Sea surface temperatures in the New Zealand region were, on average, 0.2°C above normal in September (up from near normal in August), with a July to September average also of 0.2°C above normal. Positive anomalies (differences from normal) continue to exist east of New Zealand, with negative anomalies in the central and north Tasman Sea.
Weak to moderate El Niño in place
Difference from average global SST (click to enlarge).
Monthly SOI values (click to enlarge).
Climate patterns across the equatorial Pacific over the last 1–2 months have developed an increased tendency toward El Niño conditions. A weak to moderate Pacific-wide El Niño may persist into early 2007. The situation will clarify in the next 1–2 months.
Outlook for October 2006 to December 2006
Regional outlook (click to enlarge).
The present weak to moderate El Niño will have some influence on New Zealand climate over the remainder of spring and into summer 2006–07, with probably more south-westerly quarter airflow than usual over the country during October to December.
Air temperatures are likely to be average in all regions, except for below average or average in the west of the South Island and average or above average in the east of the North Island.
Rainfalls are likely to be normal or below normal in the north and east of the North Island and the east of the South Island. Above normal rainfall is likely in the west of the South Island with normal rainfall elsewhere.
Normal or below normal soil moisture levels are expected in most areas, except in the west and south of the South Island.