Evaluation of Hurricane Beryl (2024) Intensity Forecasting using Hurricane Analysis and Forecast System (HAFS)

Hurricane Beryl, a record-breaking Category 5 Atlantic hurricane, impacted the Caribbean, Yucatán Peninsula, and U.S. Gulf Coast from late June to early July 2024, setting a precedent as the earliest Category 5 hurricane on record. This event provided mixed predictability insights: operational forecasts successfully predicted Beryl's track days in advance, but struggled with accurately forecasting the rapid intensification prior to it made landfall in Grenada. The unprecedented strength of the hurricane for the early season was linked to record-warm sea surface temperatures, low wind shear, and elevated atmospheric moisture levels.

This study focuses on the ongoing advancements in the Hurricane Analysis and Forecast System version 2 (HAFSv2), particularly in the domain of hurricane intensity forecasting, as evidenced by the case of Hurricane Beryl. Notably, HAFSv2 incorporates significant improvements in air-sea coupling, allowing for more realistic representation of ocean-atmosphere interactions crucial for predicting rapid intensification. These enhancements include better resolution of upper-ocean thermal structure and more accurate modeling of sea surface temperature and mixed layer depth.

The preliminary results indicate that HAFSv2, utilizing vortex initialization and the Gridpoint Statistical Interpolation (GSI) system, enhances the depiction of asymmetric hurricane rainbands and improves the accuracy of short-term intensity forecasts (0-18 hours). Additionally, the future plan is to integrate the Joint Effort for Data assimilation Integration (JEDI) with diverse observational data into HAFS to further improve initial conditions and asymmetric hurricane structure, enhancing forecast models' performance. This research underscores the critical need for continued improvements in intensity forecasting to better predict and mitigate the impacts of Hurricanes.