不同时间尺度的MOS方法对宁夏气温预报的影响

掌握NMC和本地客观产品的气温预报能力，对提高宁夏城镇天气预报质量和全国排名有重要的意义。基于2009年1月～2014年12月T639和ECMWF两种模式产品及宁夏20个国家级观测站气温资料，采用资料按月和季划分的2种MOS方法，预报未来168 h最高、最低气温，运用宁夏现行的检验评估方法对2015年1月到2016年6月的预报效果进行检验，并与预报员（YBY）和中央气象台指导产品（NMC）对比，结果表明：MOS方法预报宁夏气温，整体预报效果优于NMC，资料按月划分的MOS预报效果优于资料按季划分，ECMOS月和T639MOS月是最高和最低气温的最优客观产品；最低气温预报中YBY优于T639MOS月，最高气温预报中ECMOS月优于YBY；两种最优客观预报产品一致的物理量为集中在中低层或地面的相当位温或假相当位温、温度、湿位涡、高度等，但各自还有一些起关键作用的入选因子影响最高、最低气温的预报。

The influence of MOS methods of different time scale on temperature forecast in NingXia

To master the temperature forecast capabilities of NMC, local subjective and objective products in temperature forecasting is of great significance to improve the quality of urban weather forecasting in Ningxia and its national ranking in weather forecasting. Based on the two model products of T639 and ECMWF with the temperature data of 20 national observatories in Ningxia from January 2009 to December 2014, the highest and lowest temperatures of the coming 168 hours were predicted by adopting two MOS methods which grouped the data by month or by season．The verification was done on the forecasted results for the time period from January 2015 to June 2016 using the current inspection and evaluation method adopted in Ningxia，and the comparisons with YBY and NMC were also conducted. The results show that the whole effect of the MOS method is superior to the NMC, and its forecast effect with monthly grouped data is superior to that when the data was grouped in season. The T639MOS by month and ECMOS by month is the optimal objective products of the highest and lowest temperature. For predicting the lowest temperature, compared with the optimal objective product，The forecast by YBY is better than that of T639MOS by month. For predicting the highest temperature, the forecast of ECMOS by month is better than that by YBY. The physical quantities of the two best objective predictive products are the equivalent temperature, or the potential pseudo-equivalent temperature, the temperature, the wet potential vorticity and the height, which are concentrated in the middle and lower layers or the ground．However，there are some factors that play a key role in the forecast of the highest and lowest temperatures．