Formation Mechanisms of the “5·31” Record-Breaking Extreme Heavy Rainfall Process in South China in 2021

Based on the fifth-generation European Center for Medium-Range Weather Forecasts reanalysis data (ERA5), the real-time observation data from weather stations, and the radar products in Guangdong Province, we analyze the precipitation properties and formation mechanisms of the “5·31” extreme heavy ra...

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Main Authors: Fangli Chen, Huiqi Li, Sheng Hu, Shuai Jiang, Jiaojiao Li, Ruoting Wu
Format: Article
Language:English
Published: MDPI AG 2023-05-01
Series:Atmosphere
Subjects:
Online Access:https://www.mdpi.com/2073-4433/14/5/872
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author Fangli Chen
Huiqi Li
Sheng Hu
Shuai Jiang
Jiaojiao Li
Ruoting Wu
author_facet Fangli Chen
Huiqi Li
Sheng Hu
Shuai Jiang
Jiaojiao Li
Ruoting Wu
author_sort Fangli Chen
collection DOAJ
description Based on the fifth-generation European Center for Medium-Range Weather Forecasts reanalysis data (ERA5), the real-time observation data from weather stations, and the radar products in Guangdong Province, we analyze the precipitation properties and formation mechanisms of the “5·31” extreme heavy rainfall process with record-breaking 3-h accumulated rainfall in South China during 2021. The results show that the extreme heavy rainfall process is caused by the joint actions of weather systems such as a weak upper-level short-wave trough, a surface stationary front, and a low-level southwesterly jet. Before the heavy precipitation process, there is large precipitable water content and deep warm clouds, which provides a potential for the occurrence and development of the heavy rainfall process in Longhua Town of Longmen County and its surrounding areas. Simultaneously, the low-level southwesterly jet provides abundant warm-wet water vapor for the heavy rainfall area. The vertical atmospheric environmental conditions, such as strong horizontal temperature gradient, high convective available potential energy, high-temperature difference between 850 hPa and 500 hPa, and low convective inhibition, maintain for a long duration in the heavy rainfall area, which are favorable for the occurrence and development of high-efficiency convective precipitation caused by water vapor condensation due to the uplift of low-level warm-wet airflows. The combined effects of the enhanced low-level southwesterly airflow, the stationary front, the mesoscale surface convergence line generated by cold pool outflows, the terrain influence, and the train effect of the precipitation echoes make heavy precipitation near Longhua last longer and stronger than other areas, leading to the extreme heavy rainfall with the record-breaking 3-h accumulated rainfall in Longhua.
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spelling doaj.art-85d3ac379cc34410b0e93ecb93a2793b2023-11-18T00:26:08ZengMDPI AGAtmosphere2073-44332023-05-0114587210.3390/atmos14050872Formation Mechanisms of the “5·31” Record-Breaking Extreme Heavy Rainfall Process in South China in 2021Fangli Chen0Huiqi Li1Sheng Hu2Shuai Jiang3Jiaojiao Li4Ruoting Wu5Huizhou Meteorological Bureau, Huizhou 516001, ChinaGuangzhou Institute of Tropical and Marine Meteorology, China Meteorological Administration, Guangzhou 510641, ChinaGuangzhou Institute of Tropical and Marine Meteorology, China Meteorological Administration, Guangzhou 510641, ChinaHuizhou Meteorological Bureau, Huizhou 516001, ChinaHuizhou Meteorological Bureau, Huizhou 516001, ChinaHuizhou Meteorological Bureau, Huizhou 516001, ChinaBased on the fifth-generation European Center for Medium-Range Weather Forecasts reanalysis data (ERA5), the real-time observation data from weather stations, and the radar products in Guangdong Province, we analyze the precipitation properties and formation mechanisms of the “5·31” extreme heavy rainfall process with record-breaking 3-h accumulated rainfall in South China during 2021. The results show that the extreme heavy rainfall process is caused by the joint actions of weather systems such as a weak upper-level short-wave trough, a surface stationary front, and a low-level southwesterly jet. Before the heavy precipitation process, there is large precipitable water content and deep warm clouds, which provides a potential for the occurrence and development of the heavy rainfall process in Longhua Town of Longmen County and its surrounding areas. Simultaneously, the low-level southwesterly jet provides abundant warm-wet water vapor for the heavy rainfall area. The vertical atmospheric environmental conditions, such as strong horizontal temperature gradient, high convective available potential energy, high-temperature difference between 850 hPa and 500 hPa, and low convective inhibition, maintain for a long duration in the heavy rainfall area, which are favorable for the occurrence and development of high-efficiency convective precipitation caused by water vapor condensation due to the uplift of low-level warm-wet airflows. The combined effects of the enhanced low-level southwesterly airflow, the stationary front, the mesoscale surface convergence line generated by cold pool outflows, the terrain influence, and the train effect of the precipitation echoes make heavy precipitation near Longhua last longer and stronger than other areas, leading to the extreme heavy rainfall with the record-breaking 3-h accumulated rainfall in Longhua.https://www.mdpi.com/2073-4433/14/5/872extreme heavy rainfalllow-level southwesterly jetstationary frontSouth China
spellingShingle Fangli Chen
Huiqi Li
Sheng Hu
Shuai Jiang
Jiaojiao Li
Ruoting Wu
Formation Mechanisms of the “5·31” Record-Breaking Extreme Heavy Rainfall Process in South China in 2021
Atmosphere
extreme heavy rainfall
low-level southwesterly jet
stationary front
South China
title Formation Mechanisms of the “5·31” Record-Breaking Extreme Heavy Rainfall Process in South China in 2021
title_full Formation Mechanisms of the “5·31” Record-Breaking Extreme Heavy Rainfall Process in South China in 2021
title_fullStr Formation Mechanisms of the “5·31” Record-Breaking Extreme Heavy Rainfall Process in South China in 2021
title_full_unstemmed Formation Mechanisms of the “5·31” Record-Breaking Extreme Heavy Rainfall Process in South China in 2021
title_short Formation Mechanisms of the “5·31” Record-Breaking Extreme Heavy Rainfall Process in South China in 2021
title_sort formation mechanisms of the 5·31 record breaking extreme heavy rainfall process in south china in 2021
topic extreme heavy rainfall
low-level southwesterly jet
stationary front
South China
url https://www.mdpi.com/2073-4433/14/5/872
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