| Altocumulus volutus | |
| Image Location: | Altocumulus volutus (22112021).jpg |
| Image Name: | Distant altocumulus volutus cloud |
| Abbreviation: | Ac vol |
| Genus: | Altocumulus |
| Species: | Volutus |
| Altitude M: | 2,000-7,000 |
| Altitude Ft: | 7,000-23,000 |
| Level: | mid |
| Appearance: | small, single, horizontal, rolling mid-level altocumulus line |
| Precipitation: | None |
Altocumulus volutus is a type of altocumulus cloud. This cloud type has the appearance of a single, small, horizontal, rolling line, it is relatively rare compared with its counterpart stratocumulus volutus,[1] This cloud does not attach to any other cloud. It may or may not appear with altocumulus clouds of different species. When found in a thunderstorm, it forms when cold air from a thunderstorm's downdraft makes the already present warm and moist air rise, expanding and cooling as it rises. It then condenses, although the most likely scenario is that it condenses into a shelf cloud or roll cloud, rather than an altocumulus volutus cloud.[2] When found in environments where it is not associated with a thunderstorm, it forms because of wind shear (difference of wind speed and direction between the mid-levels of the atmosphere and the surface).[3]