Analysis of Retrospective Probabilistic Storm Surge Forecasts for Hurricane Iniki (1992)

The Probabilistic Tropical Storm Surge model (P-Surge) is used operationally at the National Hurricane Center (NHC) to help forecasters issue storm surge watches and warnings. The recent incorporation of a parametric wave model has allowed P-Surge to provide more reliable inundation forecasts for islands where wave set up typically contributes to a higher fraction of the total water level. Upcoming improvements to the P-Surge model for the 2025 hurricane season will include the expansion of the domain to areas in the Pacific Ocean such as the Hawaiian Islands.

Landfalling hurricanes on the Hawaiian Islands are rare which limits the verification dataset for P-Surge. Hurricane Iniki (1992) is the strongest hurricane on record and the most recent major hurricane to make landfall in the state of Hawaii. A complete analysis and verification of P-Surge hindcasts for Hurricane Iniki will be presented. The results will be used to aid forecaster awareness and guide future improvements to the model.