摘要
2005年7月15日14时到16日08时,宜昌市出现了一次强对流天气过程。根据宜昌多普勒天气雷达每6min一次体扫监测信息,分析了副热带高压外围西北侧强对流天气雷达回波的演变趋势。结果表明,在山地向平原过渡的地带,当对流云发展到最旺盛阶段并出现地面强降水时,在其基本反射率最低仰角产品中存在出流边界;弓形回波、带状回波的走向与环境风场几乎成正交时,给所经之地造成异常剧烈的天气,且灾害性大风均出现在径向速度场中具有旋转性环流的强单体移动的下风方。
A severe convection weather occurred in Yichang city during from 14：00, July 15th to 08：00, July 16th in 2005. Based on the volume scanning data of Yichang Doppler radar every 6 minutes, the evolvement of radar echo of convective cloud northwest to the Subtropical High is studied.The result shows that on the transition belt from mountain to plain, there exits a outlet boundary in the basic reflectivity product of the lowest elevation when the convective cloud develops to the most strongly stage and the heavy rain occurs. Extremely severe weather always occurs when bow echo or belt echo are vertical to the background wind field and the gale always occurs in the leeward of the moving direction of the strong cell with rotating circulation in radial velocity field.
出处
《暴雨灾害》
2007年第1期68-72,共5页
Torrential Rain and Disasters
关键词
强对流天气
旋转环流
出流边界
弓型回波
Severe convection
Rotating circulation
Outlet boundary
Bow echo
