Comparative Study on the Lightning Activities and Microphysical and Dynamical Quantities in a Thunderstorm Simulated by the Weather Research and Forecasting Model

A typical severe convective weather system with cloud-to-ground(CG) lightning flashes over the Chengdu area was simulated using the WRF model. Comparative analysis of the simulated output fields in the electrification processes of the system from the WRF-simulated and observed CG flashes was performed. The correlations of CG flashes with different microphysical and dynamical factors based on the charge separation mechanisms of microphysics were also discussed. The results showed that the temporal evolution characteristics of the maximum mass mixing ratios of ice crystal, snow crystal and graupel between -10℃ and -20℃, the region of charge separation, were nearly consistent with the maximum observed CG flashes rates. In the middle and late periods of lightning activity, the correspondence between the location of the maximum mass mixing ratios of the three kinds of hydrometeors and the locations of the maximum CG flash rates was better. They indicated the maximum areas of CG flashes. The maximum vertical velocity and the storm relative helicity(SRH) also revealed the temporal evolution trends of the CG flash rate. The SRH indicated the distribution of CG flashes. The simulated dynamic and microphysical outputs indicated the location and time of observed CG flashes, suggesting that the increasingly mature WRF model is potentially very useful for the research and forecasting of thundery weather.