Abstract:

By using Doppler radar data and automatic meteorological station data，a gust front occurred in spring in east of Hu’nan Province was analyzed． Results show that the gust front generated when the down － draft reached the ground and produced a strong divergence and converged with the lower warm moist air． The gust front presented a narrow arc in the Doppler radar reflectivity and radial  velocity diagrams，the echo intensity was weak and convergence was obvious in the radial velocity diagram． Gust fronts can cause pressure rise and produce severe winds．

Key words:  gust front, a narrow arc, formation mechanism, convergence zone

摘要：

应用多普勒雷达观测资料和自动气象站资料，对湘东地区一次春季阵风锋天气过程进行分析。表明: 阵风锋是对流风暴产生的下沉气流达到地面时产生强烈辐散，与低层暖湿空气交汇产生的剧烈天气现象。阵风锋在多普勒雷达反射率和径向速度图上表现为一条狭窄弧线，回波强度偏弱，速度图上有辐合，阵风锋在强雷暴的发生、发展和维持起了相当大的作用，阵风锋过境会引起气压涌升和产生灾害性大风。若短时预报员在观测到阵风锋后，应综合分析其他常规资料和非常规资料，根据风暴的移动路径，可以对其下游地区及时发布雷雨大风预警，大大地提高了预警时效。

关键词: 阵风锋, 窄带回波, 形成机制, 辐合区