2017年7月5日四川绵阳暴雨过程诊断分析
Diagnostic Analysis of Heavy Rainstorm Process in Mianyang, Sichuan Province on July 5, 2017

本文利用2017年7月7月4日至6日的实时观测数据以及欧洲气象预报中心2017年7月的nc数据，并且运用grads、micaps以及Fortran等工具对2017年7月5日四川绵阳暴雨过程进行诊断分析。结果表明：本次降水具有强降水时间持续较长，短时降水强度大等特点。本次暴雨过程与西南涡和低空急流紧密相关，超低空西南急流自南海、孟加拉湾输送水汽至绵阳上空，西南涡移动触发低空急流左侧风速辐合区内的不稳定能量，使绵阳上空产生上升运动，形成强降水天气。并且由于西太平洋副热带高压的阻挡作用，西南涡无法移出雨区，导致强降水时间维持较长，形成特大暴雨。
This paper uses real-time observations from July 4 to 6, 2017 and NC data from the European Mete-orological Forecast Centre in July 2017, and uses tools such as grads, micaps, and Fortran to diagnose and analyze the heavy rainfall process in Mianyang, Sichuan Province on July 5, 2017. The results show that this precipitation has the characteristics of long duration of heavy precipitation and high intensity of short-term precipitation. The rainstorm process is closely related to the southwest vortex and low-altitude jet stream, the ultra-low altitude southwest jet stream transports water vapor from the South China Sea and the Bay of Bengal to the sky above Mianyang, and the southwest vortex movement triggers the unstable energy in the wind speed convergence zone on the left side of the low-altitude jet stream, which causes upward movement over Mianyang and forms heavy precipitation weather. And due to the blocking effect of the subtropical high in the western Pacific Ocean, the southwest vortex cannot move out of the rain area, resulting in a long period of heavy precipitation, forming extremely heavy rainfall.