About IOOS

Six-day Forecast of the Potential for Slow Flooding of the Land Around Honolulu Harbor, O‘ahu, by the Ocean

Caution: The forecast below is experimental and no promise of accuracy is implied; especially, the forecast is explicitly not accurate when either a tsunami, tropical storm or hurricane warning is in effect. In these latter cases, see either tsunamis or tropical storms/hurricanes.

SLpred graphic for Honolulu Harbor, O'ahu


Red Line at Top

This sea level height indicates the point at which flooding in Mapunapuna and other nearby low-lying areas may begin to occur.

Vertical Yellow Line

Time this forecast was created.

Dark Blue Curve

Observed Sea Level at Honolulu Hbr. (Pier 4) for previous 3 days. The measurement is relative to MLLW (Mean Low Low Water), a well-defined reference level (NOAA datum description)

Cyan Curve

Forecast Sea Level at Honolulu Hbr. (Pier 4) for next 6 days. The forecast is relative to MLLW, and includes tides plus multi-day sea level variations. The forecast is updated every four hours.

Additional Information

Click here for additional information about both the plotted variables and forecast accuracy.

Click here for the detailed technical report explaining the methods for producing the PacIOOS High Sea Level Forecasts.

The Six-day High Sea Level Forecast Tool was developed by M. Guiles, D. Luther and M. Merrifield,
and is maintained by M. Guiles.

Please consider acknowledging PacIOOS in any distribution or publication of data as follows: Data provided by PacIOOS (www.pacioos.org), which is a part of the U.S. Integrated Ocean Observing System (IOOS®), funded in part by National Oceanic and Atmospheric Administration (NOAA) Award #NA11NOS0120039.