Three-month outlook

The outlook for July 2005 to September 2005

In contrast to June’s southerly conditions, a return to wind flows of average variability over New Zealand is expected for the rest of winter. Enhanced westerly flows are likely to the south of the country.

Expected conditions are mapped below. Air temperatures are expected to be near or above average in all regions. Despite this, cold outbreaks, typical of winter, will occur at times.

Rainfalls are likely to be normal or above normal in the west and south of the South Island, normal or below normal in the north and east of the North Island, and near normal elsewhere. Normal soil moisture levels and streamflows are expected in most regions, except for normal or below normal soil moisture levels in the east of the South Island, and normal or below normal.

 

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).