Three Years of Operational Prediction of Forecast Skill at NMC

Abstract

Abstract In real time since 1990, the National Meteorological Center (NMC) has been running a system to predict the forecast skill of the medium-range forecasts produced by the NMC global spectral model. The predictors used are the agreement of an ensemble consisting of operational forecasts from various centers, the persistence in the forecast, and the amplitude of the anomalies. These predictors are used in a stepwise regression scheme, with the last 60 days used as training period, and the regional anomaly correlation of the 0000 UTC NMC global forecast is predicted from days 1 to 6. By far the most important predictor of skill is the agreement between the NMC global forecast started at 0000 UTC, out to 6 days, and four other 12-h “older” forecasts (Japan Meteorological Agency, United Kingdom Meteorological Office, and the European Centre for Medium-Range Weather Forecasts, as well as the average of the NMC forecast at 0000 UTC with the previous day's forecast). The other predictors have been selected ...