Why there is no rain when clouds are scattered?

[Muthumanimaran]

Raining only occurs when there are dense clouds in the sky, when they are scattered the raining is stopped, why?

 

[Borg]

In many clouds, it actually is raining. It's just that there isn't much rain falling and it evaporates before it gets to the ground. In a larger, denser cloud, the rain reaches the ground before it has a chance to evaporate.

 

[russ_watters]

Rain comes from clouds. Clouds are opaque because they contain condensed water dropplets.

 

[rcgldr]

This is not always true. When I lived in Houston Texas, there could be a medium sized single dark cloud pouring rain as it crossed over you, with otherwise clear skies. As the cloud was approaching or leaving, you could see a "wall" of water coming down from the leading or trailing edge of the cloud.

 

[russ_watters]

Maybe I misunderstood the question. If he was asking why rain is more likely on very cloudy days than moderately cloudy days, it is because a very cloudy day has more moisture in the sky. On a moderately cloudy day, a cloud has an easier opportunity to dissipate instead of raining.

But as per the above, certain weather patterns can cause rain from lone clouds, particularly pop-up thunderstorms.

 

[davenn]

Maybe I misunderstood the question. If he was asking why rain is more likely on very cloudy days than moderately cloudy days, it is because a very cloudy day has more moisture in the sky. On a moderately cloudy day, a cloud has an easier opportunity to dissipate instead of raining.

no, not necessarily ... you can have almost 100% humidity on a sunny summer day and not a cloud in sight. ie. the air/atmosphere is very moisture laden

its the concentration of moisture per unit of volume combined with temperature that will cause condensation and then precipitation

 

[russ_watters]

no, not necessarily ... you can have almost 100% humidity on a sunny summer day and not a cloud in sight. ie. the air/atmosphere is very moisture laden

A cloud is at 100% RH (or greater), which is greater than "almost 100%.

its the concentration of moisture per unit of volume combined with temperature that will cause condensation and then precipitation

Agreed.

 

[davenn]

A cloud is at 100% RH (or greater), which is greater than "almost 100%.

Agreed.

just pointing out that you can have 100% humidity on a couldless day