Total Lightning Distribution and Heavy Rainfall Characteristics Associated With Multicellular Thunderstorms

Recently, detailed spatio-temporal analysis, using X-band multi-parameter radar-derived 3D volume scan and total lightning data in Japan, have shown the peak IC (In-Cloud lightning) occurs 5-10 mins prior to maximum ground precipitation for individual cells of a thunderstorm during heavy rainfall events, which can be useful for monitoring and short-time prediction of ground precipitation.But we found merging and/ or splitting between the cells with total lightning distribution, is a common phenomenon of multicellular TSs (ThunderStorms) which needs to be taken into account for more accurately predicting the storm evolution.In this paper, we have analyzed the preliminary observation results of two isolated, multicellular TS events with heavy precipitation (~100 mm) that showed merging and splitting between cells in their life cycle.The abrupt decrease or increase of IC lightning and precipitation volume at the time steps of splitting and merging respectively, were normalized with consideration of cell area ratio (before and after merging or separation), which resulted in a reasonable and similar trend for time series plot of IC vs ground precipitation.We also obtained a time lag between the peak IC and ground PV after applying the correction criteria.Thus, the proposed method will be promising for prediction and nowcasting the heavy ground precipitation using lightning data for multicellular TSs.