大别山西侧极端降水中尺度对流系统结构与传播特征  

The structure and propagation characteristies of the extreme-rain-producing MCS on the west side of Dabie Mountain

作　　者：张家国[1] 周金莲[1] 谌伟[1] 张蒙蒙[1] 黄小彦[1] 牛奔[1] 

机构地区：[1]武汉中心气象台,武汉430074

出　　处：《气象学报》2015年第2期291-304,共14页Acta Meteorologica Sinica

基　　金：中国气象局预报员专项(CMAYBY2013043);中国气象局关键技术集成与应用(CAMGJ2015M38)

摘　　要：2012年7月12—13日中国鄂东北连续2 d出现特大暴雨,过程最大总雨量达600 mm。重点利用卫星、雷达和地面自动气象站观测资料等,分析了7月12日大别山西南侧极端强降水型中尺度对流系统的发生发展过程、结构和传播特征等。研究表明:(1)鄂东北特大暴雨是由一个向后传播-准静态α中尺度强对流系统(后向建立中尺度对流系统)产生的。(2)该类型中尺度对流系统频发于鄂东北地区,与鄂东北东侧大别山脉对雷暴冷池的阻挡有密切关系。主要表现在,大别山山脉对雷暴冷池的阻挡导致冷空气在山前堆积并形成回流,回流使中尺度对流系统传播由向下风方转为向上风方。(3)向后传播方式演变的中尺度对流系统因少动或因列车效应明显,常在山前一定距离内产生极端强降水。(4)雷暴冷池向上风方运动导致对流单体向后向传播,是指状对流云团形成的重要机制之一。Extreme severe rain occurred in northeastern Hubei Province for two successive days on 12 - 13 July 2012, with the maxi- mum total rainfall of 600 mm. Using the satellite data, radar data and Automatic Weather Station （AWS） data, the extreme severe rain occurred on the southwest side of the Dabie Mountain on 12 July 2012 is comprehensively analyzed focusing on the occurrence and de- velopment of Mescoscale Convective System （MCS）, as well as its structure characteristics and propagation features. The results show that： （1） The back-building and quasi-stationary meso-cescale convective system （BB） exactly result in the extreme severe rain in northeastern Hubei Province on 12 July 2012. （2） This kind of MCS frequently generates in the northeast of Hubei Province, and closely related to the thunderstorm cold pool blocked by the Dabie Mountain in the east side of Hubei Province. The cold air piles up in front of the mountain and generates backflow because of the blocking, leading to the MCS spreading from downward to upwind. （3） The back-propagating MCS rarely moves or causes obvious train effect, which bring about extreme severe rain before the mountain in a certain distance. And （4） the cold outflow boundary of the thunderstorm moves upwind, giving rise to the back propagation of convec- tion cell, which is one of the important formation mechanisms for the fingerlike convective cluster.

关 键 词：极端强降水 冷池 地形 传播 锋前暖区 

分 类 号：P458.2[天文地球—大气科学及气象学]