Cumulus clouds are considerably easy to identify. They generally have a flat bottom with a puffy top and clearly defined edges. The word cumulus is derived from Latin meaning pile or heap and is very fitting, considering that cumulus clouds closely resemble a pile or heap of cotton.
Cumulus clouds are fair weather clouds close to the earth's surface. These clouds only have a life span from five minutes to about forty minutes. As the cloud ages, its edges become frayed and less defined due to cloud erosion.
Cumulus clouds often grow vertically as opposed to horizontally and form singularly, in lines or in clusters. Typically, cumulus clouds do not cause precipitation but given the right conditions, the cumulus cloud may develop into cumulonimbus clouds, causing thunderstorms, hail, lightning or even tornados.
These little puffy clouds form by convection. Warm bubbles of air called thermals rise from earth's surface. As they ascend, the water vapor inside of the thermals condenses and cools creating cloud droplets and forming the cloud. Because a cumulus cloud needs the thermal air to form, oftentimes as the sun gets ready to set you will see the cumulus clouds begin to disappear because it is not warm enough for the air to rise and condense properly.
The base of a cumulus cloud can start as low as 2000 meters and marks the height at which condensation begins to occur. This is why all the cumulus clouds in one area seem to have their base at relatively the same height. Cumulus clouds can grow up to twelve miles high and stretch over six miles across.
Cumulus clouds need a lot of moisture in the air to form, considering a medium sized cloud can hold over 1000 tons of precipitation, so they are more likely to form in a humid region even though they are found everywhere in the world. Depending on where the clouds are located can affect the clouds appearance. In windy conditions, the clouds will form in lines parallel to the wind but in mountainous regions, the cumulus clouds form lines at an angle to the wind due to the existence of lee waves. Over the ocean, cumulus clouds can appear as lines stretching out over miles and miles owing to the presence of trade winds.
These are the perfect clouds for watching, they lazily drift across the sky in an assortment of shapes. Let your creativity take hold as you imagine pictures out of the shapes these cumulus clouds make.