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投稿时间:2016-11-01 修订日期:2017-06-09
投稿时间:2016-11-01 修订日期:2017-06-09
中文摘要: 利用常规地面、高空和自动站观测资料以及NCEP 1°×1°逐6 h再分析资料,结合多普勒雷达回波和卫星资料,对比分析了2015年5月19—20日华南暴雨过程中不同性质暴雨对应的天气背景、垂直结构特征及直接造成暴雨的中尺度对流系统活动特征。结果表明:此次华南暴雨过程3个强降水中心分别与3个中尺度对流系统相关。(1)广西北部在850 hPa低涡切变线及α中尺度锋面气旋影响下,暴雨区斜压锋生结构明显,整层大气强烈上升。地面冷锋后中尺度线状对流活跃,排列紧密,持续时间较长,降雨量大。大尺度模式有较高的可参考性。(2)广东中北部暴雨区受边界层弱冷空气触发,线状对流系统在其南侧高温高湿环境中新生并传播,排列松散,移动速度较快,总降雨量不及广西北部,但局部雨强突出。边界层中尺度辐合线及γ中尺度气旋对强降水起重要作用。中尺度模式有一定的反映,预报难度较大。(3)广东东南部暴雨由暖区边界层风速辐合及地形海岸线作用产生,其降水质心低,降水效率高。模式的预报能力十分有限。针对不同特点的暴雨预报,数值模式的预报能力不同,而预报员在对天气特征准确把握的基础上,综合考虑不同数值模式的结果,有望得到更准确的预报。
中文关键词: 暴雨,低涡切变线,中尺度对流系统,暖区对流
Abstract:Using conventional observations, automatic meteorological observation data, NCEP 1°×1° reanalysis data and the data from the satellite and Doppler weather radar, the torrential rainfall event that occurred over South China from 19 to 20 May 2015 was analyzed regarding the synoptic conditions, vertical structure and mesoscale convective activities. The results show that the three rainfall centers during this rainfall process were caused by three different mesoscale convective systems respectively. Firstly, the heavy rainfall over the north of Guangxi was caused by the meso α scale vortex and shear line in the low level with the obvious frontogenesis and intense uplift. The mesoscale linear convection located behind the cold front lined more intensely, causing the rainfall to maintain a longer time with more total precipitation. The global model shows a good prediction. Secondly, the heavy rainfall over the central and northern Guangdong was triggered by the weak cold air in the boundary layer. The mesoscale linear convection moved southward because of the new born cells in the warm and wet areas in the south. The linear structure was less intense and moved rapidly, so the total precipitation was less than that in the north of Guangxi, but the local rainfall was more intense. The mesoscale convergence line in the boundary layer and the meso γ scale convective systems played an important role. The mesoscale model can reflect the mesoscale process to some extent, but has more difficulties to forecast it. Thirdly, heavy rainfall over the southeast of Guangdong in the warm sector was triggered by the land and sea topographic uplift, persisting for a long time due to the combination with the MCS B later. The forecast capability of the model is limited. Therefore, the numerical model has different forecasting capabilities according to the different characteristics of the torrential rainfall. Understanding of the characteristics of the heavy rainfall, some corrections can be achieved by subjective forecasting.
keywords: torrential rainfall, vortex and shear line, mesoscale convective system, warm sector convection
文章编号: 中图分类号: 文献标志码:
基金项目:气象预报预测业务与科研结合专项(CMAHX20160601)资助
Author Name | Affiliation |
KONG Qi | National Meteorological Centre, Beijing 100081 |
LIN Jian | National Meteorological Centre, Beijing 100081 |
引用文本:
孔期,林建,2017.2015年5月19—20日华南地区不同性质暴雨成因和预报分析[J].气象,43(7):792-803.
KONG Qi,LIN Jian,2017.Analysis on Causes and Forecasts of the Torrential Rainfall with Different Features over South China During 19 to 20 May 2015[J].Meteor Mon,43(7):792-803.
孔期,林建,2017.2015年5月19—20日华南地区不同性质暴雨成因和预报分析[J].气象,43(7):792-803.
KONG Qi,LIN Jian,2017.Analysis on Causes and Forecasts of the Torrential Rainfall with Different Features over South China During 19 to 20 May 2015[J].Meteor Mon,43(7):792-803.