I don't believe gravity is density, personally. Incoherent electrostatic acceleration creates the downward vector that you call gravity. And that's on a globe or flat earth.If gravity is density, how do clouds float? Hot things rise, so how come when we fly through clouds on a plane or helicopter don't we boil?
Water only floats from my tea kettles and hot shower heads, but then they disappeared? If you boiled a thousand gallons of water in your house can you make a thunderstorm? Why don't it rain inside my house when I make noodles?
As far as clouds floating, it’s because of density and buoyancy. Sun heats water, water evaporates—that is, it rises from Earth’s surface into the atmosphere—water is in the form of a gas, water vapor. Water vapor turns into clouds when it cools and condenses—that is, turns back into liquid water or ice. In order to condense, the water vapor must have a solid to attach onto. This solid “seed” may be a speck of dust or pollen, or a drop of water or crystal of ice.
Steam definitely floats up to the ceiling and if enough collects on the ceiling it will eventually cool and condense, and you might get a few raindrops depending on how dusty your ceiling is. And you would need violent winds and extreme temperatures for the thunderstorms. Lol