宁夏北部2012年“7.20”短时暴雨环流特征及天气学分析

利用MICAPS提供的常规气象资料和图表,对宁夏北部2012年7月20日暴雨过程的环流特征、水汽来源、不稳定层结、动力条件和强对流云团进行了分析探讨.结果表明,该次暴雨过程是在副热带高压边缘、高空槽前有利的环流背景下,低层低涡、切变线和低空急流共同作用产生的;降水前具有较好的热力不稳定条件,较好的能量储备,有力的动力条件和一定量级的水汽辐合.卫星云图和雷达反射率因子资料的中尺度系统表现为一典型以对流云为主的混合性降水云系特征.

Analysis of the circulation features and synoptic of the "7.20" short-time rainstorm in 2012 in north Ningxia

Using meteorological data and charts from MICAPS,the circulation features,moisture sources,unstable stratification,dynamics conditions and strong convective clouds of rainstorm process in the north of Ningxia,July 20,2012 was analyzed.The results show that this rainstorm process was formed on the common condition of lower vortex,shear line and low-level jet at the background of subtropical edge and front of upper trough favorable circulation.There were better thermal instability conditions,energy reserves,strong power conditions and a certain magnitude of moisture convergence before raining.Mesoscale system of satellite cloud picture and radar reflectivity factor data expressed that a typical characteristic was mixed convective cloud-based cloud system.