Development on the Atmosphere-Ocean Coupled Basin-scale HWRF System: Targeting Research-to-Operation Transition

The basin-scale Hurricane Weather Research and Forecasting model (HWRF) is an experimental modeling system that is capable of producing forecasts for multiple tropical cyclones simultaneously with Movable Multi-Level Nesting (MMLN) technique.  NOAA’s Hurricane Research Division and its collaborators developed the configuration of multiple sets of MMLN under the support of Hurricane Forecast Improvement Project (HFIP). The goal of the basin-scale HWRF is to provide reliable and consistent forecast guidance for track and intensity from genesis to landfall, including rapid intensification, for forecast centers in NCEP. In this study, we focus on the development of an atmosphere-ocean coupling capability for the basin-scale HWRF, the sensitivity of the atmosphere-ocean coupling approach, applications of the coupled system on the real-time/retrospective tropical cyclone forecasts, and new products produced by this system. For the first time with the coupled basin-scale HWRF, we also quantify the ocean impact on tropical cyclone intensity forecast errors. A transition roadmap from research to operation highlights the next steps for the coupled basin-scale HWRF system.