The median peak current and number of return strokes (multiplicity) of +CG and CG flashes are found to be quite different during the cool season, but more similar during the warm season. The greatest peak current (~ 30 kA) and smallest multiplicity (~ 1.4) of +CG flashes occur during the cool season. The warm season is characterized by smaller peak current (~ 20 kA) and larger multiplicity (> 1.5) of +CG flashes. Since +CG lightning generally is thought to consist of a single return stroke, our warm season multiplicities of ~1.7 are unexpected. This value may represent cloud pulses that are misclassified by the NLDN as weak peak current +CG flashes, or it may actually describe characteristics of the +CG lightning.
The threshold for determining weak positive events recently was increased from +10 kA to +15 kA. An important finding is that more than 40 % of all positive events (> 10 kA) in Florida during June, July, August, and October range between 10 15 kA. The unusual warm season characteristics of +CG lightning suggest that numerous ambiguous events are retained in our dataset, even though we used the new threshold of +15 kA. Thus, the threshold value requires further study. Daily CG lightning patterns near Jacksonville and Miami are analyzed during March and July 2003. On a given day, there is more +CG lightning during March than July in both Jacksonville and Miami. Also, when lightning does occur, the percentage of positive flashes generally is greater in Jacksonville than Miami.