Lifetime Performance of the Operational Hurricane Weather Research and Forecasting (HWRF) Model for North Atlantic Tropical Cyclones

Abstract The Hurricane Weather Research and Forecasting (HWRF) model was the flagship hurricane model at NOAA’s National Centers for Environmental Prediction for sixteen years and a state-of-the-art tool for tropical cyclone (TC) intensity prediction at the National Weather Service and across the globe. HWRF was a joint development between NOAA research and operations, specifically the Environmental Modeling Center and the Atlantic Oceanographic and Meteorological Laboratory. Significant support also came from the National Hurricane Center, Developmental Testbed Center, University Corporation for Atmospheric Research, universities, cooperative institutes, and the TC community. In the North Atlantic basin, where most improvement efforts focused, HWRF intensity forecast errors decreased by 45-50% at many lead times between 2007 and 2022. These large improvements resulted from increases in horizontal and vertical resolution as well as advances in model physics and data assimilation. HWRF intensity forecasts performed particularly well over the Gulf of Mexico in recent years, providing useful guidance for a large number of impactful landfalling hurricanes. Such advances were made possible not only by significant gains in computing, but also through substantial investment from the Hurricane Forecast Improvement Program.