This report is a novel initiative at analysing and characterizing attempted leader in Melaka, Malaysia which located at vicinity of tropic region. The electric fields generated by the lightning were recorded using High Speed Transient Recorder (Lecroy HDO4024) with 90 nanosecond resolution in 2 seconds duration. This study examined a total of 237 electric radiation field recorded from three thunderstorms in 1 January 2019 to 3 January 2019. Uniquely, the attempted leader from 5 samples only appeared as positive initial peak which were not identical to negative return stroke peak. Further, the average duration of the attempted leader of the positive initial polarity is 7.4 ms. The arithmetic mean of individual pulse durations and the arithmetic mean of pulse intervals are 50.3 μs and 803.3μs, respectively. The current results are compared with the existence results in northern and subtropical regions. Obviously, for a certain condition, the interval pulse duration, individual pulse duration, total pulse duration and average number of pulses are different compared to Sweden and Florida data.

<span>This paper presents the characteristic of the positive attempted leaders preceded by positive narrow bipolar pulses (NPBPs). Attempted leaders are the preliminary breakdown process with no subsequent event (return stroke). On the other hand, narrow bipolar pulse is the lightning event commonly isolated and produces a strong electromagnetic field (in a short period). Attempted leaders hardly occurred in the tropics, and the preceding of the NBP (the combination) should be considered unique. In this present study, we found four samples in which the arithmetic means of duration of NPBPs pulse was 32.19 µs, with separation between the positive attempted leader was 1.86 ms apart. For the positive attempted leader, the arithmetic means of the whole pulse train, individual pulse and interval pulse of positive attempted leaders were 3.47 ms, 29.66 µs and 486.53 µs, respectively. The pulse train in this study seems to fade out fast compared to the isolated positive attempted leader pulse train. Next, the NPBP's pulse duration in this study shows well in agreement with the type of isolated NPBPs indicates that the association does not affect its pulse duration characteristic already present in the title.</span>

<p>Ninety (90) waveforms recognized as attempted leader were identified with both positive (84 events) and negative (6 events) initial polarity observed from four consecutive years of data (N=10,206). The positive attempted leader shows no correlation with the number of thunderstorms producing it during monsoon. Meanwhile, the negative attempted leader during monsoon and both polarity of attempted leader (positive and negative) during inter-monsoon shows positive correlation with the number of thunderstorms producing it. In this study, the yearly statistical distribution of negative cloud-to-ground (CG) lightning flashes which were classified as positive preliminary breakdown pulses (214 events) and negative preliminary breakdown pulses (4982 events) in accordance of their preliminary polarity were also presented. In addition, there is no relationship of attempted leader and the initial breakdown of negative ground flash since both mechanisms performed as a negative correlation.</p>