气象2023，Vol.49Issue(12)：1451-1467,17.DOI:10.7519/j.issn.1000-0526.2023.102301
"23·7"河北太行山东麓罕见特大暴雨特征及成因
Evolution Characteristics and Formation of the July 2023 Severe Torrential Rain on the Eastern Foothills of Taihang Mountains in Hebei Province
摘要
Abstract
Influenced by the weakening low pressure of Typhoon Doksuri,the Beijing-Tianjin-Hebei Region suffered the unprecedented extremely severe torrential rain from 29 July to 1 August 2023,with catastrophic floods in the Haihe River Basin causing serious casualties and economic losses.A preliminary analysis of this rarely seen severe precipitation event is conducted in this article based on conventional observations,S-band Doppler weather radar data,wind profile radar data,and ERA5 reanalysis data.The results show that this extremely severe torrential rain process was characterized by enormous accumulated rainfall,and long duration,affected significantly by terrain.Typhoons Doksuri and Khanun provided extremely favora-ble water vapor conditions,but the high pressure barrier formed in northern part of North China blocked the northward typhoons.The North China Region experienced three stages:intermittent rainfall,typhoon inverted-trough precipitation and convective precipitation during the weakening stage of the inverted-trough,and the superposition of precipitation areas in three stages was the main cause for the formation of the extremely severe torrential rain.During the stage of weakening inverted-trough,the shear line at 850 hPa moved slowly due to the obstruction of the Taihang Mountains,causing the long duration of pre-cipitation.The atmosphere was in a near neutral state with stable rainfall intensity in the early stages.From the afternoon of 30 July,convective precipitation began to strengthen.The convergence line formed by the northerly wind which was generated by the outflow of the cold pool in the central rainfall area of Hebei Province and the surface southeast wind triggered the release of unstable energy and also strength-ened the development of triggered convective cells into mesoscale convective system(MCS)in the high-energy area of southeastern Hebei.This MCS moved into Baoding,resulting in the"train effect".The convergence line between the surface north wind generated by the cold pool of Taihang Mountains and the southeast wind triggered the release of unstable energy,which was the reason for the maintenance of severe precipitation in southwestern Hebei over the night of 30 July.On the morning of 31 July,a south-east low-level jet over 20 m·s-1was established again,leading to the extremely severe torrential rain exceeding 110 mm·h-1in the southern part of Beijing.关键词
太行山东麓/"23·7"特大暴雨/北上台风/地形作用Key words
eastern foothills of Taihang Mountains/July 2023 severe torrential rain/northward typhoon/topographical effect分类
大气科学引用本文复制引用
杨晓亮,金晓青,孙云,陈碧莹,梁天,杨敏,闫雪瑾,李江波.."23·7"河北太行山东麓罕见特大暴雨特征及成因[J].气象,2023,49(12):1451-1467,17.基金项目
内蒙古自然科学基金项目(2020MS04020)、中国气象局东北冷涡科研业务能力提升攻关团队共同资助 （2020MS04020）
