云南中部一次飑天气过程的雷达回波特征

The Echo Analysis of a Squall Event over Central Yunnan

利用地面资料和雷达回波 ,分析了 2 0 0 2年 9月 8日云南中部一次飑天气的发生、发展和演变情况 ,得出低纬高原飑天气出现时天气和要素变化为 :雷暴最先出现 ,随后湿度急升 ,气温直线下降。在这突变过程中出现大风、大雨和冰雹 ,气压出现跳跃。飑线水平尺度长不到 1 0 0km ,宽仅 1 0km ,生消史两个小时左右。其雷达回波有前期征兆 ,发生演变过程 。

The initiation, development and evolution of the squall line on Sep. 8th,2002 over central part of Yunnan Province are analyzed by using the surface observation and radar echo data. The result shows that the weather and physical factors as follows: the thunderstorm occurred, the humidity rose rapidly, and the temperature lapsed when the squalls occurred over the low latitude plateau. The strong wind, heavy rain and hail occurred, and the pressure was discontinuons during the chopping process. The length of squall line is less than 100km and the width is only about 10km. The life time of the squall is about 2 hours. Before it occurred, the radar echo had certain premonitory and changing character.