A study of total lightning characteristics of thunderstorms over Gangetic West Bengal

We report the preliminary results of observation of total lightning characteristics of pre-monsoon summer time thunderstorms over the Gangetic West Bengal (GWB) around Kolkata. We have analysed 35 thunderstorms during March to early June 2018 over GWB. Total lightning flash rate, which includes both in-cloud (IC) and cloud-to-ground (CG) lightning, has been found to increase rapidly during the initial stage of the thunderstorm much before the occurrence of damaging wind and intense lightning. Four categories of lightning rate curves are found and out of which two categories tend to produce damaging wind, intense lightning and heavy rainfall. Samples of both in-cloud and cloud to ground lightning electric field waveforms are also presented here.