| Altocumulus lacunosus | |
| Image Location: | Altocumulusclouds.jpg |
| Image Name: | Altocumulus stratiformis lacunosus cloud, next to altocumulus floccus |
| Abbreviation: | Ac la |
| Symbol: | Clouds CM 3.svg |
| Genus: | alto-, meaning high, cumulo-, meaning heap, and lacunosus, meaning full of gaps |
| Variety: | lacunosus (full of gaps) |
| Altitude M: | Above |
| Altitude Ft: | Above |
| Level: | mid-level |
| Appearance: | Perforated with round, frayed holes |
| Precipitation: | uncommon |
Altocumulus lacunosus is a type of altocumulus cloud. The term lacunosus is from Latin, meaning "full of gaps". This type of cloud appears as holes present in an altocumulus cloud cover resembling a honeycomb. It is considered to be rare, since it is typically short-lived.[1] Lacunosus cloud types (including this one) forms when a layer of cold air and a layer of warmer air come in contact with each other. This then causes the cold air to sink in the form of localized downdrafts. These downdrafts then strike through the cloud and create the holes.[2] [3]