Seasonal climate summary southern hemisphere (spring 1989): the 1988/89 positive phase of the Southern Oscillation draws to an end

An analysis of Pacific basin tropical indicators and the southern hemisphere circulation for the austral spring, September to November 1989, is presented, along with a discussion of seasonal rainfall and temperature over the Australian region. During the season, sea-surface temperatures were slightly below normal over the central and eastern equatorial Pacific, whilst in the western equatorial Pacific they were slightly above normal. Surface winds associated with the Walker Circulation were, on average, marginally stronger than normal. A notable exception was over the western Pacific in November when strong westerly bursts occurred on two occasions. The five-month mean of the Southern Oscillation Index showed a general decline since spring 1988 to near-zero values in spring 1989. Seasonal rainfall over the eastern half of Australia was very variable and temperatures over the continent showed a tendency to be slightly above normal.