The formation of noctilucent clouds is a ... hinting at the power and energy building beneath. Altocumulus castellanus clouds resemble castles in the sky, with towering turrets and spires that ...

Kelvin-Helmholtz clouds are a type of formation, not type of clouds on their own. They tend to appear on these five cloud types: cirrus, altocumulus, cumulus, stratus, and stratocumulus.