An Examination of the Synoptic and Mesoscale Environments Involved in Tornado Outbreaks from Hurricane's Frances (2004) and Jeanne (2004) over Northeast Coastal Georgia and Southern South Carolina

During the 2004 hurricane season, five different tropical systems produced tornadoes across the Charleston, SC NOAA/National Weather ServiceWeather Forecast Office (WFO) County Warning Area (CWA). The two largest outbreaks occurred in September when the remnants of hurricanes Frances and Jeanne crossed from Florida into Georgia and produced a combined 26 tornadoes across southeast Georgia and southeast South Carolina. While both storms were similar in strength and took nearly the same track across Florida and Georgia (placing the Charleston CWA in the favored right front quadrant), they showed substantial differences in their respective tornado outbreaks. The remnants of Jeanne produced 6 tornadoes across the CWA, while the remnants of Frances helped to spin up a record 20 tornadoes. These two tropical tornado outbreaks will be reviewed with an assessment of the synoptic and mesoscale environment. Contributing factors to the larger number of tornadoes associated with Frances include a more favorable positioning of the jet in the westerlies to the north of the storm, deep layer moisture profiles, and slower forward speed maintaining favorable wind profiles over the area for a longer period of time.