Three-month outlook

The outlook for December 2004 to February 2005

Lower than normal mean sea-level pressures are expected southeast of New Zealand, with stronger than normal west to southwest wind flow over the country. Sea surface temperatures around New Zealand are expected to be near average over the coming three months.

Air temperatures are expected to be near average in the North Island and eastern South Island, and average or below average elsewhere in the South Island.

Normal or below normal rainfall is expected in the north and east of the North Island, and above normal rainfall is expected in the west and south of the South Island. Rainfalls are expected to be near normal elsewhere.

A gradation of soil moisture levels and streamflows is expected, ranging from below normal conditions in the north and east of the North Island to normal or above normal conditions in the west and south of the South Island.

The present weak El Niño in the tropical Pacific should continue through summer 2004-05.

 

A. Climate models give no strong signals about how the climate will evolve, so we assume that there is an equal chance (33%) of the climate occurring in the range of the upper, middle or lower third (tercile) of all previously observed conditions.

B. There is a relatively strong indication by the models (60% chance of occurrence) that conditions will be below average, but, given the variable nature of climate, the chance of average or above-average conditions is also shown (30% and 10% respectively).