Tropical cyclone Yasi was one of the most powerful tropical cyclones (TCs) to impact the Queensland coast since records began. Prior to Yasi, the sea surface temperatures (SSTs) in the Coral Sea were higher than average by 1-2°C due to a La Nina event. We will discuss the results of a simple sensitivity study to analyse the influence of these increased SSTs on the resultant track, size and intensity of TC Yasi.

The Weather Research and Forecasting (WRF) model is forced using reanalysis and observed SST data over the period 31^st January to 4^th February 2013. The ability of the model to simulate TC Yasi is evaluated. The model is able to closely simulate the correct track, with the modeled landfall occurring within 50 km and 3-hours of the observed event. SST anomalies of between -4°C and 4°C are applied in 1 degree increments to the SST data, forming a set of nine simulations. The influence of these SST anomalies on a number of variables is assessed. An increase in SST results in an increase in intensity, precipitation and destructiveness of the storm, however there is little influence on track. Decreases in SSTs result in an increase in the radius of maximum winds, although the radius of gale-force winds decreases. These results, as well as limitations of this study, will be discussed.