Comparison of Different Physics Schemes on Hurricane Forecasts within the UFS-Based HAFS and SRW Applications

This study investigates the impacts of different schemes on hurricane forecasts using the Unified Forecast System (UFS) based Hurricane Analysis and Forecast System (HAFS). HAFS will provide an advanced analysis and forecast system for cutting-edge research on modeling, physics, data assimilation, and coupling to earth system components for high-resolution hurricane predictions. The physics schemes used include the planned operational HAFSv1a, HAFSv1b, the operational Global Forecast System (GFS) version 16, the proposed future GFS v17_p8, Rapid Refresh Forecast System (RRFS) v1beta. The results from HAFS are compared with the results from the Short-Range weather application (SRW App) and observed results. The impacts of different physics schemes on the hurricane right-of-track bias (e.g., hurricanes Lorenzo and Barry) or left-of-track bias (e.g., hurricane IAN) and intensity are investigated. Influences of changing the land surface model, planetary boundary layer (PBL) schemes, and microphysics on hurricane intensity and track will be investigated through sensitivity studies. The model QPF (Quantitative Precipitation Forecast) is verified with observations (e.g., Multi-Radar/Multi-Sensor System gauge corrected data). The forecast wind, specific humidity and temperature during hurricane landing are validated with North American Model (NAM) Data Assimilation System (NDAS) data. More detailed results will be reported in this presentation.