Outlook and outcome – April 2003 to June 2003

Rainfall occurred as predicted over much of the country apart from the northeast of the North Island where it was above normal and parts of Waikato to north Auckland which were drier than normal.

Temperatures were expected to be near average over the North Island and the northern South Island, and average or below average elsewhere. Resulting temperatures were above average almost everywhere.

Below normal river flows occurred in the eastern regions of both islands as predicted. Apart from above normal flows in the far north, the predicted normal or below normal river flows occurred elsewhere.

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 April to June 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.