气象科学2025，Vol.45Issue(4)：504-514,11.DOI:10.12306/2024jms.0049
基于CMA-GFS4.0模式西南低涡暴雨过程偏差特征分析
Analysis on deviation characteristics of southwest vortex rainstorm process based on CMA-GFS4.0 model
摘要
Abstract
The China Meteorological Administration Global Forecast System(CMA-GFS)has been upgraded to version 4.0 in May 2023.To evaluate the forecast capability and bias characteristics of CMA-GFS before and after the upgrade,this study compares and analyzes the performances of CMA-GFS,the Regional Numerical Weather Prediction System(CMA-MESO),and the European Centre for Medium-Range Weather Forecasts(ECMWF)in predicting southwest low vortex-induced heavy rainfall events in Sichuan in 2022 and 2023.The comparative evaluation shows that:the CMA-GFS model underestimates the extreme heavy rainfall event;with the rainfall scores in 2022 significantly higher than those of ECMWF and CMA-MESO;while in 2023,the scores decreased and were slightly lower than those of ECMWF.A multi-dimensional evaluation and diagnostic analysis of CMA-GFS was conducted for a typical southwest low vortex case from July 26-28,2023,including the circulation pattern and low vortex system.The results indicate that:the position and movement of the main influencing system forecasted by the CMA-GFS 4.0 model are consistent with the observation,with accurate rainfall location prediction,offering useful guidance for the low vortex heavy rainfall events;the forecasted wind speed is significantly underestimated from the initial field,especially the component of southward wind,leading to an under forecast of the low-level jet stream,implying that the weak dynamic forecast associated with wind speed is a major factor for the underestimated rainfall intensity;the underestimation of low-level energy and instability conditions are related to the dry bias in the lower atmosphere,resulting in weaker convective intensity and shorter duration;Biases in the early stages of the southwest low vortex are relatively prominent,but the biases decrease and even reverse during the peak stage of the vortex.关键词
CMA-GFS4.0/西南低涡/偏差特征Key words
CMA-GFS4.0/southwest vortex/deviation characteristics分类
天文与地球科学引用本文复制引用
徐琳娜,安琳莉,康岚,邓梦雨..基于CMA-GFS4.0模式西南低涡暴雨过程偏差特征分析[J].气象科学,2025,45(4):504-514,11.基金项目
四川省科学技术厅重点研发项目(2024YFFK0407) （2024YFFK0407）
中国气象局气象能力提升联合研究专项(22NLTSZ006) （22NLTSZ006）
高原与盆地暴雨旱涝灾害四川省重点实验室科技发展基金(SCQXKJYJXMS202312 （）
SCQXKJYJXZD2403) （）
