浙江梅雨气候特征及其梅汛期暴雨的形势分析

The characteristics of Heavy rain and its Analysis of synoptic circumstances During Plum Flood Period in ZheJiang

利用浙江省1954～2008年55年梅汛期逐日气象资料,对浙江入梅日期、出梅日期、梅雨日数、梅雨期降水总量进行了统计分析,发现入梅日期、出梅日期、梅雨期降水总量具有年际变化特征,梅雨期天气形势、梅雨日数、梅雨期总降水量有着一定的对应关系。文中着重对1979～2008年30年浙江出现暴雨前24小时的形势特点进行分析,分成四种类型,分析总结出各型的高低层配置及暴雨落区,并对影响浙江梅汛期降水的主要因子进行分析,找出一些浙江梅汛期暴雨的预报指标。

By use of daily data of plums rain during plums flood periods from 1954 to 2008,the dates of beginning and ending,lasting day,total rainfalls of the Mei-Yu periods were analysed. And the results show that the dates of beginning and ending and total rainfalls of the Mei-Yu period featured annual variations,and lasting day,synoptic circumstances and total rainfalls of the Mei-Yu period have some corresponding relations. The focus is on synoptic circumstances of former 24 hours before the appearing of heavy rain. Then four types were obtained from the synoptic circumstances. The configurations between circumstances of low and high levels and positions of heavy rain were summarized. At last the main factors affecting rainfalls were analysed and some forecasting indexes were taken.