天津地区一次局地大暴雨过程MCS传播发展机制

利用常规观测资料、卫星云图、雷达、风廓线组网资料对2017年8月8日-9日天津地区局部大暴雨天气进行分析,得到以下结论：A、B两个中尺度雨团先后影响天津,A雨团持续了4个小时,雨强相对较大；B雨团持续了3个小时,雨强相对较小；对应有两个MCS,强降水发生在TBB低值中心偏向温度梯度最大的区域；降水回波的移动路径和强度特征存在差异,A雨团回波为自西北向东南方向移动的带状的高质心降水回波；B雨团回波自西南向东北方向移动,为低质心降水回波带状回波,高质心降水回波雨强高于低质心降水回波。新型探测资料有助于分析中尺度影响系统,判断对流系统的移动方向。用风廓线组网资料对比两个阶段降水的中尺度系统,A雨团为上冷下暖的高低空配置,B雨团降水出现在整层西南气流中,引导风的不同,导致回波的移动方向、天气剧烈程度的不同；变压梯度、温度梯度等环境因素对判断局地对流暴雨发生的环境条件有一定指示性。

Dissemination and Development Mechanism of MCS during a heavy rainstorm in Tianjin

Using observation data, satellite, radar and wind profile data, the local heavy rain in tianjin on August 8-9, 2017 was analyzed, and the conclusions: two mesoscal rain clusters, A and B, successively affected tianjin. B. The rain cluster lasted for 3 hours, and the rain intensity was relatively low. For two MCS, the heavy precipitation occurred in the area with the maximum temperature gradient in the direction of the TBB low value center. The movement path and intensity characteristics of precipitation echo are different. The echo of rain cluster A is A zonal high-quality precipitation echo moving from northwest to southeast. The echo of rain cluster B moves from southwest to northeast, which is the banded echo of low-quality precipitation, and the intensity of echo of high-quality precipitation is higher than that of low-quality precipitation. The new detection data is helpful to analyze mesoscale influence system and determine the direction of movement of convection system. The mesoscale system of precipitation in the two stages is compared with the wind profile network data. The rain cluster A is A high-low air configuration with upper cold and lower warm. Environmental factors such as pressure gradient and temperature gradient have certain indication for judging the environmental conditions of local convective rainstorm.