I'm attempting to give my fantasy world weather/clouds, (some might be light-producing to add to other light sources, so if there's a scientific way to do that, please give it to me). There are multiple waterfalls and waterways, most of which are saltwater due to the fact that the water comes from the ocean (flooding doesn't happen because magic). So would it function normally or would something need to be different?
I think the answer may be as simple as having a Water Cycle. That is, evaporation and transpiration (evaporation from plants), leading to condensation (clouds), leading to precipitation, then runoff and pooling, leading back to evaporation...
You can't get much more realistic than mimicking nature. So if you have water and plants in a warm climate, clouds and rain are probably a given.
You might want to seriously consider the "heat source". The Sun is a reliable, giant nuclear reactor. Having a reliable heat source for evaporation could be important (like geothermal pool or high temperature rocks -- the Earth's core is also a reactor).
If you prefer a "fantasy" source, you could:
- Have creatures that release a cloud-like gas.
- Have pillars from underground releasing the clouds (where you don't know the source, but it always comes from the same place).
- Have two substances interact to form clouds, like a big bang.
- Have a cloud spirit/elemental.
And, alternatively, you could just add them to your realm without an explanation. Sometimes leaving mysteries charges the imagination of others.