Table of Contents


Rapid Cyclogenesis describes a fast and intensive development of an extratropical cyclone (mid-latitude cyclone). The criterion of rapid development is the rate of central sea-level pressure's deepening being greater than or equal to 1 hPa per hour, generally over a period of 12 hours or longer.

In a sequence of satellite images rapid cyclogenesis is seen as the evolution of a low level cloud head into an occlusion cloud spiral. Processes in the upper troposphere are essential in such developments.

A Rapid Cyclogenesis (RaCy) is characterized by a rapid and intensive development phase in the beginning. In most cases this takes place within about 12 hours. Such a development is accompanied by special cloud configurations in satellite images. They show the development of a cloud head on the poleward side of a mainly west-to-east oriented frontal cloud zone into a highly developed cyclonic cloud spiral. Some of the cloud configurations deviate from classical cyclogenesis processes. After the rapid deepening the cyclone will, with its fully developed cloud spiral, in most cases, persist for several days.

I. Appearance in Satellite Data

Learn about how to recognise and detect Rapid Cyclogenesis in satellite images.

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II. Meteorological Physical Background

Find out more about the meteorlogical and physical background of Rapid Cyclogenesis.

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III. Key Parameters

Learn which key parameters to use for monitoring Rapid Cyclogenesis.

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IV. Typical Appearance In Vertical Cross Sections

Find out the typical appearance of Rapid Cyclogenesis in vertical cross sections.

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V. Weather Events

Explore the weather events associated with Rapid Cyclogenesis.

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