Outlook and outcome – October 2004 to December 2004

Rainfall was normal or above in the southwest North Island and the east of both Islands, which was higher than predicted. The west of the South Island was drier than forecast. Rainfall was near normal elsewhere.

Air temperatures were average (as predicted) in the south west of the North Island, but lower than expected elsewhere in the country.

North Island river flows were normal or above normal, which was generally higher than predicted. Flows were above normal in the southeast of the South Island, generally below predicted levels in the west, and normal or below normal in the north where normal flows had been predicted.


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 October to December 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.