Abstract:
Using the strong wind data from 125 national stations and the ground lightning data of Yunnan Province from 2019 to 2021, the thunderstorm gale weather cases in Yunnan are counted. tthe physical parameters that are of great significance to the thunderstorm gale are selected. The NCEP reanalysis data is used to statistic the physical quantity threshold of thunderstorm gale cases in Yunnan and based on the statistically determined thresholds and physical quantity data of ECMWF numerical model, the dichotomy is adopted to conduct thunderstorm gale probability forecast in Yunnan. Among the forecast tests of three thunderstorm gale processes in Yunnan, which happened in the middle and northeast Yunnan on August 4 were all hit, but a wide range of false alarms occurred in western and southwestern Yunnan, resulting in a high false rate and low critical success index in this process. The forecast of thunderstorm gale in central, northeastern and northwestern Yunnan on August 5 was correct, and the false alarm range in western and southern Yunnan was small, and the false alarm rate was significantly lower than that on August 4. On July 7, a large-scale thunderstorm gale weather process occurred in Yunnan from northeast to southwest, the forecast area of thunderstorm gale was basically consistent with the actual situation, showing the characteristics of high hit rate and low false alarm rate. The average hit rate, critical success index and false alarm rate of the three processes were 0.873, 0.203 and 0.789, respectively.