初夏四川盆地东北部一次暴雨过程分析

Analysis of an Early Summer Rainstorm over Northerast Sichuan Basin

本文利用NCEP1°×1°6小时再分析资料及常规观测资料,针对2014年6月2日发生在四川盆地东北部的一次暴雨天气过程进行分析,并就风与温度与2011年5月1~2日的过程进行对比,其结果表明：（1）此次过程主要是由华北冷涡后的冷平流、东南气流引导的暖湿空气及低层偏东气流引导的冷空气共同作用而形成。（2）两次过程都存在低层偏东气流引导华北低涡中冷空气入川,且与强降水落区有较好的对应关系。（3）强降水关键区在整个过程中一直处于高湿状态。（4）低层水汽输送主要以由东向西和由南向北输送为主。（5）强降水爆发期从400h Pa以下皆为水汽的辐合上升运动,且在中高层持续加强。

Use NCEP 6- hour reanalysis data（ 1° × 1°） and conventional observation data to analyse a rainstorm process in northerast Sichuan Basin in June 2,2014. And compared with the process happened on May 1 ~ 2,2011 in wind and temperature. The results show that：（ 1） The heavy rain is mainly caused by the cold advection after cold vortex in North China and warm moist air guided by southeast air flow and cold air guided by low- level easterly airstream.（ 2） By low- level easterly airstream,the cold air in North vortex was leaded to Sichuan in both process. There is a good corresponding relationship between easterly airstream and the rainfall area.（ 3） The key area of strong precipitation had been in a high humidity condition in the whole process.（ 4） The low level moisture mainly drived from east to west and from south to north.（ 5） The moisture from below400 h Pa are all convergence in the strong precipitation outbreak period and continued to strengthen in mid- high levels.