Potential vorticity Diagnostics of Hurricane Movement. Part 1: A Case Study of Hurricane Bob (1991) Wu, Chun-Chieh ; Emanuel, Kerry A. Abstract Publication: Monthly Weather Review Pub Date: 1995 DOI: 10.1175/1520-0493(1995)123<0069:PVDOHM>2.0.CO;2 Bibcode: 1995MWRv..123...69W