2009年湖南主汛期一次暴雨过程分析

利用常规观测资料和区域自动站降水资料、1°×1°NCEP再分析资料、FY-2C静止气象卫星TBB图像以及多普勒雷达等资料,对造成湖南2009年6月8～10日强降水过程成因进行了分析。结果表明,该次强降水是在西太平洋副高的一次增强北抬并迅速南落,中低空切变线长时间维持及摆动,温湿能配置下形成的。分析发现雷达产品和卫星TBB图象、低层θse和CAPE高能区以及强的辐合上升区等与降水时段和落区对应关系较好。T639和EC对500hPa西太平洋副高的西脊点位置的预报,都随着时效的延长,位置都偏东,强度偏弱,导致湖南强降水预报的落区存在一定偏差。

Analysis of A Heavy Rainstorm Process in Main Flood Season of 2009 in Hunan Province

A heavy rainstorm process in Hunan Province on June from 8 to 10th,2009 was synthetically analyzed with conventional observations data,precipitation data from regional automatic stations,1°×1°NCEP reanalyzed data,contour of TBB from FY-2C geostationary satellite,Doppler radar etc.The result indicated that the whole process is caused by West Pacific Ocean subtropical high north a enhancement lifts and rapid south falls,on low and middle-level atmosphere shear line at Hunan long time maintenance and swinging and high moisture and energy stratified instability disposition.It was found that the heavy rainstorm area had a better corresponding to radar product and satellite TBB image,the high potential pseudo-equivalent temperature(θse)at low level,and high convergence available potential energy(CAPE),strong convergence and upward current.T639 and EC models all have poor accuracy in the location of the westedge of the subtropical high that along with the effectiveness extension,the position are easterly,the intensity is weak.This fact is thought to be one of the reasons causing predict the forecasting error the area of the heavy rainfall in Hunan.