浙江北部地区一次短时暴雨过程非常规资料特征分析

Analysis of non-conventional observational data for a short-time rainstorm process in the north of Zhejiang province

基于常规气象站观测资料,结合逐时云顶亮温TBB资料、区域自动站观测资料、多普勒雷达资料、风廓线雷达及闪电定位资料等非常规观测资料,对2013年6月24日14—20时浙江北部地区的局地短时暴雨过程进行诊断分析。结果表明:此次浙江北部地区局地强对流发生在高温高湿、对流有效位能中等及垂直风切变较弱的环境下,地面辐合线和低层弱切变是触发强对流的主要机制。中尺度对流雨团具有后向传播的特点,强降水落区与地面辐合线有较好的对应关系。风廓线雷达的连续观测可部分揭示影响系统的细节特征:近地面层的冷空气活动加强了大气对流不稳定度,低层东风急流输送了水汽,对流系统承载层气流和入流层气流方向相反,导致对流系统停滞少动,产生局地暴雨。

Based on the conventional meteorological data, hourly TBB data, meteorological data from automatic weather stations, Doppler radar data, wind profile radar data and lightning data etc. , a local short-time heavy rain process from 14：00 to 20：00 on June 24,2013 in the north of Zhejiang province was diagnosed. The results show that the local severe convective weather occurs under high temperature and humidity, moderate convective available potential energy, weak vertical wind shear conditions, and surface convergence line and low level wind shear are its important trigger mechanisms. The mesoscale rainstorm is characterized with back-propagation. There is corre- sponding relationship between falling area of strong precipitation and surface convergence line. The continuous ob- servation data from wind profile radar can provide detailed information about influencing system. For example, the cold air activities near the surface layer strength convective instability of the atmosphere; low layer easterly jet pro- vides water vapor; airflow direction for bearing layer is opposite of inflow direction in the convective system, which results in convective system moving slowly and generating heavy rain in a local area.