Global Setting – September 2012
The Pacific Ocean is still close to El Niño thresholds, but the atmosphere has yet to show patterns typical of El Niño. The global forecast models indicate the conditions are likely to remain close to thresholds or transition towards a weak and short-lived El Niño over the next three months. For New Zealand however they do not show signs of the southwesterly and westerly anomalies that are usually associated with El Niño events. Higher than normal pressures are expected South of Australia and New Zealand at the mid-latitudes, and lower pressures than normal are forecast to the north of the North Island. This pattern is expected to be associated with weaker than normal westerly flow over the country.
Sea surface temperatures
Sea surface temperatures are expected to be warmer than normal around the South Island, and cooler than normal to the east and north of the North Island.