前汛期两次暴雨过程对比分析研究

Variation in the Two Rainstorm Courses of First Rainy Season Precipitation

利用自动站逐时降水资料、MICAPS常规资料、卫星云图及日本GPV客观分析场资料对浙江省2008年5月28日和6月9日两次暴雨过程进行分析。结果表明:0528暴雨是由高空槽配合低层切变东移南压所致,0609暴雨是由暖切变(梅雨锋)长时间维持所致,影响系统完全不同;两次暴雨都由低空急流为其提供充沛的水汽;700 hPa正螺旋度带与天气系统对应较好,850 hPa、925 hPa正螺旋度带与冷性系统配合较一致,而对应暖切变反映信号较弱,暴雨中心出现距正螺旋度中心东南侧1～2纬距;地形作用对降水起加强作用,暴雨中心一般在地形作用最强处。

using hourly precipitation data of automatism station and routine data of MICAPS and nephogram and external analysis data of Japonic GPV mode,Variation in the two rainstorm courses of first rainy season precipitation is analyzed in Zhejiang. The result is that：the origin of the two rainstorm courses is distinct,the first rainstorm is caused by trough and shear line,the second is by warm shear line which lasting long time. The lower-troposphere strong offer abundant water vapor for the two rainstorms. The plus helix strip of 700 hPa is corresponding to weather system preferably ,and that of 850 and 925hPa is corresponding to cold weather system preferably, but is of a sort to warm shear line, the center of rainstorm is situated on southeast of the plus helix strip. The effect of terrain potentiate to precipitation, the center of rain- storm is currently situated on situs where the effect of terrain is furthest.