浙北一次高空冷涡后部雷暴大风的成因分析  

Analysis on Causes of a Thunderstorm Gale in the Rear of High-Level Cold Vortex in Northern Zhejiang Province

作　　者：吴福浪 杨丽敏 张晶晶 陶俞锋 曹文 杨明珠 Wu Fulang;Yang Limin;Zhang Jingjing;Tao Yufeng;Cao Wen;Yang Mingzhu(Meteorological Station of Ningbo Air Traffic Management Station of CAAC,Ningbo 315154,China;Meteorological Observatory of Tibet Autonomous Region,Lhasa 850000,China;Ningbo Meteorological Service Center,Ningbo 315012,China;Shandong Air Traffic Management Sub-bureau of CAAC,Ji’nan 250107,China)

机构地区：[1]中国民用航空宁波空中交通管理站气象台,宁波315154 [2]西藏自治区气象台,拉萨850000 [3]宁波市气象服务中心,宁波315012 [4]民航山东空中交通管理分局,济南250107

出　　处：《气象与环境科学》2024年第4期51-59,共9页Meteorological and Environmental Sciences

基　　金：宁波市气象科技计划项目(NBQX2019013B)。

摘　　要：利用区域自动气象站资料、NCEP/FNL再分析资料、多普勒天气雷达产品等,对2020年4月12日出现在浙江北部的区域性雷暴大风天气成因进行综合分析。结果表明:(1)此次雷暴大风过程属于高空冷平流强迫类型。强烈的高低空温度差动平流为雷暴大风提供了有利的热力条件,强垂直风切变有利于对流风暴的维持和发展。(2)雷达回波PPI图上,两个β中尺度对流风暴分别呈弓形和带状回波;径向速度图上的强烈MARC特征、1 km高度以下出现20 m·s^(-1)以上的速度大值区、VWP产品的大风速核下降,都可作为雷暴大风临近预警的参考。(3)降水拖曳和蒸发冷却形成地面冷池和辐合线,辐合线有利于对流云团的维持和发展;对流云团后侧入流急流增强了1 h正变压,同时促使地面辐合线逐渐远离回波主体;在冷池密度流和变压梯度共同作用下形成地面大风,地面8级以上大风主要分布在地面冷池移动前方和1 h正变压中心附近。The causes for the formation of the regional thunderstorm gale in northern Zhejiang Province on April 12,2020 is analyzed based on the regional automatic weather station data,NCEP/FNL reanalysis data and Doppler weather radar products.The results show that:(1)This thunderstorm gale process was of the high-level cold advection forcing type.The strong high-low level temperature differential advection provided favorable thermal conditions for the thunderstorm gale,and the strong vertical wind shear was beneficial to the maintenance and development of convective storms.(2)The twoβmeso-scale convective storms were respectively bow-shaped and ribbon-shaped echoes on the PPI image of radar echo.The strong mid-level radial convergence feature on the radial velocity image,the large velocity range above 20 m·s^(-1) below 1 km altitude,and the high wind speed core descending on the VWP product can all be used as reference indices for nowcasting thunderstorm and strong wind approaching warnings.(3)The surface cold pool and convergence line were formed by precipitation drag and evaporative cooling,and the convergence line was conducive to the maintenance and development of the convective cloud cluster.The inflow jet in the back of the convective cloud cluster strengthened the 1 h positive pressure,and,meanwhile,gradually drove the surface convergence line away from the echo main body.The surface strong winds were formed by the combined action of cold pool density flow and pressure gradient,and the gale above Scale 8 was mainly distributed in front of the surface cold pool movement and near the 1 h positive pressure center.

关 键 词：雷暴大风 高空冷涡 温度差动平流 中层径向辐合 冷池 

分 类 号：P458.3[天文地球—大气科学及气象学]