In order to improve the ability to apply the products of T639, a synoptic verification on its medium range forecasting in Spring 2013 is made in comparison with the NWP of ECMWF and Japan models. The results show that all the three models have good performances on the aspect of predicting the large scale circulation evolution and adjustment in Asian. As a whole, the ECMWF model is better in forecasting most weather systems compared with the T639 and Japan models. Taking the sandstorm process during 8-9 March 2013 as a case, it is found that the ECMWF model is more effective than the other two models in medium range forecasting of the surface high pressure system that causes the sand and dust weather process this time.