2020年山东最强暴雨过程预报难点分析  

Analysis on the severest precipitation process of Shandong in 2020

作　　者：孙兴池[1,2] 史茜 盛春岩[2,3] 孟宪贵 韩永清[1] SUN Xingchi;SHI Qian;SHENG Chunyan;MENG Xiangui;HAN Yongqing(Shandong Meteorological Observatory,Jinan 250031,China;Key Laboratory for Meteorological Disaster Prevention and Mitigation of Shandong,Jinan 250031,China;Shandong Institute of Meteorological Sciences,Jinan 250031,China)

机构地区：[1]山东省气象台,济南250031 [2]山东省气象防灾减灾重点实验室,济南250031 [3]山东省气象科学研究所,济南250031

出　　处：《气象科学》2025年第1期109-117,共9页Journal of the Meteorological Sciences

基　　金：山东省气象局重点科研项目(2012sdqxz04,2019sdqxz07);山东省自然科学基金面上资助项目(ZR2020MD055);山东省重点研发计划资助项目(2016GSF120017);中国气象局预报员专项项目(CMAYBY2020-070)。

摘　　要：采用气象观测、黑体亮温(Blackbody Temperature,TBB)及美国国家环境预报中心(National Centers for Environment Prediction,NCEP)1°×1°再分析等资料,分析2020年8月5—7日山东年度最强降水过程的预报难点。结果表明:(1)暖区暴雨由于本地动力条件差、预报难度大,移入的强对流天气区可能是其重要的触发机制:移入雨区的向外流出气流与暖湿环境的风场形成地面辐合线,进入对流不稳定环境中,触发暖区暴雨;虽然这类地面辐合线较弱,但由于整层大气高温高湿且具有深厚的不稳定层结条件,弱动力作用即可触发潜在对流不稳定释放产生暖区暴雨。因此,对于弱强迫形势下的暖区暴雨,除了分析其有利的天气形势和温湿条件,进一步分析初始回波在何时、何地生成和移入本地是提高暴雨落区预报的精准度的有利措施。(2)本次强降水过程,高低空形势配置和降水机制类似于江淮梅雨的“无脚锋”,地面分析不出锋面,但高空锋明显,暴雨区与高空锋区的上升支有关。(3)本次过程济南本地层结条件较差,可能是造成大范围暴雨区中出现济南附近小雨量区的主要原因。(4)短时强降水的发生对应TBB的明显下降,1 h雨量超过20 mm的雨区对应TBB在214 K以下。Based on the conventional observation data,the Blackbody Temperature(TBB)data and the NCEP 1°×1°reanalysis data,the difficulties in forecasting the annual severest precipitation process in Shandong on August 5-7,2020 were analyzed.Results show that the immigrant strong convection may be an important trigger for the warm-zone rainstorm,which is difficult to forecast due to the weak local dynamic environment.The surface convergence line is formed after the interaction between the outward airflow from the immigrant rain area and the wind field in the warm-humid environment.The convergence line enters the potential unstable environment and triggers the warm-zone rainstorm.Although this kind of surface convergence line is weak,the whole layer is quite unstable due to the high temperature and high humidity.The weak dynamic effect can trigger the release of high instability energy,and finally the warm-zone rainstorm occurs.Therefore,in addition to analyzing the favorable weather conditions,the detailed analysis on when and where the upstream echoes will impact the studied area could help improve the forecast accuracy of warm-zone rainstorm.The heavy rainfall processes in Shandong during the rainy season are generally located between the subtropical high and the 500 hPa trough.The weather conditions and precipitation mechanisms of the Shandong rainstorm are similar to those of the Jiang-Huai Meiyu.There is often no significant surface front,but an obvious upper-air front.The rainstorm is related to the ascending flow in the upper-air frontal area.For the weak-rainfall center embedded in the large-scale rainstorm area,the analysis on local stratification conditions should be strengthened,and the convective inhibition energy is a very important parameter.The short-term heavy rainfall corresponds to a significant decrease of TBB,and the area with 1 h rainfall larger than 20 mm corresponds to the area with TBB below 214 K.

关 键 词：暖区暴雨 触发机制 高空锋区 层结条件 

分 类 号：P458[天文地球—大气科学及气象学]