The potential for long-range prediction of seasonal mean temperature in Australia

The contribution of synoptic-scale weather to the interannual variability of seasonal mean temperature has been estimated, for 19 Australian stations, using an autoregressive modelling approach. It is concluded that synoptic-scale fluctuations can contribute more than 50 per cent of the observed variance of the seasonal means in some areas. The contribution is lower in the tropics and in the period June-November, than in the extra-tropics and for the rest of the year. The results are similar to those obtained using a spectral analysis approach. It is suggested that in the areas and seasons where the synoptic events play a major role in determining the interannual variability, accurate long-range predicition of seasonal mean temperature is unlikely to eventuate. In the other regions and seasons, where the synoptic events play only a minor role in determining the interannual variability, long-range prediction could be feasible.