Sometimes the right combination of clouds and wind can cause threatening clouds and conditions. A hurricane is often characterized by a gigantic swirling of cumulus clouds that reach to high altitudes. A tornado is an example of clouds twisted to the shape of wind. While ominous clouds indicate bad weather, sometimes they are good. A mammatus cloud is formed by sinking air in a thunderstorm, and it signals the end of the storm.
Clouds influence the weather in many ways.
We've all seen cloudy days that look dreary, and the sunny days with no clouds. Sometimes clouds enhance a day, sometimes they do not. A blanket of clouds at night helps to retain heat in the atmosphere. Rainy clouds cause rain, and excess water vapor from clouds is the basis of rainbows. The weather channel is a great source of information about what the clouds are going to do next.