A waterspout is a columnar vortex forming over water that is, in its most common form, a non-supercell tornado over water that is connected to a cumuliform cloud.
12.
"' Cumulus humilis "'is a cumuliform cloud with little vertical extent that is commonly referred to as " fair weather cumulus " and common in the summer.
13.
Near the equator, increased cloudiness is due to the presence of the low-pressure Intertropical Convergence Zone ( ITCZ ) where very warm and unstable air promotes mostly cumuliform and cumulonimbiform clouds.
14.
"' Stratus clouds "'are low-level clouds characterized by horizontal layering with a uniform base, as opposed to convective or cumuliform clouds that are formed by rising thermals.
15.
Cold fronts are usually faster moving and generate a narrower line of clouds which are mostly stratocumuliform, cumuliform, or cumulonimbiform depending on the stability of the warm air mass just ahead of the front.
16.
Mid-level stratocumuliform and cumuliform clouds of the genus altocumulus are not always associated with a weather front but can still bring precipitation, usually in the form of virga which does not reach the ground.
17.
However, very warm unstable air can also be present around fronts and low-pressure centers, often producing cumuliform and cumulonimbiform clouds in heavier and more active concentrations because of the combined frontal and convective lifting agents.
18.
Among many meteorologists, the funnel cloud term is strictly defined as a rotating cloud which is not associated with strong winds at the surface, and condensation funnel is a broad term for any rotating cloud below a cumuliform cloud.
19.
A "'pyrocumulus cloud "', or "'fire cloud "', is a dense cumuliform cloud associated with fire or volcanic eruptions that may produce dry lightning ( lightning without rain ).
20.
Howard's original system established three physical categories or " forms " based on appearance and process of formation : " cirriform " ( mainly detached and wispy ), " cumuliform " or cirrostratus.
