eli5: How do (presumably very heavy) clouds stay suspended in the sky? More specifically how are they floating AND flat on the bottom?

Question

And what causes them to suddenly drop all of that water in the form of rain.

Judging by the amount of rain they must weigh a ton.

In: 337

Answer 1

So the first question is actually very simple – clouds are a combination of hot air, wind, and liquid water droplets. When water vapor condenses into liquid droplets, it releases heat into the surrounding air. Because of the hot air, they’re lower density enough to stay suspended, and the wind keeps the water droplets moving upward more than they fall.

And when they can’t stay suspended any more (due to the air getting less hot or the wind blowing downward instead of up or the droplets getting too big relative to the wind and hotness of the air), that’s when you get rain.

Clouds are flat because you have to reach a certain altitude before the water vapor can condense into droplets, and the transition between ‘unable to condense’ and ‘able to condense’ is usually a smooth line