Three-month outlook

The outlook for July to September 2003

A mild late winter is expected, with above average temperatures in all districts except the east of the South Island, where above average or average temperatures are expected. Despite this, typical winter cold spells are also likely, with frosty conditions at times in inland places. Local sea surface temperatures are likely to remain above average and local circulation patterns are expected to favour an enhanced westerly wind flow.

Normal or below normal rainfall is expected in the east of the North Island. Normal or above normal rainfall is expected in the north and west of the South Island, with near normal rainfall likely elsewhere.

Soil moisture levels and river flows are predicted to be normal in the north and west of the North Island and north of the South Island, normal or below normal in the east of both islands, and normal or above normal in the west of the South Island.

The El Niño event in the tropical Pacific has ended, and is unlikely to return later in the year. The tropical Pacific may be moving towards moderate La Niña conditions, but the situation remains unclear.

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).