Performance of HMON Forecast in 2017−18

Hurricanes in a Multi-scale Ocean coupled Non-hydrostatic model (HMON) is one of National Centers for Environmental Prediction (NCEP)’s operational hurricane models, which has provided real-time numerical guidance to National Hurricane Center (NHC) for North Atlantic, East Pacific and Central Pacific basins since 2017. The model is based on the Non-hydrostatic Multi-Model on the B grid (NMMB) dynamic core, includes well-tuned physics package, moving nests, vortex initialization and coupled to HYbrid Coordinate Ocean Model (HYCOM). The objective for the HMON development was to replace the GFDL Hurricane model and provide high-resolution intensity forecast guidance to forecasters, by using the state-of-the-art numerical approaches. With two years of robust retrospective testing, evaluation, developments, and real-time performance, HMON shows different characteristics from the Hurricane Weather and Forecast (HWRF) modeling system. HMON has performanced very well for strong storms, especially for predicting rapid intensification (RI) of storms. In addition, 10-member HMON ensemble forecasts were set up as a real-time experiments to support HFIP projects. HMON performance for the 2017-2018 hurricane seasons including comparisons of specific RI forecasts will be presented and discussed.