Invited Speaker: A new multi-decadal reforecast global ensemble reforecast data set using the NCEP GFS

Using a 14.5-million CPU-hour grant from the Department of Energy, NOAA/ESRL is developing a new ensemble reforecast data set using the NCEP GFS model. At this point it is anticipated that 10 or 11 ensemble forecast members will be generated at T255L64 resolution through 8 days lead, and thereafter at T190L64 resolution to 16 days. The reforecasts will span a 30-year periods, with at least one ensemble (at 00Z initial time) and perhaps two (also 12Z) per day. The data set will archive all the variables relevant to hydrologic prediction. The talk will provide more details on this data set, and we hope by January 2011 to have generated some of the reforecasts and will be able to show statistically calibrated probabilistic QPF products generated using this data set. Based on previous results with an earlier generation version of the GFS, we expect that the post-processed precipitation products will be able to correct for systematic errors in the forecast model and provide an ensemble of realistic, reliable, downscaled precipitation forecasts that can be used in hydrologic prediction applications.