一次飑线(冰雹)天气过程中尺度分析

利用常规天气图、物理量、多普勒雷达Web GIS拼图、自动站雨量等资料,采用中尺度分析和特征提取方法,对2013-03-19~20日上饶市出现的一次大范围冰雹飑线过程进行分析,结果表明:高空西南小槽东移、中低层较强的西南急流和地面冷空气南下是此次冰雹飑线过程发生、发展和消亡的主要影响天气系统;冰雹飑线回波在发展演变中没有形成典型的"弓"状回波,飑线回波的走向和移动与其东部的中低层急流一致;同时出现冰雹和超短时强降水是这次冰雹飑线天气过程的重要特征,其回波强度达到65~70dBz,强回波梯度大;过程中CAPE几乎为0。中低层西南急流和强垂直风切变是这次冰雹飑线天气过程的重要动力和维持机制。

Mesoanalysis of a squall line process with hailstone

By using routine synoptic data,physical quantity,Web GIS radar mosaic products and rainfall data from AWS,based on the methods of mesoanalysis and feature extraction,a wide range squall line process with hailstone in Shangrao city on March 19-20th,2013 was analyzed.The results show that the occurrence,development and disappearing of the squall line process with hailstone are mainly affected by the small southwest trough moving eastward in the upper altitude,the strong southwest jet stream in the low and medium altitude and the ground cold air moving southward.There is no typical bow echo when echoes of the squall line with hailstone were developing.Moving direction of the squall line echoes is in accordance with the jet stream in the low and medium altitude.The important characteristics of this squall line process are appearing the hailstone and ultra-short time strong precipitation together,its echo intensity up to 65-70 dBz,and strong echoes gradient is large. During the whole squall line process,the value of CAPE is almost zero.The southwest jet stream in the low and medium altitude and strong vertical wind shear become the significant dynamic and support mechanism for this weather process.