Hagemeyer (1998) found 16 cases of significant tornadoes associated with tropical and hybrid cyclones in Florida history. In 15 of the 16 cases the cyclones were recurving in the eastern Gulf of Mexico leaving Florida in the right-front quadrant of the cyclone, the favored area for outer rainband tornado development. These results indicate the influence of an upper low or trough northwest of Florida. It is likely that there are synoptic patterns that favor significant tornado events in Florida such as surface cyclone development in the southern Gulf of Mexico or northwest Caribbean and south to southwest steering currents. A review of the official tropical cyclone tracks for the 13 hurricane seasons with 16 total significant tropical/hybrid cyclone tornado events revealed some interesting patterns. Eight of the 13 years (11 cases) had one or less Cape Verde cyclone per year, but they accounted for 90% of all significant tropical/hybrid tornado fatalities. Four of the 13 significant tornado years had active Atlantic seasons (1964 and 1994-96), but all 4 significant events in these years were late season events (October and November) that developed in the Gulf and Caribbean. The years 1947 and 1982 had two significant tornado events each, and in both years only one cyclone formed in the tropical Atlantic. The deadliest and most widespread significant tornado event occurred in 1972 and no Atlantic tropical cyclones occurred that year.
Further investigation confirmed that years of enhanced significant tornado activity where years of reduced Atlantic tropical cyclone activity due in some part to El Nino conditions. It would appear conditions which inhibit Cape Verde type tropical cyclones may be more favorable for cyclone development in the Gulf of Mexico and Caribbean. Storms during these years then have a greater chance of affecting Florida and encountering westerly shear and resultant hybrid influences that would favor the development of more significant tornadoes. Strong El Ninos, which tend to inhibit Cape Verde tropical cyclones, were recorded in 1972 and 1982 and these were years of record significant tropical and hybrid cyclone tornado activity. Preliminary results of this study will be presented along with detailed case studies of the tropical cyclone seasons of 1972 and 1982. An discussion of El Nino's impact on a synoptic environment favorable for significant tropical and hybrid cyclone tornadogenesis in Florida will also be presented