副高控制下一次浙北局地短时暴雨观测分析

沈晓玲; 张诚; 曹宁宁; 陆俊

doi:10.12086/j.issn.1004-4965.2026.042

副高控制下一次浙北局地短时暴雨观测分析

doi: 10.12086/j.issn.1004-4965.2026.042

1. 浙江省绍兴市气象台, 绍兴 312000;
2. 华东区域相控阵天气雷达应用联合实验室, 上海 200030;
3. 浙江省绍兴市气象博物馆, 绍兴 312000

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出版历程

Analysis of a local short-time rainstorm in northern Zhejiang under the background of subtropical high

1. Shaoxing Meteorological Bureau, Shaoxing Zhejiang 312000, China;
2. East China Phased Array Weather Radar Application Joint Laboratory, Shanghai 200030, China;
3. Shaoxing Meteorological Museum, Shaoxing Zhejiang 312000, China

摘要

摘要: 利用多源观测资料及ERA5再分析资料，对2024年7月14日浙北一次副高控制下局地短时暴雨过程的环流背景、对流系统演变特征、双偏振参量和风场特征进行了分析，结果表明：（1）本次过程发生在副高控制的弱天气背景下，地面弱辐合线是其主要触发机制，高湿背景、大的CAPE值和K指数、较低的LCL等均有利于短时暴雨的发生。（2）强降水发生在地面弱辐合线上，后向传播特征明显，“列车效应”显著。过程分为两个阶段，第一阶段回波呈团状分布，由多个单体合并发展为多单体风暴，第二阶段回波呈带状分布，降水主要由3个单体先后产生。（3）不同阶段对流风暴的微物理特征有所不同。第一阶段降水中包含了低浓度的大雨滴和高浓度的小雨滴，第二阶段单体A降水粒子前期以高浓度的大雨滴为主，后期以高浓度的小雨滴为主，单体B以较高浓度的大雨滴为主，单体C以低浓度的大雨滴为主。暴雨中心强降水主要由单体A、B造成，为高质心降水。（4）不同阶段对流风暴的风场特征也有所不同。水平方向上风暴内部800m高度上多表现为气旋式旋转，其中单体B存在完整的涡旋环流；中低层表现为风向风速辐合，其中第一阶段辐合高度较为深厚。垂直方向上多偏西或西南气流，降水粒子集中在气流辐合处。
- 局地短时暴雨 /
- 副高 /
- 地面辐合线 /
- 双偏振参量 /
- 风场
Abstract: Using multi-source observation data and ERA5 reanalysis data, the circulation background, convection system evolution characteristics, dual polarization parameters and wind characteristics of a local short-time rainstorm process under the background of subtropical high in northern Zhejiang on July 14, 2024 are analyzed,The results indicated that:(1) This process took place under the weak weather background controlled by the subtropical high, and the weak convergence line on the ground was the main trigger mechanism. High humidity background, large CAPE,K index and low LCL were all conducive to the occurrence of short-term rainstorm. (2)The rainstorm occured on the weak convergence line on the ground, with obvious backward propagation characteristics and significant "train effect". The process could be divided into two stages. In the first stage, the echoes were distributed in clusters, evolving from multiple individual storms to multiple individual storms. In the second stage, the echoes were distributed in bands, and precipitation is mainly generated by three individual storms.(3)The microphysical characteristics of convective storms varied at different stages. The first stage of precipitation included low concentrations of large raindrops and high concentrations of small raindrops. In the second stage, the precipitation particles of Unit A were mainly high concentration of large raindrops in the early stage, and high concentration of small raindrops in the later stage while Unit B were mainly slightly high concentration of large raindrops and Unit C were mainly low concentration of large raindrops. The rainstorm center was mainly caused by Unit A and B,which were high centroid precipitation. (4)The wind characteristics of convective storms varied at different stages.In the horizontal direction the storm at 800m mostly exhibited cyclonic rotation, with unit B having a complete vortex circulation. The middle and lower layers showed convergence of wind direction and speed, with the first stage of convergence being relatively deep. In the vertical direction, there were more westward or southwestern airflows, and precipitation particles were concentrated at the convergence of the airflows.
- local short-time rainstorm /
- subtropical high /
- ground convergence line /
- dual polarization parameter /
- wind field