ECWMF高分辨率模式2m温度预报在六盘水市的误差分析及订正指标

Analysis of Bias and Research of Correction Index For the 2m Temperature Forecast of ECWMF High Resolution Model in Liupanshui

采用气候概率统计和多时效平均的思路,对2018—2019年的欧洲中期天气预报中心(ECWMF)高分辨率模式2 m温度产品在六盘水市的预报误差进行统计分析,并对采用指标订正后的2020年度模式预报准确率进行检验评估。结果表明:ECWMF高分辨率模式对六盘水市的温度预报误差随时效的增加而逐渐减小,且各时效平均的最高温度年均预报误差和误差标准差要明显高于最低温度;对于六盘水而言,模式的温度预报在初夏(6月)可靠性最高,而在春季(3—4月)最低;通过采用预报误差最大占比对逐月多时效平均的模式最低温度预报进行订正,以及根据天气类型采用不用订正方式与订正指标对模式24 h最高温度预报进行订正,能够大幅提升全市未来5 d(120 h)综合最低温度和24 h内的最高温度预报准确率,分别稳定在90%和70%以上;经过订正后,全市的2020年度平均最低温度预报准确率与实际相当,而24 h最高温度预报准确率要高于实际预报准确率。

Using the idea of climate probability statistics and multi-time average,the prediction bias of 2 m temperature products of ECWMF high-resolution model in Liupanshui from 2018 to 2019 were analyzed,and the prediction accuracy of the model revised by the index in 2020 was tested.The results show that the temperature prediction bias of ECWMF high-resolution model in Liupanshui area decreases gradually with the increase of aging,and the average annual prediction bias and standard deviation of the maximum temperature of each aging are significantly higher than the minimum;the model has the highest reliability in early summer(June)and lowest in spring(March-April)in Liupanshui;by adopting the maximum proportion of prediction bias to the model minimum temperature forecast which monthly multi-time averaged for correction,and adopting the different correction method and correction index to correct the model 24 h maximum temperature forecast according to the weather type,the prediction accuracy of the comprehensive minimum temperature in the next five days(120 h)and the maximum temperature in 24 h in Liupanshui area can be greatly improved which near are 90%and above 70%respectively;after revision,the prediction accuracy of the average minimum temperature in 2020 in Liupanshui area is equivalent to the actual situation,while the prediction accuracy of the maximum temperature in 24 h is higher than the actual prediction accuracy.