###
DOI:
本文二维码信息
2014年5月8-9日引发珠江口区域强降水的两个长生命史MCS特征分析
陈涛, 张芳华, 符娇兰, 于超
(国家气象中心)
Analysis of two Successive Rainstorm-induced Long-lived Mesoscale Convective Systems struck Pearl River Delta during 8~9 May 2014 .
ChenTao, Zhangfanghua, Fujiaolan, Yuchao
(National Meteorology Center)
摘要
相似文献
本文已被:浏览 63次   下载 16
投稿时间:2019-02-26    修订日期:2019-06-10
中文摘要: 2014年5月8日上午至9日白天,广东中南部珠江口地区连续受MCS-A1、MCS-A2两个长生命史中尺度对流系统影响,形成长时间强降水。其中5月8日中午后华南内陆地区MCS-A1逐步增强,从广西东部向广东珠江口方向移动,陆上活动时间超过11小时;MCS-A2从9日凌晨至上午影响持续影响珠江口沿海地区,维持时间超过9小时,导致珠江口沿海地区出现400 mm以上单站降水量。过程发生前8日早上华南南部内陆地区具有弱地面温度梯度,8日中午MCS-A1对流触发与广西南部地面南风增强、华南南部云开大山-云雾山中尺度地形抬升有紧密关系;在弱斜压环境条件下,MCS-A1从层云伴随线状对流结构演变为中尺度涡旋组织结构。8日夜间MCS-S1入海后,与陆上遗留冷池相关的地面温度边界稳定在珠江口西侧沿海地区;9日凌晨西南低空急流增强后,MCS-A2在珠江口沿海残留冷池边界附近开始发展,在向上游迎风方向传播的过程中,逐步形成多条平行β中尺度线状对流组织结构,对流系统整体移动缓慢,造成珠江口沿海地区出现较高的总降水量。计算表明MCS-A2冷池边界扩张速度与低层垂直切变相对平衡,有利于形成较为直立的对流单体,增强的边界层水汽输送、更高的对流单体高度有利于产生较高的降水强度。通过总结这两个华南地区长生命史MCS发生发展过程,表明通过分析对流反馈造成的边界层\近地面层热动力特征变化,对于分析MCS发展特征、提高华南前汛期中尺度暴雨预报能力具有重要意义。
Abstract:Two successive long-lived Mesoscale Convective Systems (MCS-A1, MCS-A2) struck district of Pearl River Delta of South China during 8~9 May 2014, and induced extreme precipitation around Pearl River Delta. MCS-A1 inland of south China sustained longer than 11 hours from morning of 8 May which slowly moving towards southeast from east of Guangxi Province to Pearl River Delta in Guangdong Province,and successive MCS-A2 sustained more than 8 hours which induce rainfall of more than 400 mm along the coast the Pearl River Delta during late night of 8 May to noon of 9 May. Weak cold surface layer sustained in the South China with weak surface temperature gradience on the morning of 8 May before convection burst, the initialization of convection is connected with surface southern wind strengthening and topographic lifting near noon of 8 May. It is revealed that MCS-A1 evolved from Training Line\ Adjoining Stratiform (TL/AS) to mesoscale vortex in convective organization under weak baroclinic environment. With propagation of surface cool pool due to MCS-A1’s precipitation in the early night of 8 May, surface temporal and wind convergence boundary was pushed to the southwest coast of Guangdong Province. In the late night of 8 May MCS-A1 moved out of mainland, MCS-A2 was developing adjoint to the remnant cool pool boundary induced by MCS-A1 with low-level southwest wind enhancing in the early morning of 9 May. MCS-A2 was composed by multiple parallel β-mesoscale line-type convective systems, the extreme rainfall was related with quasi-stationary cool pool boundary, train-moving cells in β-mesoscale line-type convective systems with higher precipitation efficiency. From the deep night of 8 May to morning of 9 May, the balance between cool pool outflow and low-level vertical shear could sustain much upright convective cells for MCS-A2. In conclusion, with carefully researching on convective feedback to boundary and surface layer, the forecast skills could be improved for heavy rainfall events in weak synoptic-forcing environment during the pre-rainy season in South China.
文章编号:201902260083     中图分类号:P458    文献标志码:
基金项目:国家重点研发计划(2017YFC1502103);中国气象局暴雨专家创新团队专项CMACXTD002-3;行业专项201400603
引用文本:
陈涛,张芳华,符娇兰,于超,0.[en_title][J].Meteor Mon,():-.
ChenTao,Zhangfanghua,Fujiaolan,Yuchao,0.Analysis of two Successive Rainstorm-induced Long-lived Mesoscale Convective Systems struck Pearl River Delta during 8~9 May 2014 .[J].Meteor Mon,():-.