复盘河南“21·7”极端降水的可预报性及对决策气象服务的思考  

Reviewing the Predictability of Extraordinary Rainstorm in Henan in July 2021 and the Meteorological Services for Decision-Making

作　　者：赵培娟[1,2] 胡玉梅 孔海江[2,4,5] 吕林宜 席乐 Zhao Peijuan;Hu Yumei;Kong Haijiang;Lyu Linyi;Xi Le(CMA·Henan Key Laboratory of Agrometeorological Support and Applied Technique,Zhengzhou 450003,China;Henan Provincial Meteorological Observatory,Zhengzhou 450003,China;Jiyuan Meteorological Office,Jiyuan 459000,China;Anyang National Climate Observatory,Anyang 455000,China;Henan Key Laboratory of Integrated Air Pollution Control and Ecological Security,Kaifeng 475004,China)

机构地区：[1]中国气象局·河南省农业气象保障与应用技术重点实验室,郑州450003 [2]河南省气象台,郑州450003 [3]济源市气象局,河南济源459000 [4]安阳国家气候观象台,河南安阳455000 [5]河南省大气污染综合防治与生态安全重点实验室,河南开封475004

出　　处：《气象与环境科学》2022年第2期38-51,共14页Meteorological and Environmental Sciences

基　　金：中国气象科学研究院灾害天气国家重点实验室开放课题项目(2021LASW-A09);中国气象局·河南省农业气象保障与应用技术重点实验室应用技术研究基金项目(KM201902)。

摘　　要：2021年7月18日20时22日08时,500 hPa副热带高压异常偏北偏东,低纬度台风“烟花”与副高之间的东南风急流直达河南中部,与位于郑州、卢氏、南阳之间的强中尺度低涡系统共同作用,导致河南北中部出现历史罕见的极端暴雨过程。极端暴雨造成了严重的城市内涝、电力和交通中断、中小河流决口、水库超汛泄洪、农田房屋被淹及人员伤亡等灾害。采用多尺度观测资料和数值预报产品,对此次极端暴雨及其关键影响系统中尺度低涡、极端雨强的可预报性等进行复盘及根据降水强度对郑州城市积涝和水库超限的关键节点分析结果表明:(1)“21·7”极端暴雨的主要影响系统中尺度低涡预报难度较大,根据实时监测信息作出判断低涡出现的时刻较实况可提前约6 h;(2)雨强≥100 mm/h的降水出现频次高、范围大,其有效预报预警提前量仅30~60 min;(3)郑州及豫北发生重大气象灾害的关键节点与雨强≥80 mm/h出现密切相关,100 mm/h以上的雨强呈多时次、多站点,且落区集中是发生严重城市内涝和水库出现险情的最直接原因。关于此次极端降水决策气象服务的思考与经验有:(1)重视最新天气实况分析,在极端降水可预报性低的情况下,加强实时气象观测资料、特别是降水实况分析,是提高预报预警准确率的最有效手段;(2)准确把握灾害性天气的致灾关键节点,尽可能加大预警提前量,是决策气象服务获取实效的关键。From 20:00 BT 18 to 08:00 BT 22 July,2021,central and northern Henan experienced a rare extreme torrential rain event,causing serious urban waterlogging,power outage,traffic stop,river and reservoir breaches,flooding of farmland and even casualties.This was because,on the one hand,the subtropical high at 500 hPa lay anomalously northward and eastward;and on the other hand,the southeast jet between the low-latitude typhoon and the subtropical high reached central Henan,working together with a strong mesoscale vortex system located over Nanyang,Lushi and Zhengzhou.By using the multi-scale observations and numerical weather prediction products as well as the weather analysis,we review the extreme rainstorm and the predictability of the mesoscale vortex and extreme precipitation intensity of the critical impact system.Besides,based on the hourly precipitation intensity,the critical time points of urban waterlogging and reservoir water level that exceeded the flood limit in Zhengzhou are analyzed.The results indicate that:(1)it was difficult to forecast the mesoscale vortex,which was the main influence system of the July 2021 extreme rainstorm.The time of low vortex judgment based on real-time monitoring information could have been about 6 h earlier than the actual situation.(2)The hourly precipitation intensity≥100 mm/h occurred extensively with high frequency,and its effective time of forecasting and warning advanced only 3060 min.(3)The major meteorological disasters in Zhengzhou and northern Henan were closely related to the hourly rainfall intensity≥80 mm/h,and the most direct causes for the serious urban waterlogging and reservoir danger were the multi-time,multi-station and concentrated hourly rainfall intensity≥100 mm/h.The lessons learned from the decision-making meteorological services of this extreme rainstorm include:(1)Pay high attention to the observation analysis.In the case of low predictability of extreme precipitation,strengthening the analysis of real-time meteorological observation data,espec

关 键 词：极端暴雨 复盘 可预报性 雨强 决策气象服务 

分 类 号：P458.121.1[天文地球—大气科学及气象学]