PREDICTING DECADAL VARIATIONS IN ATLANTIC TROPICAL CYCLONE NUMBERS AND AUSTRALIAN RAINFALL

Significant relationships on time scales longer than 5 years are demon strated between northern Pacific sea surface temperatures, North Atlan tic tropical cyclone numbers, and northeastern Australian rainfall. In agreement with previous work, the global nature of these correlations suggests that they are indications of an intrinsic interdecadal mode of oscillation in the global ocean-atmosphere system. The persistence in time of the sea surface temperature variations may enable forecasts to be made of North Atlantic tropical cyclone numbers several years i n advance. A similar capability for the prediction of north-eastern Au stralian rainfall is also shown. Thus these relationships may be usefu l as an aid in long-term planning decisions.