Current Status and Future Plans for NAEFS

The North American Ensemble Forecast System (NAEFS) is an international project to produce operational multi-center ensemble products. NWS and MSC have been operationally exchanging raw forecasts since September 2004. The first operational NAEFS implementation for bias correction and climate-based anomaly forecasts started in May 2006. Currently (February 2007), there are NAEFS runs twice per day (00UTC and 12UTC) for every 6-hours (up to 384 hours lead-time) with an exchange of about 50 variables between NWS and MSC, from a combined NAEFS ensemble of 30 members at 00UTC and 12UTC; an ensemble of 14 members is run at NCEP at 06UTC and 18UTC (not including the control forecast). Recently, the experimental week-2 temperature anomaly forecast has been set up as part of the daily base. The coming implementations for 2007 will mainly add an additional 6 ensemble members to the current 14 members in each cycle at NCEP (in March), and an additional 4 ensemble members to the existing 16 members of the two cycles at CMC (in June). The over-all statistical evaluation has demonstrated a significant improvement in the probabilistic forecast from the NAEFS combined, bias corrected forecast. In the future, NAEFS will focus on the both model improvement (such as adding stochastic physic process, etc.,) and post-processing (hind-casting for bias correction, downscaling, 2nd moment adjustment, etc.,). Work on precipitation calibration has been planned for the coming year, which will be based on global rain-gage, radar and satellite information.