Outlook and outcome – October 2003 to December 2003

Rainfall: the South Island was drier than expected and, it was wetter than expected in parts of the east of the North Island.

December was warmer than average in many places, but October and November temperatures were generally below average. As a result mean temperatures for the three months as a whole were lower than predicted.

River flows were expected to be normal or above normal in most locations, but normal or below normal in the east of the South Island. Flows were normal or above normal in the North Island, and normal or below normal in the South Island.

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.