| This study examines the large-scale fields of eight stronger and eight weaker cyclones prior to rapid cyclogenesis to help explain their subsequent deepening rate. The cyclones all commenced their rapid development within the same small geographical region over the Kuroshio and are compared using composites, ensembles and individual case studies.;Colder air and stronger anticyclogenesis over East Asia track the stronger cases along the Kuroshio, while the weaker cases tend to track across Japan. Anticylogenesis is also present to the east of the stronger cases which hence have warm advection ahead of them. The weaker cases generally form as transitory features in the northerly flow to the west of large cyclones and so have cold advection ahead of them. This affects a deep layer, producing a ridge-trough couplet at 500 mb for the stronger cases and a more zonal flow above the weaker cases. |
