass flooding everywhere. As it rains and drains over forty days and nights, the oceans rise.
Science has found a large scar on the floor of the Atlantic Ocean, where the crust is fully eroded away, and the mantle is exposed. This suggests such a scenario may have happened. It is hard to tell when, until they can test the scar to see how fresh it is. El Niño might form from a smaller sub ocean water vent; old faithful.
The supersonic water in the upper mantle is part of a mineral matrix like water in a sponge. If we lower the pressure the supersonic water changes phase into super critical or hydrothermal water, with much less permeability in that same mantle mineral phase. The water separates out. and the mantle solids separate out, to fill the scar.
The legends of Atlantis, seems to place a catastrophic event in the Atlantic Ocean.
