摘要
利用T-mode斜交旋转主成分分析法,对湖南2021年汛期(4—9月)逐小时850 hPa风场进行环流分型,在此基础上开展同期华南快速循环同化模式(CMA-GD-R3)小时降水预报性能检验。结果表明:影响湖南2021年汛期的主要环流型为西南涡切变型、切变型、副热带高压边缘南风型和台风外围东风型4类;模式小时降水预报的晴雨准确率和分级降水TS评分日变化特征明显,晴雨准确率夜间高于白天,分级降水TS评分峰值出现在早晨,各环流型的临近时效降水预报效果较好,短时强降水发生频次最高的西南涡切变型晴雨准确率较低,副热带高压边缘南风型在较大量级降水表现相对较差;SAL(structure amplitude and location)检验显示,西南涡切变型、切变型过程模式位置预报较接近实况,强度预报表现为前弱后强,副热带高压边缘南风型过程预报落区分散,位置预报不稳定,整体强度较实况明显偏弱,台风外围东风型过程在短时预报时效落区接近实况,强度预报显著偏弱,该方法能较客观地反映模式降水预报空间偏差。
The circulation classification of 850 hPa hourly wind field in the rainy season in Hunan Province from April to September in 2021 is carried out by using the T-mode oblique rotating principal component analysis method.On this basis,the evaluation is carried out for the hourly precipitation forecast of Rapid Updating Cycle Assimilation and Forecasting System in South China(CMA-GD-R3)in the same period.The results show that the main circulation types affecting the rainy season in Hunan in 2021 are the southwest vortex shear type,the shear type,the southerly type at the edge of the subtropical high and the easterly type at the periphery of the typhoon.The model shows good forecasting ability for the clear-rainy accuracy rate and graded precipitation.The daily variations of clear-rainy accuracy rate and TS of hourly precipitation forecast of CMA-GD-R3 are obvious.The clear-rainy accuracy rate is higher in the night time than that during the day,the peak value of TS score for graded precipitatin appears in the morning,and the effects of rainfall nowcasting of all circulation types are better.The southwest vortex shear type,which has the highest frequency of short-term heavy precipitation,has the lowest accuracy.The southerly type at the edge of the subtropical high has relatively poor performance in heavier precipitation.The SAL test shows that the rainfall location forecast of the model in the cases of the southwest vortex shear type and the shear type is closer to the observation.The intensity forecast is weak first but then strong.The precipitation location forecast in the cases of the southerly type at the edge of the subtropical high is scattered,and the location forecast is unstable.The overall intensity is obviously weaker than the observation.The location forecast in the cases of the easterly type at the periphery of the typhoon is close to the observation in the short-time forecast,and the intensity forecast is significantly weaker.The SAL method can more objectively reflect the structure,intensity,and location deviation in the hourly precipitation forecast.
作者
陈龙
陈静静
胡媚
陈鹤
CHEN Long;CHEN Jingjing;HU Mei;CHEN He(Hunan Meteorological Observatory,Changsha 410118;Hunan Key Laboratory of Meteorological Disaster Prevention and Mitigation,Changsha 410118)
出处
《气象》
CSCD
北大核心
2024年第4期434-448,共15页
Meteorological Monthly
基金
中国气象局创新发展专项(CXFZ2023J025)
珠江流域(华南区域)气象科研开放基金项目(ZJLY202310)
湖南省重点领域研发计划项目(2019SK2161)
湖南省气象局重点科研课题(XQKJ22A005)共同资助。
