西北东部暖区大暴雨中尺度系统演变特征  

Characteristics of Mesoscale System Evolution of Torrential Rain in Warm Sector over Northwest China

作　　者：赵庆云[1] 傅朝[1] 刘新伟[1] 陈晓燕[1] 周晓军 

机构地区：[1]兰州中心气象台,兰州730020 [2]兰州市气象局,兰州730020

出　　处：《高原气象》2017年第3期697-704,共8页Plateau Meteorology

基　　金：公益性行业(气象)科研专项(GYHY201306006);中国气象局关键技术集成与应用项目(CMAGJ2015M62)

摘　　要：2013年6月19日20:00至20日08:00,西北地区东部出现了罕见的暖区大暴雨,最大降水量达258 mm,小时最大降水量达65 mm,且伴随雷电天气。利用卫星、雷达、区域自动气象站、高空、地面观测资料和NCEP再分析资料,重点分析六盘山西南侧极端降水中尺度对流系统的发生发展及传播特征。结果表明:近似的喇叭口地形及六盘山的阻挡,使700 h Pa偏南风在六盘山的西南侧形成一支长约200~300 km的低空急流;低空急流激发对流云带发展、加强,大暴雨主要由对流云带中一个向前传播的β中尺度对流云团产生;雷达强回波中心高度低于4 km,低质心暖云降水特征明显,对流带中具有多单体结构,大于35 d BZ强回波单体呈南北带状分布,对流单体以每小时1次的频次沿低空急流自南向北移动,显著的"列车效应"形成了六盘山西南侧带状大暴雨区。Torrential rain in warm sector occurred over Northwest China from 19 to 20 June 2013,with the maximum total rainfall of 258 mm and the maximum hourly rainfall of 65 mm,along with thunder and lightning. The evolution of mesoscale convective system was analyzed focusing on the development and propagation at Southwest side of Liupan Mountain,by using the data of satellite,CINRAD,automatic weather stations,the conventional observation,and NCEP/NCAR reanalysis data. The results show that,due to the bell-like terrain and the block of Liupan mountain,a low-level jet formed as long as 200~300 km at southwest side of the mountain on700 hPa. The low level jet triggered the development of convective cloud band. The forward propagation of Meso-β-scale convective cloud cluster（MCS） was the major cause of Torrential rain. The radar echoes showed obvious characteristics of low center of mass warm cloud precipitation,the zonal distribution in north and south of strong echo monomer greater than 35 dBZ,the movement of convective cells with 1 time·h^（-1） along the low level jet from south to north. The significant train effect formed zonal torrential rain at southwest side of the Liupan Mountains.

关 键 词：地形 低空急流 对流云带 对流单体传播 暖区大暴雨 

分 类 号：P458.2[天文地球—大气科学及气象学]