GRAPES模式对2011/2012年冬季寒潮天气过程预报能力的检验

利用台站常规观测资料和NCEP-FNL再分析资料，检验了GRAPES（Global/Regional Assimilation and Prediction Enhanced System）对2011/2012年冬季我国寒潮天气过程的预报能力。结果表明，GRAPES模式能较好地预报出该冬季4次寒潮过程的明显降温、高低空环流形势及冷平流的入侵，模式对2月22日寒潮的预报效果较差。对于强降温预报，在1月18日、2月5日及2月14日寒潮过程中，模式在新疆部分地区、云贵高原和四川盆地的预报效果较差。在2月22日寒潮中，我国东部地区出现了较大偏差，模式预报的500 hPa上阻塞高压及东亚大槽等系统的强度和位置出现较大偏差。4次过程中，模式预报的冷、暖平流在我国东北部大小兴安岭及长江流域以南有较大偏差。对于2月22日寒潮，模式预报新疆地区、大兴安岭和辽宁的冷平流范围和强度、及长江流域以南暖平流的范围和强度都要大于实况，导致此次寒潮温度预报误差大，这可能与在地形区域模式物理过程存在一定误差有关。

Verification of forecasting capability of cold wave process in the winter of 2011/2012 with GRAPES

GRAPES(Global/Regional Assimilation and Prediction Enhanced System) is a new generation numerical weather prediction model in China,and its ability to forecast cold wave processes occurred from December 2011 to February 2012 is tested by using conventional station observation data and NCEP-FNL reanalysis data.The results are shown as follows:GRAPES can forecast the significant cooling,the circulation patterns of upper and lower altitudes,and the invasion of cold advection in the four cold wave processes occurred in the winter of 2011/2012.The prediction effect is worse in the cold wave occurred on 22 February than the other three.As for the forecast of strong cooling,the prediction results are bad in parts of Xinjiang,the Yunnan-Guizhou Plateau and the Sichuan Basin in the cold wave processes occurred on 18 January,5 February and 14 February.It also shows a large deviation in eastern China in the cold wave occurred on 22 February.There are forecast deviations of strength and location of blocking high,East Asian trough and other systems at 500 hPa in the cold wave occurred on 22 February.The large deviations in cold and warm advection forecast in the four cold waves exist in Xing''an Mountains in Northeast China and south of the Yangtze River basin.Forecast results of range and strength of both cold advection in Xinjiang,Greater Khingan Range and Liaoning and warm advection in south of the Yangtze River basin are larger than observations in the cold wave occurred on 22 February,leading to the large temperature forecast deviation,which may be related to the error of model physical process in the terrain region.