摘要
利用常规观测资料、加密地面资料、卫星云图和多普勒雷达回波等资料,从天气形势、物理量场和回波演变特征等方面对2011年6月11日午后发生在豫北地区的强对流天气进行分析发现：高空冷平流和24 h显著降温区叠加在低层暖区之上,形成上干冷下暖湿的位势不稳定层结,为强对流的产生提供了层结条件;地面暖低压发展和辐合中心、辐合线是这次强对流天气的触发机制;0-6 km较大的垂直风切变有利于强对流天气的发展和维持。卫星云图和雷达产品显示：对流云团的发展和移动与地面切变线、雷达回波一致,并可预测强天气落区。当回波中心强度≥50 d Bz、回波顶高≥12 km、垂直累积液态含水量≥45 kg/m^2时,极易造成短时强降水和冰雹天气。三体散射特征和中气旋的出现对确定发布冰雹预警有指示意义,17：50第一次观测到三体散射特征发布冰雹预警,时效在20-90 min。垂直液态含水量在强降水发生前20 min开始剧增,为判别短时强降水等强对流天气提供有效依据。
Using conventional meteorological observations data, encrypted ground data, satellite im- ages and Doppler radar data, the strong convective weather in the afternoon on 11 June 2011 occurred in northern Henan was analyzed on the basis of weather situation, physical quantity fields and echo evolution characteristics. The results showed that cold advection and significant cooling zone were superimposed on the lower warm sector, which offered stratified conditions for strong convection; the development of ground warm low, the emergence of convergence center and convergence line were the triggering mecha- nism; the larger vertical wind shear in the range of 0-6 km was also conducive to the development and maintenance of strong convective weather. Satellite images and radar products showed that the develop- ment and movement of convective clouds were consistent with the ground shear line and radar echo, which could predict the rainfall areas of the strong weather. When the intensity of the echo center ≥ 50 dBz, echo top ≥12 km, vertically integrated liquid water content ≥ 45 kg/m^2, short-term heavy rainfall and hail weather happened easily. The appearance of the three-body scattering and cyclones were of indi- cating significance for determining the release hail warning. The three-body scattering was observed and the hail warning was released at 17：50 for the first time, which aging from 20 to 90 minutes. Vertical liquid water content began to surge 20 minutes before the heavy rainfall occurred, which provided an effective basis for determining short-term heavy rainfall and other strong convective weather.
出处
《气象与环境科学》
2015年第4期84-91,共8页
Meteorological and Environmental Sciences
基金
河南省重点科技攻关计划项目(112102310033)资助
关键词
强对流天气
不稳定层结
地面辐合线
三体散射
中气旋
垂直液态含水量
strong convective weather
unstable stratification
ground convergence line
three-body scattering
cyclone
vertical liquid water content
