With the 50th anniversary of the Apollo moon landing in 2019, multiple SpaceX rocket launches, and a return to Mars in 2020, the United States is once again looking up to the sky and the stars. But what about the sky closer to home?
Meteorology is the study of the atmosphere, especially as it relates to weather patterns and conditions. Among other things, it includes the classification and observation of different types of clouds. Clouds can tell us a lot about the weather, but the casual weather-report watcher probably doesn't know the various types or what they may signify. Here's a brief overview of the names of the clouds in the sky, where they’re located, and just what they represent for your weather forecast.
High-Altitude Clouds
In the highest altitude of the sky, you have four main types of clouds: cirrocumulus, cirrus, cirrostratus, and cumulonimbus.
Cirrocumulus clouds are usually white, but sometimes gray, and very small. When there are a lot of them, the sky can look like fish scales (commonly known as a mackerel sky). They’re most common in winter and tend to show cold, but fair, weather.
Cirrus clouds are the most common high-altitude clouds. Thin and wispy, they tend to foretell fair weather and can reveal the direction of the wind at their elevation.
Cirrostratus clouds are high and thin, like sheets that cover the sky. They're so thin, in fact, that the sun and moon can shine through them, creating a halo. These clouds tend to come 12 to 24 hours before snow or rain.
The last high-altitude clouds, cumulonimbus, are harbingers of heavy rain, thunderstorms, and lightning. They are the lowest of the high-altitude clouds and are also called thunderheads, due to their mushroom-like shape. The rain they produce is heavy, but short.
Mid-Altitude Clouds
In the mid-altitude range, you have two different types of clouds: altocumulus and altostratus.
Altocumulus clouds look like gray puffballs and tend to appear in groups. If you see them on a warm humid morning, thunderstorms will be coming in soon.
Altostratus clouds are dark blue or gray clouds that cover the whole sky in a thick sheet. If the sun or moon shines through, the light will be watery or fuzzy. When these appear, continuous snow or rain may be on the way.
Low-Altitude Clouds
Finally, there are three low-level cloud types: stratus, cumulus, and stratocumulus.
Stratus clouds mean rain if it’s warm and snow when it’s cold. They're thick, heavy gray clouds. When they’re especially low, they are called "fog clouds."
Cumulus clouds are the quintessential puffy white cotton-ball clouds. If they continue to grow vertically, they turn into cumulonimbus clouds.
Stratocumulus clouds are low, lumpy, and gray, and appear in either waves or lines. But with stratocumulus clouds, the forecast is dry.