Analysis and Model Verification of Extreme rainfall Processes in Huabei of China in 2023

Abstract

         From July 29 to August 1, 2023, extreme heavy rainfall occurred in the Chinese HUABEI region. Heavy rainstorm occurred in the most areas of Beijing, Tianjin and Hebei province, with the maximum accumulated precipitation of 1103.4 mm. The daily precipitation of 14 national meteorological observatories in Hebei and Beijing exceeded the historical extreme value, and the accumulated precipitation of 26 national meteorological observatories in three days exceeded the historical extreme value. The process intensity exceeded the three extreme rainstorm processes in the history of HUABEI region. Studying the causes of extreme heavy precipitation in HUABEI and evaluating the predictive performance of the model for extreme heavy precipitation is beneficial for improving the application and forecasting ability of the model. This article analyzes the weather scale characteristics and anomalies of this precipitation process from factors such as height field, wind field, divergence field, vorticity field, and water vapor. The dynamic and thermal structure of the vortex and the cause of the upper level continental high are analyzed using the method of cyclone phase space map and full type vorticity equation. Finally, the predictive ability of the model for extreme precipitation is tested.