2023年5月4—5日铜鼓大暴雨天气分析

Weather analysis of heavy rainstorm in Tonggu on May 4th—5th,2023

为了做好铜鼓大暴雨天气的预警预报工作,文章使用江西省气象资料查询系统和铜鼓县国家基本气象站气象数据、MICAPS平台、江西雷达拼图平台和宜春SA雷达基数据反演PUP产品等资料,对2023-05-04—2023-05-05铜鼓县大暴雨过程进行分析。结果表明:铜鼓大暴雨过程中,铜鼓国家基本气象站降雨量为152.7 mm/12 h,赣西北和赣东北为两个暴雨区;铜鼓国家基本气象站地面气象要素中,2 min平均风速和分钟内最大瞬时风速均较小;在两次短时强降水出现前,2 min平均风速和分钟内最大瞬时风速都有一个峰值;气温、水汽压变化较小;本站气压在短时强降水发生前有个升压过程,在短时强降水结束后有个降压过程;短时强降水高峰期不是闪电频次最密集时段;铜鼓大暴雨的天气系统在100 hPa高度上有明显出流区、500 hPa低槽、850 hPa切变(低涡)和西南急流、地面西南倒槽,在倒槽中江西北部存在辐合线;铜鼓回波特征为絮状回波团和回波短带;45 dBZ强回波面积≥100 km~2,强盛时强回波面积为457 km~2和650 km~2;强降水回波45 dBZ回波顶高度在7 km~8 km,比低质心强降水的回波顶偏高1 km~2 km。研究结果为监测预警铜鼓飑线天气提供了分析依据。

In order to do a good job in the early warning and forecast of heavy rainstorm in Tonggu,the process of heavy rainstorm in Tonggu on May 4th—5th,2023 was analyzed by using the data of meteorological data query system of Jiangxi,the meteorological data of Tonggu National Basic Meterological station,MICAPS platform,Jiangxi radar jigsaw platform,Yichun SA radar base data retrieval products.The results show that the rainfall at Tonggu Notional Basic Metorological Station during the heavy rainstorm is 152.7 mm/12 h,and the northwest and northeast of Jiangxi are two rainstorm regions.The average wind speed within 2 minutes and the maximum instantaneous wind speed within a minute are both relatively small in the ground meteorological elements of Tonggu Notional Basic Metorological Station.Before the occurrence of two short-term heavy rainfall events,there was a peak in both the 2 minute average wind speed and the maximum instantaneous wind speed within a minute.Temperature and water vapor pressure have relatively small changes.The atmospheric pressure at this station undergoes a process of increasing pressure before the occurrence of short-term heavy rainfall,and a process of decreasing pressure after the end of short-term heavy rainfall.The peak period of short-term heavy rainfall is not the period with the highest lightning frequency.The weather system of Tonggu heavy rainstorm is that there are obvious outflow areas at 100 hPa height,500 hPa trough,850 hPa shear(vortex),southwest jet stream and surface southwest trough at 100 hPa height,and there is a convergence line in northern Jiangxi.The echo characteristics of the Tonggu are flocculent echo clusters and short echo bands.A strong echo area of 45 dBZ≥100 km~2,when the strong echo area is 457 km~2 and 650 km~2.The height of the 45 dBZ echo top in heavy precipitation is below 7 km—8 km,which is 1 km—2 km higher than the echo top in low centroid heavy precipitation.The research results provide an analytical basis for monitoring and warning of the squall line weather in Tonggu.