Outlook and outcome – September 2003 to November 2003

Rainfall was as predicted in the north and southwest of the North Island, but higher than normal in the east and in parts of Waikato. Canterbury was wetter than expected, while parts of the west and southwest of the South Island received near normal rain as predicted.

Spring temperatures were mostly lower than expected. River flows were higher than predicted in Canterbury and Fiordland and in most of the North Island. Below normal flows in central Otago, and normal elsewhere in the South Island, were much in line with predictions.

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 September to November 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.