Impact of Three-Way Atmosphere-Wave-Ocean Coupling on HWRF Forecasting for 2017 High-Impact Hurricanes

Hurricanes are strongly coupled air-sea systems with vigorous atmosphere-wave-ocean interactions. The Hurricane Weather Research and Forecast (HWRF) modeling system, as one of NCEP’s primary operational hurricane models, is a sophisticated, high-resolution, air-sea coupled model designed to resolve inner-core features of hurricanes and to improve our understanding of various aspects for further improving hurricane forecasting. Currently, in the operational HWRF configuration for the North Atlantic (NATL) basin, HWRF is two-way coupled to the Princeton Ocean Model (POM) considering impacts of oceanic feedback, and one-way coupled to the WAVEWATCH III (WW3) sea surface wave model producing hurricane wave forecasts. However, the sea surface wave related feedback impacts are not taken into account in the HWRF system. With recent developments, a three-way atmosphere-wave-ocean coupled HWRF system is established, which includes various wave-ocean interaction processes as well as the impacts of sea surface wave related feedback to the atmosphere. Experiments are conducted by using this three-way coupled system for 2017 NATL high-impact hurricanes. Compared to the two-way atmosphere-ocean coupled model, it is shown that the three-way atmosphere-wave-ocean coupled HWRF system can further improve hurricane forecasts.