The Mysteries of Clouds: Types, Formations, and Weather Predictions
Look up at the sky, and you’ll likely see a beautiful canvas of light or dark clouds. Clouds are more than just picturesque elements in the sky; they play a vital role in the Earth’s atmosphere, serving as indicators of impending weather events. As such it is important for everyone to know more about clouds: what they are, their various types, and how they can be used to predict weather changes.
What Are Clouds?
Clouds are visible masses of water droplets or ice crystals suspended in the Earth’s atmosphere. They form when moist air rises, cools, and condenses around tiny particles called cloud condensation nuclei (CCN). These particles can be dust, pollen, or even pollution. As the air cools, it loses its capacity to hold water vapor, causing the vapor to condense into tiny water droplets or ice crystals. These millions of droplets or crystals come together to form the visible cloud.
Different Types of Clouds
Understanding these different cloud types and their characteristics can help individuals better understand the atmosphere surrounding them. The first three types of clouds we will discuss are shelf, “mothership”, and green clouds as they are often the most researched by the public and have strong associations with severe weather. Then we will discuss the remaining types of clouds that are essential to meteorologists and forecasting.
Shelf clouds are often observed at the leading edge of severe thunderstorms, indicating the approach of turbulent weather. Shelf clouds are low, horizontal, and wedge-shaped cloud formations that often resemble a long, ominous, and dark shelf hanging beneath a larger cloud mass. Shelf clouds can be menacing in appearance, with a dark, ragged edge and a smooth, rolling, or curved front.
These clouds typically form along the leading edge of a thunderstorm or a squall line. They result from a combination of moist, warm air rising and cooler, denser air descending rapidly from the storm. Shelf clouds are often seen in severe thunderstorms, particularly those with strong outflow winds. When a shelf cloud approaches, it signals the arrival of turbulent weather conditions. While not typically associated with tornadoes, they are indicative of strong winds, heavy rain, and the potential for hail.
Mothership Clouds (Supercell Storm Clouds)
“Mothership Clouds”, or super cell thunderstorms, are eerie in appearance and dangerous in nature. Within these massive cloud structures are likely powerful thunderstorms, severe in nature, and even tornadoes. They get their namesake for their physical structures that resemble the underside of a flying saucer or spaceship. They often have a dome-like shape with a flat base and a towering, rounded upper portion. Mothership clouds are often characterized by their unique, otherworldly appearance, with a dark or ominous base and a towering, sculpted upper structure.
These clouds are associated with supercell thunderstorms, which are the most severe and long-lasting type of thunderstorm. Mothership clouds form within the rotating updraft of a supercell. Supercells are capable of producing extremely severe weather, including large hail, damaging winds, and tornadoes. When you see a mothership cloud, it signifies that a supercell storm is in progress or forming. The presence of a mothership cloud often warrants immediate attention and can be a precursor to destructive weather events.
Green clouds are a rare but visually striking atmospheric phenomenon. While they may appear otherworldly, they serve as a reminder of the unpredictable and potentially dangerous nature of severe weather, emphasizing the importance of staying informed and taking appropriate safety measures when such clouds are spotted. The green coloration of clouds is primarily attributed to the scattering of sunlight by water droplets or ice crystals within the clouds.
Green clouds are most commonly observed in association with severe weather events, particularly thunderstorms or severe thunderstorms. During these storms, the setting sun or low-angle sunlight can pass through the atmosphere at an angle that enhances the scattering of shorter wavelengths of light, such as green and blue. This can lead to the greenish appearance of the clouds.
Sometimes, the green tint can be intensified if the storm contains large hail. The presence of hailstones in a storm cloud can enhance the scattering of light, contributing to the green color. Certain atmospheric conditions, such as a combination of moisture, particulate matter, and sunlight angles, can create the conditions necessary for green clouds to form. These conditions are relatively rare but not unheard of.
Green clouds are often seen as a sign of impending severe weather. Thunderstorms that produce green clouds can bring a range of hazardous weather conditions, including:
- Hail: Green clouds are frequently observed in hail-producing storms. Large hailstones can cause significant damage to crops, buildings, and vehicles.
- Tornadoes: While not a direct indicator of tornadoes, greenish clouds in a severe thunderstorm may precede the development of tornadoes, particularly in supercell thunderstorms.
- Strong Winds: Severe thunderstorms can produce strong winds capable of causing damage, and green clouds may be a visual cue for the presence of such storms.
Safety Precautions: If you observe green clouds, it’s important to take them as a sign of potentially severe weather and take appropriate precautions:
- Have a business plan in place and have employees seek shelter indoors to protect personnel from hail, strong winds, lightning, and other hazards associated with severe thunderstorms.
- Stay informed about weather conditions by monitoring weather forecasts and warnings issued by local authorities. Have battery powered radios in shelter locations throughout the facility or office.
- If you are in an area prone to tornadoes, be especially vigilant and have a business emergency plan in place for seeking shelter in case a tornado warning is issued.
Cirrus clouds are high-altitude clouds that appear wispy, delicate, and thin, often forming feathery streaks or filaments across the sky. They are composed of ice crystals and form in the upper reaches of the troposphere. These clouds are typically associated with stable and fair weather conditions.
The presence of cirrus clouds often indicates that a warm front is approaching. While they do not produce precipitation themselves, they can be a sign of changing weather, with rain or snow expected within the next 24 to 48 hours.
Cumulus clouds are characterized by their fluffy, puffy, and often cauliflower-like appearance. They usually have a flat base and can develop into various shapes. Cumulus clouds form at low to middle altitudes when warm, moist air rises and cools, leading to the condensation of water vapor. They are associated with fair weather when small and isolated but can grow into larger, more developed clouds.
While cumulus clouds themselves do not indicate immediate precipitation, their growth into cumulonimbus clouds signals the potential for thunderstorms and heavy rainfall.
Stratus clouds are low-altitude clouds that form in uniform, flat, and featureless layers. They often cover the sky, creating a gray or overcast appearance. These clouds form when moist air is lifted gently and cools, causing the water vapor to condense into a continuous layer of cloud cover.
Overcast skies with stratus clouds typically bring light precipitation in the form of drizzle, light rain, or snow. They can persist for extended periods, leading to prolonged periods of damp and gloomy weather.
Nimbus clouds are associated with precipitation and often appear dark and heavy. The term “nimbo-” is used in conjunction with other cloud names to indicate various forms of rain or stormy weather, such as “nimbostratus” or “cumulonimbus.” Nimbus clouds form when there is sufficient moisture and uplift of air to produce precipitation.
When you see nimbus clouds, it’s a strong indicator of ongoing precipitation, whether it’s light rain, heavy rain, or snow.
Altocumulus and Altostratus Clouds
Altocumulus clouds are mid-level clouds characterized by their white or gray patches, rolls, or layers. They form at middle altitudes and can indicate fair weather or the approach of a warm front. Altostratus clouds are mid-level clouds that often create a uniform, gray, and overcast sky. They are associated with the potential for precipitation, usually in the form of rain or snow.
Cumulonimbus clouds are towering, anvil-shaped clouds that can reach high into the atmosphere. They are often dark and foreboding, with a flat, anvil-like top. These clouds develop from cumulus clouds that grow vertically due to strong updrafts. They form at various altitudes, including low, middle, and high levels of the troposphere.
Cumulonimbus clouds are associated with severe weather events, including thunderstorms, heavy rain, hail, strong winds, and sometimes tornadoes. They are a visual indicator of imminent stormy weather and can be highly destructive.
Clouds Aren’t the Only Weather Predictor
Clouds can be an essential aspect of staying weather aware as they often precede specific weather events. However, while they can be a good factor for predicting weather, they aren’t the only parts of a reliable forecast. Meteorological experts rely on several factors and advancements in technology and Numerical Weather Prediction to produce accurate weather data. If you’d like to learn more about Climavision and how we are combining meteorological expertise with advancements in weather forecasting technology, contact us.