Couldn't find element LayerAd

Error finding content

Altocumulus Clouds - Windows to the Universe

Shop Windows to the Universe

Warnings: The True Story of How Science Tamed the Weather by Mike Smith tells the story of our storm warning system. See our online store book collection.
This is a photograph of altocumulus clouds.
Click on image for full size
Courtesy of UCAR Digital Image Library

Altocumulus

Altocumulus clouds are part of the Middle Cloud group. They are grayish-white with one part of the cloud darker than the other. Altocumulus clouds usually form in groups.

Altocumulus clouds are about as wide as your thumb when you hold up your hand at arm's length to look at the cloud.

If you see altocumulus clouds on a warm sticky morning, then expect thunderstorms by late afternoon.


Last modified September 25, 2007 by Becca Hatheway.

Shop Windows to the Universe Science Store!

The Fall 2009 issue of The Earth Scientist, which includes articles on student research into building design for earthquakes and a classroom lab on the composition of the Earth’s ancient atmosphere, is available in our online store.

Windows to the Universe Community

News

Opportunities

You might also be interested in:

Cool It! Game

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

Middle Clouds

The middle cloud group is made up of Altostratus and Altocumulus clouds. Middle clouds are made of ice crystals and water droplets. The base of a middle cloud above the surface can be anywhere from 2...more

Thunderstorms

Thunderstorms are one of the most exciting and dangerous types of weather. Over 40,000 thunderstorms happen around the world each day. Thunderstorms form when very warm, moist air rises into cold air....more

Altostratus

Altostratus clouds belong to the Middle Cloud group. An altostratus cloud usually covers the whole sky. The cloud looks gray or blue-gray. The sun or moon may shine through an altostratus cloud, but will...more

Stratocumulus

Stratocumulus clouds belong to the Low Cloud group. These clouds are low, lumpy, and gray. These clouds can look like cells under a microscope - sometimes they line up in rows and other times they spread...more

Cloud Formation and Weather Fronts

Weather fronts can cause clouds to form. Fronts happen when two large masses of air collide into each other at the Earth's surface. Warm fronts produce clouds when warm air replaces cold air by sliding...more

Altocumulus

Altocumulus clouds are part of the Middle Cloud group. They are grayish-white with one part of the cloud darker than the other. Altocumulus clouds usually form in groups. Altocumulus clouds are about...more

Cirrocumulus

Cirrocumulus clouds belong to the High Cloud group. They are small rounded puffs that usually appear in long rows. Cirrocumulus are usually white, but sometimes appear gray. Cirrocumulus clouds are the...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part by the National Science Foundation and NASA, our Founding Partners (the American Geophysical Union and American Geosciences Institute) as well as through Institutional, Contributing, and Affiliate Partners, individual memberships and generous donors. Thank you for your support! NASA AGU AGI NSF