After reading these facts, the next time it’s “partly cloudy,” you might have a little more knowledge!

Studies indicate that 67% of Earth is covered by clouds at any given time.

•    It might look like a giant marshmallow, but a cloud is really a mass of water droplets or ice crystals suspended in the atmosphere. They form when water vapor condenses in the air. There are three necessary items for clouds to form – moisture, condensation, and temperature.

•    Clouds are classified according to their shape and their height in the atmosphere. Cumulus clouds have a flat base and are often    described as puffy or cotton-like. The word translates from the Latin word for “heap” or “pile.” They are low-level clouds, usually less than 6,600 feet (2,000 m) in altitude. They can form in long lines called cloud streets that extend over 300 miles (480 km). Cumulus clouds usually form during high-pressure weather systems, such as following a cold front. An individual cloud is about 0.62 miles (1 km) wide.

Stratus clouds are also low-level clouds, but are flat and hazy, varying from dark gray to white. The Latin word for “layer” gives them their name. They might bring a light drizzle or a dusting of snow.    Another low-level cloud, the stratocumulus, consists of large, dark, rounded masses in lines or waves. While they don’t usually generate precipitation, you’ll see them at the beginning or end of a storm, in the form of a thunderhead.   

• Mid-level clouds include altocumulus and altostratus. You’ll see altocumulus clouds in groups, about 0.62 miles (l km) thick. If you spot these grayish-white clouds on a warm, humid morning, there’s a good chance for a thunderstorm by late afternoon.    The gray or blue-gray altostratus clouds indicate a continuous rain or snow storm might be on its way.   

    The highest clouds in the sky are cirrus, cirrocumulus, and cirrostratus. They’ll be found at heights between 16,000 and 49,000 feet (5 to 15 km). Cirrus clouds are composed of ice crystals that form when water vapor deposits onto tiny particles of dust or smoke. They have a wispy appearance, sometimes resembling hair tufts, generally occurring during fair weather. Cirrocumulus are small rounded puffy clouds, resembling the scales of a fish when in a group. Widespread in winter, they’re a sign of fair, but cold weather. Cirrostratus are high, thin sheets of clouds that often cover the entire sky. Watch for them 12 to 24 hours before a rain or snow storm.

Nimbus clouds are precipitation bearers, whether it be rain, hail, snow, or sleet. Because they are dense with water, these low-altitude clouds have a darker appearance, grayish-black in color and spread across the sky uniformly.

    A cumulus cloud might look like a cottony puff, but a typical one, 0.62 miles (1 km) across, weighs an astounding 1.1 million pounds (498,951 kg), about the weight of 100 elephants! Cumulonimbus clouds contain about six times as much weight as the average cumulus cloud.    A ferocious thunderstorm might contain billions and billions of pounds of water in just one small part of the sky. How can a cloud that heavy just float in the air? Because the air below it is even heavier and denser!

    As you watch clouds drift lazily across the sky, you can figure they are traveling at speeds ranging from 30 to 120 miles per hour (48 km/hr to 194 km/hr.) During the air currents known as jet streams, cirrus clouds might travel more than 100 mph (160 km/hr).

    When a cloudburst occurs, dropping a huge amount of precipitation in a short period of time, flooding is frequently the result. In 2005, more than 57 inches (1,448 mm) of rain fell in Mumbai, India, in just 10 hours, history’s worst cloudburst.