How do clouds hold so much water but then, as if someone opened a valve, it just starts falling out? Why doesn’t it constantly just trickle out?

Question

How do clouds hold so much water but then, as if someone opened a valve, it just starts falling out? Why doesn’t it constantly just trickle out?

In: Other

Answer 1

Clouds aren’t floating up there, at all. The cloud is water vapor, which is finely dispersed liquid, not the gas phase.

The reason clouds stay up there is a large amount of rising air and water vapor creating an updraft. It rains when the water forms droplets large enough that this updraft can’t support them anymore.