Tropical Cyclone Harold provided invaluable data for future disaster response and planning

Good data is at the heart of planning for and responding to natural disasters in the Pacific. The region has invested heavily in tools to monitor changes in the environment, and be better prepared for the extreme conditions that can threaten Island nations. 

TC Harold damage at Liku’alofa Beach Resort on Nuku’alofa, Tonga. Presentation by Tonga Met Service.  © Royal New Zealand Air.png
Aerial view of TC Harold damage at Liku’alofa Beach Resort on Nuku’alofa, Tonga. Presentation by Tonga Met Service. © Royal New Zealand Air Force



Tropical Cyclone Harold provided a good opportunity to put some of those tools to use. The wind, waves and water levels during this storm have been simulated into a high-resolution model to show how waves impacted Pacific coastlines during the disaster. The data obtained from this model can now help inform future disaster response and planning.

Pacific Community (SPC) Team Leader, Oceanography, Mr. Herve Damlamian, explained how such models are invaluable to his work. “They provide detailed insights on the range of wave height and storm surge experienced along the coastlines of Vanuatu, Fiji, and Tonga. Correlating this with on-the-ground impact surveys helps us connect the dots between the range of hazard intensity experienced on the coastal zone and its related impacts on buildings and key island infrastructure such as power plants, roads, etc.. Overall such a model supports our increased regional risk knowledge.”  

The animation shows the reconstruction of TC Harold's winds, storm tide (a combination of storm surge and tide) and waves based on the best track data produced by the Fiji Meteorological Service. From the 02 to 10 April, TC Harold coincided with king high tides in some locations along its track, resulting in catastrophic damage in Vanuatu, Fiji and Tonga.

Apart from the gale force winds associated with Tropical Cyclones, major damage in coastal areas is produced by high water levels at the shoreline. This coastal flooding or inundation is due to the interaction of storm surge, tides, and the action of extremely high waves.  

The high-resolution model was shared recently as part of a presentation by the Tonga Meteorological Services to the National Emergency Management Committee, reporting on the end of the Tropical Cyclone season for 2019/20.

Deputy Director Tonga Met Service, Laitia Fifita, presentation to NEMO, May 2020 (c) Tonga Met Service.JPG
Deputy Director Tonga Met Service, Laitia Fifita


In his presentation to the committee, Deputy Met Director, Mr. Laitia Fifita reported that, “The SPC model demonstrated to stakeholders the application and importance of real time data in terms of Early Warning to show the intensity of wave height and storm surge during a natural disaster.”

The state-of-the-art numerical model which accounts for the influence of sea mounts and other ocean floor features, was developed by SPC Oceanographer, Dr. Antonio Espejo. The high performance of the model was validated by comparing the results against known measurements of sea level and waves from tide gauges and wave buoys.

SPC’s Acting Deputy Director Oceans and Maritime Programme, Mr Jens Kruger is confident in the investment being made in these systems.“The good agreement between model results and measurements provides technicians, stakeholders and community members with the confidence that such technology could be further explored to strengthen Tropical Cyclone driven risk and forecast information.”

He adds, “This modelling work demonstrates the continuous effort that SPC is doing to advance cutting-edge technological approaches the Pacific, strengthening our knowledge about extreme events and our capacities to make more resilient communities.”

Tide Gauge, Port Vila, Vanuatu (c) SPC.jpg
Tide gauge in Port Vila, Vanuatu, part of a network of sea level monitoring infrastructure under the COSPPac project. © SPC


For more information, contact:
Merana Kitione ([email protected])
Capacity Development and Communications Officer, GEM


Geoscience, Energy and Maritime
Melanesia Regional Office