Harbor Surge Forecast - Pacific Islands Ocean Observing System
Original (non-English) name
Acronym
Harbor Surge Forecast - PacIOOS
Citation
Abstract
Harbors are intended to protect boats and other floating platforms from being ripped from moorings or battered against docks by wave-driven currents, often called “surges”, and swell waves. The PacIOOS Harbor Surge Forecast provides advance notice of potentially dangerous surges in Hawaiian harbors, allowing boaters to take precautionary measures to secure their vessels.
Harbors provide safe haven from short-period swell waves (3 to 30 seconds) by effectively damping the swell through an arrangement of barrier jetties and channels. However, these familiar, often large, swell waves that challenge surfers along Hawaiʻi’s coasts are associated with strong currents that add to their danger to maritime activities.
As the swell waves interact with the coast they also produce currents at longer periods, including rip-currents, which are well known to beachgoers. These longer-period currents more easily invade harbors than the shorter-period swell waves, behaving very much like tsunamis. The PacIOOS Harbor Surge Forecast is the result of developing an empirical and theoretical understanding of how swell waves produce currents at all periods within Hawaiian harbors. The forecast is updated hourly (about 15 minutes after the hour) and dates and times are shown in local time.