Sea surface temperatures in the New Zealand region continued to cool in December to 0.8 °C below normal for the month and 0.3 °C below normal for the October to December mean. Temperatures were between 1 to 1.5 °C below average in parts of the eastern Tasman Sea and to the east of the country, and are likely to remain below normal on average for the next three months.
El Niño may weaken in autumn
Difference from average global SST (click to enlarge).
Monthly SOI values (click to enlarge).
A moderate El Niño has peaked in the tropical Pacific, and will continue to influence New Zealand’s climate to at least February 2007. Several indicators suggest that the event may weaken during autumn.
Outlook for January to March 2007
Regional outlook (click to enlarge).
Atmospheric circulation patterns for January to March are likely to feature a stronger than normal westerly or southwesterly airflow over the country, with below average mean sea level air pressures over the south or to the southeast of New Zealand, and higher pressures to the north.
Air temperatures are expected to be average in the east of the North Island, and average or below average in all other regions. Rainfall is expected to be normal or below normal in all regions except the west of the South Island, where normal or above normal rainfall is expected. Soil moisture and riverflows are expected to be normal or below normal in many areas except the west and south of the South Island, where they are likely to be above normal or normal.