* Stratus (St): These are flat, featureless, gray clouds that cover the entire sky. They often produce drizzle or light rain.
* Stratocumulus (Sc): These are gray or white clouds that appear as patches or rolls. They often have a "lumpy" or "cotton-ball" appearance. They may produce light rain or snow.
* Nimbostratus (Ns): These are dark, thick, gray clouds that often cover the entire sky. They produce continuous rain, snow, or sleet.
* Cumulus humilis (Cu hum): These are small, white, fluffy clouds that look like cotton balls. They are often associated with fair weather.
* Cumulus congestus (Cu con): These are larger, towering cumulus clouds that can develop into thunderstorms.
It's important to note that while these clouds form at the lowest altitude, they can sometimes extend upward into higher levels of the atmosphere. For example, cumulus congestus clouds can grow into cumulonimbus clouds, which are towering storm clouds that can reach the tropopause.
