Tornadoes Associated with Cyclones of Tropical Origin-Practical Features

Abstract

Abstract The frequency of reports of tornadoes associated with tropical cyclones is shown to have increased during the past decade to a level worthy of professional attention. Tornado incidence is demonstrated to be related to the direction of movement of the tropical cyclone, and to the intensity of the cyclone as it approaches the coast. A heading slightly cast of north is most favorable for tornado occurrence. Most tornadoes have occurred with tropical cyclones from the Gulf of Mexico which reached hurricane intensity, or with intensifying tropical depressions. Compact spatial distributions of tornadoes are disclosed upon relating occurrences to five selected stages in the life history of the associated tropical cyclone. The best relationships on location within the parent cyclone are obtained with respect to true azimuth, and are superior to those obtained using an orientation from heading along the tropical cyclone track. By eliminating the tornadoes associated with the extratropical stage of the tro...