Performance of 2020 Real-Time Atlantic Hurricane Forecasts from High-Resolution Global-Nested Hurricane Models: HAFS-globalnest and GFDL T-SHiELD

Abstract The global-nested Hurricane Analysis and Forecast System (HAFS-globalnest) is one piece of NOAA’s Unified (UFS) application for hurricanes. In this study, results are analyzed from 2020 real-time forecasts by HAFS-globalnest a similar model, the Tropical Atlantic version GFDL’s High‐resolution prediction on Earth‐to‐Local Domains (T-SHiELD). produced highest track forecast skill compared to several operational experimental models, while T-SHiELD showed promising skills as well. intensity generally had positive bias at longer lead times primarily due lack ocean coupling, much smaller particularly times. With introduction modified planetary boundary layer scheme an increased number vertical levels, in layer, HAFS storm size than occurred 2019 HAFS-globalnest. Despite that were comparable GFS HWRF, both suffered persistent right-of-track cases 4–5-day reasons related strength subtropical ridge over western North continuing be investigated diagnosed. A few key case studies very active hurricane season, including Hurricanes Laura Delta, examined.