When water droplets become large enough in a cloud what happens?
Water vapor (that has evaporated) condenses into cloud droplets in the cooler atmosphere. Many of these droplets form clouds. When enough water molecules with the clouds form together, they become too heavy for the upward flowing air to keep them in the cloud. The droplets then fall back down to earth as precipitation, rain being the most common form.
One theory explaining how the behavior of individual droplets leads to the formation of clouds is the collision-coalescence process. Droplets suspended in the air will interact with each other, either by colliding and bouncing off each other or by combining to form a larger droplet. Eventually, the droplets become large enough that they fall to the earth as precipitation. The collision-coalescence process does not make up a significant part of cloud formation as water droplets…
All snow begins as snow through what is called the Bergeron process. Water droplets within a cloud get drawn to the tiny ice crystals in the cloud due to their lower vapor pressure. In doing so, they diffuse onto the ice crystals, causing them to grow. When they become large enough, they fall out of the cloud as snowflakes.
Simple answer: They don't. Clouds ARE water - tiny, tiny droplets of water just like fog. If colder air moves into a cloud, it causes there to be even more water droplets forming. When the droplets get close enough together, they start touching and turning themselves into even larger droplets. Then the "even larger" water droplets touch, and make water drops . . . at some point in this process, the water droplets grow large…
When the sun shines on the sea, it evaporates. The water droplets form clouds. This is called condensation. When the clouds hit a weather front the water droplets fully condense into droplets, which, when they get heavy enough, drop out of the cloud as rain. Then the whole cycle starts over again. This process is called the water cycle.