Extended-range Ensemble Forecasting of the Genesis of Tropical Cyclone Nargis (2008): Modulation of Madden-Julian Oscillation

A conventional atmosphere-ocean coupled system initialized with NCEP FNL analysis has successfully predicted the genesis of Tropical Cyclone Nargis (2008) 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. This northward-propagating Intra-Seasonal Variability (ISV), after reaching the Bay of Bengal, fosters the genesis of Tropical Cyclone Nargis. Present finding demonstrates that a realistic MJO/ISV prediction will make the extended-range forecasting of tropical cyclone genesis possible and also calls for improved representation of the MJO/ISV in contemporary weather and climate forecast models.