Analysis of the Water Vapor, Instability Conditions and Dynamics Characteristics of an Extreme Rainstorm Event in Liaoning Province

Abstract

This paper presents a diagnostic analysis of the dynamic, thermal, and water vapor characteristics of a regional extreme rainstorm in Liaoning Province on September 19, 2021, using automatic station observations and ERA5 reanalysis data, and concludes that the storm occurred under favorable circulation conditions. The storm had two water vapor belts, which converged in western Liaoning. The front was convectively unstable and symmetrically unstable before the end of the precipitation, and the convective instability weakened as the precipitation intensified. With the front moving rapidly to the northern coast of the Bohai Sea. The frontal center moves northward rapidly and extends down to near 950 hPa and the warm tongue of the high altitude extends down to the south of the frontal surface strengthens, the warm and humid airflow and low altitude rapids occur explosively, causing strong airflow to strengthen the tilted rise and enhance the symmetric instability, which makes the precipitation enhance.