Outlook and outcome – August to October 2002

Rainfall was near normal, as expected, in parts of both main islands, but higher than predicted in the southwest of the South Island and lower than predicted in the north of the North Island, around Wellington, and in the east of the South Island.

Air temperatures were lower than predicted over the North Island. Pockets of the east and south of the South Island were warmer than predicted.

River flows were lower than predicted in the north of the North Island and in the north and east coast of the South Island. Flows were near normal in many other places.

The outcome maps shown here give the tercile rankings of the rainfall totals and mean temperatures that eventuated for these months. Terciles were obtained by dividing ranked August to October data from the past 30 years into three groups of equal frequency (lower, middle and upper one-third values) and assigning the data for the present year to the appropriate group. (Click to enlarge)

As an approximate guide, middle tercile rainfalls often range from 80 to 115% of the historical average. Middle tercile air temperatures typically occur in the range of the average plus or minus 0.5°C.