Journal of Arid Meteorology

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Causes Analysis of Continuous Rainstorm over Dalian Area
 of Liaoning Province in July 2013

LI Yan1, LIU Yong2, SAI Han1   

  1. 1. Dalian Meteorological Observatory of Liaoning Province, Dalian 116001, China;
    2. Liaoning Provincial Meteorological Bureau, Shenyang 110001, China
  • Online:2016-08-31 Published:2016-08-31

大连地区2013年7月连续性暴雨成因

李燕1刘勇2赛瀚1   

  1. 1.辽宁省大连市气象台,辽宁大连116001;2.辽宁省气象局,辽宁沈阳110001
  • 作者简介:李燕(1973- ),女,辽宁大连人,高级工程师,主要从事天气预报研究. E-mail:LYDW0211@163.com
  • 基金资助:

    环渤海区域科技协同创新基金(QYXM201502)和中国气象局预报员专项(CMAYBY2014-013)共同资助

Abstract:

Based on the meteorological observation data from automatic weather stations and NCEP reanalysis data, the causes of seven continuous rainstorms over Dalian area of Liaoning Province in July 2013 were analyzed. The results showed that the maintenance of Ural and Okhotsk blocking high was conductive to cold air from Siberian moving southward to the Lake Baikal, and the cold air gathered and strengthened into a low trough during the continuous rainstorm in July 2013. The West Pacific subtropical high in July 2013 was stronger than the normal, and its location was to the west and north. Two moisture convergence belts from North China and East China gathered to Dalian. The low vortex in the southwest of Dalian moving eastward was an important mesoscale convective system in triggering rainstorm. The occurrence and maintenance of strong upward movemont resulted from the vertical structure of potential pseudo-equivalent temperature with unstable-neutral-stable, and the strong vapor flux convergence and favorable configuration of vorticity and divergence provided powerful dynamic and thermal conditions for rainstorm.

Key words: continuous rainstorm, subtropical high, blocking high, low-pressure system, unstable stratification

摘要:

利用加密自动站资料、NCEP再分析资料,对2013年7月发生在大连地区的7次连续暴雨过程的成因进行分析。结果表明:2013年7月大连地区连续暴雨期间,乌拉尔山和鄂霍次克海均有强高压维持,有利于西伯利亚冷空气南下至贝加尔湖并长期维持形成大槽。副热带高压异常偏强,位置稳定偏西、偏北,为大连连续暴雨天气建立了有利的大尺度环流背景。来自华北、华东的2条水汽辐合带向大连地区汇合,大连西南方多低值系统东北传是暴雨发生发展过程中重要的中尺度对流系统。θse垂直方向的“不稳定层结—中性层结—稳定层结”结构促使强烈上升运动的产生和维持,同时强烈的水汽通量辐合与涡度、散度场的有利配置为连续暴雨提供了强大的热力动力条件。

关键词: 连续暴雨, 副热带高压, 阻塞高压, 低值系统, 不稳定层结

CLC Number: