“2004．6”湘西北低空急流暴雨的中尺度分析

THE MESOSCALE ANALYSIS OF"04.6"LLJ RAINFALL IN NORTH-WEST REGION OF HUNAN PROVINCE

利用常规观测、T213、雷达和MM5中尺度模式输出资料对2004年6月23—24日湘西北地区的暴雨和大暴雨进行了天气动力学和中尺度分析。结果表明:这场暴雨是在有利的天气背景条件下产生的,造成强降水的雨团在时空尺度上具有中尺度系统的特征,中尺度辐合线和低空急流为降水发生提供了有利的触发条件。

A dynamical and mesoscale analysis of a heavy LLJ rainfall event on June 24, 2004 in North-West Hunan province is made with routine observation,MM5 data and radar images. It＇s found that the heavy rainfall occurred under the favorable environmental conditions. The rain clusters that brought heavy rainfall have the features of meso-β system at the scales of time and space. The mesoscale convergence line and LLJ provided favorable triggering effect for the occurrence of the heavy rainfall.