Normally, there are those black clouds that will give you one of a few clues that is going to rain. The research is that anytime that there is water, land, and sea the sun will melt the water. The dew point happens to call when it water to air and is related to the humidity. . It then cools down and becomes water drops, and this is what is done to make these clouds.
Usually you can see the sun through the white clouds. Depending on the altitude, these are soaked in water, grow in size and are filled with water, and when the clouds become very full, then they finally rain. Another name for these storm clouds are nimbus clouds. In other information for the clouds is the thickness, not much light will get between the thick clouds.
There is a scale that for a clear cloud the thickness is 2-8 and for cloudy the thickness is 9-10. The specific names of these clouds are Cirrus which is thicker and white clouds, and the Nimbostratus is low and dark clouds more of a pattern. Then the Cumulonimbus is the big thunderclouds, which is the very thick clouds. These thunderstorms are colors of either black or dark green.
This is when the thunderstorm is the actual stage. From the beginning, the storms have 3 stages, and lasts roughly about 10 minutes and will go for about 10-20 minutes. As an example, of the droplets of water you can actually see this effect if you look carefully at the spout of a boiling kettle of water.
The middle part of the clouds in the area of 6500 and 20,000 feet and can tell you if bad weather is getting closer and you may want to watch for it. Sometimes depending on where you are at, a block the dark clouds except wider and spinning can be defined as a tornado. The dark clouds will get bigger and wider the strength of the tornado occurs.
Observing the dark, solid clouds are is a great way of observing the severeness of weather. There are such things that are referred to supercells. Which means that this is far more dangerous storm coming. The very dark black clouds or scary looking ones are a great way of telling if a storm is coming. If it is rotating then it is usually going to produce a tornado.