Abstract:The temporal and spatial distributions of thunderstorm gales in Yunnan are analyzed based on conventional observation data, observed lightning data and significant weather reports from 2011 to 2020. The results are as follows. Thunderstorm gales tend to occur from February to August, characterized by a bimodal pattern, and seen mostly in April. It is easier to see thunderstorm gales in spring than in summer and the daily peaks often appear from 16:00 BT to 17:00 BT. The durations of most thunderstorm gales are 1-4 hours. The high frequency areas are mainly distributed near mountains, including the east of Jade Dragon Snow Mountain, the east of Cangshan Mountain, the Ailao Mountain and the Wuliang Mountain. According to different types of large scale circulation background, three basic synoptic situation configurations of regional thunderstorm gales in Yunnan are proposed, that is, the southern branch trough type, low pressure trough type and quasi-barotropic type. The thunderstorm gale of the southern branch trough type occurs most. The physical parameters are calculated based on NCEP reanalysis data, representing the environmental characteristics such as thermal, dynamical and water vapor conditions, and then the characteristics of physical parameters are analyzed, considering the influence of monthly variation and different backgrounds of atmospheric circulation. The index thresholds of thunderstorm gales are worked out. The results show that the dynamic condition for thunderstorm gale in spring is much better than in summer, and the thermal condition is more significant in summer. The dynamic condition of southern branch trough type or vapor conditions of quasi-barotropic type is better than other weather types. Most meteorological physical parameters tend to increase 6 hours before most thunderstorm gales occur, which indicates that they develop to be more favorable for thunderstorm gale. This finding could provide useful information to the nowcasting and warning of thunderstorm gales.