1.1.3. Different types of convective clouds – from fair weather clouds to thunderstorms
Convection forms distinct types of clouds. Convective clouds are divided into two types (genera): cumulus and cumulonimbus. Each successive type and species displays more vertical development as a result of more convective energy being available. The more convective energy is available, the higher the convective cloud will reach. In terms of how high convection goes, there are two types of convection. If convective clouds reach above ~6 km high, it is called deep convection. If convective clouds do not reach as high, it is called shallow convection. Only deep convection produces strong rain showers and thunderstorms.
In convective clouds, there are five distinct stages of vertical development: three stages of cumulus clouds (humilis, mediocris, congestus) and two stages of cumulonimbus, which is already a thunderstorm. Cumulus clouds are generally ‘harmless’ billowing convective clouds with tops reminiscent of cauliflower. Only the largest of the three, Cumulus congestus can produce stronger rain showers. Cumulonimbus clouds develop from Cumulus congestus stage into Cumulonimbus calvus, which may then evolve into a Cumulonimbus capillatus or a Cumulonimbus capillatus incus.
Let us now explore each stage and then go on to numerous examples of each stage.