Of the six landfalling TCs that spawned tornadoes, two produced major outbreaks that rival the reigning champion, Hurricane Beulah of 1967. Frances spawned some 108 tornadoes from 4-8 September, only to be followed by Ivan, with another 108 tornadoes during 15-17 September. Ivan produced at least 4 killer tornadoes, the first TC to accomplish this feat since 1891, according to severe weather historian Tom Grazulis (Grazulis 1993). As of the end of September 2004, landfalling TCs had accounted for six of the 14 killer tornadoes in the United States, and 11 of the 28 deaths. More complete statistics will be presented at the conference in San Diego.
One of the biggest ironies of the 2004 season was the fact that all the TC tornadoes occurred east of a line extending from near Pensacola, Florida, up through the Appalachian Mountains. This was the result of a persistent flow pattern that featured a recurrent long-wave trough over or west of the Appalachians, with the western tip of the Bermuda High lying just east of the Georgia coast. As a consequence, many Atlantic coast states experienced the brunt of a number of major tropical cyclones, and saw either their biggest annual tornado totals or biggest tornado outbreaks of record. States like Virginia and South Carolina now sport larger peak annual tornado totals records than states farther west like Alabama and Mississippi. The TCs of 2004 have truly rewritten the tornado record books!
Although the favored geographical region for TC tornadoes in 2004 was unusually far east, the characteristics of the TCs themselves were well in line with what previous research has shown to be predictive of TC tornado productivity (see, e.g., McCaul 1991). The two biggest tornado producers, Frances and Ivan, were both quite large, and had peak intensity ratings of category 4 and 5 respectively, before interacting with the North American continent. Furthermore these TCs moved at moderate forward speeds, consistent with earlier climatologies which showed that TCs that move either too slowly or too fast tend to have diminished tornado potential. The TC tornado outbreaks were also well-behaved in the sense that nearly all the tornadoes occurred in the right-front or northeast quadrants of the TCs. Furthermore, the weak baroclinic boundaries identified in a recently published study of a 1994 TC tornado outbreak (McCaul {\etal} 2004) were also evident in the major TC tornado events of 2004. The tornadic potentials of Frances, Ivan and Jeanne were duly noted by the Storm Prediction Center, which for the first time issued a number of Moderate Risk outlooks for expected TC tornado activity.
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