HAFS Realtime Experiment

The Hurricane Forecast Improvement Program (HFIP) real-time experiments serve as the back-bone of R2O transition for hurricane models and products in NOAA. The purpose of these experiments is to demonstrate that the application of advanced science, technology, and increased computing will lead to the desired increase in accuracy, and other improvements in forecast performance as laid out in the HFIP strategic plan. While operational models have to work within the allowed operational computing resource limitations, HFIP real-time experiments assume that resources will be found to greatly increase available computer power in operations above that planned for the next two to five years. These experiments allow for advances in model dynamics, physics, innovative techniques in data assimilation and product generation within the framework of operation and next-generation NOAA hurricane models that cannot be tested on current operational computers because of size and time requirements, but can instead be tested on NOAA R&D machines such as the Jet and Orion systems. Model configurations and approaches must be at least at RL4 or higher to be selected for obtaining HFIP computational resources on the R&D machines following a call for proposal in early April. The HFIP real-time experiments start on August 1 and end on October 31.

Progress of these real-time runs are evaluated after each season to identify techniques that appear particularly promising to operational forecasters and/or modelers. These potential advances can then be blended into operational implementation plans through subsequent model upgrades, or further developed outside of operations with subsequent testing. While products from these experimental models are not used to generate forecast warnings, they are shared with the hurricane community and are available to the NHC forecasters for providing additional guidance as well as for obtaining critical inputs for further improving NOAA models and products. Additionally, these experiments have provided for a continuous and active collaboration between NCEP/EMC, AOML/HRD, NCEP/NHC, ESRL/GSL, NCAR and DTC which culminates in successful testing and evaluation, and subsequent implementation of significant improvements to the operational Hurricane models at NOAA/NWS/NCEP.

For almost a decade, HFIP real-time experiments have been conducted  using versions of operational models (HWRF, HMON). Starting in the 2019 hurricane season, experimental versions of the UFS-based HAFS system were introduced to the suite. For the 2020 hurricane season, three regional configurations (including an 11 member-ensemble) and one global nested version of the HAFS system would be run in near-real time in NOAA Jet and Orion systems. The experimental products from these runs will be available on the HFIP web-site. Led jointly by developers at NWS/NCEP and OAR/AOML, these efforts would efficiently and effectively transition the latest advances to operations for Hurricane models next year and serve as prime examples of successful community-driven R2O efforts for the broader UFS community. UFS-based HAFS advancement and initial operational implementation targets would benefit immensely from a continuation of these HAFS-based HFIP experiments and expedient usage of NOAA’s R&D HPC resources in a broad community-based development effort.