The ultimate goal of this project is to understand why some weak tropical disturbances become "organized" and intensify into major storms while other similar disturbances do not. In his previous work, Dr. Molinari showed that upper tropospheric cyclonic vorticity anomalies often interact with mature hurricanes to produce renewed intensification. Using similar techniques and from the perspective of large-scale processes, he will examine the initial stages of hurricane development. Particular attention will be given to (1) the opposing influences of vertical shear and upper tropospheric cyclonic vorticity, and (2) the origin and effects of lower tropospheric "surges", which often precede tropical cyclone development. The approach will be to conduct several case studies, employing large-scale analyses and available aircraft reconnaissance data. The importance of this research lies in its potential contribution to improved hurricane prediction.