The formation of clouds was the topic of the following reader question- Can you actually watch a cloud coalesce (I talking actual formation, not shift from one form to another) in the sky? Or does it happen too high for the naked eye to see?
Answer:
Cloud formation occurs as gaseous water molecules coalesce and collect on particles of dust, sea salt and other cloud condensation nuclei in the atmosphere. If you were to sit long enough outside, you could actually see a cloud forming, but the results might be a bit boring if you are looking at a clear sky waiting for a cloud. In other words, the weather conditions must be conducive to cloud formation.
But there is more to this question than meets the eye. As a cloud shifts shape in the atmosphere, you are actually watching clouds form right before your eyes. The shifting shape of clouds is often due to winds aloft and shifts in temperature in the atmosphere. As a cloud moves and shifts, there is a constant coalesce of water molecules occurring. In other words, clouds are usually building or dissipating as you watch them.
The formation of a cloud happens at a microscopic level, but with billions of molecules collecting on cloud nuclei at the same time, a cloud can appear in moments. For instance, an anvil cloud can grow and take shape right before your eyes. As updrafts fuel a developing thunderstorm, clouds are forming and climbing higher into the atmosphere at a relatively rapid speed. In yet another example of cloud formation, think of fog. Fog is essentially a cloud next to the ground. You can sit and watch fog form over a field if you watch long enough.
Make Your Own Cloud
If you want to see a cloud form very rapidly, you simply need to complete an easy at-home experiment. Making a cloud in a bottle will cause the coalescence of water molecules on smoke particles right before your eyes. Of course in this instance, the formation is very rapid. A slow-motion camera might be able to catch the cloud formation at a rate more easily seen.
More Cloud Formation Examples
- In another interesting observation, remember that clouds can be composed of liquid or solid (ice) particles. In many instances, cirrus clouds high in the sky can actually take on a wispy look because the ice crystals are falling towards the ground and get blown by winds.
- In the case of a typical thunderstorm cloud, you can see the cloud falling right out of the sky, piece by piece...as rain! Rain is simply a lot of the water particles in a cloud further aggregating into a larger form that eventually falls from the cloud.
- You can see clouds instantly form at the tail end of an airplane. These man-made clouds are called contrails.
- You can also see a cloud form when you go outside on a cold and wintry day. Breathing in and out will instantly make a cloud form in front of you.
- You can gather more information by researching the various types of clouds commonly found in the atmosphere and their associated weather map symbols.