2020年春季华东地区一次大范围大风天气过程分析

Analysis of A Large-scale Gale Weather Process in East China in the Spring of 2020

为揭示2020年4月12日华东地区大范围的大风天气过程成因,利用常规气象观测资料、多普勒雷达观测资料和美国国家环境预报中心(NCEP/NCAR 1°×1°)再分析资料,对此次大风天气的影响系统和物理量场特征进行诊断分析。结果显示:此次大风是混合型大风,最大阵风40.8 m/s(13级),雷暴大风和动量下传大风叠加是主要原因,地面气压梯度和变压梯度也起到一定作用;冷涡后部冷空气不断补充南下、中高层干冷空气的侵入,加强了对流发生区域的大气层结不稳定;高空冷平流和低层暖平流环境下,锋面和边界层辐合线是雷暴大风天气的触发机制;此次过程中水汽条件一般,以雷暴大风天气为主,降水较弱。本研究可为今后类似影响系统下春季大风天气预报预警提供借鉴。

In order to reveal the cause of the large-scale spring gale weather process in East China in 2020,based on the conventional doppler radar observation data and(NCEP/NCAR1°×1°) reanalysis data,the synoptic situation and physical quantity field characteristics of the strong wind werther process,the results show that:The strong wind is a mixed gale,maximum gust of 40.8 m/s(level 13),the superposition of thunderstorms and strong downward momentum winds is the main reason;the ground pressure gradient and the variable pressure gradient also plays a certain role.the cold air behind the cold vortex is constantly replenished southward,and the intrusion of dry and cold air from the middle and upper levels has strengthened the instability of atmospheric stratification in the convection area.,in high-altitude cold advection and low-level warm advection,the convergence line of front and boundary layer is the trigger mechanism of thunderstorm and windy weather.the water vapor conditions in the convective weather were general,mainly thunderstorms and windy weather,and the precipitation was weak.This study can provide a reference for the forecast and early warning of spring gale under similar impact systems in the future.