Global setting and climate outlook
Global setting and climate outlook
El Niño-Southern Oscillation remains neutral
Neutral conditions now prevail in the tropical Pacific and are likely to continue through to summer. Some warm surface water is showing up along the Equator near South America, but this layer of warm water is shallow. The Southern Oscillation Index (SOI) is positive at +0.8, with the three-month mean also slightly positive. The near-equatorial trade winds are slightly stronger than normal throughout the entire equatorial Pacific.
Sea surface temperatures(SST) around New Zealand
Sea surface temperature (SST) anomalies in the New Zealand region overall are minimal. The August SST anomaly in the New Zealand zone was –0.1 °C, and the average anomaly for the three month period June to August was +0.1 °C. SSTs around New Zealand are expected to remain near normal.
Outlook for September to November 2008
In the New Zealand region, mean sea level pressures are likely to be higher than normal, especially over the South Island, with lighter winds than normal over the country. Air temperatures are likely to be average or above over the entire country. Rainfall is likely to be near or below normal over much of the South Island, and the north of the North Island, with near normal rainfall elsewhere. Normal or below normal soil moisture levels and stream flows are likely in the north of the North Island and below normal conditions are likely in the south and west of the South Island. Elsewhere, normal conditions are likely.