Abstract:Based on the EOF decomposing of 500 hPa height, 850 hPa temperature, sea level pressure field forecasts with historical elements, and assuming that the EOF spatial functions (feature vectors) are basically stable, the time function based on EOF principal components series, multiple linear regression prediction equation of time sequence of basic element value and the average temperature anomaly near and at the forecasting and prediction sites were established, moreover, combining with the ECMWF ensemble prediction products, the objective forecasting products with nationwide medium term average temperature anomaly were generated and applied into work, which was verified by using the same symbol ratio. Results show that the objective forecasting products in the test period has 0.77 symbol ratio, significantly higher than the same symbol ratio (0.63) of the similar products directly calculated by ECMWF 2 m temperature products; the objective forecasting products perform well not only in the distribution scope, but in the anomaly amplitude effects. In addition, the correlation analysis also proved that the same symbol ratio method is reasonable in the medium-term temperature anomaly forecast verification.