“23.7”河北罕见特大暴雨过程降水演变与中尺度特征分析  

Analysis of precipitation evolution and mesoscale characteristics for a severe torrential rain event in Hebei from 29 July to 2 August 2023

作　　者：杨晓亮 杨敏[4] 金晓青 孙云 梁天 谷欣蕊 闫雪瑾 张珊 张唯 YANG Xiaoliang;YANG Min;JIN Xiaoqing;SUN Yun;LIANG Tian;GU Xinrui;YAN Xuejin;ZHANG Shan;ZHANG Wei(China Meteorological Administration Xiong'an Atmospheric Boundary Layer Key Laboratory,Xiong'an New Area 071800;Key Laboratory of Meteorology and Ecological Environment of Hebei Province,Shijiazhuang 050021;Hebei Meteorological Observatory,Shijiazhuang 050021;Hebei Provincial Meteorological Administrative&Technical Service Center,Shijiazhuang 050021;Cangzhou Meteorological Office of Hebei Province,Cangzhou 061001)

机构地区：[1]中国气象局雄安大气边界层重点开放实验室,雄安071800 [2]河北省气象与生态环境重点实验室,石家庄050021 [3]河北省气象台,石家庄050021 [4]河北省气象行政技术服务中心,石家庄050021 [5]河北省沧州市气象局,沧州061001

出　　处：《暴雨灾害》2024年第1期1-12,共12页Torrential Rain and Disasters

基　　金：河北省重点研发计划项目(21375404D);中国气象局雄安大气边界层立体监测和精细化模拟青年创新团队;河北省气象局灾害性天气机理研究创新团队。

摘　　要：2023年7月29日至8月2日,受台风“杜苏芮”北上减弱低压影响,河北出现罕见特大暴雨天气过程(以下简称“23.7”暴雨过程),其中位于冀南的邢台市梁家庄自动站52 h累积降水量高达1003.4 mm。利用常规地面与探空资料以及区域自动站资料、雷达拼图与ERA5再分析资料等,对“23.7”暴雨过程的降水演变特征、环流形势与环境条件、中尺度特征进行了初步分析。结果表明:此次暴雨过程具有持续时间长、累计雨量大、覆盖范围广等特征;台风“杜苏芮”登陆北上后,受500 hPa华北北部“高压坝”阻挡而停滞,河北大部地区整层水汽总量达到其气候平均态的2倍以上,环境大气具有低的抬升凝结高度和自由对流高度及一定的对流不稳定能量,以及850 hPa倒槽切变线稳定少动提供的持久辐合抬升条件,使得降水回波长时间维持在河北西南部太行山前和河北中部。边界层东南风急流伴随台风倒槽向北发展,急流核风速在河北中部超过22 m·s^(-1),大暴雨过程中地形作用明显。边界层急流影响河北西南部期间,回波强度30~40 dBz、质心高度低于6 km的多个对流单体先后移过梁家庄站上空,造成梁家庄站累计出现24 h的短时强降水;边界层急流北移后,8 m·s^(-1)左右的偏东风使太行山前层积混合云降水回波继续长时间维持造成雨区重叠,是梁家庄站52 h累积降水量超过1000 mm的主要原因。Affected by the weakening of the low-pressure system caused by the northward movement of the typhoon"Doksuri",Hebei en⁃countered an unprecedented severe torrential rain event(hereinafter referred to as"23.7"severe torrential rain)from 29 July to 2 August 2023,in which the accumulated rainfall in 52 hours is up to 1003.4 mm at Liangjiazhuang station in Xingtai of southern Hebei.Using rou⁃tine upper-air and surface weather observations,regional automatic weather station data,radar mosaic of reflectivity factor,ERA5 reanalysis data,and other relevant data,we conducted the analysis on the precipitation evolution characteristics,circulation patterns,environmental conditions,and mesoscale features of the"23.7"severe torrential rain.The results indicate that the"23.7"severe torrential rain is character⁃ized by long duration,large accumulated rainfall and wide coverage.After landing and moving northward,Typhoon"Doksuri"is blocked by the high pressure barrier in northern North China at 500 hPa and stagnates.Total content of water vapor over most areas of Hebei reached more than twice the climate average state.All the factors,that low lifting condensation level,low free convection height,moderate convective instability energy,as well as the lasting convergence uplift provided by the stability and stagnation of inverted trough at 850 hPa,are the causes of maintaining precipitation echo for a long time in central Hebei and in the foothills of Taihang Mountains in southwestern Hebei.The southeasterly boundary layer jet moves northwards along with the typhoon inverted trough,and the jet core is located in central Hebei,with the wind speed exceeding 22 m·s^(-1)and terrain plays a significant role in the rainfall event.During the influence of boundary layer jet on southwestern Hebei,multiple convective cells with echo intensity of 30~40 dBz and centroid height lower than 6 km successively pass over the Liangjiazhuang station,causing a total of 24 hours of short-term severe rainfall at the station.After the boundary layer

关 键 词：特大暴雨 台风“杜苏芮” 边界层急流 地形作用 

分 类 号：P458.121.1[天文地球—大气科学及气象学]