摘要
利用常规MICAPS资料和多普勒雷达资料,对2017年8月3—4日辽宁省岫岩县特大暴雨过程的天气环境背景及雷达回波特征进行分析。结果表明,此次降水过程特点为影响范围广、降水强度强、持续时间长;天气形势为高空东北冷涡提供冷空气输送,西太平洋副高及台风"海棠"带来源源不断的水汽;中尺度系统为高空急流、低空西南急流水汽输送,低层有明显的切变线系统辐合形势,地面有辐合线存在,同时岫岩县山区地形明显,更加有利于辐合抬升及水汽堆积;大连、丹东地区700 hPa以下有比较深厚的湿层,850 hPa风速最大可达22 m/s,比湿最大可达22 g/kg,辽宁省南部地区的水汽条件较好。K指数大于35℃,沙氏指数(SI)和抬升指数(LI)小于0℃,层结不稳定。CAPE值均大于1 000 J/kg,不稳定能量不断堆积;岫岩此次降水过程主要降水时段分为3个阶段,此次降水过程的雷达回波为明显的"列车效应",并具有后向传播及低质心暖性降水的特征。
Based on the conventional MIC APS data and Doppler radar data,the weather environment background and radar echo characteristics of the torrential rainstorm process in Xiuyan County,Liaoning Province from August 3 to 4,2017 were analyzed.The results showed that the precipitation process was characterized by a wide range of influence,strong precipitation intensity and long duration;the weather situation provided cold air transport for the northeast cold vortex,the West Pacific subtropical high and the typhoon’Haitang’brought continuous water vapor.The system was high-altitude jet,low-altitude southwest rapids water vapor transport,the lower layer had obvious convergent line system convergence situation,the ground had convergence line,and the topography of Xiuyan County was obvious,which was more conducive to convergence and water vapor accumulation.There was a relatively deep wet layer below 700 hPa in Dandong and Dalian area.The wind speed of 850 hPa was up to 22 m/s,and the maximum humidity was up to 22 g/kg.The water vapor condition in southern Liaoning Province was better.The K index was greater than 35℃,the Sha’s index(SI)and the uplift index(LI)were less than 0℃,and the delamination was unstable.The CAPE values were all greater than 1 000 J/kg,and the unstable energy was continuously accumulated.The main precipitation period of the precipitation process of Xiuyan was divided into three stages.The radar echo of the precipitation process was an obvious"train effect"and had the characteristics of backward propagation and low centroid warm precipitation.
作者
朱宪龙
肖光梁
纪永明
ZHU Xian-long;XIAO Guang-liang;JI Yong-ming(Liaoning Provincial Meteorological Disaster Monitoring and Warning Center,Shenyang Liaoning 110166)
出处
《现代农业科技》
2019年第2期144-147,共4页
Modern Agricultural Science and Technology
