利用2019—2020年5—9月ECMWF(European Center for Medium-Range Weather Forecast)、GRAPES-GFS(中国气象局GRAPES全球数值预报业务系统,Global/Regional Assimilation and Prediction System-Global Forecast System)大尺度数值模式3...利用2019—2020年5—9月ECMWF(European Center for Medium-Range Weather Forecast)、GRAPES-GFS(中国气象局GRAPES全球数值预报业务系统,Global/Regional Assimilation and Prediction System-Global Forecast System)大尺度数值模式36 h预报时效的24 h降水量预报和加密降水观测资料,基于CRA空间检验技术识别、分离青藏高原东北侧暴雨目标(ECMWF模式18个,GRAPES-GFS模式11个),定量分析了两种模式对暴雨预报的空间误差(落区、强度和形态误差)特征,总结大尺度数值模式在青藏高原东北侧暴雨预报中的适用性。结果表明:(1)两种模式的降水预报形态误差占比均最大。ECMWF预报的强度误差占比最小,落区误差次之,而GRAPES-GFS的落区误差占比最小,强度误差次之。(2)两种模式预报的暴雨落区位置均较实况偏西偏北。暴雨大值中心ECMWF偏西偏南,而GRAPES-GFS仅偏西。(3)对暴雨雨区面积的预报两种模式均明显偏小,容易造成暴雨漏报,对最大降水量和平均雨强的预报GRAPES-GFS模式均偏弱超过40%,ECMWF预报的平均雨强偏弱11.49%,最大降水量偏强1.47%。(4)两种模式对甘肃陇东南地区和陕西西南部的暴雨预报效果较好,而对陕北及宁夏等偏北地区的预报效果较差。展开更多
The rainfall forecast performance of the Tropical Cyclone(TC)version Model of Global and Regional Assimilation PrEdiction System(GRAPESTCM)of the China Meteorological Administration for landfalling Super Typhoon Lekim...The rainfall forecast performance of the Tropical Cyclone(TC)version Model of Global and Regional Assimilation PrEdiction System(GRAPESTCM)of the China Meteorological Administration for landfalling Super Typhoon Lekima(2019)is studied by using the object-oriented verification method of contiguous rain area(CRA).The major error sources and possible reasons for the rainfall forecast uncertainties in different landfall stages(including near landfall and moving further inland)are compared.Results show that different performance and errors of rainfall forecast exist in the different TC stages.In the near landfall stage the asymmetric rainfall distribution is hard to be simulated,which might be related to the too strong forecasted TC intensity and too weak vertical wind shear accompanied.As Lekima moves further inland,the rain pattern and volume errors gradually increase.The Equitable Threat Score of the 24 h forecasted rainfall over 100 mm declines quickly with the time-length over land.The diagnostic analysis shows that there exists an interaction between the TC and the mid-latitude westerlies,but too weak frontogenesis is simulated.The results of this research indicate that for the current numerical model,the forecast ability of persistent heavy rainfall is very limited,especially when the weakened landing TC moves further inland.展开更多
文摘利用2019—2020年5—9月ECMWF(European Center for Medium-Range Weather Forecast)、GRAPES-GFS(中国气象局GRAPES全球数值预报业务系统,Global/Regional Assimilation and Prediction System-Global Forecast System)大尺度数值模式36 h预报时效的24 h降水量预报和加密降水观测资料,基于CRA空间检验技术识别、分离青藏高原东北侧暴雨目标(ECMWF模式18个,GRAPES-GFS模式11个),定量分析了两种模式对暴雨预报的空间误差(落区、强度和形态误差)特征,总结大尺度数值模式在青藏高原东北侧暴雨预报中的适用性。结果表明:(1)两种模式的降水预报形态误差占比均最大。ECMWF预报的强度误差占比最小,落区误差次之,而GRAPES-GFS的落区误差占比最小,强度误差次之。(2)两种模式预报的暴雨落区位置均较实况偏西偏北。暴雨大值中心ECMWF偏西偏南,而GRAPES-GFS仅偏西。(3)对暴雨雨区面积的预报两种模式均明显偏小,容易造成暴雨漏报,对最大降水量和平均雨强的预报GRAPES-GFS模式均偏弱超过40%,ECMWF预报的平均雨强偏弱11.49%,最大降水量偏强1.47%。(4)两种模式对甘肃陇东南地区和陕西西南部的暴雨预报效果较好,而对陕北及宁夏等偏北地区的预报效果较差。
基金supported in part by Key Program for International S&T Cooperation Projects of China(No.2017YFE0107700)the National Natural Science Foundation of China(Grant No.41875080)+1 种基金Scientific Research Program of Shanghai Science and Technology Commission(No.19dz1200101)in part by Shanghai Talent Development Fund and Fujian Key Laboratory of Severe Weather Open Foundation(2020TFS01).
文摘The rainfall forecast performance of the Tropical Cyclone(TC)version Model of Global and Regional Assimilation PrEdiction System(GRAPESTCM)of the China Meteorological Administration for landfalling Super Typhoon Lekima(2019)is studied by using the object-oriented verification method of contiguous rain area(CRA).The major error sources and possible reasons for the rainfall forecast uncertainties in different landfall stages(including near landfall and moving further inland)are compared.Results show that different performance and errors of rainfall forecast exist in the different TC stages.In the near landfall stage the asymmetric rainfall distribution is hard to be simulated,which might be related to the too strong forecasted TC intensity and too weak vertical wind shear accompanied.As Lekima moves further inland,the rain pattern and volume errors gradually increase.The Equitable Threat Score of the 24 h forecasted rainfall over 100 mm declines quickly with the time-length over land.The diagnostic analysis shows that there exists an interaction between the TC and the mid-latitude westerlies,but too weak frontogenesis is simulated.The results of this research indicate that for the current numerical model,the forecast ability of persistent heavy rainfall is very limited,especially when the weakened landing TC moves further inland.
