2019年夏季冀东北地区一次长生命史弓状飑线过程分析

Analysis of a Long Life Arcshaped Squall Line Event Over Northeast Hebei Province in 2019

选取2019年7月25日冀东北地区出现的一次长生命史弓状飑线过程,利用常规和加密气象观测数据、ERA5(0.25°×0.25°)再分析数据、卫星资料以及多普勒雷达资料等进行分析发现:7月25日过程出现在午后,飑线自西北向东南移动,影响槽比较浅薄,属于弱天气尺度强迫下产生的强对流天·气,本次过程主要由地面辐合线和干线触发;在高分辨率的葵花卫星云图上,有大范围对流云泡排列成带并向南压;本次飑线过程雷达回波特征有明显弓形,属于飑线型弓形回波,为中α尺度,形态多变,生命期长达6 h。

Select a long life history arcuate squall line process in Northeast Hebei on July 25, 2019, and use conventional and encrypted meteorological observation data, era5(0.25°×0.25°) reanalysis data, satellite data and Doppler radar data show that the process on July 25 occurred in the afternoon, the squall line moved from northwest to Southeast, and the influence trough was relatively shallow. It belongs to strong convective weather under weak Weather Scale forcing. This process is mainly triggered by ground convergence line and trunk line. On the high-resolution sunflower satellite cloud image, there are large-scale convective cloud bubbles arranged in a belt and pressed southward.The radar echo characteristics of this squall line process have obvious bow, belonging to squall line bow echo, which is medium. The scale and shape are changeable, and the life span is up to 6 h.