3D Modeling on Relationships among Intracloud Lightning,Updraft and Liquid Water Content in a Severe Thunderstorm Case

A three-dimensional hail-bin cloud model coupled with electrification process has been developed and used for simulating lightning process in a severe thunderstorm in Beijing City in China. The characteristics of intracloud lightning channel and its relationship with updraft and liquid water content have been analyzed. Results indicate that in the evolution of the thunderstorm, snow particles are often formed where updraft is weaker and liquid water content (LWC) is lower. Snow particles develop there, and gain charges in the non-inductive charging process with graupel there. Therefore, intracloud lightning flash often initiates where updraft is weaker and LWC is less. After initiation, the upward leaders propagate to the area where LWC is less, while LWC where the downward leaders propagate to depends on the evolution stage of the thunderstorm. The upward leaders could propagate to the area where LWC is a little greater but not the maximum in the mature stage of the thunderstorm. However, the downward leaders could propagate to the center areas of LWC during the process of the decay of the thunderstorm.