“2009.08.13”云南省大理州强降水天气过程分析

在利用常规资料、自动站降水资料分析2009年8月12～14日大理州强降水天气过程的影响系统、物理量特征基础上,还利用大理国家气候观象台的风廓线雷达资料探讨了强降水发生前风廓线雷达各项产品的表现,结果表明此次区域性强降水过程,其主要影响系统是500 hPa上的两高辐合区和700 hPa上的切变线;强降水出现前各物理量特征表现明显;风廓线雷达资料中信噪比与强降水对应关系非常密切,垂直速度的变化对强降水有一定预示作用,强降水出现前水平风随高度存在多层切变且切变层次突然增多并抬升。

HEAVY PRECIPITATION SYNOPTIC PROCESS ANALYSIS OF DALI IN YUNNAN

The regular observation data and precipitation data by-hour of automatic meteorological station were used to analysis the impact system and physical characteristics of the synoptic process of Dali in Yunnan Province which occur in 12Aug 2009 to 14Aug 2009.And the characteristic of wind-profiling radar data of Dali national climate observatory was analyzed before the heavy precipitation.It showed that the mainly impact system of the regional heavy rainfall was two high convergence zone in 500 hPa and shear line in 700 hPa.Many physical characteristics were obvious before the heavy precipitation.There is a very close relationship between signal noise ratio of wind profiler radar and heavy rainfall.The change of vertical velocity was necessarily indicative of the role of heavy rainfall.There was multi-level horizontal wind shear with height before the onset of heavy rainfall and a sudden increase in shear layers and uplift.