A lighting locating system employing two wideband, gated magnetic direction finders was used to study the negative cloud-to-ground lighting in 111 storms that occurred on 8 days during August 1979 in the Tampa Bay area of Florida. The storms were classified as (1) single-peak storms-spatially isolated groupings of lightning whose cloud-to-ground flashing rate vs. time curves exhibited a single peak; (2) multiple-peak storms-spatially isolated groupings of lightning with multiple-peak flashing rates; and (3) storm systems-two or more related single-peak and/or multiple-peak storms. The following parameters are given for single-peak storms, multiple-peak storms, and storm systems: duration, area, number of ground flashes, means ground flash density, mean ground flashing rate, and maximum ground flashing rate averaged over a 5-min interval. Ground flash counts are corrected for the location system detection efficiency, which varied from about 75% at close range to about 55% at 100 to 150 km. The mean duration of single-peak storms, multiple-peak storms, and storm systems was 41, 77, and 130 min, respectively; the mean area 103, 256, and 900 km2, respectively; and the mean number of lighting flashes to ground 73, 270, and 887, respectively. The mean ground flash density for single-peak storms, multiple-peak storms, and storm systems was 18¿10-3, 15¿10-3, and 9.7¿10-3 km-2 min-1, respectively: and the mean ground flashing rate 1.7, 3.4, and 6.8 min-1, respectively. The highest maximum ground flashing rate averaged over a 5-min interval for all single-peak storms, multiple-peak storms, and storm systems was 17, 22, and 32 min-1, respectively, while the mean of the maximum flashing rates was 3.7 7.3, and 14 min-1, respectively. The relation between storm duration D in minutes and number of ground flashes Ng for single- and multiple-peak storms can be described by log10 Ng=0.014D+1.2.