基于模式物理量参数的云南雷暴大风概率预报技术研究

Research on Probability Forecast Technology of Thunderstorm and Gale in Yunnan Based on Model Physical Parameters

利用2019—2021年云南125个国家站大风数据和云南省地闪资料,统计云南雷暴大风个例,并挑选对雷暴大风有重要意义的物理量参数,结合NCEP再分析资料确定云南雷暴大风个例的物理量阈值,再基于ECMWF数值模式预报产品及确定的阈值,采用二分法进行云南雷暴大风概率预报。结果表明:在云南三次雷暴大风过程预报检验中,8月4日云南中部及东北部雷暴大风均命中,但在云南西部及西南部出现大范围的虚警,导致此次过程虚警率较高和临界成功指数较低;8月5日云南中部、东北及西北部雷暴大风预报正确,且云南西部及南部虚警范围小,虚警率较8月4日明显降低;7月7日云南自东北向西南出现大范围的雷暴大风天气过程,雷暴大风预报落区与实况基本吻合,呈现命中率高、虚警率较低的特征;三次过程命中率、临界成功指数、虚警率平均为0.873、0.203、0.789。

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.