Outlook and outcome – March 2003 to May 2003

Rainfall was near or below normal as expected in the east of the North Island and in south Canterbury and east Otago. It was wetter than expected in central and north Canterbury, and north of Auckland. Lower than predicted rainfall was recorded in western regions and in the south of the South Island.

Temperatures were near average as predicted in the east and far south of the country, but higher than predicted elsewhere.

Normal or below normal river flows were expected in most regions. Above normal flows occurred in Northland, Coromandel, and the East Cape. Normal flows occurred in Bay of Plenty, Hawke’s Bay, and the central Southern Alps, and below normal 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 March to May 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.