Watch for clouds with an obvious puffy shape, billowing into forms resembling cotton balls or mounds of whipped cream.
Step2
Look for cumulus clouds at any altitude.
Step3
Watch out for thunderstorms when cumulus clouds begin to build in mounds rising higher and higher.
Variations of Cumulus Clouds
Step1
Look above 18,000 feet for cirrocumulus clouds, which most often resemble long rows of puffs.
Step2
Watch between 6,500 and 18,000 for altocumulus clouds, which can appear partly white and partly gray.
Step3
Classify puffy clouds under 6,500 feet as stratocumulus.
Step4
Watch closely as cumulus clouds begin to increase in size vertically. A weather change may be imminent.
Step5
Look out when cumulus clouds change to cumulonimbus clouds, readily identifiable when the tops begin to shear off because of high winds. Cumulonimbus clouds may quickly evolve into thunderstorms.
Tips & Warnings
Cumulus clouds on the horizon at sunrise or sunset can be wonderfully colorful and good subjects for photographic studies.
Cumulus clouds form when air warms and rises. As it rises, it cools, the water vapor carried aloft begins to condense, and fluffy cumulus clouds begin to form.
For a detailed explanation for making a visual estimate of where these altitudes are in the sky, see the Related Site, "Measuring Angles and Distances." For 18,000 feet, try to visualize 60 American football fields all in a row.
Weather watching is fun, but quickly seek shelter when there's a severe thunderstorm with heavy lightning.