Impacts of Increasing Model Resolutions and Shortening Forecast Lead Times on QPFs in South China During the Rainy Season  

作　　者：张旭斌 李静珊 罗亚丽 宝兴华 陈靖扬 肖辉 文秋实 ZHANG Xu-bin;LI Jing-shan;LUO Ya-li;BAO Xing-hua;CHEN Jing-yang;XIAO Hui;WEN Qiu-shi(Guangzhou Institute of Tropical and Marine Meteorology/Guangdong Provincial Key Laboratory of Regional Numerical Weather Prediction,CMA,Guangzhou 510641 China;Guangdong Ecological Meteorology Centre(Pearl River Delta Center for Environmental Meteorology Prediction and Warning),Guangzhou 510640 China;Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters&School of Atmospheric Sciences,Nanjing University of Information Science and Technology,Nanjing 210044 China;Fujian Key Laboratory of Severe Weather&Key Laboratory of Straits Severe Weather,CMA,Fuzhou 350007 China;State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences,Beijing 100081 China;Guangzhou Institute of Tropical and Marine Meteorology,CMA,Guangzhou 510641 China)

机构地区：[1]Guangzhou Institute of Tropical and Marine Meteorology/Guangdong Provincial Key Laboratory of Regional Numerical Weather Prediction,CMA,Guangzhou 510641 China [2]Guangdong Ecological Meteorology Centre(Pearl River Delta Center for Environmental Meteorology Prediction and Warning),Guangzhou 510640 China [3]Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters&School of Atmospheric Sciences,Nanjing University of Information Science and Technology,Nanjing 210044 China [4]Fujian Key Laboratory of Severe Weather&Key Laboratory of Straits Severe Weather,CMA,Fuzhou 350007 China [5]State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences,Beijing 100081 China [6]Guangzhou Institute of Tropical and Marine Meteorology,CMA,Guangzhou 510641 China

出　　处：《Journal of Tropical Meteorology》2023年第3期277-300,共24页热带气象学报（英文版）

基　　金：National Key Research and Development Program of China(2017YFC1501603);National Natural Science Foundation of China(41975136,42075014);Startup Foundation for Introducing Talent of NUIST(2023r121);Guangdong Basic and Applied Basic Research Foundation(2019A1515011118);Guangzhou Municipal Science and Technology Planning Project of China(202103000030)。

摘　　要：This study investigated the impacts of increasing model resolutions and shortening forecast lead times on the quantitative precipitation forecast(QPF)for heavy-rainfall events over south China during the rainy seasons in 2013-2020.The control experiment,where the analysis-forecast cycles run with model resolutions of about 3 km,was compared to a lower-resolution experiment with model resolutions of about 9 km,and a longer-term experiment activated 12 hours earlier.Rainfall forecasting in the presummer rainy season was significantly improved by improving model resolutions,with more improvements in cases with stronger synoptic-scale forcings.This is partially attributed to the improved initial conditions(ICs)and subsequent forecasts for low-level jets(LLJs).Forecasts of heavy rainfall induced by landfalling tropical cyclones(TCs)benefited from increasing model resolutions in the first 6 hours.Forecast improvements in rainfall due to shortening forecast lead times were more significant at earlier(1-6 h)and later(7-12 h)lead times for cases with stronger and weaker synoptic-scale forcings,respectively,due to the area-and case-dependent improvements in ICs for nonprecipitation variables.Specifically,significant improvements mainly presented over the northern South China Sea for low-level onshore wind of weak-forcing cases but over south China for LLJs of strong-forcing cases during the presummer rainy season,and over south China for all the nonprecipitation variables above the surface during the TC season.However,some disadvantages of higher-resolution and shorter-term forecasts in QPFs highlight the importance of developing ensemble forecasting with proper IC perturbations,which include the complementary advantages of lower-resolution and longer-term forecasts.

关 键 词：south China QPF model resolution forecast lead time 

分 类 号：P456.7[天文地球—大气科学及气象学]