Wave Modelling under a High Resolution Tropical Cyclone Model

Tropical cyclone wind and waves are a major hazard to offshore industries in Western Australia (WA), with significant risks to safety and infrastructure, and substantial economic consequences. Wave forecasts for the region issued by the Bureau of Meteorology are largely limited to the resolution of the global (0.4 degree) and regional (0.1 degree) operational wave model products, and also limited by the resolution and accuracy of the atmospheric model that supplies the wind forcing. Hence these products are limited in accuracy during tropical cyclone (TC) season.

This poster describes that part of a project to improve tropical cyclone forecasting for northwest WA which focuses on the development of a sophisticated and highly accurate sea state forecast for the TC season (AUSWAVE-TCX). For this purpose a dedicated high-resolution wave grid was nested in the global domain. The new domain is forced with winds from a new high-resolution tropical cyclone model, ACCESS-TCX, which has significantly improved intensity prediction skill over our former system. The performance of the wave mode was tested globally with the soon-to-be operational upgrade of the Australian global atmospheric model and for a number of TCs that occurred in the 2014/15 season. Initial validation show improved results when compared to current products from the Australian operational wave model. Once in operation, the system will provide a forecast of sea state for North West WA twice-daily.