The MJO and the 2005 Hurricane Season

The record-breaking 2005 Atlantic hurricane season provided an ideal testbed to examine the relationship between the MJO and tropical cyclones in the Western Hemisphere. During August, tropical cyclone development gradually shifted eastward from the eastern Pacific to the western Atlantic with the passage of the MJO's convective envelope. This envelope circumnavigated the globe, and the pattern repeated in September–October. This study will examine the modulation of convection, low-level vorticity, and vertical wind shear by this MJO event. Satellite estimates of upper tropospheric water vapor also indicate a connection between these MJO signals in the Northern Hemisphere and extratropical systems in the Southern Hemisphere. These relationships and their impacts on tropical cyclone activity will be explored.