飑线过程分析及其影响——以武汉机场一次飑线发生为例

Analysis of a Squall Line Process and Its Influence——Taking Wuhan Airport as an Example

利用武汉新一代多普勒雷达、常规天气图和地面观测资料,对2011年7月26日武汉机场的一次强对流天气过程进行诊断,主要分析了飑线的多普勒基本反射率因子与基本速度特征,并与超极单体进行了比较分析。结果发现这次过程是受高空槽配合弱冷空气东移与南方暖湿空气共同影响;副高的东退形成正不稳定能量区,K指数高,低层水气和能量形成了对流不稳定层,特别是中高层,有弱冷空气入侵,形成了中低层的垂直风切变,前方的斜上升气流,后方的下沉气流使飑线得以维持;正是飑线过境时出现了阵风锋,强下冲气流及地面大风及雷暴高压;与超级单体形成的下击暴流相比,在飑线运动的前方形成的雷雨及地面大风范围更大,强度更强。这次飑线过程对农业、交通及日常生活造成了较大影响,最后提出要提高对灾害天气预警能力及气象服务能力。

This article used new generation Doppler radar data in Wuhan, and also used conventional sounding data and surface observational data to diagnosis a strong convective weather process in July 26, 2011 in Wuhan airport . In this paper, we mainly analyzed the Doppler base reflectivity factor and basic velocity characteristics of the squall line, which compared with the super monomers. The results showed that this process was caused by the combining of the weak cold air moving eastward with a high trough and the south warm and wet air. Subtropical high retreated eastward to form a positive unstable energy region, the K index was high, the lower water vapor and energy formed a convective instability layer, especially in the senior, in this squall line process, a weak cold air invaded, which formed a vertical wind shear in the lower, the ramp updraft in the front and the downdraft in the behind made the squall line maintaining. This squall line brought a gust front, strong downbursts,strong ground winds and thunderstorm high. Compared to downburst caused by super cells, the thunderstorms and strong ground winds on front of the moving squall line were greater and stronger. This squall line process has greater impact on agriculture, traffic and our human daily lives, and also brings a great threat to aviations, so we have to study them by analysis in order to improve the early warning capabilities and service capabilities about strong thunderstorm weathers.