New models developed by researchers to provide 7.5 days of wave predictions

University of Hawaiʻi at Mānoa
Melissa Iwamoto, (808) 956-6556
PacIOOS Outreach & Prog Coordinator, SOEST
Heather Kerkering, (808) 956-8784
PacIOOS Director, SOEST
Posted: Jul 30, 2013

Map of Mariana Islands WW3 surf forecast on PacIOOS Voyager.
Map of Mariana Islands WW3 surf forecast on PacIOOS Voyager.
Boundaries of the wave model regions are outlined in yellow.
Boundaries of the wave model regions are outlined in yellow.

Mariners and ocean recreationalists in Guam and the Northern Mariana Islands will benefit from new high-resolution wave forecasts offered by the Pacific Islands Ocean Observing System (PacIOOS).  The new forecasts provide 7.5 days of predicted wave height, period and direction—updated twice per day.

“Mariners, harbor masters, ocean safety officers, swimmers and surfers in the Mariana Islands now have access to high-resolution forecasts to help plan their ocean excursions,” said PacIOOS Director Heather Kerkering.  “Wave forecasts can help improve the efficiency of harbor operations and save time and money.  But more importantly, better forecasts can save lives.”

The best way to access the wave forecasts is under the “surf forecast” menu item in the PacIOOS Voyager, a free online mapping platform ( ).

The wave forecasts are delivered using the WaveWatch 3 (WW3) and Simulating Waves Nearshore (SWAN) models, both developed by researchers at the University of Hawai‘i at Mānoa’s School of Ocean and Earth Sciences and Technology (SOEST).

The regional WW3 model covers the Mariana Islands from Saipan to Guam at 3 arcmin resolution (approximately 5km).  For Guam’s nearshore waters and Apra Harbor, Guam, the nested SWAN model provides additional wave forecast detail at 0.3 and 0.03 arcmin resolution, respectively (approximately 500m and 50m). The forecasting system incorporates real-time validation at two PacIOOS wave buoys off Guam: Ipan (#52200) and Ritidian Point (#52202).

These models were developed by Kwok Fai Cheung, professor of ocean and resources engineering, and Ning Li, a postdoctoral researcher, both at SOEST.  Cheung and Li use global and local wind forcing data from the regional Weather Research and Forecasting (WRF) model developed by PacIOOS/SOEST researcher Yi-Leng Chen, professor of meteorology.  WRF data is also available on the PacIOOS Voyager (under “weather forecast” menu item).

About PacIOOS ( and online mapping at

Based within the School of Ocean and Earth Science and Technology at the University of Hawai‘i at Mānoa, PacIOOS is the Pacific Islands regional component of the U.S. Integrated Ocean Observing System (IOOS®).  PacIOOS is a partnership of data providers and users working together to enhance ocean observations and develop, disseminate, evaluate, and apply ocean data and information products designed to address the environmental, economic, and public safety needs of stakeholders who call the Pacific Islands home.

For more information, visit: