Weather 101: A Tutorial on Cloud Types
Clouds are an ever-changing aspect of weather. Clouds can often be a great visual indicatorof certain weather patterns, and they can even act as a harbinger of upcoming weatherconditions. In this brief tutorial, we will discuss four primary types of clouds, as wellas some combinations or hybrids within these categories. We’ll show some specific examplesof each, and some of the weather elements associated with these different cloud types.Clouds are categorized by their structural characteristics and the height in the atmosphereat which they develop. The four main forms of clouds are cirro-form, cumulo-form, strato-form,and nimbo-form. There can be different combinations or hybrids of these cloud types.Cirrus clouds are high level clouds that typically form between 16,000 and 50,000 feet abovethe surface. The Latin word “cirro” means curl of hair. Many times cirrus clouds canmimic curls of hair due to the thin, wispy structure they exhibit. “Cirro” can alsobe used as a prefix to describe high level clouds. Cirrus clouds are composed of tinyice crystals suspended in the upper parts of the troposphere, the layer of the atmospherewhere all weather occurs. Cirrus clouds are often thought of as “indirect” indicatorsof weather patterns. Sometimes they may accompany a strong jet stream in the upper atmosphere.Cirrus clouds can also be seen preceding surface fronts by more than a day or two.
Cumulus clouds might be one of the more recognizable cloud types. “Cumulo” is Latin for heapor pile. Cumulus clouds often are detached or isolated from other clouds, and will oftenappear as fluffy white cotton balls or perhaps even cauliflower. These clouds are consideredlow level clouds, usually forming between a few hundred to a few thousand feet abovethe surface. In the desert Southwest and much of New Mexico these cloud bases will oftenform at higher levels than other parts of the country due to the warm and arid conditions.Strato-form clouds or layer clouds often appear as a sheet or layer of cloud that exhibitslittle definition or features. In other words they will typically appear as a hazy whiteor gray mass. Stratus clouds are primarily thought of as low clouds, but can be observedin the middle to upper parts of the atmosphere as well. Mid level stratus clouds are referredto as altostratus and high level stratus are commonly identified as cirrostratus.Nimbo-form clouds are also representative of a hybrid or combination of different cloudcategories. “Nimbo” is Latin for rain. The two common nimbo-form cloud types arenimbostratus and cumulonimbus. As you can probably guess, nimbostratus clouds are layered,producing rain or precipitation. These clouds can extend into the middle to upper partsof the troposphere, but are typically only seen in the lower parts since they will usuallyobscure any clouds above. Cumulonimbus are also a unique hybrid of cloud that extendsfrom the lower to the upper parts of the troposphere and are otherwise known as thunderstorm clouds.We briefly mentioned cirrostratus, but another high level cloud is cirrocumulus. These aresimilar to altocumulus, the difference being that altocumulus form in the mid levels ofthe troposphere while cirrocumulus clouds are in the highest part of the troposphere.Altocumulus clouds have some variations of their own.
One such variation that frequents New Mexico is the altocumulus standing lenticular, sometimessimply referred to as lenticular, lennies, or wave clouds. These clouds are common onthe leeward side of topographical barriers such as mountains where a stable layer ofair is found above the crest or peaks of the topography.Stratocumulus clouds are another combination of two previously mentioned categories: stratusand cumulus
So, we’ve discussed a few of the more common cloud types. We invite you to scan the skies,and maybe you can identify a few of these cloud types on your own. For more informationrefer to the National Weather Service website, including the “Jetstream” website whereyou can learn more about clouds with additional charts and imagery.