Three-month outlook

The outlook for December 2001 to Febuary 2002

The El Niño–Southern Oscillation is in near neutral phase at present, with no major changes in this situation expected over the next three months. Sea-surface temperatures near New Zealand should remain above average through the summer, especially east of the country.

Large scale pressure patterns are likely to favour the formation of anticyclones to the east of New Zealand, accompanied by enhanced depression activity over the north Tasman Sea, and a tendency for weaker westerlies over much of the country.

Temperatures are expected to be average to above average in all districts. Rainfalls are expected to be near average in many places, but tending towards above average in the northern North Island, and towards below average in the southwest of the South Island.

There is a lower than average risk of an ex-tropical cyclone affecting northern New Zealand over the next three months.

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).