Extended‐range ensemble forecasting of tropical cyclogenesis in the northern Indian Ocean: Modulation of Madden‐Julian Oscillation

A conventional atmosphere‐ocean coupled system initialized with NCEP FNL analysis has successfully predicted a tropical cyclogenesis event in the northern Indian Ocean with a lead time of two weeks. The coupled forecasting system reproduces the westerly wind bursts in the equatorial Indian Ocean associated with an eastward‐propagating Madden‐Julian Oscillation (MJO) event as well as the accompanying northward‐propagating westerly and convective disturbances. After reaching the Bay of Bengal, this northward‐propagating Intra‐Seasonal Variability (ISV) fosters the tropical cyclogenesis. The present finding demonstrates that a realistic MJO/ISV prediction will make the extended‐range forecasting of tropical cyclogenesis possible and also calls for improved representation of the MJO/ISV in contemporary weather and climate forecast models.