Mid level clouds

Mid-level clouds are Altostratus and Altocumulus. Altostratus clouds are usually grayish clouds that cover part or all of the sky. These clouds are composed of water droplets or ice crystals. At sea, Altostratus clouds are an important weather indicator. These clouds can indicate that rain or snow is approaching, associated with poor visibility and huge waves with heavy swell.
Altocumulus clouds are a detailed cloud deck of cumuliform clouds. These clouds are composed mainly of water droplets. Ice crystals are only present at very low temperature. When altocumulus clouds are in parallel bands, a warm front with continuous rain or snow can be expected. Altocumulus clouds rising from their flat base indicate heavy showers and thunderstorms.