Incipient explosive marine cyclogenesis: coastal development

A case of incipient explosive marine cyclogenesis along the east coast of North America from February 1974 is investigated. The cyclone was noteworthy for deepening 36 mb in 15 h as it crossed a region of anomalously warm sea surface temperatures beneath a very favorable flow configuration aloft for explosive development. The precyclogenetic environment featured coastal frontogenesis and cyclonic vorticity production in association with oceanic sensible and latent heat fluxes in the westward-flowing air in advance of the cyclone. The resulting relatively high values of surface vorticity in the coastal baroclinic zone probably helped to contribute to the intensity of the ensuing cyclogenesis, as a peak cyclonic vorticity tendency of ~ 30 × 10^-9 s^-2 was computed in the coastal baroclinic zone at the time of most rapid surface intensification.