2013年四川盆地持续性特大暴雨过程对比分析

利用NCEP1°×1°再分析资料和地面加密自动站资料,采用动力诊断分析方法,对造成盆地连续出现突破气象历史记录的暴雨洪涝灾害的6月18~20日川西大暴雨、6月29日~7月2日持续性特大暴雨和7月8~11日川西持续性特大暴雨过程进行对比分析,对暴雨过程的形成机制进行探讨,得出以下结论：盆地持续性暴雨具有东高西低的环流形势,大尺度环流背景的稳定少动,以及中尺度影响系统的稳定维持或发展,是形成持续性暴雨的关键之一;低空急流的长时间维持是暴雨持续时间的原因之二;在持续性暴雨天气过程中,中层能量条件的维持是一个重要的关注点;持续性暴雨过程中,对流持续发展的关键之一是长时间存在着强盛的垂直上升气流;冷空气的参与为暴雨的持续发生也有一定的作用。

Comparative Analysis of Continuous Rainstorm in Sichuan Basin in 2013

Based on NCEP 1°×1° reanalyzed data,Sichuan meteorological observation stations data, in the way of combi- ning synoptic meteorology and dynamic diagnostics, the continuous rainstorm and flood disasters during the period of 18th - 20th June, 29th June -2nd July, 8th - llth July in 2013 are compared and analyzed. In 29th June -2nd July, 8th -11th July in 2013, daily rainfall amount broke history meteorological record of Sichuan province. Discussed of formation mechanism of the basin rainfall and comparative analyzed of the similarities and differences of persistent heavy rainfall. The result show that, the one of the key for basin persistent rainstorm weather was generated under the favorable ＂high east and low west＂ rainfall situation, the stable large scale circulation background and the stable mesoscale system provide favorable background to the continuous heavy rain. There is stable low-level jet near rainstorm area is important to rainfall duration. Energy condition of the middle level is an important concern in the continuous heavy rain. Vertical upward flow exists in long time which results in a long life of the convective system. The cold air flow is beneficial to heavy rain to continuous.