ECMWF细网格2m温度在江西省的预报能力检验

Verification of 2 m Temperature Prediction Ability of ECMWF Fine Grid Model in Jiangxi Province in 2014

利用ECMWF对2014年江西省92个国家区域自动站02时和14时2 m温度的24、48、72 h预报结果,采用预报准确率、平均误差、平均绝对误差和皮尔森相关系数等统计量对其进行检验评估。结果表明:不同预报时效02时预报准确率均高于14时预报准确率;随预报时效的延长,02时预报准确率无明显变化,14时预报准确率下降较明显。02时预报准确率对地形不敏感,14时预报准确率受地形影响明显,山区和丘陵地区准确率明显低于平原地区。02时绝大多数样本和14时夏、秋两季样本的预报结果偏低,且预报误差主要由系统误差造成,14时冬、春两季样本的预报结果有的偏高、有的偏低,误差的主要成分为随机误差,可能与江西省气候特点有关。温度预报误差≥5℃的大值预报误差出现频次呈现明显季节变化特征,02时出现的次数夏、秋两季明显少于冬、春两季,14时出现的次数冬、春两季明显少于夏、秋两季。

Based on the outputs of the ECMWF （European Centre for Medium-Range Weather Forecasts） fine grid model for the 92 automatic weather stations in Jiangxi in 2014, its forecast capability of the 2 m temperatures at 02 ： 00（ CST, the same below） and 14：00 for 24, 48 and 72 hour periods is verified in terms of the forecast accuracy, mean error, mean absolute error and Pearson correlation coefficient. The results show that the accuracy for that at 02：00 is higher than that at 14：00. With the extension period of validity, the accuracy for that at 02：00 does not vary clearly, while it decreases obviously for that at 14：00. The accuracy is not sensitive to terrain for that at 02：00. However, for that at 14：00, the accuracy in mountainous areas is lower than that in plain area. Most samples at 02：00 and all samples at 14：00 in summer and autumn present low forecast results. For most stations, the number of days with forecast errors ≥5 ℃ vary seasonally, for those at 02：00, they are less in summer and autumn than those in spring and winter, while it is the opposite result for those at 14：00.