Stratus are low-lying clouds that resemble a covering or a blanket (Latin for stratus) in the sky. They generally sit below 6,000 feet and often have a gray tinge to them. Stratus clouds appear when a fog has lifted and rarely produce more precipitation than a drizzle. Another characteristic of a stratus cloud is that it will be much wider than it is tall. Stratus clouds form at other sky levels with different prefixes to indicate their location in the skyline.
Cirrus clouds are high in the sky (18,000 feet and higher) and made of ice crystals. Cirrus clouds are thin and wispy, often resembling strands of hair. Cirrostratus clouds have been known to bend sunlight, forming rainbow streaks and halos around the sun, because of the high content of ice crystals in them. The appearance of cirrus clouds can be an indication of snow or rain occurring in a few days. Cirrocumulus is another common cirrus cloud that causes a rippling pattern across the sky. This pattern is often referred to as a "mackerel" sky.
Cumulus clouds rest below 6,000 feet; stratocumulus clouds are below 6,000 feet as well but are the widespread blanket variety; and altocumulus clouds coincide with altostratus clouds in the middle area of the sky between 6,000 and 20,000 feet. Cumulus clouds are billowy fluffy clouds that often move fast, providing the much-loved shapes you often see in the sky. Cumulus clouds are characteristically as tall as they are wide.They form from rising pockets of air on sunny days and bear fair weather until they climb into upper regions of the sky.
Cumulonimbus clouds begin near the ground and can soar to 50,000 feet high. When the cumulonimbus continues to grow upward it becomes a thunderstorm cloud and can bring lighting, thunder, rain, hail, heavy winds and even tornadoes. A cumulonimbus cloud may begin as a cumulus cloud, but as it grows and towers vertically into middle and high regions of the sky it becomes a cumulonimbus. Cumulonimbus clouds are characteristically taller than they are wide. The top of this cloud often resembles a head of cauliflower.