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Name: rick
Status: other
Grade: other
Location: CA
Country: N/A
Date: 1/9/2005

How big to clouds get? I often see a jet fly through some clouds dwarfing the jet.

Rick -

The answer to your question depends somewhat on how you define cloud. But a case can be made for some of the clouds being huge. For instance along a warm front warm air (being lighter than the cold air) climbs over the cold air. As it does so it cools to the dew point and a cloud forms. The cloud can be as long as the front... hundreds of miles.

Typically clouds do not grow vertically above about 20,000 or 30,000 feet (4 to 6 miles), but compared to an airplane that is still large. One type of cloud - the cumulonimbus - grows vertically to heights of 60,000 or 70,000 feet (12 to 14 miles). Those are the large storms we call thunder heads.

On the other side of the spectrum even the "steam" coming off a cup of coffee is a cloud. That one is quite small and short lived, but still technically a cloud.

Larry Krengel

Dear Rick-

Cloud size depends on several factors...the type of cloud, the amount of moisture in the air at the level the clouds are forming, the amount of "mixing" or turbulence at the cloud level, and others. But the stratus type of clouds, are arrayed in a continuous sheet, and can stretch for thousands of miles. If you look at a visible satellite picture, you can see clouds stretching completely across the United States, especially in the wintertime.

Wendell Bechtold, meteorologist
Forecaster, National Weather Service
Weather Forecast Office, St. Louis, MO


Clouds come in a large range of sizes, from only a few feet across for the smallest puffy, fair weather, cumulus cloud to gigantic in the case of a huge cumulonimbus thunderstorm cloud (which can be several miles across).

Then again, if you have a cloud cover, like on a grey winter day, the cloud can extend for several hundred miles north, south, east, and west.

David R. Cook
Atmospheric Physics and Chemistry Section
Environmental Research Division
Argonne National Laboratory

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