But they can also form a wide variation of shapes and sizes, from castle towers, to a spool of wool, to blanketing the entire sky. Cumulus clouds are the default cloud when it comes to doodling ...

Obviously, clouds come in all shapes and sizes ... that look like cotton balls on nice days and are called "fair weather cumulus" clouds. Cumulus clouds are individual clouds.

At these heights, the atmosphere is cold enough that clouds are typically composed of ice crystals, not water droplets. These clouds often look thin, wispy, and delicate—but they can provide valuable ...