Analysis of lightning characteristics in a MCS with damaging straight-line wind

One severe thunderstorm with damaging straight-line wind occurred on 21 June 2005 in north Shandong Province. Based on the analysis of lightning activities, radar echo and cloud image, it was found that the cloud-to-ground (CG) flash rates increased rapidly at initial stage, and they were very high (about above 20 fl/5min) all along the mature stage. At the dissipating stage, positive CG flashes gradually dominated. Almost all negative CG flashes occurred in the convective precipitation regions, whereas most positive CG flashes corresponded to stratiform precipitation regions. For the advent of the peak value, the hourly flash rate lagged behind the minimum brightness temperature, and the area of cold cloud shield with temperature <;-50°C lagged behind the hourly flash rate. Gust occurred in the regions with dense CG flashes. The pulse of CG flash rate was slightly ahead of the occurrence of severe surface wind. The damaging wind was due to downburst. The maximum wind speed observed at weather station was approximate to the maximum potential speed calculated by WINDEX.