Outlook and outcome – April to June 2002

These Checkpoint maps differ from the print issue of The Climate Update, where a substitute map set was accidentally included during printing.

Rainfall was expected to be near normal in most regions and below normal in the east. The outcome was as expected in the North Island and most of the South Island. Parts of Southland and Otago received 125 -175% of normal.

Air temperatures were normal or above normal in all regions as predicted.

Normal river flows were expected for most regions of the country, except in the east. Much of the Waikato, Bay of Plenty, the southwest of the North Island, Canterbury, and the West Coast had normal flows. Flows were below normal in the east of the North Island, Marlborough, and inland Otago, and above normal in Northland, Nelson-Buller, and coastal Otago-Southland.

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 February to April 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.