The SREF system was developed to provide a multi-regional model, short-range (0-3 days) ensemble prediction system to provide operationally relevant and useful guidance on the probability distribution of weather elements or events. The probabilistic information provided by SREF will help meet the NWS FY05 strategic goal of providing probabilistic gridded products to the NWS/WFOs, service centers and other users. The NCEP multi-Initial Condition (multi-IC) and multi-model Short Range Ensemble Forecasting (SREF) system has been operationally running since May 2001 (Du et al. 2003). This system is run twice per day (09 and 21 UTC) at 48 km with 15 model members. Forecasts are output at 3 hour intervals out to 63 hours.

The SREF web page: http://www.emc.ncep.noaa.gov/mmb/SREF/SREF.html
SREF overview: http://wwwt.emc.ncep.noaa.gov/mmb/SREF-Docs/SREF-TPB2004.pdf
SREF Home Page: http://wwwt.emc.ncep.noaa.gov/mmb/SREF-Docs/