吉林一次暴雨天气过程成因分析——以2019年8月14-15日为例

Cause Analysis of a Rain-storm Weather Process in Jilin--Taking August 14-15,2019 as an Example

利用地面观测资料、NCEP再分析资料、台站观测资料等对2019年8月14—15日出现在吉林省的一次暴雨天气过程成因进行分析。结果表明:200 hPa高空急流入口右侧对反气旋环流的生成和发展有促进作用,与正散度中心有很好的对应关系;500 hPa西风槽、西太平洋副热带高压及台风共同作用,对西南急流强度的增大和冷暖空气交绥极为有利;850 hPa风切变区几乎与台风倒槽重叠,说明低空急流位置和维持时间直接影响短时强降水;大的降水落区与高能区外围和能量锋区过渡区始终保持一致;台风水汽是此次暴雨天气的主要水汽来源,而间接来源则是中国南海与西太平洋的水汽;低空抬升运动一直存在,与200 hPa高空处的辐散相对应,进而形成高低空抽吸效应,对强降水天气的发生和发展提供了有利的条件。

Based on the ground observation data,NCEP reanalysis data and station observation data,this paper analyzes the cause of a rainstorm weather process that occurred in Jilin Province on August 14~15,2019.The results show that the right side of the 200 hPa upper jet inlet can promote the formation and development of the anticyclone circulation,and has a good relationship with the positive divergence center.The joint action of 500 hPa westerly trough,Western Pacific subtropical high and typhoon is extremely beneficial to the increase of southwest jet intensity and the intersection of cold and warm air.The 850hPa wind shear zone almost overlaps with the typhoon inverted trough,indicating that the location and duration of the low-level jet directly affect the short-term heavy rainfall.The large precipitation area is consistent with the periphery of the high energy area and the transition area of the energy front area.Typhoon water vapor is the main water vapor source of this rainstorm,while the indirect source is water vapor in the South China Sea and the Western Pacific.The lowlevel lifting movement has always existed,which corresponds to the divergence at 200 hPa,and then forms the high-level and lowlevel suction effect,which provides favorable conditions for the occurrence and development of heavy precipitation.