Evaluation of ocean forecast performance for Royal Australian Navy exercise areas in the Tasman Sea

The variability of sea surface height (SSH) and sea surface temperature (SST) in eddy-resolving re-analyses and forecasts of the East Australian Current (EAC) separation and eddy-shedding region is investigated. The baseline skill attainable by a naive forecasting method is established using root mean square errors and correlation coefficients. The forecasting system is assessed against this baseline and found to be skilful throughout the forecast period for SSH, and for four days (of six) for SST. A skilful forecast is much more likely than an unskilful one. However, a ‘failure mode’ of the model, associated with eddy merging, is identified.