Clouds form when the
dewpoint of
water is reached in the presence of
condensation nuclei in the
troposphere. Atmosphere is a dynamic system, and the local conditions of
turbulence,
uplift and other parameters give rise to many types of clouds. Various types of clouds occur frequently enough to have acquired a name of their own, often these are further specified with additional descriptive name. Furthermore, some atmospheric processes can make the clouds organize in distinct patterns such as '
wave cloud' or '
actinoform cloud', these are large scale structures and not always readily identifiable from single point of view.
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[Slang], a thunderstorm
anvil which spreads upwind, against the flow aloft. A back-sheared anvil often implies a very strong
updraft and a high severe weather potential.