Analysis of the causes of extreme rainfall in Guangxi caused by typhoon"CHABA"
By using multi-source meteorological data,the causes of extreme rainfall in Guangxi affected by typhoon"CHABA"in 2022 were analyzed.The results showed that:(1)the rainfall in Guangxi under the influence of Typhoon"CHABA"was characterized by large and wide range cumulative rainfall and daily rainfall,extensive and intense of short-term heavy precipitation with a long duration,strong extremes and heavy disasters.(2)Typhoon"CHABA"had made landfall and entered Guangxi with strong intensity,staying in Guangxi for a long time,with a rare track across the eastern part of Guangxi on a south-to-north direction,which was the main reason for the extreme precipitation.The typhoon itself and the monsoon entrainment provided abundant water vapor and energy sources for the heavy rainfall area.The strong upward movement formed by the combination of the body circulation,the wind speed convergence of the low-level southwesterly jets,the sea-land difference,the topographic uplift,and the obvious mesoscale convergence lines both on the ground and in the boundary layer were the physical mechanism for the generation of extreme rainfall.(3)There were obvious mesoscale convective system MCS activities within the typhoon cloud system,forming supercell storms,which was the direct cause of heavy rainfall.The thick warm clouds,strong radar reflectivity located below 5 km,large diameter and dense precipitation particles form high precipitation efficiency,which was an important factor in generating short-term heavy precipitation.(4)In operational forecasting,it is of great significance to strengthen the analysis of multi-channel water vapor sources and the increasing effect of various weather systems,especially small-and medium-sized weather systems,on the precipitation of typhoons,which is the focus of the extreme precipitation forecasting of typhoons.
typhoonextreme rainfallextreme short-term rainfallmesoscale convective systems
国家科技期刊平台
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