P49 The Experimental Regional Ensemble Forecast System (ExREF)

Bernardet, Ligia, National Oceanic and Atmospheric Administration (NOAA) and Cooperative Institute for Research in the Environmental Sciences (CIRES), Steve Albers, NOAA and Cooperative Institute for Research in the Atmosphere (CIRA), Linda Wharton, NOAA and CIRES, Isidora Jankov, NOAA and CIRA, David Reynolds, NOAA, Kelly Mahoney, Ellen Sukovich, NOAA and CIRES, Wallace Hogsett, Dave Novak, and Jun Du, NOAA

The Experimental Regional Ensemble Forecast (ExREF) system is a tool for the development of NWP methodologies. ExREF is run in near-realtime by NOAA/ESRL/GSD and its products are made available through a website, an ftp site, and via the Unidata Local Data Manager.

The ExREF has eight WRF-ARW members with 9-km grid spacing over North America. It uses multiple physics and a variety of initial and boundary conditions.

ExREF has been a component of the Hydrometeorology Testbed NWP suite. Its results are distributed to the National Weather Service Weather Forecast Office and River Forecast Center in Sacramento, California, where they are ingested in the Advanced Weather Interactive Processing System (AWIPS) to provide guidance on the forecasting of extreme precipitation events. ExREF is also being supplied to the NWS Weather Prediction Center where it is being tested for use in the upcoming Flash Flood and Intense Rainfall Experiment. Finally, ExREF is being used as a proving ground for new methodologies in ensemble forecasting. An alternative initialization technique, discussed in a companion poster by Jankov et al., is being tested and will be evaluated by the Developmental Testbed Center for potential operational implementation in the NWS operational Short Range Forecasting System.