A different subtype known as altocumulus floccus is sometimes created when castellanus clouds break up. Altocumulus floccus: Ac flo: Individual small bundles with fringy lower parts, frequently with schleps. Altocumulus clouds Altocumulus are located above the lower cumulus principal cloud type. Altocumulus are extremely varied. Within the cloud. Altocumulus (From Latin Altus, "high", cumulus, "heaped") is a middle-altitude cloud genus that belongs mainly to the stratocumuliform physical category characterized by globular masses or rolls in layers or patches, the individual elements being larger and darker than those of cirrocumulus and smaller than those of stratocumulus. The ‘castellanus’ cloud species can be found amongst four cloud types: cirrus, cirrocumulus, altocumulus, and stratocumulus.

Floccus clouds look like small tufts with rounded tops and fraying bases, which may indicate trails of rain or snow.

photographer: place: time: Uwe Reiss - - imprint your photos your photos This occurs due to air instability resulting from the slow rising of warm damp air coming from cold frontal system. There is also a hint of more vertical development and less horizontal spreading. Altocumulus clouds chiefly consist of super-cooled water droplets of minus 10C, but ice crystals are often present. Altocumulus castellanus clouds form due to the atmospheric convection at mid-level clouds. Such clouds usually develop into thunderstorms when seen in the morning as was the case here. The layer of castellanus clouds is roughly 5 km above ground (16,400 feet altitude). These small towers, some of which are taller than wide, usually stand on a common base and appear to be arranged in line. Altocumulus Castellanus A middle cloud with vertical development that forms from altocumulus clouds. Altocumulus stratiformis: Ac str: Expanded horizontal fields or layers. Altocumulus castellanus: Ac cas: from a common cloud bank such as growing turrets. This is evident on the first two thumbnails. Altocumulus lenticularis: Ac … Altocumulus castellanus: Ac cas: from a common cloud bank such as growing turrets. Usually they do not produce rain, but might indicate a weather change within a day or so.

Cirrocumulus clouds come in four species which are common to all three genus-types that have limited-convective or stratocumuliform characteristics: stratiformis, lenticularis, castellanus, and floccus. Altocumulus floccus: Ac flo : Individual small bundles with fringy lower parts, frequently with schleps. This appearance is evident by a zoomed in cloud cover photo (first thumbnail) looking akin to small cumulus clouds because of their higher base at 3700 metres as indicated by the weather sounding on the second thumbnail. If the vertical development was a little greater, they could be classed as Altocumulus castellanus, a type further described lower down this page. The cloud meteorologically described here had transformed into altocumulus castellanus as the same cloud continued moving eastwards hence becoming especially evident when seen from the opposite side of the setting sun and illuminated by it. Viewed from below, this cloud has a horizontal and fairly extensive base, resembling a layer of Altocumulus. Subsequently, billowing tops start to form from the main deck and condensation within air pockets result to the castellanus effect. This rain or snow, which does not reach ground level but trails from the bottom of the clouds, is known as virga. Castellanus clouds can form as: high-altitude clouds (cirrus castellanus or cirrocumulus castellanus), mid-altitude clouds (altocumulus castellanus), and ; low-altitude clouds (stratocumulus castellanus). The altocumulus clouds occur as discrete units clearly separated from each other. Altocumulus stratiformis: Ac str: Expanded horizontal fields or layers. Altocumulus Castellanus have, at the top, cumuliform protuberances in the form of small towers, which generally give these clouds a jagged appearance. Translated from latin, meaning castle, the four types of castellanus clouds are respectively abbreviated as ‘Ci cas’, ‘Cc cas’, ‘Ac cas’, and ‘Sc cas’.