攀西地区2021年夏季多模式降水预报检验

Verification of Multi-Model Precipitation Forecast in Panxi Region in Summer of 2021

为提高定量降水预报产品在攀西地区的预报能力,对2021年夏季格点预报(Grid Weather Forecasting,GWF)、西南区域模式(South West Center-WRF ADAS Real-time Modeling System,SWCWARMS)、欧洲中心中期预报(European Centre for Medium-Range Weather Forecasting,ECMWF)及中国气象局中尺度模式(China Meteorological Administration Meso-Scale Model,CMA-MESO)降水预报情况进行了检验分析。结果表明:(1)ECMWF模式雨日空报最明显,但其暴雨量级预报较实况偏干,其余各家产品中各量级降水均以湿偏差为主。有雨日数在攀西地区南部预报效果较好,其余地方空报较大。大雨日数在凉山州中部预报偏差较大,攀西地区南部预报偏差较小。(2)从16次过程检验来看,各预报产品在8月份过程中的表现优于其余月份,GWF产品25 mm以上TS(Threat Score)评分高于20分的过程次数最多且预报效果最稳定,CMAMESO模式空报最大。(3)各产品3 h累计强降水开始时间大多早于实况,SWCWARMS模式雨强偏大且对于持续时间较长的过程预报效果较好,而GWF、ECMWF模式累计雨量较实况偏小。

In order to improve the forecast capability of quantitative precipitation products in Panxi Region,the precipitation forecasts in summer 2021 of Grid Weather Forecasting(GWF),South West Center-WRF ADAS Real-time Modeling System(SWCWARMS),European Centre for Medium-Range Weather Forecasting(ECMWF) and China Meteorological Administration Meso-Scale Model(CMAMESO) are tested and analyzed.The results show that:(1) ECMWF has the most obvious bias about the rainy days,but the forecast of rainstorm magnitude is drier than the observation,while the forecast deviations of various magnitudes of other products are mainly wet.The forecast effect of rainy days is better in the south of Panxi region than that in other places which have a bigger false alarm rate.The central part of Liangshan Prefecture has a larger deviation of heavy rain days,while the southern part of Panxi region performs better.(2)According to the 16 process tests,the performance of all forecast products in August is better than that in other months.GWF products above 25 mm has the largest number of processes with TS(Threat Score) score over 20 points,which has the most stable forecast effect,while CMA-MESO model has the largest false alarm rate.(3) The start time of 3h cumulative heavy precipitation for each product is mostly earlier than the observation.The rain intensity of SWCWARMS is too high but it has a better forecast effect of the process with longer duration,while the cumulative precipitation of GWF and ECMWF is smaller than the observation.