Model Physics Development for Improved Wind Forecasts in WFIP3

An updated version of the High-Resolution Rapid Refresh (HRRR) physics is run within the Weather Research and Forecasting (WRF) model for testing and development during the third Wind Forecast Improvement Project (WFIP3). The focus is on improving low-level wind forecasts off the coast of Rhode Island and Massachusetts. This project provides a first opportunity to characterize model forecast errors for offshore turbine-layer winds along with a subsequent effort to improve the representation of moist-turbulent mixing within the marine boundary layer to improve wind forecasts. We strive to further develop the updated HRRR physics at both current (∆x = 3 km) and future (∆x = 1 km) operational horizontal grid spacing.

Many in situ, profiling, and scanning instruments are deployed on islands, barges, and buoys within the WFIP3 region between winter 2023 and summer 2025. During the project, several forecast error modes have been identified; some of the most systematic and egregious errors are associated with precipitating frontal passages. Most efforts to improve the wind forecast biases have focused on further development of the Mellor-Yamada-Nakanishi-Niino eddy diffusivity/mass flux (MYNN-EDMF) turbulent mixing scheme and the Thompson-Eidhammer aerosol-aware microphysics scheme. This presentation will highlight the WFIP3 testing and development activities, showing the improvements in forecasts of turbine-layer winds over the operational version. Examples of case studies will be presented to illustrate the improvements. Ongoing and future WFIP3 physics development will be noted.