2018年6-7月四川持续性暴雨的成因分析

针对2018年6~7月四川持续性暴雨天气,初步分析了持续性暴雨的成因。结果表明:暴雨持续期间南亚高压位置稳定且偏强。四川位于其东北侧的高空急流出口区。乌拉尔山阻塞高压和巴湖低涡较常年偏强且稳定,为四川持续性暴雨发生提供有利的环流背景。副高西侧外围的偏南气流为水汽从南海向四川输送提供了有利的通道。持续活跃的干冷空气频繁南下与西南暖湿气流在四川交绥,同时水汽也在四川地区强烈的持续辐合上升,为暴雨的持续发生提供了有利的动力和水汽条件。高原低值系统的东传是四川持续性暴雨发生的重要天气尺度系统。

The Causation Analysis of Persistent Heavy Rain in Sichuan during June-July, 2018

Counter the persistent heavy rain in Sichuan during June-July 2018.Analytical characteristics of circulation during continuous persistent heavy rain.the results show that South Asia High is stable and strong during heavy rain.Sichuan is located in the high level jet stream outlet area to its northeast,The Ural Blocking High and The Palestinian Lake’s low vortex are stronger and more stable than normal,Providing a favorable circulation background for the occurrence of persistent heavy rain in Sichuan.The warm moist air is continuous transported to the Sichuan basin by the south airflow on the edge of subtropical high.Dry cold air frequently moves south and southwest warm and humid air flows in Sichuan basin.At the same time,water vapor in Sichuan basin is also strong continuous convergence rise,It provides favorable power and moisture conditions for the continuous occurrence of rainstorm.The low vortex which continued to move eastward is the important heavy rain producing mesoscale convective system.