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| Evolution characteristics of a mesoscale convective rainstorm system in the eastern Sichuan Basin |
| Li Jinxin1, Li Xiaorong1,2,3, Liu Yuanjiang1,2,3 |
1. Nanchong Meteorological Bureau,Nanchong 637000;
2. Research and Innovation Team on Severe Weather Monitoring,Forecasting and Early Warning Technology,Nanchong 637000;
3. Nanchong Key Laboratory of Strong Climate Research in Northeast Sichuan,Nanchong 637000 |
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Abstract The article analyzes a severe convective rainstorm event that occurred in eastern Sichuan on August 9-10,2024,utilizing data from ERA5,regional automatic weather stations,a new generation of Doppler weather radar,and FY-4 satellite data.The results indicate that the 100 hPa South Asia High is of the western type,while the 500 hPa Subtropical High retreats eastward and rises northward,causing changes in the location of the rain belt.There is weak convergence between 700 hPa and 850 hPa in eastern Sichuan;the atmospheric unstable energy is strong,with θse decreasing with height from 600 to 850 hPa.The positive vorticity in the lower layers interacts with the negative vorticity in the upper layers,providing lifting conditions for atmospheric ascending motion.Water vapor continues to converge,providing favorable conditions for water vapor.When short-term heavy precipitation occurs,radar echoes often exhibit tightly structured band-like echoes with high development heights and obvious backward propagation characteristics.On the profile map,the precipitation characteristics of low-centroid warm clouds are evident;the precipitation caused by the MCC system has a large range,strong rainfall intensity,and a relatively concentrated distribution.On the satellite cloud image,the minimum TBB reaches -90 ℃,and there is a certain positive correlation between the area of the -80 ℃ cold cloud region and the total precipitation of the MCC.The larger the area of the -80 ℃ cold cloud region,the greater the total precipitation of the MCC.
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Received: 27 June 2025
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2025, Vol. 42 
