四川盆地西南部短时强降水天气特征分析

本文通过对2008~2013年四川盆地西南部短时强降水时空分布分析,发现四川盆地西南部短时强降水的中心在雅安和峨嵋;从短时强降水的年际、月际以及日变化分布来看,短时强降水在2008年是谷值年;短时强降水集中时段在7~8月,5月和9月短时强降水较少,特别是大量级短时强降水更少;短时强降水出现在00~04时最多,尤其是02~03时。根据落区分型对盆地西南部短时强降水建立预报模型,盆地西南部短时强降水的天气尺度影响系统主要是南亚高压稳定,高原低槽或切变发展配合中低层南风,近地层东北风与西南部地形的辐合抬升更容易触发对流发展,中低层的风场对强降水落区更有指导意义。 

Synoptic Characteristic Analysis of Short-time Hard Rain in Southwest Sichuan Basin

By spatial and temporal characteristics analysis of short-time hard rain in south-west China Sichuan basin from year 1998 to 2013,results show that the short-time hard rain centers are ya'an city and e'mei city in this region. The strongest short-time hard rain year is 2008 and the most maximum numbers in month of the short-time hard rain is July and August,less in May and September,especially the heavy short-time hard rain in May and September is rare. From the daily change of the short-time hard rain,the most often appearance time is during 00~04 hour. The prediction model of short-time hard rain is founded by rain falling prediction region. By analysis of influence weather systems,the low-to-middle level wind fields are the good instructional signs to rain falling region of short-time hard rain. By analysis of the terrain in this region,the relationship between the short-time hard rain and the terrain is deeply concerned.