基于逻辑回归法的浙江省低涡型暴雨落区预报研究  

The potential falling area forecast for rainstorm induced by vortex in Zhejiang Province based on logistic regression algorithm

作　　者：蔡志颖 郑艳 张程明 段晶晶 吴俊杰 肖王星 CAI Zhiying;ZHENG Yan;ZHANG Chengming;DUAN Jingjing;WU Junjie;XIAO Wangxing(Ningbo Meteorological Observatory,Ningbo 315000;Ningbo Zhenhai Meteorological Bureau,Ningbo 315200;Shanghai Typhoon Institute of China Meteorological Administration,Shanghai 200030)

机构地区：[1]浙江省宁波市气象台,宁波315000 [2]浙江省宁波市镇海区气象局,宁波315200 [3]中国气象局上海台风研究所,上海200030

出　　处：《暴雨灾害》2024年第1期32-44,共13页Torrential Rain and Disasters

基　　金：浙江省宁波市重点研发计划暨“揭榜挂帅”项目(2023Z139);浙江省宁波市自然科学基金项目(2018A610210);浙江省宁波市气象局一般项目(NBQX2023001B)。

摘　　要：大气低涡是造成我国南方地区暴雨洪涝的重要天气系统,大气低涡背景下的暴雨突发性、局地性强,其发生时间、强度和落区一直是气象预报业务的难点。为提高浙江省暴雨预报准确率,本文利用1979—2020年浙江省逐日格点降水观测数据和美国国家环境预测中心气候预测系统再分析数据集,首先分析了浙江省内近42 a由大气低涡造成的区域性暴雨事件(以下简称低涡型暴雨)的气候特征;然后将850 hPa垂直速度、水汽通量散度、速度散度、低空急流、切变线以及700 hPa垂直速度作为预报因子,基于“配料法”并结合逻辑回归方法构建了低涡型暴雨落区预报模型;最后基于该模型利用2021年欧洲中期天气预报中心预报产品进行暴雨落区预报,并使用同期实况降水进行了系统性检验和天气过程检验。结果表明,该模型总体性能较好,提前24 h和12 h时效的暴雨预报能力均有提升,可将12%的准确率和20%左右的命中率分别提升至14%和40%附近,漏报率从75%以上降至60%附近,但存在着一定程度的空报。The atmospheric low-level vortex is an important weather system that causes rainstorm and flood in southern China.The vortex in⁃duced rainstorm is sudden and local,and its occurence time,intensity and falling area have always been difficult for meteorological forecast⁃ing.In order to improve the accuracy of rainstorm prediction in Zhejiang Province and improve the localization application of the prediction model,based on daily precipitation data of Zhejiang Province from 1979 to 2020 and reanalysis dataset from the National Centers for Envi⁃ronmental Prediction Climate Forecast System,climatic characteristics of the heavy rain in Zhejiang Province induced by low-level vortex is studied,the vortex induced rainstorm in Zhejiang mostly occurs in the rainy season and has obvious interannual variation characteristics.Then,the 850 hPa vertical velocity,water vapor flux divergence,velocity divergence,low-level jet,shear line and 700 hPa vertical velocity are used as ingredient factors,and the potential falling area forecast for heavy rain induced by vortex is constructed by using logistic regres⁃sion algorithm.Finally,the forecast products of the European Medium-Range Weather Prediction Center are used to forecast the rainstorm falling area based on this model,and the actual data of the same period are used for systematic test and weather process test.Results show that the overall performance of the model is good,and the rainstorm prediction ability of 24 h and 12 h ahead is improved,which can in⁃crease from 12%accuracy and 20%to around 14%and 40%respectively,and the omission rate drops from more than 75%to around 60%,but there is a certain degree of empty report.The forecast model of Zhejiang Province based on logistic regression method has a good indica⁃tor for the prediction of such rainstorm areas,and is of great significance for meteorological disaster prevention and mitigation.

关 键 词：浙江省 低涡型暴雨 配料法 逻辑回归 落区预报 

分 类 号：P456.8[天文地球—大气科学及气象学]