I WONDER - Are Clouds Heavy?

Clouds, though appearing light, carry significant amounts of water. A typical cumulus cloud weighs around 250 tonnes, surpassing the weight of the Statue of Liberty. Storm clouds are even heavier, with thunderstorm clouds capable of holding nearly 10 million tonnes of water.

How does the weight of a cumulus cloud compare to the Statue of Liberty?

Why do storm clouds hold more water than regular cumulus clouds?