Cloud heads - Precursors to rapid cyclogenesis
The cloud head has been known about for several years, and has been found to be precursor to the development of depressions containing hurricane force winds. The appearance of a cloud head preceded such notable British events as the 'Great Storm' of October 1987, and the 'Burns Day Storm' of January 1990. It is shown that cloud heads are not uncommon in the New Zealand area. Often however, some of the essential features are only weakly present. In such cases, 'rapid' cyclogenesis will occur, without necessarily the development of hurricane force winds.